Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02913682 2015-11-27
PROCESSES FOR PREPARING MAGNESIUM CHLORIDE BY HCI LEACHING OF
VARIOUS MATERIALS
TECHNICAL FIELD
[0002] The present disclosure relates to improvements in the field of
chemistry applied
to the treatment of various ores. For example, it relates to processes for
treating materials
comprising at least one metal chosen from aluminum, iron, zinc, copper, gold,
silver,
molybdenum, cobalt, magnesium, lithium, manganese, nickel, palladium,
platinum, thorium,
phosphorus, uranium and titanium, and/or at least one rare earth element
and/or at least
one rare metal.
BACKGROUND OF THE DISCLOSURE
[0003] There have been several known processes for the production of
alumina,
titanium oxide, magnesium oxide, hematite, nickel, cobalt rare earth elements,
rare metals
etc. Many of them have the disadvantage of being inefficient to segregate and
extract value
added secondary products, thus leaving an important environmental impact.
SUMMARY OF THE DISCLOSURE
[0004] According to one aspect, there is provided a process for preparing
alumina and
optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
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heating the precipitate under conditions effective for converting AICI3 into
A1203 and recovering gaseous HCI so-produced; and
recycling the gaseous HCI so-produced by contacting it with water so as to
obtain a composition having a concentration higher than HCI azeotrope
concentration ( 20.2
weight %) and reacting the composition with a further quantity of aluminum-
containing
material so as to leaching it.
[0005] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid; and
optionally reacting the precipitate with a base; and
heating the precipitate under conditions effective for converting it into
A1203
[0006] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid; and
optionally reacting the precipitate with a base; and
heating the precipitate under conditions effective for converting it into
A1203
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[0007] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
heating the precipitate under conditions effective for converting AlC13 into
A1203 and recovering gaseous HCI so-produced; and
recycling the gaseous MCI so-produced by contacting it with water so as to
obtain a composition having a concentration of about 18 to about 45 weight %
or about 25
to about 45 weight % and reacting the composition with a further quantity of
aluminum-
containing material so as to leaching it.
[0008] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
heating the precipitate under conditions effective for converting AlC13 into
A1203 and recovering gaseous HCI so-produced; and
recycling the gaseous HCI so-produced by contacting it with water so as to
obtain a composition having a concentration of about 18 to about 45 weight %
or about 25
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to about 45 weight % and using the composition for leaching the aluminum-
containing
material.
[0009] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising:
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
heating the precipitate under conditions effective for converting AlC13 into
A1203 and recovering gaseous NCI so-produced; and
recycling the gaseous HCI so-produced by contacting it with the leachate so
as to precipitate the aluminum ions in the form of AlC13=6H20.
[0010] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and Separating the
precipitate from the
liquid; and
heating the precipitate under conditions effective for converting AlC13 into
A1203.
[0011] According to another aspect, there is provided a process for
preparing alumina
and optionally other products, the process comprising :
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leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid; and
heating the precipitate under conditions effective for converting AlC13 into
A1203 and optionally recovering gaseous HCI so-produced.
[0012] According to one aspect, there is provided a process for preparing
aluminum and
optionally other products, the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
heating the precipitate under conditions effective for converting AlC13 into
A1203; and
converting A1203 into aluminum.
[0013] According to another aspect, there is provided a process for
preparing aluminum
and optionally other products, the process comprising ;
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions and a solid, and separating the solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
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heating the precipitate under conditions effective for converting AlC13 into
A1203 and optionally recovering gaseous HCI so-produced; and
converting A1203 into aluminum.
[0014] According to another aspect, there is provided a process for
preparing various
products, the process comprising :
leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising a chloride of the first metal, and separating the precipitate from
the liquid; and
heating the precipitate under conditions effective for converting the chloride
of
the first metal into an oxide of the first metal.
[0015] According to another aspect, there is provided a process for
treating serpentine,
the process comprising :
leaching serpentine with HCI so as to obtain a leachate comprising
magnesium ions and a solid, and separating the solid from the leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising MgC12, and separating the precipitate from the liquid; and
heating the precipitate under conditions effective for converting MgCl2 into
MgO and optionally recovering gaseous HCI so-produced.
[0016] According to another aspect, there is provided a process for
treating serpentine,
the process comprising :
leaching serpentine with HCI so as to obtain a leachate comprising
magnesium ions and a solid, and separating the solid from the leachate;
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reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising MgC12, and separating the precipitate from the liquid; and
heating the precipitate under conditions effective for converting MgCl2 into
MgO.
[0017] According to another aspect, there is provided process for treating
a magnesium-
containing material, the process comprising :
leaching the magnesium-containing material with NCI so as to obtain a
leachate comprising magnesium ions and a solid, and separating the solid from
the
leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising MgC12, and separating the precipitate from the liquid; and
heating the precipitate under conditions effective for converting MgC12 into
MgO and optionally recovering gaseous HCI so-produced.
[0018] According to another aspect, there is provided a process for
treating a
magnesium-containing material, the process comprising :
leaching the magnesium-containing material with HC1 so as to obtain a
leachate comprising magnesium ions and ions from at least one metal and a
solid, and
separating the solid from the leachate; and
precipitating the at least one metal by reacting the leachate with a
precipitating agent so as to obtain a liquid comprising the magnesium ions and
a precipitate
comprising the precipitated at least one metal, and separating the precipitate
from the
liquid.
[0019] According to another aspect, there is provided a process for
treating a material
comprising magnesium and at least one other metal, the process comprising :
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leaching the material with HCI so as to obtain a leachate comprising
magnesium ions and ions from the at least one other metal and a solid, and
separating the
solid from the leachate; and
precipitating the at least one other metal by reacting the leachate with a
precipitating agent so as to obtain a liquid comprising the magnesium ions and
a precipitate
comprising the precipitated at least one metal, and separating the precipitate
from the
liquid;
treating the liquid so as to cause precipitation of Mg(OH)2; and
treating the precipitate so as to substantially selectively isolate the at
least
one metal therefrom.
[0020] According to another aspect, there is provided a process for
preparing alumina,
the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions, magnesium ions and a solid, and separating the solid
from the
leachate;
substantially selectively precipitating MgC12 from the leachate and removing
the MgCl2 from the leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
heating the precipitate under conditions effective for converting AlC13 into
A1203 and optionally recovering gaseous HCI so-produced; and
heating the M9Cl2 under conditions effective for converting it into MgO and
optionally recovering gaseous HCI so-produced.
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[0021] According to another aspect, there is provided a process for
preparing aluminum,
the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions, magnesium ions and a solid, and separating the solid
from the
leachate;
substantially selectively precipitating MgCl2 from the leachate and removing
the MgCl2 from the leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
heating the MgCl2 under conditions effective for converting it into MgO and
optionally recovering gaseous HCI so-produced;
heating the precipitate under conditions effective for converting AlC13 into
A1203 and optionally recovering gaseous HCI so-produced; and
converting the A1203 into alumina.
[0022] According to another aspect, there is provided a process for
preparing alumina,
the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions, magnesium ions and a solid, and separating the solid
from the
leachate;
substantially selectively precipitating MgC12 from the leachate and removing
the MgC12 from the leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
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optionally treating the precipitate with a base;
heating the precipitate under conditions effective for converting the
precipitate
into A1203 and optionally recovering gaseous HCI so-produced; and
heating the MgCl2 under conditions effective for converting it into MgO and
optionally recovering gaseous HCI so-produced.
[0023] According to another aspect, there is provided a process for
preparing aluminum,
the process comprising :
leaching an aluminum-containing material with HCI so as to obtain a leachate
comprising aluminum ions, magnesium ions and a solid, and separating the solid
from the
leachate;
substantially selectively precipitating MgCl2 from the leachate and removing
the MgC12 from the leachate;
reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising the aluminum ions in the form of AlC13, and separating the
precipitate from the
liquid;
optionally treating the precipitate with a base;
heating the MgCl2 under conditions effective for converting it into MgO and
optionally recovering gaseous NCI so-produced;
heating the precipitate under conditions effective for converting the
precipitate
into A1203 and optionally recovering gaseous HCI so-produced; and
converting the A1203 into alumina.
[0024] According to another aspect, there is provided a process for
treating serpentine,
the process comprising :
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leaching serpentine with HCI so as to obtain a leachate comprising
magnesium ions and a solid, and separating the solid from the leachate;
controlling the temperature of the leachate so as to substantially selectively
precipitate the magnesium ions in the form of magnesium chloride, and removing
the
precipitate from the leachate, thereby obtaining a liquid; and
heating the MgCl2 under conditions effective for converting MgCl2 into MgO
and optionally recovering gaseous HCI so-produced.
[0025] According to another aspect, there is provided a process for
treating a
magnesium-containing material, the process comprising:
leaching the magnesium-containing material with NCI so as to obtain a
leachate comprising magnesium ions, and a solid, and separating the solid from
the
leachate;
controlling the temperature of the leachate so as to substantially selectively
precipitate the magnesium ions in the form of magnesium chloride, and removing
the
precipitate from the leachate, thereby obtaining a liquid; and
heating the MgC12 under conditions effective for converting MgC12 into MgO
and optionally recovering gaseous HCI so-produced.
[00261 According to another aspect, there is provided a process for
preparing various
products, the process comprising:
leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate;
controlling the temperature of the leachate so as to precipitate the the first
metal in the form of a chloride, and removing the precipitate from the
leachate,
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reacting the leachate with HCI so as to obtain a liquid and a precipitate
comprising a chloride of the second metal, and separating the precipitate from
the liquid;
optionally heating the chloride of the first metal under conditions effective
for
converting it into an oxide of the first metal, and optionally recovering the
so-produced HCI;
and
optionally heating the chloride of the second metal under conditions effective
for converting it into an oxide of the second metal, and optionally recovering
the so-
produced HCI.
[0027] According to another aspect, there is provided a process for
preparing various
products, the process comprising:
leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate:
controlling the temperature of the leachate so as to precipitate the the first
metal in the form of a chloride, and removing the precipitate from the
leachate;
controlling the temperature of the leachate so as to precipitate the the
second
metal in the form of a chloride, and removing the precipitate from the
leachate;
optionally heating the chloride of the first metal under conditions effective
for
converting it into an oxide of the first metal, and optionally recovering the
so-produced HCI;
and
optionally heating the chloride of the second metal under conditions effective
for converting it into an oxide of the second metal, and optionally recovering
the so-
produced HCI.
[0028] According to another aspect, there is provided a process for
preparing various
products, the process comprising :
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leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate;
reacting the leachate with HCI so as to obtain a precipitate comprising the
first
metal in the form of a chloride, and removing the precipitate from the
leachate;
reacting the leachate with HCI so as to obtain a precipitate comprising a
second metal in the form of a chloride, and removing the precipitate from the
leachate;
optionally heating the chloride of the first metal under conditions effective
for
converting it into an oxide of the first metal, and optionally recovering the
so-produced HCI;
and
optionally heating the chloride of the second metal under conditions effective
for converting it into an oxide of the second metal, and optionally recovering
the so-
produced NCI.
[0029] According to another aspect, there is provided a process for
preparing various
products, the process comprising :
leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate;
controlling the concentration of HCl in the leachate and/or the temperature of
the leachate so as to precipitate the first metal in the form of a chloride,
and removing the
precipitate from the leachate;
controlling the concentration of HCI in the leachate and/or the temperature of
the leachate so as to precipitate a second metal in the form of a chloride,
and removing the
precipitate from the leachate;
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optionally heating the chloride of the first metal under conditions effective
for
converting it into an oxide of the first metal, and optionally recovering the
so-produced NCI;
and
optionally heating the chloride of the second metal under conditions effective
for converting it into an oxide of the second metal, and optionally recovering
the so-
produced HCI.
[0030] According to another aspect, there is provided a process for
preparing various
products, the process comprising :
leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate;
controlling the concentration of HCI in the leachate and/or the temperature of
the leachate so as to precipitate the first metal in the form of a chloride,
and removing the
precipitate from the leachate;
reacting the leachate with HCI so as to obtain a precipitate comprising a
second metal in the form of a chloride, and removing the precipitate from the
leachate,
optionally heating the chloride of the first metal under conditions effective
for
converting it into an oxide of the first metal, and optionally recovering the
so-produced HCI;
and
optionally heating the chloride of the second metal under conditions effective
for converting it into an oxide of the second metal, and optionally recovering
the so-
produced HCI.
[00311 According to another aspect, there is provided a process for
preparing various
products, the process comprising:
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leaching a material comprising a first metal with HCI so as to obtain a
leachate comprising ions of the first metal and a solid, and separating the
solid from the
leachate;
reacting the leachate with HCI so as to obtain a precipitate comprising the
first
metal in the form of a chloride, and removing the precipitate from the
leachate;
controlling the concentration of HCI in the leachate and/or the temperature of
the leachate so as to precipitate a second metal in the form of a chloride,
and removing the
precipitate from the leachate;
optionally heating the chloride of the first metal under conditions effective
for
converting it into an oxide of the first metal, and optionally recovering the
so-produced HCI;
and
optionally heating the chloride of the second metal under conditions effective
for converting it into an oxide of the second metal, and optionally recovering
the so-
produced NCI.
[0032] According to another aspect, there is provided a process for
preparing various
products, the process comprising:
leaching a material comprising magnesium and iron with NCI so as to obtain a
leachate comprising magnesium ions and iron ions and a solid, and separating
the solid
from the leachate;
reacting the leachate with HCI so as to obtain a precipitate comprising
magnesium chloride, and removing the precipitate from the leachate so as to
obtain a liquid
comprising iron chloride;
treating the liquid under conditions effective for converting the iron
chloride
into iron oxide and optionally recovering HCI; and
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optionally heating the magnesium chloride under conditions effective for
converting it into magnesium oxide, and optionally recovering the so-produced
HCI.
[0033] According to another aspect, there is provided a process for
preparing various
products, the process comprising :
leaching a material comprising magnesium and iron with NCI so as to obtain a
leachate comprising magnesium ions and iron ions and a solid, and separating
the solid
from the leachate;
controlling the concentration of HCI in the leachate and/or the temperature of
the leachate so as to precipitate magnesium chloride, and removing the
precipitate from the
leachate, thereby obtaining a liquid;
treating the liquid under conditions effective for converting the iron
chloride
into iron oxide and optionally recovering HCI; and
optionally heating the magnesium chloride under conditions effective for
converting it into magnesium oxide, and optionally recovering HCI.
[0034] According to another aspect, there is provided a process for
preparing various
products, the process comprising:
leaching a material comprising magnesium, aluminum and iron with HCI so as
to obtain a leachate comprising magnesium ions, aluminum ions and iron ions
and a solid,
and separating the solid from the leachate;
controlling the concentration of HCI in the leachate and/or the temperature of
the leachate so as to precipitate magnesium chloride, and removing the
precipitate from the
leachate,
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reacting the leachate with HCI so as to obtain a precipitate comprising
aluminum chloride, and removing the precipitate from the leachate so as to
obtain a liquid
comprising iron chloride;
optionally treating the liquid under conditions effective for converting the
iron
chloride into iron oxide and optionally recovering HCI;
optionally heating the precipitate under conditions effective for converting
aluminum chloride into into alumina and optionally recovering gaseous HCI so-
produced;
and
optionally heating the magnesium chloride under conditions effective for
converting it into magnesium oxide, and optionally recovering HCI.
[0035] According to another aspect, there is provided a process for
preparing various
products, the process comprising :
leaching a material comprising magnesium, aluminum and iron with HCI so as
to obtain a leachate comprising magnesium ions, aluminum ions and iron ions
and a solid,
and separating the solid from the leachate;
reacting the leachate with HCI so as to obtain a precipitate comprising
aluminum chloride, and removing the precipitate from the leachate;
controlling the concentration of HCI in the leachate and/or the temperature of
the leachate so as to precipitate magnesium chloride, and removing the
precipitate from the
leachate so as to obtain a liquid comprising iron chloride
optionally treating the liquid under conditions effective for converting the
iron
chloride into iron oxide and optionally recovering FICI;
optionally heating the precipitate under conditions effective for converting
aluminum chloride into into alumina and optionally recovering gaseous HCI so-
produced;
and
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optionally heating the magnesium chloride under conditions effective for
converting it into magnesium oxide, and optionally recovering HCI.
BRIEF DESCRIPTION OF DRAWINGS
[0036] In the following drawings, which represent by way of example only,
various
embodiments of the disclosure:
[0037] Fig. 1 shows a bloc diagram of an example of process for preparing
alumina and
various other products according to the present disclosure;
[0038] Fig. 2 is an extraction curve for Al and Fe in which the extraction
percentage is
expressed as a function of a leaching time in a process according to an
example of the
present application;
[0039] Fig. 3 shows a bloc diagram of another example of process for
preparing alumina
and various other products according to the present disclosure;
[0040] Fig. 4 is a schematic representation of an example of a process for
purifying/concentrating HCI according to the present disclosure;
[0041] Fig. 5 is a schematic representation of an example of a
process for
purifying/concentrating HCI according to the present disclosure;
[0042] Fig. 6 shows another bloc diagram of an example of process for
preparing
alumina and various other products according to the present disclosure;
[0043] Fig. 7 shows another bloc diagram of an example of process for
preparing
alumina and various other products according to the present disclosure;
[0044] Fig. 8 shows another bloc diagram of an example of process for
preparing
various products
[0045] Fig. 9 shows another bloc diagram of an example of process according
to the
present disclosure;
[0046] Figs. 10A and 10B show further bloc diagrams of examples of
processes
according to the present disclosure;
[0047] Figs. 11A and 11B show a further bloc diagrams of examples of
processes
according to the present disclosure; Figs. 12A and 12B show further bloc
diagrams of
examples of processes according to the present disclosure;
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[0048] Fig. 13 shows another bloc diagram of an example of process for
preparing
alumina and various other products according to the present disclosure;
[0049] Fig. 14 shows another bloc diagram of an example of process for
preparing
alumina and various other products according to the present disclosure;
[0050] Fig. 15 shows solubilisation curves of various metal chlorides as a
function of HCI
concentration;
[0051] Fig. 16 shows solubilisation curves of MgC12 at various
temperatures;
[0052] Fig. 17 shows solubilisation curves of various metal chlorides as a
function of
HCI concentration; and
[0053] Fig. 18 shows a bloc diagram of an example of process for preparing
alumina
and various other products according to the present disclosure.
DETAILLED DESCRIPTION OF VARIOUS EMBODIMENTS
[0054] The following non-limiting examples further illustrate the
technology described in
the present disclosure.
[0055] The aluminum-containing material can be for example chosen from
aluminum-
containing ores (such as aluminosillicate minerals, clays, argillite,
nepheline, mudstone,
beryl, cryolite, garnet, spinel, bauxite, carbonatite, kyanite, kaolin,
serpentine or mixtures
thereof can be used). The aluminum-containing material can also be a recycled
industrial
aluminum-containing material such as slag, red mud or fly ashes.
[0056] The expression "red mud" as used herein refers, for example, to an
industrial
waste product generated during the production of alumina. For example, such a
waste
product can comprise silica, aluminum, iron, calcium, and optionally titanium.
It can also
comprise an array of minor constituents such as Na, K, Cr, V, Ni, Ba, Cu, Mn,
Pb, and/or
Zn etc. For example, red mud can comprises about 15 to about 80 % by weight of
Fe203,
about 1 to about 35 % by weight A1203, about 1 to about 65 % by weight of
Si02, about 1 to
about 20 % by weight of Na20, about 1 to about 20 % by weight of CaO, and from
0 to
about 35 % by weight of Ti02. According to another example, red mud can
comprise about
30 to about 65 % by weight of Fe203, about 10 to about 20 % by weight A1203,
about 3 to
about 50 % by weight of Si02, about 2 to about 10 % by weight of Na20, about 2
to about 8
% by weight of CaO, and from 0 to about 25 % by weight of TiO2.
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(00571 The expression "fly ashes" as used herein refers, for example, to an
industrial
waste product generated in combustion. For example, such a waste product can
contain
various elements such as silica, oxygen, aluminum, iron, calcium. For example,
fly ashes
can comprise silicon dioxide (Si02) and aluminium oxide (A1203). For example,
fly ashes
can further comprises calcium oxide (CaO) and/or iron oxide (Fe203). For
example fly
ashes can comprise fine particles that rise with flue gases. For example, fly
ashes can be
produced during combustion of coal. For example, fly ashes can also comprise
at least one
element chosen from arsenic, beryllium, boron, cadmium, chromium, chromium VI,
cobalt,
lead, manganese, mercury, molybdenum, selenium, strontium, thallium, and/or
vanadium.
For example, fly ashes can also comprise rare earth elements and rare metals.
For
example, fly ashes can be considered as an aluminum-containing material.
[0058] The expression "slag" as used herein refers, for example, to an
industrial waste
product comprising aluminum oxide and optionally other oxides such as oxides
of calcium,
magnesium, iron, and/or silicon.
[0059] The expression "rare earth element" (also described as "REE") as
used herein
refers, for example, to a rare element chosen from scandium, yttrium,
lanthanum, cerium,
praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium,
dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. The expression
"rare
metals" as used herein refers, for example, to rare metals chosen from indium,
zirconium,
lithium, and gallium. These rare earth elements and rare metals can be in
various form
such as the elemental form (or metallic form), under the form of chlorides,
oxides,
hydroxides etc. The expression "rare earths" as used in the present disclosure
as a
synonym of "rare earth elements and rare metals" that is described above.
[0060] The expression "at least one iron chloride" as used herein refers to
FeCl2, FeCI3
or a mixture thereof.
[0061] The term "hematite" as used herein refers, for example, to a
compound
comprising cl-Fe203, 7-Fe203, 1.3-Fe0.0H or mixtures thereof.
[0062] The term "serpentine" as used herein refers, for example, to an ore
that
comprises Mg and optionally iron. For example, the ore can also comprise
nickel, aluminum
and/or cobalt. For example, the serpentine can be chosen from antigorite,
chrysotile and
lizardite.
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[0063] The expression "iron ions" as used herein refers, for example to
ions comprising
to at least one type of iron ion chosen from all possible forms of Fe ions.
For example, the
at least one type of iron ion can be Fe2+, Fe3+, or a mixture thereof.
[0064] The expression "aluminum ions" as used herein refers, for example to
ions
comprising to at least one type of aluminum ion chosen from all possible forms
of Al ions.
For example, the at least one type of aluminum ion can be Al3+.
[0065] The expression "at least one aluminum ion", as used herein refers,
for example,
to at least one type of aluminum ion chosen from all possible forms of Al
ions. For example,
the at least one aluminum ion can be Al3+.
[0066] The expression "at least one iron ion", as used herein refers, for
example, to at
least one type of iron ion chosen from all possible forms of Fe ions. For
example, the at
least one iron ion can be Fe2+, Fe3+, or a mixture thereof.
[0067] The expression "at least one precipitated iron ion", as used herein
refers, for
example, to at least one type of iron ion chosen from all possible forms of Fe
ions that was
precipitated in a solid form. For example, the at least one iron ion present
in such a
precipitate can be Fe2+, Fe3+, or a mixture thereof.
[0068] Terms of degree such as "about" and "approximately" as used herein
mean a
reasonable amount of deviation of the modified term such that the end result
is not
significantly changed. These terms of degree should be construed as including
a deviation
of at least 1:5% or at least 10% of the modified term if this deviation would
not negate the
meaning of the word it modifies.
[0069] The expression "substantially selectively isolate" as used herein
when referring to
isolating a compound refers, for example, to isolating such a compound
together with less
than 30, 25, 20, 15, 10, 5, 3, 2 or 1 A) of impurities. Such impurities can
be other
compounds such as other metals.
[0070] The expressions "substantially selectively precipitating",
"substantially selectively
precipitate" and their equivalents as used herein when referring to
precipitating a compound
refers, for example, to precipitating such a compound together with less than
30, 25, 20, 15,
10, 5, 3, 2 or 1 % of impurities. Such impurities can be other compounds such
as other
metals.
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[0071] For example, the material can be leached with HCI having a
concentration of
about 10 to about 50 weight /0, about 15 to about 45 weight %, of about 18 to
about 45
weight % of about 18 to about 32 weight A), of about 20 to about 45 weight
A), of about 25
to about 45 weight %, of about 26 to about 42 weight %, of about 28 to about
40 weight %,
of about 30 to about 38 weight %, or between 25 and 36 weight %. For example,
HCI at
about 18 wt % or about 32 wt % can be used.
[0072] Leaching can also be carried out by adding dry highly concentrated
acid ( for
example, 85 %, 90 % or 95 %) in gas phase into the aqueous solution.
Alternatively,
leaching can also be carried out by using a weak acid solution (for example <3
wt /0).
[0073] For example, leaching can be carried out by using HCI having a
concentration of
about 18 to about 32 wt % in a first reactor and then, by using HCI having
concentration of
about 90 to about 95 %, or about 95 to about 100 % (gaseous) in a second
reactor.
[0074] For example, leaching can be carried out by using HCI having a
concentration of
about 18 to about 32 wt % in a first reactor then, by using HCI having
concentration of
about 90 to about 95 % (gaseous) in a second reactor; and by using HCI having
concentration of about 90 to about 95 % (gaseous) in a third reactor.
[0075] For example, leaching can be carried out under an inert gas
atmosphere (for
example argon or nitrogen).
[0076] For example, leaching can be carried out under an atmosphere of NH3.
[0077] For example, the material can be leached at a temperature of about
125 to about
225 C, about 150 to about 200 C, about 160 to about 190 C, about 185 to
about 190 C,
about 160 to about 180 C, about 160 to about 175 C, or about 165 to about 170
C.
[0078] For example, the material can be leached at a pressure of about 4 to
about 10
barg, about 4 to about 8 barg, or about 5 to about 6 barg.
[0079] For example a first leaching can be carried out at atmospheric
pressure and then,
at least one further leaching (for example 1, 2 or 3 subsequent leaching
steps) can be
carried out under pressure.
[0080] For example, leaching can be a continuous leaching or semi-
continous.
[0081] For example, the material can be an aluminum-containing material.
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[0082] For example, the material can be an iron-containing material.
[0083] For example, the material can be a zinc-containing material.
[0084] For example, the material can be a copper-containing material.
[0085] For example, the material can be a gold-containing material.
[0086] For example, the material can be a silver-containing material.
[0087] For example, the material can be a molybdenum-containing
material.
[0088] For example, the material can be a cobalt-containing material.
[0089] For example, the material can be a magnesium-containing
material.
[0090] For example, the material can be a lithium-containing
material.
[0091] For example, the material can be a manganese-containing
material.
[0092] For example, the material can be a nickel-containing material.
[0093] For example, the material can be a palladium-containing
material.
[0094] For example, the material can be a platinum-containing
material.
[0095] For example, the material can be a magnesium-containing
material.
[0096] For example, the material can be a lithium-containing
material.
[0097] For example, the material can be a thorium-containing
material.
[0098] For example, the material can be a phosphorus-containing
material.
[0099] For example, the material can be a an uranium-containing
material.
[00100] For example, the material can be a titanium-containing material.
[00101] For example, the material can be a rare earth elements-containing
material.
[00102] For example, the material can be a rare metal-containing material.
[00103] The processes of the present disclosure can be effective for treating
various
materials. The at least one material can be an aluminum-containing material,
The
aluminum-containing material can be an aluminum-containing ore. For example,
clays,
argillite, mudstone, beryl, cryolite, garnet, spinal, bauxite, serpentine or
mixtures thereof
can be used as starting material. The aluminum-containing material can also be
a recycled
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industrial aluminum-containing material such as slag. The aluminum-containing
material
can also be red mud.
[00104] The at least one material can be a nickel-containing material. The
nickel-
containing material can be a nickel-containing ore.
[00105] The at least one material can be a zinc-containing material. The zinc-
containing
material can be a zinc-containing ore.
[00106] The at least one material can be a copper-containing material. The
copper-
containing material can be a copper-containing ore.
[00107] The at least one material can be a titanium-containing material. The
titanium-
containing material can be a titanium-containing ore.
[00108] The at least one material can be a magnesium-containing material. The
magnesium-containing material can be a magnesium-containing ore.
[00109] The processes of the present disclosure can be effective for treating
various
nickel-containing ores. For example, niccolite, kamacite, taenite, limonite,
garnierite,
laterite, pentlandite, serpentine, or mixtures thereof can be used.
[00110] The processes of the present disclosure can be effective for treating
various zinc-
containing ores. For example, smithsonite, warikahnite, sphalerite, serpentine
or mixtures
thereof can be used.
[00111] The processes of the present disclosure can be effective for treating
various
copper-containing ores. For example, copper-containing oxide ores, can be
used. For
example, chalcopyrite, chalcocite, covellite, bornite, tetrahedrite,
malachite, azurite, cuprite,
chrysocolla, or mixtures thereof can also be used.
[00112] The processes of the present disclosure can be effective for treating
various
titanium-containing ores. For example, ecandrewsite, geikielite, pyrophanite,
ilmenite, or
mixtures thereof can be used.
[00113] The processes of the present disclosure can be effective for treating
various
magnesium-containing ores. For example, the magnesium-containing ore can be
chosen
from serpentine, asbestos, antigorite, chrysotile, lizardite, brucite,
magnesite, dolomite,
kieserite, bischofite, langbeinite, epsomite, kainite, carnallite,
astrakanite, laterite, geikielite
and polyhalite.
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[00114] For example, in the processes, the leachate can be treated with HC1
that is in
gaseous form.
[00115] For example, the processes can comprise reacting the leachate with
gaseous
HCI so as to obtain the liquid and the precipitate comprising the first metal
under the form of
a chloride.
[00116] For example, the processes can comprise reacting the leachate with dry
gaseous
HCI so as to obtain the liquid and the precipitate comprising the first metal
under the form of
a chloride.
[00117] For example, precipitating AlC13 can comprise crystallizing
AlC13=6H20.
[00118] For example, the processes can comprise reacting the leachate with
acid of at
least 30% wt. that was recovered, regenerated and/or purified as indicated in
the present
disclosure so as to obtain the liquid and the precipitate comprising the
aluminum ions in the
form of AlC13=6H20.
[00119] For example, the processes can further comprise recycling the gaseous
HCI so-
produced by contacting it with water so as to obtain a composition having a
concentration of
about 18 to about 45 weight % or 25 to about 45 weight %.
[00120] For example, the processes can further comprise recycling the gaseous
NCI so-
produced by contacting it with water so as to obtain a composition having a
concentration of
about 18 to about 45 weight % or about 25 to about 45 weight % and using the
composition
for leaching the material.
[00121) For example, the liquid can comprise iron chloride. Iron chloride can
comprise at
least one of FeCl2, FeCI3, and a mixture thereof.
[00122] For example, the liquid can have an iron chloride concentration of at
least 30%
by weight; and can then be hydrolyzed at a temperature of about 155 to about
350 C.
[00123] For example, the liquid can be concentrated to a concentrated liquid
having an
iron chloride concentration of at least 30% by weight; and then the iron
chloride can be
hydrolyzed at a temperature of about 155 to about 350 C while maintaining a
ferric chloride
concentration at a level of at least 65% by weight, to generate a composition
comprising a
liquid and precipitated hematite, and recovering the hematite.
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(00124] For example, non-hydrolysable elements with hematite can be
concentrated back
to a concentration of about 0.125 to about 52 A) wt. in circulation loop in
view of selective
extraction.
[00125] For example, the liquid can be concentrated to a concentrated liquid
having a
concentration of the at least one iron chloride of at least 30% by weight; and
then
hydrolyzed at a temperature of about 155 to about 350 C.
[00126] For example, the liquid can be concentrated to a concentrated liquid
having a
concentration of the at least one iron chloride of at least 30% by weight; and
then the at
least one iron chloride is hydrolyzed at a temperature of about 155 to about
350 C while
maintaining a ferric chloride concentration at a level of at least 65% by
weight, to generate
a composition comprising a liquid and precipitated hematite, and recovering
the hematite.
[00127] For example, the liquid can be concentrated to a concentrated liquid
having a
concentration of the at least one iron chloride of at least 30% by weight; and
then the at
least one iron chloride is hydrolyzed at a temperature of about 155 to about
350 C while
maintaining a ferric chloride concentration at a level of at least 65% by
weight, to generate
a composition comprising a liquid and precipitated hematite; recovering the
hematite; and
recovering rare earth elements and/or rare metals from the liquid.
[00128] For example, the at least one iron chloride can be hydrolyzed at a
temperature of
about, 150 to about 175, 160 to about 175, 155 to about 170, 160 to about 170
or 165 to
about 170 C.
[00129] For example, the liquid can be concentrated to a concentrated liquid
having an
iron chloride concentration of at least 30% by weight; and then the iron
chloride can be
hydrolyzed at a temperature of about 155 to about 350 C while maintaining a
ferric chloride
concentration at a level of at least 65% by weight, to generate a composition
comprising a
liquid and precipitated hematite; recovering the hematite; and recovering rare
earth
elements and/or rare metals from the liquid.
[00130] For example, the processes can further comprise, after recovery of the
rare earth
elements and/or rare metals, reacting the liquid with HCI so as to cause
precipitation of
MgCl2, and recovering same.
[00131] For example, the processes can further comprise calcining MgC12 into
MgO.
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[00132] For example, the processes can further comprises, after recovery of
the rare
earth elements and/or rare metals, reacting the liquid with HCI, and
substantially selectively
precipitating Na2SO4. For example, Na2SO4 can be precipitated by reacting the
liquid with
H2SO4.
[00133] For example, the processes can further comprises, after recovery of
the rare
earth elements and/or rare metals, reacting the liquid with HCI, and
substantially selectively
precipitating K2SO4. For example,K2SO4 can be precipitated by adding H2SO4.
[00134] For example, the liquid can be concentrated to a concentrated liquid
having an
iron chloride concentration of at least 30% by weight; and then the iron
chloride can be
hydrolyzed at a temperature of about 155 to about 350 C while maintaining a
ferric chloride
concentration at a level of at least 65% by weight, to generate a composition
comprising a
liquid and precipitated hematite; recovering the hematite; and reacting the
liquid with
HCI.For example, such processes can further comprises reacting the liquid with
H2SO4 so
as to substantially selectively precipitate Na2SO4. The processes can also
comprise further
reacting the liquid with H2SO4 so as to substantially selectively
precipitating K2SO4.
[00135] For example, the processes can comprise reacting dry individual salts
(for
example Na or K salts) obtained during the processes with H2SO4 and recovering
HCI while
producing marketable K2SO4 and Na2SO4 and recovering hydrochloric acid of
about 15 to
about 90 % wt.
[00136] For example, sodium chloride produced in the processes can undergo a
chemical
reaction with sulfuric acid so as to obtain sodium sulfate and regenerate
hydrochloric acid.
Potassium chloride can undergo a chemical reaction with sulfuric acid so as to
obtain
potassium sulfate and regenerate hydrochloric acid. Sodium and potassium
chloride brine
solution can alternatively be the feed material to adapted small chlor-alkali
electrolysis cells.
In this latter case, common bases (NaOH and KOH) and bleach (Na0C1 and KOCI)
are
produced.
[00137] For example, the processes can further comprise, after recovery of the
rare earth
elements and/or rare metals, recovering NaCl from the liquid, reacting the
NaCI with H2SO4,
and substantially selectively precipitating Na2SO4.
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[00138] For example, the processes can further comprise, downstream of
recovery of the
rare earth elements and/or rare metals, recovering KCI from the liquid,
reacting the KCI with
H2SO4, and substantially selectively precipitating K2SO4.
[00139] For example, the processes can further comprise, downstream of
recovery of the
rare earth elements and/or rare metals, recovering NaCI from the liquid,
carrying out an
electrolysis to generate NaOH and Na0C1.
[00140] For example, the processes can further comprise, downstream of
recovery of the
rare earth elements and/or rare metals, recovering KCI from the liquid,
reacting the KCI,
carrying out an electrolysis to generate KOH and KOCI.
[00141] For example, the liquid can be concentrated to a concentrated liquid
having a
concentration of the at least one iron chloride of at least 30% by weight; and
then the at
least one iron chloride is hydrolyzed at a temperature of about 155 to about
350 C while
maintaining a ferric chloride concentration at a level of at least 65% by
weight, to generate
a composition comprising a liquid and precipitated hematite; recovering the
hematite; and
extracting NaCI and/or KCI from the liquid.
[00142] For example, the processes can further comprise reacting the NaCI with
H2SO4
so as to substantially selectively precipitate Na2SO4.
[00143] For example, the processes can further comprise reacting the KCI with
H2SO4 so
as to substantially selectively precipitate K2SO4.
[00144] For example, the processes can further comprise carrying out an
electrolysis of
the NaCI to generate NaOH and Na0C1,
[00145] For example, the processes can further comprise carrying out an
electrolysis of
the KCI to generate KOH and KOCI.
[00146] For example, the processes can comprise separating the solid from the
leachate
and washing the solid so as to obtain silica having a purity of at least 95
A), at least 96%, at
least 97%, at least 98%, at least 99%, at least 99.5 % or at least 99.9%.
[00147] For example, the processes can comprise reacting the leachate with
gaseous
HCI so as to obtain the liquid and the precipitate comprising the aluminum
ions in the form
of AlC13.6H20.
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[00148] For example, the processes can comprise reacting the leachate with dry
gaseous
HCI so as to obtain the liquid and the precipitate comprising the aluminum
ions in the form
of AlC13=6H20.
[00149] For example, the processes can comprise reacting the leachate with
acid of at
least 30% wt. that was recovered, regenerated and/or purified as indicated in
the present
disclosure so as to obtain the liquid and the precipitate comprising the
aluminum ions in the
form of AlC13=6H20.
[00150] For example, the processes can comprise reacting the leachate with
gaseous
HCI so as to obtain the liquid and the precipitate comprising the aluminum
ions, the
precipitate being formed by crystallization of AlC13.6H20.
[00151] For example, the processes can comprise reacting the leachate with dry
gaseous
HCI so as to obtain the liquid and the precipitate comprising the aluminum
ions, the
precipitate being formed by crystallization of AlC13.6H20.
[00152] For example, aluminum ions can be precipitated under the form of AlC13
(for
example AlC13=6H20) in a crystallizer, for example, by adding HCI having a
concentration of
about 26 to about 32 wt %.
[00153] For example, the gaseous HCI can have a HCI concentration of at least
85 % wt.
or at least 90 % wt.
[00154] For example, the gaseous HCI can have a HCI concentration of about 90
% wt.,
about 90 % to about 95 % wt., or about 90 % to about 99 % wt..
[00155] For example, during the crystallization of AlC13.6H20, the liquid
can be
maintained at a concentration of HCI of about 25 to about 35 A) by weight or
about 30 to
about 32 %) by weight.
[00156] For example, the crystallization can be carried out at a temperature
of about 45 to
about 65 C or about 50 to about 60 C.
[00157] For example, the HCI can be obtained from the gaseous HCI so-produced.
[00158] For example, in the processes of the present disclosure, a given
batch or
quantity of the material will be leached, will then be converted into AlC13
and when the HCI
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generated during calcination of AlC13 into A1203 will be used for example to
leach another
given batch or quantity of the material.
[00159] For example, the processes can comprise heating the precipitate at a
temperature of at least 180, 230, 250, 300, 350, 400, 450, 500, 550, 600, 650,
700, 750,
800, 850, 900, 925, 930, 1000, 1100, 1200 or 1250 C for converting AlC13 or
Al(OH)3 into Al203.
[00160] For example, converting ACJ3 into A1203 can comprise calcination of
AlC13.
[00161] For example, calcination is effective for converting AlC13 into beta-
A1203.
[00162] For example, calcination is effective for converting AlC13 into alpha-
A1203.
[00163] For example, converting A1C13 into A1203 can comprise carrying out a
calcination
via a two-stage circulating fluid bed reactor.
[00164] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
via a two-stage circulating fluid bed reactor that comprises a preheating
system.
[00165] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
at low temperature, for example, about 300 to about 600 C, about 325 to about
550 C,
about 350 to about 500 C, about 375 to about 450 C, about 375 to about 425
C, or about
385 to about 400 C and/or injecting steam.
[00166] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
at low temperature, for example, at least 180 C, at least 250 C, at least
300 C, at least
350 C and/or injecting steam.
[00167] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
at low temperature, for example, less than 600 C and/or injecting steam.
[00168] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
by using coal as combustion source and by using a degasification unit.
[00169] For example, steam (or water vapor) can be injected at a pressure of
about 200
to about 700 psig, about 300 to about 700 psig, about 400 to about 700 psig,
about 550 to
about 650 psig, about 575 to about 625 psig, or about 590 to about 610 psig.
(00170] For example, steam (or water vapor) can be injected and a plasma torch
can be
used for carrying fluidization.
[00171] For example, the steam (or water vapor) can be overheated.
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[00172] For example, the steam (or water vapor) can be at a temperature of
about 300 to
about 400 C.
[00173] For example, acid from the offgases generated during calcination can
be then
treated via a gas phase purification process.
[00174] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
by means of carbon monoxide (CO).
[00175] For example, converting AlC13 into A1203 can comprise carrying out a
calcination
by means of a Refinery Fuel Gas (RFG).
[00176] For example, calcination can be carried out by injecting water vapor
or steam
and/or by using a combustion source chosen from fossil fuels, carbon monoxide,
a Refinery
Fuel Gas, coal, or chlorinated gases and/or solvants.
[00177] For example, calcination can be carried out by injecting water vapor
or steam
and/or by using a combustion source chosen from natural gas or propane.
[00178] For example, calcination can be carried out by providing heat by means
of
electric heating, gas heating, microwave heating.
[00179] The obtained alumina can be washed by demineralized water so as to at
least
partially remove NaCI and/or KCI.
[00180] For example, the fluid bed reactor can comprise a metal catalyst
chosen from
metal chlorides.
[00181] For example, thee fluid bed reactor can comprise a metal catalyst
that is FeC13,
FeCl2 or a mixture thereof.
[00182] For example, the fluid bed reactor can comprise a metal catalyst
that is Fe0I3.
[00183] For example, the preheating system can comprise a plasma torch.
[00184] For example, steam can be used as the fluidization medium heating.
Heating can
also be electrical.
[00185] For example, a plasma torch can be used for preheating the calcination
reactor.
[00186] For example, a plasma torch can be used for preheating air entering in
the
calcination reactor.
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[00187] For example, a plasma torch can be used for preheating a fluid bed.
[00188] For example, the calcination medium can be substantially neutral in
terms of 02
(or oxidation). For example, the calcination medium can favorize reduction
(for example a
concentration of CO of about 100 ppm).
[00189] For example, the calcination medium is effective for preventing
formation of C12.
[00190] For example, the processes can comprise converting AlC13=6H20 into
A1203 by
carrying out a calcination of AlC13=6H20 that is provided by the combustion of
gas mixture
that comprises:
CH4 : 0 to about 1% vol;
C2H6 : 0 to about 2% vol;
C3H6 : 0 to about 2% vol;
C4H10 : 0 to about 1% vol;
N2: 0 to about 0.5% vol;
H2: about 0.25 to about 15.1 % vol;
CO : about 70 to about 82.5 % vol; and
CO2: about 1.0 to about 3.5% vol.
[00191] Such a mixture can be efficient for reduction in off gas volume of
15.3 to 16.3%;
therefore the capacity increases of 15.3 to 16.3 % proven on practical
operation of the
circulating fluid bed. Thus for a same flow it represents an Opex of
0.65*16.3% = 10.6%.
[00192] For example, the air to natural gas ratio of (Nm3/h over Nm3/h) in
the fluid bed
can be about 9.5 to about 10
[00193] For example, the air to CO gas ratio of (Nm3/h over Nm3/h) in the
fluid bed can be
about 2 to about 3.
[00194] For example, the processes can comprise, before leaching the material,
a pre-
leaching removal of fluorine optionally contained in the material.
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[00195] For example, the processes can comprise leaching of the material with
HCI so as
to obtain the leachate comprising aluminum ions and the solid, separating the
solid from the
leachate; and further treating the solid so as to separate Si02 from TiO2 that
are contained
therein.
[00196] For example, the processes can comprise leaching the material with HCI
so as to
obtain the leachate comprising aluminum ions and the solid, separating the
solid from the
leachate; and further treating the solid with HCI so as to separate Si from Ti
that are
contained therein.
[00197] For example, the processes can comprise leaching the material with HCI
so as to
obtain the leachate comprising aluminum ions and the solid, separating the
solid from the
leachate; and further treating the solid with HCI at a concentration of less
than 20 % wt., at
a temperature of less than 85 C, in the presence of MgC12, so as to separate
Si from Ti that
are contained therein.
[00198] For example, converting AlC13 into A1203 can comprise carrying out a
one-step
calcination.
[00199] For example, calcination can be carried out at different temperatures
with steam.
Temperature applied of superheated steam can be of about 350 C to about 550 C
or about
350 C to about 940 C or about 350 C to about 1200 C.
[00200] For example, multi stage evaporation step of the hydrolyser can be
carried out to
reduce drastically energy consumption.
[00201] For example, the processes can be effective for providing an A1203
recovery yield
of at least 93 %, at least 94 %, at least 95 %, about 90 to about 95 A),
about 92 to about
95 %, or about 93 to about 95 %.
[00202] For example, the processes can be effective for providing a Fe203
recovery yield
of at least 98 %, at least 99 %, about 98 to about 99.5 %, or about 98.5 to
about 99.5 %.
[00203] For example, the processes can be effective for providing a MgO
recovery yield
of at least 96 %, at least 97 %, at least 98 %, or about 96 to about 98 %.
[00204] For example, the processes can be effective for providing a HCI
recovery yield of
at least 98 %, at least 99 %, or about 98 to about 99.9 %
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[00205] For example, the processes can be effective for providing chlorides of
rare earth
elements (REE-CI) and chlorides of rare metals (RM-CI) in recovery yields of
about 75 % to
about 96.5 `)/0 by using internal processes via an internal concentration
loop.
[00206] For example, the processes can be effective for providing hydrochloric
acid
recovery yield of about 99.75 % with non-hydrolysable elements.
[00207] For example, the material can be argillite.
[00208] For example, the material can be bauxite.
[00209] For example, the material can be red mud.
[00210] For example, the material can be fly ashes.
[00211] For example, the material can be chosen from industrial refractory
materials.
[00212] For example, the material chosen from aluminosilicate minerals.
[00213] For example, the processes can be effective for avoiding producing red
mud.
[00214] For example, the alumina and the other products are substantially
free of red
mud.
[00215] For example, HCI can be recycled. For example, such a recycled HCI can
be
concentrated and/or purified.
[00216] For example, gaseous HCI can be concentrated and/or purified by means
of
H2SO4. For example, gaseous HCI can be passed through a packed column where it
is
contacted with a H2SO4 countercurrent flow. For example, by doing so,
concentration of HCI
can be increased by at least 50 % wt., at least 60 % wt., at least 70 % wt.,
at least 75 `)/0
wt., at least 80 % wt., about 50 % wt. to about 80 % wt., about 55 `)/0 wt. to
about 75 % wt.,
or about 60 % wt. For example, the column can be packed with a polymer such as
polypropylene(PP) or polytrimethylene terephthalate (PTT).
[00217] For example, gaseous HCI can be concentrated and/or purified by means
of
CaCl2 or LiCI. For example, gaseous HCI can be passed through a column packed
with
CaCl2 or Lid.
[00218] For example, AlC13.6H20 obtained in the processes of the present
disclosure can
be further purified as descriobed in International publication No.
W02014/075173.
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[00219] For example, MgC12 can be substantially selectively precipitated from
the
leachate and removed therefrom and then, the leachate can be reacted with HCI
so as to
obtain the liquid and the precipitate comprising the aluminum ions in the form
of AlC13, and
separating the precipitate from the liquid.
[00220] For example, the leachate can be reacted with HCI so as to obtain the
liquid and
the precipitate comprising the aluminum ions in the form of AICI3, and
separating the
precipitate from the liquid, and then the M9Cl2 is substantially selectively
precipitated from
the leachate and removed therefrom.
[00221] For example, the aluminum-containing material can beleached with HCI
so as to
obtain the leachate comprising aluminum ions, magnesium ions and the solid,
and the solid
is separated from the leachate at a temperature of at least 50, 60, 75 or 100
C. For
example, a filtration can be carried out and the temperature of the leachate
can have a
value as previously indicated.
[00222] For example, MgC12 can be substantially selectively precipitated from
the leachate
at a temperature of about 5 to about 70 C, about 10 to about 60 C, about 10
to about 40
or about 15 to about 30 C.
[00223] For example, the processes can comprise, before reacting the leachate
with HCI
so as to obtain the liquid and the precipitate, controlling the temperature of
the leachate so
as to substantially selectively precipitate a second metal in the form of a
chloride, and
removing the precipitate from the leachate.
[00224] For example, the processes can comprise, after reacting the leachate
with HCI so
as to obtain the liquid and the precipitate, controlling the temperature of
the leachate so as
to substantially selectively precipitate a second metal in the form of a
chloride, and
removing the precipitate from the leachate.
[00225] For example, the processes can further comprises treating the
precipitate under
conditions effective for converting the chloride of the first metal it into an
oxide of the first
metal and optionally recovering gaseous HCI so-produced.
[00226] For example, the processes can further comprises treating the
precipitate under
conditions effective for converting the chloride of the second metal it into
an oxide of the
second metal and optionally recovering gaseous HCI so-produced.
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[00227] For example, the solid can be treated with HCI and the metal chloride
so as to
obtain a liquid portion comprising Ti and a solid portion containing Si and
wherein the liquid
portion is separated from the solid portion.
[00228] For example, the solid can be treated with HCI and the metal chloride
so as to
obtain a liquid portion comprising TiC14.
[00229) For example, the process can further comprise converting TiCI4 into
Ti02.
[00230] For example, TiCI4 can be converted into TiO2 by solvent extraction of
the third
liquid fraction and subsequent formation of titanium dioxide from the solvent
extraction.
[00231] For example, TiCI4 can be reacted with water and/or a base to cause
precipitation
of Ti02.
[00232] For example, TiCI4 can be converted into TiO2 by means of a
pyrohydrolysis,
thereby generating HCI.
[00233] For example, TiCI4 can be converted into TiO2 by means of a
pyrohydrolysis,
thereby generating HCI that is recycled.
[00234] For example, the metal chloride can be MgC12 or ZnC12.
[00235] For example, the solid can comprise TiO2 and Si02 and the solid is
treated with
012 and carbon in order to obtain a liquid portion and a solid portion, and
wherein the solid
portion and the liquid portion are separated from one another.
[00236] For example, the liquid portion can comprise TiCl2 and/or TiCI4.
[00237] For example, the liquid portion can comprise TiC14.
[00238] For example, the process can further comprise heating TiCl4 so as to
convert it
into Ti02.
[00239] For example, the obtained TiO2 can be purified by means of a plasma
torch.
[00240] For example, the various products obtained by the processes of the
present
disclosure such as alumina, hematite, titanium oxides, magnesium oxides, rare
earth
elements and rare metals can be further purified by means of a plasma torch.
For example,
the rare earth elements and rare metals, once isolated, can be individually
injected into a
plasma torch so as to further purify them.
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[00241] For example, the processes can further comprise converting alumina
(A1203) into
aluminum. Conversion of alumina into aluminum can be carried out, for example,
by using
the Hall¨HerouIt process. References is made to such a well known process in
various
patents and patent applications such as US 20100065435; US 20020056650; US
5,876,584; US 6,565,733. Conversion can also be carried out by means of other
methods
such as those described in US 7,867,373; US 4,265,716; US 6,565,733
(converting alumina
into aluminum sulfide followed by the conversion of aluminum sulfide into
aluminum.). For
example, aluminium can be produced by using a reduction environment and carbon
at
temperature below 200 C. Aluminum can also be produced by reduction using
potassium
and anhydrous aluminum chloride ( VVohler Process).
[00242] For example, controlling the temperature of the leachate so as to
precipitate the
the first metal in the form of a chloride, and removing the precipitate from
the leachate, can
be carried out before reacting the leachate with HCI so as to obtain a liquid
and a
precipitate comprising a chloride of the second metal, and separating the
precipitate from
the liquid.
[00243] For example, controlling the temperature of the leachate so as to
precipitate the
the first metal in the form of a chloride, and removing the precipitate from
the leachate, can
be carried out after reacting the leachate with HD so as to obtain a liquid
and a precipitate
comprising a chloride of the second metal, and separating the precipitate from
the liquid.
[00244] For example, reacting the leachate with HCI so as to obtain a
precipitate
comprising the first metal in the form of a chloride, can be carried out by
substantially
selectively precipitating the first metal chloride.
[00245] For example, reacting the leachate with HCI so as to obtain a
precipitate
comprising the second metal in the form of a chloride, can be carried out by
substantially
selectively precipitating the second metal chloride,
[00246] For example, controlling the temperature of the leachate so as to
precipitate the
the first metal in the form of a chloride can be carried out substantially
selectively.
[00247] For example, controlling the temperature of the leachate so as to
precipitate the
second metal in the form of a chloride can be carried out substantially
selectively.
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[00248] For example, controlling the concentration of HCI in the leachate
and/or the
temperature of the leachate so as to precipitate the first metal in the form
of a chloride, can
be carried out substantially selectively.
[00249] For example, controlling the concentration of HCI in the leachate
and/or the
temperature of the leachate so as to precipitate the second metal in the form
of a chloride,
can be carried out substantially selectively.
[00250] For example, the first metal can chosen from aluminum, iron, zinc,
copper, gold,
silver, molybdenum, cobalt, magnesium, lithium, manganese, nickel, palladium,
platinum,
thorium, phosphorus, uranium and titanium, and/or at least one rare earth
element and/or at
least one rare metal
[00251] For example, the liquid can comprise a second metal.
[00252] For example, the second metal can be chosen from aluminum, iron, zinc,
copper,
gold, silver, molybdenum, cobalt, magnesium, lithium, manganese, nickel,
palladium,
platinum, thorium, phosphorus, uranium and titanium, and/or at least one rare
earth
element and/or at least one rare metal
[00253] For example, the process can comprise separating the precipitate from
the liquid
and heating the second metal in order to convert a chloride of the second
metal into an
oxide of the second metal.
[00254] For example, the second metal can be magnesium.
[00255] For example, the second metal can be aluminum.
[00256] For example, the first metal can be aluminum and the second metal
can be
magnesium.
[00257] For example, the second metal can be aluminum and the first metal
can be
magnesium.
[00258] For example, the processes can comprise
separating the solid from the leachate;
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leaching the solid with an acid so as to obtain another leachate; and
recovering a third metal from the another leachate.
[00259] For example, the third metal can be chosen from aluminum, iron, zinc,
copper,
gold, silver, molybdenum, cobalt, magnesium, lithium, manganese, nickel,
palladium,
platinum, thorium, phosphorus, uranium and titanium, and/or at least one rare
earth
element and/or at least one rare metal.
[00260] For example, the third metal can be titanium.
[00261] For example, the acid can be chosen from HCI, HNO3, H2SO4 and mixtures
thereof.
[00262] For example, the process can comprise recovering the third metal from
the
another leachate by precipitating the third metal.
[00263] For example, the third metal can be precipitated by reacting
it with HCI.
[00264] For example, the process can further comprise heating the third metal
in order to
convert a chloride of the third metal into an oxide of the third metal.
[00265] For example, the first metal can be magnesium.
[00266] For example, the first metal can be nickel.
[00267] For example, the second metal can be magnesium.
[00268] For example, the second metal can be nickel.
[00269] For example, the process can comprise reacting the leachate with
gaseous HCI
so as to obtain a liquid and a precipitate comprising MgCl2.
[00270] For example, the process comprises reacting the leachate with gaseous
HCI so
as to obtain a liquid and a precipitate comprising MgC12.
[00271] For example, Neel recovered from the processes of the present
disclosure can
be reacted with SO2, so as to produce HCI and Na2SO4. Such a reaction that is
an
exothermic reaction can generate steam that can be used to activate a turbine
and
eventually produce electricity.
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[00272] For example, U and/or Th can be tretaed with the processes of the
present
disclosure. For example, these two elements can be in such processes in
admixtures with
iron ions and they can be separated therefrom by means of at least one ion
exchange resin.
[00273] For example, the processes can comprise substantially selectively
precipitating
the magnesium ions by reacting the leachate with the precipitating agent.
[00274] For example, the precipitating agent can be Mg(OH)2.
[00275] For example, the at least one metal can be nickel.
[00276] For example, the at least one metal can be cobalt.
[00277] For example, the at least one metal can be iron.
[00278] For example, the at least one metal can be aluminum.
[00279] In the processes of the present disclosure, when the material to be
treated
comprises aluminum and magnesium, magnesium can be first removed from the
leachate
by controlling temperature of said leachate so as to substantially selectively
cause
precipitation (or crystallization) of MgCl2, remove it from the leachate and
then substantially
selectively cause precipitation of AlC13 by reacting the leachate with HCI
(for example
gaseous HCI). Alternatively, the leachate can be reacted with HCI to
substantially
selectively cause precipitation (or crystallization) of AlC13 (for example
gaseous NCI). In
such a case the temperature can be maintained for example above 50, 60, 70,
BO, or 90 C.
AlC13 is then removed from the leachate and then, temperature of the leachate
is controlled
so as to substantially selectively cause precipitation of MgCl2. Depending on
the
concentration of Al vs Mg in the starting material one scenario or the other
can be selected.
For example, if the concentration of Mg is greater than the concentration of
Al, Mg can be
removed first from the leachate. For example, if the concentration of Al is
greater than the
concentration of Mg, Al can be removed first from the leachate.
[00280] In the processes of the present disclosure, when the material to be
treated
comprises aluminum, iron and magnesium. Magnesium can be first removed from
the
leachate by controlling temperature of said leachate so as to substantially
selectively cause
precipitation (or crystallization) of MgCl2, remove it from the leachate and
then substantially
selectively cause precipitation of AlC13 by reacting the leachate with HCI
(for example
gaseous NCI). Then, the remaining composition comprising iron chloride can be
treated so
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as to convert iron chloride into iron oxide by using one of the methods
discussed in the
present disclosure. Alternatively, the leachate can be reacted with HC1 to
substantially
selectively cause precipitation (or crystallization) of AlC13 (for example
gaseous HCI). In
such a case the temperature can be maintained for example above 50, 60, 70,
80, or 90 C.
AlC13 is then removed from the leachate and then, temperature of the leachate
is controlled
so as to substantially selectively cause precipitation of MgC12. Then, the
remaining
composition comprising iron chloride can be treated so as to convert iron
chloride into iron
oxide by using the methods discussed in the present disclosure.
[00281] For example, the precipitate can be reacted with a base (for example
KOH or
NaOH). For example, AlC13 can be converted into Al(OH)3 before calcination.
[00282] According to one example as shown in Fig. 1, the processes can involve
the
following steps (the reference numbers in Fig. 1 correspond to the following
steps) :
1- The aluminum-containing material is reduced to an average particle size
of
about 50 to about 80 pm.
2- The reduced and classified material is treated with hydrochloric acid
which
allows for dissolving, under a predetermined temperature and pressure, the
aluminum with
other elements like iron, magnesium and other metals including rare earth
elements and/or
rare metals. The silica and titanium (if present in raw material) remain
totally undissolved.
3- The mother liquor from the leaching step then undergoes a separation, a
cleaning stage in order to separate the solid from the metal chloride in
solution.
4- The spent acid (leachate) obtained from step 3 is then brought up in
concentration with dry and highly concentrated gaseous hydrogen chloride by
sparging this
one into a crystallizer. This results into the crystallization of aluminum
chloride hexahydrate
(precipitate) with a minimum of other impurities. Depending on the
concentration of iron
chloride at this stage, further crystallization step(s) can be required. The
precipitate is then
separated from the liquid. For example, particle size of crystals can be about
100 to about
500 microns, about 200 to about 400 microns, or about 200 to about 300
microns.
Alternatively, particle size of crystals can be about 100 to about 200
microns, about 300 to
about 400 microns or about 400 to 500 microns.
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5- The aluminum chloride hexahydrate is then calcined (for example by means
of a rotary kiln, fluid bed, etc) at high temperature in order to obtain the
alumina form.
Highly concentrated gaseous hydrogen chloride is then recovered and excess is
brought in
aqueous form to the highest concentration possible so as to be used (recycled)
in the acid
leaching step. Acid can also be directly sent in gas phase to the acid
purification stage to
increase HCI concentration from about 30 wt % to about 95 wt %. This can be
done, for
example, during drying stage.
6- Iron chloride (the liquid obtained from step 4) is then pre-concentrated
and
hydrolyzed at low temperature in view of the Fe203 (hematite form) extraction
and acid
recovery from its hydrolysis. All heat recovery from the calcination step
(step 5), the
leaching part exothermic reaction (step 1) and other section of the processes
is being
recovered into the pre-concentrator.
10- After the
removal of hematite, a solution rich in rare earth elements and/or
rare metals can be processed. As it can be seen in Fig.3, an internal
recirculation can be
done (after the removal of hematite) and the solution rich in rare earth
elements and/or rare
metals can be used for crystallization stage 4. Extraction of the rare earth
elements and/or
rare metals can be done as described in WO/2012/126092 and/or WO/2012/149642.
Other non-hydrolysable metal chlorides (Me-CI) such as MgCl2 and others then
undergo the following steps:
7- The solution rich in magnesium chloride and other non-hydrolysable
products
at low temperature is then brought up in concentration with dry and highly
concentrated
gaseous hydrogen chloride by sparging it into a crystallizer. This
results into the
precipitation of magnesium chloride as an hexahydrate, for example after
sodium and
potassium chloride removal.
8- Magnesium chloride hexahydrate is then calcined (either through a rotary
kiln,
fluid bed, etc.) and hydrochloric acid at very high concentration is thus
regenerated and
brought back to the leaching step.
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9- Other Me-CI undergo a standard pyrohydrolysis step where
mixed oxides
(Me-0) can be produced and hydrochloric acid at the azeotropic point (20.2%
wt) is
regenerated.
11- Ti contained in the solid obtained from step 3 can be
treated so as to separate
Si from Ti and thus obtain Si02 and Ti02.
[00283] NaCI produced in this process can undergo chemical reaction with H2SO4
to
produce Na2SO4 and HCI at a concentration at or above azeotropic
concentration.
Moreover, KCI can undergo chemical reaction with H2SO4 to produce K2SO4 and
HCI
having a concentration that is above the azeotropic concentration. Sodium and
potassium
chloride brine solution can be the feed material to adapted small chlor-alkali
electrolysis
cells. In this latter case, common bases (NaOH and KOH) and bleach (Na0C1 and
KOCI)
are produced as well as HCI.
[00284] For example, the liquid can be concentrated to a concentrated liquid
having an
iron chloride concentration of at least 30% by weight; and then the iron
chloride can be
hydrolyzed at a temperature of about 155 to about 350 C while maintaining a
ferric chloride
concentration at a level of at least 65% by weight, to generate a composition
comprising a
liquid and precipitated hematite, and recovering the hematite.
[00285] For example, the liquid can be concentrated to a concentrated liquid
having an
iron chloride concentration of at least 30% by weight; and then the iron
chloride can be
hydrolyzed at a temperature of about 155 to about 350 C while maintaining a
ferric chloride
concentration at a level of at least 65% by weight, to generate a composition
comprising a
liquid and precipitated hematite; recovering the hematite; and recovering rare
earth
elements and/or rare metals from the liquid. For example, the process can
further comprise,
after recovery of the rare earth elements and/or rare metals, reacting the
liquid with HCI so
as to cause precipitation of MgC12, and recovering same.
[00286] As previously indicated, various aluminum-containing materials can be
used as
starting material of the processes disclosed in the present disclosure.
Examples with clays
and bauxite have been carried out. However, the person skilled in the art will
understand
that the continuous processes can handle high percentages of silica (>55%) and
impurities
as well as relatively low percentages of aluminum (for example as low as about
15%) and
still being economically and technically viable. Satisfactory yields can be
obtained (>93-
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95%) on A1203 and greater than 75%, 85 or 90 % on rare earth elements and/or
rare
metals. No pre-thermal treatment in most cases are required. The processes
disclosed in
the present disclosure involve special techniques on leaching and acid
recovery at very
high strength, thereby offering several advantages over alkaline processes.
[00287] In step 1 the mineral, whether or not thermally treated is
crushed, milled, dried
and classified to have an average particle size of about 50 to about 80 pm.
[00288] In step 2, the milled raw material is introduced into the
reactor and will undergo
the leaching phase.
[00289] The leaching hydrochloric acid used in step 2 can be a recycled or
regenerated
acid from steps 5, 6, 8, 9, 10 and 11 (see Fig. 3) its concentration can vary
from 15% to
45% weight. percent. Higher concentration can be obtained using membrane
separation,
cryogenic and/or high pressure approach. The acid leaching can be carried out
under
pressure and at temperature close to its boiling point thus, allowing a
minimal digestion time
and extended reaction extent (90%-100%). Leaching (step 2) can be accomplished
in a
semi-continuous mode where spent acid with residual free hydrochloric acid is
replaced by
highly concentrated acid at a certain stage of the reaction or allowing a
reduced
acid/mineral ratio, thereby reducing reaction time and improving reaction
kinetics. For
example, kinetic constant k can be : 0.5 ¨ 0.75 g/mole.L. For example,
leaching can be
continuous leaching.
[00290] As previously indicated, alkali metals, iron, magnesium, sodium,
calcium,
potassium, rare earth elements and other elements will also be in a chloride
form at
different stages. Silica and optionally titanium can remain undissolved and
will undergo
(step 3) a liquid/solid separation and cleaning stage. The processes of the
present
disclosure tend to recover maximum amount of free hydrochloric acid left and
chlorides in
solution in order to maximize hydrochloric acid recovery yield, using
techniques such as
rake classifying, filtration with band filters, centrifugation, high pressure,
rotofilters and
others. Thanks to step 13, Ti contained in the solid obtained from step 3 can
be treated so
as to separate Si from Ti and thus obtain Si02 and Ti02. Various possible
strategies can be
used to separated Si from Ti as previously indicated. For example, the solid
can be further
leached (for example with HCI in the presence of a metal chloride (for example
MgCl2 or
ZnCl2) so as to solubilize Ti (for example in the form of TiCI4) while the Si
remains solid.
Alternatively, the solid can be reacted with Cl2 (see Figs. 10A and 108). he
purified silica
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can then optionally undergo one or two additional leaching stages (for example
at a
temperature of about 150 to about 160 C) so as to increase the purity of
silica above 99.9
0/0.
[00291] Pure Si02 (one additional leaching stage) cleaning with nano water
purity 99%
min. Mother liquor free of silica is then named as spent acid (various metal
chlorides and
water) and goes to the crystallization step (step 4). Free HCI and chlorides
recovery can be
at least 99, 99.5 or 99.9 %
[00292] In step 4, the spent acid (or leachate) with a substantial amount of
aluminum
chloride is then saturated with dry and highly concentrated gaseous hydrogen
chloride
obtained or recycled from step 5 or with aqueous HCI > 30% wt., which results
in the
precipitate of aluminum chloride hexahydrate (AIC13 = 6H20). The precipitate
retained is
then washed and filtered or centrifuged before being fed to the calcination
stage (step 5).
The remaining of the spent acid from step 4 is then processed to acid recovery
system
(steps 6 to 8) where pure secondary products will be obtained.
[00293] In step 5, aluminum oxide (alumina) is directly obtained from high
temperature
conditions. The highly concentrated hydrogen chloride in gaseous form obtained
can be fed
to steps 4 and 7 for crystallization where it can be treated through
hydrophobic membranes.
The excess hydrogen chloride is absorbed and used as regenerated acid to the
leaching
step 2 as highly concentrated acid, higher than the concentration at the
azeotropic point
(>20.2%). For example, such a concentration can be about 18 to about 45 weight
%, about
25 to about 45 weight % or between 25 and 36 weight /0. Acid can also be
redirected in
gas phase directly (> 30 wt %) to acid purification.
[00294] After step 4, various chlorides derivatives (mainly iron with
magnesium and rare
earth elements and rare metals) are next subjected to an iron extraction step.
Such a step
can be carried out for example by using the technology disclosed in WO
2009/153321.
Moreover, hematite can be seeded
for crystal growth. For example, hematite seeding can comprise recirculating
the seeding.
[00295] In step 6, a hydrolysis at low temperature (155-350 C) is carried out
and pure
Fe203 (hematite) is being produced and hydrochloric acid of at least 15%
concentration is
being regenerated. The method as described in WO 2009/153321 is processing the
solution of ferrous chloride and ferric chloride, possible mixtures thereof,
and free
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hydrochloric acid through a series of steps pre-concentration step, oxidation
step where
ferrous chloride is oxidized into ferric form, and finally through an
hydrolysis step into an
operational unit called hydrolyser where the ferric chloride concentration is
maintained at 65
weight % to generate a rich gas stream where concentration ensures a hydrogen
chloride
concentration of 15-20.2% and a pure hematite that will undergo a physical
separation step.
Latent heat of condensation is recovered to the pre-concentration and used as
the heating
input with excess heat from the calcination stage (step 5).
[00296] The mother liquor from the hydrolyser (step 6) can be recirculated
partially to first
step crystallization process where an increase in concentration of non-
hydrolysable
elements is observed. After iron removal, the liquor is rich in other non-
hydrolysable
elements and mainly comprises magnesium chloride or possible mixture of other
elements
(various chlorides) and rare earth elements and rare metals that are, for
example, still in the
form of chlorides.
[00297] Rare earth elements and rare metals in form of chlorides are highly
concentrated,
in percentage, into the hydrolyser operational unit (step 6) and are extracted
from the
mother liquor (step 10) where various known techniques can be employed to
extract a
series of individual RE-0 (rare earth oxides). Among others, the processes of
the present
disclosure allows to concentrate to high concentration the following elements,
within the
hydrolyser: scandium (Sc), galium (Ga), yttrium (Y), dysperosium (Dy), cerium
(Ce),
praseodynium (Pr), neodynium (Nd), europium (Eu), lanthanum (La), samarium
(Sm),
gadolinium, (Gd), erbium (Er), zirconium (Zr) and mixtures of thereof.
Technologies that
can be used for extracting rare earth elements and/or rare metals can be
found, for
example, in Zhou et al. in RARE METALS, Vol. 27, No. 3, 2008, p223-227, and in
US
2004/0042945. The person skilled in the
art will also understand that various other processes normally used for
extracting rare earth
elements and/or rare metals from the Bayer process can also be used. For
example,
various solvent extraction techniques can be used. For certain elements, a
technique
involving octylphenyl acid phosphate (OPAP) and toluene can be used. HCI can
be used as
a stripping agent. This can be effective for recovering Ce203, Sc203, Er203
etc. For
example, different sequence using oxalic acid and metallic iron for ferric
chloride separation
can be used.
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[00298] The spent acid liquor from steps 6 and 10 rich in value added metals,
mainly
magnesium, is processed to step 7. The solution is saturated with dry and
highly
concentrated gaseous hydrogen chloride from step 5, which results in the
precipitation of
magnesium chloride hexahydrate. For example, same can be accomplished with HCI
in
aqueous form over 30% wt. The precipitate retained, is fed to a calcination
stage step 8
where pure MgO (>98% wt.) is obtained and highly concentrated hydrochloric
acid (for
example of at least 38 %) is regenerated and diverted to the leaching step
(step 2). An
alternative route for step 7 is using dry gaseous hydrochloric acid from step
8.
[00299] In step 9, metal chlorides unconverted are processed to a
pyrohydrolysis step
(700-900 C) to generate mixed oxides and where hydrochloric acid from 15-20.2%
wt.
concentration can be recovered.
[00300] According to another example as shown in Fig. 3, the processes can be
similar to
the example shown in Fig, 1 but can comprise some variants as below discussed.
[00301] In fact, as shown in Fig. 3, the processes can comprise (after step 6
or just before
step 10) an internal recirculation back to the crystallization step 4. In such
a case, The
mother liquor from the hydrolyser (step 6) can be recirculated fully or
partially to the
crystallization of step 4 where a concentration increase will occur with
respect to the non-
hydrolysable elements including rare earth elements and/or rare metals.
[00302] Such a step can be useful for significantly increasing the
concentration of rare
earth elements and/or rare metals, thereby facilitating their extraction in
step 10.
[00303] With respect to step 7, the solution rich in magnesium chloride and
other non-
hydrolysable products at low temperature is, as previously discussed, then
brought up in
concentration with dry and highly concentrated gaseous hydrogen chloride by
sparging it
into a crystallizer. This can result into the precipitation of magnesium
chloride as an
hexahydrate (for example after sodium and potassium chloride removal). This
can also be
accomplished with NCI in aqueous form.
[00304] As shown in Fig. 3, an extra step 11 can be added. Sodium chloride can
undergo
a chemical reaction with sulfuric acid so as to obtain sodium sulfate and
regenerate
hydrochloric acid at a concentration at or above the azeotropic point.
Potassium chloride
can undergo a chemical reaction with sulfuric acid so as to obtain potassium
sulfate and
regenerate hydrochloric acid at a concentration above the azeotropic
concentration.
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Sodium and potassium chloride brine solution can be the feed material to
adapted small
chlor-alkali electrolysis cells. In this latter case, common bases (NaOH and
KOH) and
bleach (Na0C1 and KOCI) are produced and can be reused to some extent in other
areas of
the processes of the present disclosure (scrubber, etc.).
[00305] The following are non-limitative examples.
Example 1
Preparation of alumina and various other products
[00306] As a starting material a sample of clay was obtained from the Grande
Vallee area
in Quebec, Canada.
[00307] These results represent an average of 80 tests carried out from
samples of about
900 kg each.
[00308] Crude clay in the freshly mined state after grinding and
classification had the
following composition:
A1203: 15% - 26%;
Si02 : 45% - 50%;
Fe203 : 8% - 9%;
MgO: 1% ¨ 2%;
Rare earth elements and/or rare metals : 0.04% - 0.07%;
LO1 : 5% - 10%.
[00309] This material is thereafter leached in a two-stage procedure at 140-
170 C with
18-32 weight % HCI. The HCI solution was used in a stoichiometric excess of 10-
20%
based on the stoichiometric quantity required for the removal of the acid
leachable
constituents of the clay. In the first leaching stage of the semi-continuous
operation (step
2), the clay was contacted for 2.5 hours with required amount or certain
proportion of the
total amount of hydrochloric acid. After removal of the spent acid, the clay
was contacted
again with a minimum 18 weight % hydrochloric acid solution for about 1.5 hour
at same
temperature and pressure.
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[00310] A typical extraction curve obtained for both iron and aluminum for a
single stage
leaching is shown in Fig. 2.
[00311] The leachate was filtered and the solid was washed with water and
analyzed
using conventional analysis techniques (see step 3 of Fig. 1). Purity of
obtained silica was
of 95.4% and it was free of any chlorides and of HCI.
[00312] In another example, the purity of the silica was 99.67 % through an
extra leaching
step.
[00313] After the leaching and silica removal, the concentration of the
various metal
chlorides was :
AlC13 : 15-20%;
FeCl2: 4-6%;
FeCI3 : 0.5-2.0%;
MgCl2: 0.5-2.0 %;
REE-CI : 0.1 ¨ 2 %
Free HCI : 5-50 g/I
[00314] Spent acid was then crystallized using about 90 to about 98% pure dry
hydrochloric acid in gas phase in two stages with less than 25 ppm iron in the
aluminum
chloride hexahydrate formed. The concentration of HCI in solution (aqueous
phase) was
about 22 to about 32% or 25 to about 32 %, allowing 95.3 % of A1203 recovery.
The
recovered crystallized material (hydrate form of AlC13 having a minimum purity
of 99.8 %)
was then calcined at 930 C or 1250 C, thus obtaining the a form of the
alumina. Heating at
930 C allows for obtaining the beta-form of alumina while heating at 1250 C
allows for
obtaining the alpha-form.
[00315] Another example was carried out at low temperature (decomposition and
calcination at about 350 C) and the a form of the alumina was less than 2 %.
[00316] HC1 concentration in gas phase exiting the calcination stage was
having a
concentration greater than 30% and was used (recycled) for crystallization of
the AlC13 and
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MgC12. Excess of hydrochloric acid is absorbed at the required and targeted
concentration
for the leaching steps.
[00317] Iron chloride (about 90-95% in ferric form) is then sent to a
hydrothermal process
in view of its extraction as pure hematite (Fe203). This can be done by using
the technology
described in WO 2009/153321 of low temperature hydrolysis with full heat
recovery from
calcining, pyrohydrolysis and leaching stage.
[00318] Rare earth elements and rare metals are extracted from the mother
liquor of the
hydrolyzer where silica, aluminum, iron and a great portion of water have been
removed
and following preconcentration from hydrolyser to crystallization. It was
observed that rare
earth elements can be concentrated by a factor of about 4.0 to 10.0 on average
within the
hydrolyzer itself on a single pass through it i.e. without concentration loop.
The following
concentration factors have been noted within the hydrolyzer (single pass):
Ce > 6
La > 9
Nd > 7
Y > 9
[00319] Remaining magnesium chloride is sparged with dry and highly
concentrated
hydrochloric acid and then calcinated to MgO while recovering high
concentration acid (for
example up to 38.4%).
[00320] Mixed oxides (Me-0) containing other non-hydrolysable components were
then
undergoing a pyrohydrolysis reaction at 700-800 C and recovered acid (15-20.2%
wt.) was
rerouted for example to the leaching system.
Overall yields obtained:
A1203 : 93.0-95.03% recovery;
Fe203 : 92.65-99.5% recovery;
Rare earth elements: 95% minimum recovery (mixture);
MgO: 92.64-98.00% recovery;
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Material discarded : 0-5% maximum;
HCI global recovery: 99.75% minimum;
HCI strength as feed to leaching 15-32% (aqueous); 95 % (gas)
Red mud production : none.
Example 2
Preparation of alumina and various other products
[00321] A similar feed material (bauxite instead of clay) was processed as per
in example
1 up to the leaching stage and revealed to be easily leachable under the
conditions
established in example 1. It provided an extraction percentage of 100% for the
iron and
over 90-95% for aluminum. The technology was found to be economically viable
and no
harmful by-products (red mud) were generated. Samples
tested had various
concentrations of A1203 (up to 51%), Fe203 (up to 27%) and MgO (up to 1.5%).
Gallium
extraction of 97.0 % was observed. Scandium extraction was 95 A).
Example 3
HCI gas enrichment and purification: H2SO4 route
[00322] H2SO4 can be used for carrying out purification of HCI. It can be
carried out by
using a packing column with H2SO4 flowing counter currently (see Fig. 4). This
allows for
converting the recovered HCI into HCI having a concentration above the
azeotropic point
(20.1% wt) and increase its concentration by about 60 to about 70% at minimum.
[00323] Water is absorbed by H2SO4 and then H2SO4 regeneration is applied
where
H2SO4 is brought back to a concentration of about 95 to about 98% wt. Water
release at
this stage free of sulphur is recycled back and used for crystallization
dissolution, etc.
Packing of the column can comprise polypropylene or polytrimethylene
terephthalate (PTT).
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[00324] Combustion energy can be performed with off gas preheating air and
oxygen
enrichment. Oxygen enrichment: +2% represents flame temperature increase by:
400 C
maximum.
[00325] Thus, HCI of the processes of the present disclosure can thus be
treated
accordingly.
Example 4
HCI gas enrichment and purification: calcium chloride to calcium chloride
hexahydrate (absorption / desorption process)
[00326] As shown in Fig. 5, CaCl2 can be used for drying HCI. In fact, CaCl2
can be used
for absorbing water contained into HCI. In such a case, CaCl2 is converted
into its
hexahydrate form (CaCl2 = 6H20) and one saturated system is eventually
switched into
regeneration mode where hot air recovered from calcination off gas of alumina
and
magnesium oxide spray roasting is introduced to regenerate the fixed bed.
Alternatively,
other absorbing agent such as LiCI can be used instead of CaCl2. Such an ion /
exchange
type process can be seen in Fig. 4 and the cycle can be inversed to switch
from one
column to another one.
[00327] The person skilled in the art would understand that the processes
described in
examples 3 and 4 (see Fig.s 4 and 5) can be used in various different manners.
For
example, these processes can be combined with the various processes presented
in the
present disclosure. For example, such purifications techniques can be
integrated to the
processes shown in Figs. 1, 3, 6, to 8 or 11 to 14 . For example, these
techniques can be
used downstream of at least one of step chosen from steps 5, 6, 8, 9, 10, 11,
13 and 20
(see Figs. 1, 3, 8, 13 and 14). They can also be used downstream of step 4
and/or step 7.
They can also be used downstream of at least one of step chosen from steps 104
to 111
(see Figs. 6 and 7). Moreover, they can be used in Figs. 11 and 12 for example
in steps
215, 216, 315 or 316.
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Example 5
Preparation of alumina and various other products
[00328] This example was carried out by using a process as represented in
Figs. 6 and 7.
It should be noted that the processes represented in Figs. 6 and 7 differ
mainly by the fact
that Fig. 7 shows an stage i.e. stage 112.
Raw material preparation
[00329] Raw material, clay for example, was processed in a secondary crusher
in the clay
preparation plant 101. Dry milling and classifying occurs on a dry basis in
vertical roller mills
(for example Fuller-Loesche LM 30.41). The clay preparation 101 included three
roller mills;
two running at a capacity of approximately 160-180 tph and one on standby. Raw
material,
if required, can be reduced to 85% less than 63 microns. Processed material
was then
stored in homogenization silos before being fed to the acid leaching plant
102. Below in
Table 1 are shown results obtained during stage 101. If the ore contains the
fluorine
element, a special treatment can be applied before carrying out the 102 stage.
In presence
of hydrochloric acid, fluorine can produce hydrofluoric acid. This acid is
extremely corrosive
and damaging for human health. Thus, before leaching 102, an optional
treatment fluorine
separation 112 can be done. Stage 112 can comprise treating the processed
material
coming from stage 101 with an acid in a pre-leaching treatment so as to remove
hydrofluoric acid. Therefore, depending on the composition of the raw
material, a fluorine
separation stage 112 (or pre-leaching stage 112) can be carried out.
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Table 1.
Clay preparation
Rate 290 tph __
Si02: 50.9%
A1203: 24.0%
Fe203: 8.51% _____
CaO: 0.48%
Composition feed MgO: 1.33%
(main constituents) Na20:
K20: 2.86%
MnO: 0.16%
Cr203: 0.01%
Ti02: _______________________ 0.85%
P205: 0.145%
Sr0: 0.015% __
BaO: 0.05%
V205 0.0321%
Other (including H20 and
9.63%
___________________ REE): __
Obtained particle size 85% <63 pm
Residual moisture 0.5-0.7%
Yield 99.5% min
Acid Leaching
[00330] Next, acid leaching 102 was performed semi-continuously in an 80 m3
glass-lined
reactor. Semi-continuous mode comprises replacing reacted acid 1/3 in the
reaction period
with higher concentration regenerated acid, which greatly improves reaction
kinetics. The
reactor arrangement comprises for example, a series of three reactors. Other
examples
have been carried out with a first leaching at 1 atm was carried out and then,
a second and
third semi-continous or continuous leaching was carried out with aqueous or
gaseous HCI.
[00331] Leaching was performed at high temperature and pressure (about 160 to
about
195 C and pressures of about 5 to about 8 barg) for a fixed period of time.
Reaction time
was a function of the reaction extent targeted (98% for A1203), leaching mode,
acid
strength, and temperature/pressure applied.
[00332] Spent acid recovered out of the acid leaching 102 was then filtered
103 from
unreacted silica and titanium dioxide and washed through an automated filter
press where
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all free HCI and chloride are recovered. Step 113 can then be carried out in
various
manners as indicated previously for step 13.This allows, for example, a
maximum quantity
of about 30 ppm Si02 going into spent liquor. Cleaned silica at a
concentration of :=96 % +
Si02 is then produced. Various options are possible at that point. For
example, the 96%
silica can undergo final neutralization through caustic bath, cleaning, and
then bricketing
before storage. According to another example, the silica purified by adding
another leaching
step followed by a solid separation step that ensures TiO2 removal (see stage
113 in Figs. 6
and 7). In that specific case, high purity silica 99.5%+ is produced. In stage
113, titanium
and silicium can be separated from one another in various manners. For
example, the solid
obtained from stage 103 can be leached in the presence of MgCl2 at a
temperature below
90 or 80 C and at low acid concentration. For example, acid concentration can
be below
25 or 20 %. The acid can be HC1 or H2SO4. In such a case, titanium remains
soluble after
such a leaching while titanium is still in a solid form. The same also applies
when the solid
is treated with C12. These solid and liquid obtained after stage 113 are thus
separated to
provide eventually TiO2 and S102. Water input and flow for silica cleaning is
in a ratio of 1:1
(silica/water) (150 t/h Si02 /150 t/h H20), but comprises of wash water
circulation in closed
loop in the process and limited amount of process water for final cleaning of
the silica and
recovery of all chlorides and free HCI generated at the leaching stage. Below
in Table 2 are
shown results obtained during stage 102.
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Table 2.
Acid Leaching
Equivalent solid feed rate 259.6 tph
Operation mode Semi-continuous
3.10 @ 23% wt
Acid to clay ratio (Equivalent to 3.35 with semi-continuous at
__________________________ 18.0 % wt)
Regenerated acid
18.0-32.0%
concentration
150-155 C (Pilot)
Operating temperature
165-200 C ( Plant)
MAWP _________________ 120 psig
Fe203 + 6 HCI 2 FeCl3 + 3H20
A1203 + 6 HCI 2 AlC13 + 3 H20 _________________
Typical chemical
Mg0 + 2 HCI MgC12 + H20
reactions
K20 + 2 HCI 2 KCI + H20
Re203 + 6 HCI 2 ReCI3 + 3H20
Spent acid flow to
600-1100 m3/h
crystallization
FeCI3 4.33% __
FeCl2 0.19%
Practical chemical AlC13 16.6%
composition after step MgC12 __ 0.82%
102 without solid (Si02) NaCl 1.1%
KCI 1.2%
______________________ CaCl2 0.26%
Iron 100%
Extraction yields
A1203 98%
Si02 Recovery 99.997%
- ________ -
Activation energy only and self-sustained
Energy consumption exothermic reaction from 130 C
AlC13 Crystallization
100333] Spent acid, with an aluminum chloride content of about 20 to about 30
%, was
then processed in the crystallization stage 104. Dry and highly concentrated
HCI (>90%
wt.) in gas phase was sparged in a two-stage crystallization reactor, which
allows the
crystallization of aluminum chloride hexahydrate.
[00334] The flow rate of acid through these reactors is about 600 to about 675
m3th and
the reactor was maintained at about 50 to about 60 C during this highly
exothermic
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reaction. Heat was recovered and exchanged to the acid purification 107 part
of the plant
thus ensuring proper heat transfer and minimizing heat consumption of the
plant.
Aluminum chloride solubility decreases rapidly, compared to other elements,
with the
increase in concentration of free HCI in the crystallization reactor. The
concentration of
AlC13 for precipitation/crystallization was about 30%
[00335] The HCI concentration during crystallization was thus about 30 to
about 32 % wt.
[00336] The aqueous solution from the crystallization stage 104 was then
submitted to
the hydrothermal acid recovery plant 105, while the crystals are processed
through the
decomposition/calcination stage in the calcination plant 106.
[00337] A one-step crystallization stage or a multi-step crystallization stage
can be done.
For example, a two-steps crystallization stage can be carried out.
[00338] Below in Tables 3A and 3B are shown results obtained during stage 104.
Table 3A.
!Aluminum chloride crystallization
Number of crystallization
2
steps
Operating temperature __ 50-60 C
Sparging HCI concentration 90% (=aseous) __
AlC13 = 6H20 (s)
Typical chemicals formed
Metal chlorides a=
AlC13 = 6H20 residual __ <5% (practical); 8 /0
_
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Table 3B.
Typical crystals composition main constituents
obtained at pilot scale and feeding calcination
Component Weight distribution (%)
AlC13 = 6H20 99.978
BaCl2 = 2H20 J 0000
CaCl2 = 6H20 0.0009
CrCI4 1
0.0022
CuCl2 = 2H20 0.0000
FeCI3 6H20 0.0019
KCI
0.0063
MgC12 = 6H20 j 0.0093
MnCl2 4H20 0.0011
NaCI 0.0021
SiCI4 0.0004
SrCl2 = 6H20 0.0000
TiCI4 0.0001
VCI4 0.0000
Free Cr 0.0000
Calcination and hydrothermal acid recovery
[00339] The calcination 106 comprises the use of a two-stage circulating fluid
bed (CFB)
with preheating systems. The preheating system can comprise a plasma torch to
heat up
steam to process. It processes crystals in the decomposition/calcination
stage. The majority
of the hydrochloric acid was released in the first stage which was operated at
a temperature
of about 350 C, while the second stage performs the calcination itself. Acid
from both
stages (about 66 to about 68% of the recovered acid from the processes) was
then
recovered and sent to either to the acid leaching 102 or to the acid
purification 107. In the
second reactor, which was operated at a temperature of about 930 C, acid was
recovered
through the condensation and absorption into two columns using mainly wash
water from
the acid leaching sector 102. Latent heat from this sector was recovered at
the same time
as large amounts of water, which limits net water input,
[00340] In the iron oxides productions and acid recovery 105 system, which
comprises,
aqueous solution from the crystallization 104 first undergoes a pre-
concentration stage
followed by processing in the hydrolyzer reactor. Here, hematite was produced
during low
temperature processing (about 165 C). A recirculation loop was then taken from
the
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hydrolyzer and is recirculated to the pre-concentrator, allowing the
concentration of REE,
Mg, K, and other elements. This recirculation loop, allows rare earth element
chlorides
and/or rare metal chlorides and various metal chlorides concentration to
increase without
having these products precipitating with hematite up to a certain extent.
[00341] Depending on acid balance in the plant, recovered acid is sent
either directly to
the 102 or 107 stage.Table 4 shows results obtained in stage 105.
Table 4.
Hydrothermal acid recovery
Flowrate from crystallization to 592 m3/h (design)
HARP 600 m3/h (design)
Operating hydrolyser
155-170 C
temperature
Regenerated acid concentration 27.4% ______
Regenerated acid flowrate 205,2 tph HC1
I Hematite total production rate 24 TPH (design) __
HCI recovery > 99.8%
Reflux (recirculation loop) rate in
I between hydrolyzer and pre- 56 tph
[ concentrator
Rare earth element chlorides
and/or rare metal chlorides rate 12.8 t/h
in recirculation loop
Hematite quality obtained and/or projected
Fe2O3 purity >99.5%
Hydrolysable chlorides <0.2%
Moisture __________________________ Max 20% after filtration
PSD 25-35 microns
LDensity (bulk) 2-3 kg/I _________
Typical chemical reaction in stage 105
2FeC13 + 3H20 Fe203 + 6 NCI
155-170 C
[00342] Table 5 shows results obtained in stage 106.
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Table 5.
Calcination Plant 106
= Two-stage circulating fluid bed
(CFB) with pre-heating system
Process characteristics:
= Two-stage hydrochloric acid
re. eneration
Production rate (practical) About 66 tph
CFB feed rate 371 tph @ 2-3% humidity*
Typical chemical reaction occurring
2(AICI3 = 6 H20) + Energy A1203 + 6 HCI + 9H20 __
Typical alumina chemical composition obtained from
aluminum chloride hexahydrate crystals being fed to
calcination
Component _________________ Weight distribution (%)
A1203 99.938
Fe2 03 0.0033
S102 _____________________________ 0.0032
Cr203 0.0063
V205 0.0077 __
Na _________________ 0.0190
MgO 0.0090 __
________ P205 0.0039
0.0053 ____________________________________
Ca _________________ 0.0020 __
MnO 0.0002
-
Free Cr Undetectable ___
Rare earth elements and rare metals extractions
[00343] The stream that was taken out of 105 recirculation then was treated
for rare earth
elements and are metals extraction 108, in which the reduction of the
remaining iron back
to iron 2 (Fe2+), followed by a series of solvent extraction stages, was
performed. The
reactants were oxalic acid, NaOH, DEHPA (Di-(2-ethylhexyl)phosphoric acid) and
TBP (tri-
n-butyl phosphate) organic solution, kerosene, and HCI were used to convert
rare earth
element chlorides and rare metals chlorides to hydroxides. Countercurrent
organic solvent
with stripping of solution using HCI before proceeding to specific calcination
from the rare
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earth elements and rare metals in form of hydroxide and conversion to high
purity individual
oxides. A ion exchange technique is also capable of achieving same results as
polytrimethylen terephtalate (PET) membrane.
[00344] Iron powder from 105, or scrap metal as FeO, can be used at a rate
dependent
on Fe3+ concentration in the mother liquor. NCI (100% wt) at the rate of 1 tph
can be
required as the stripped solution in REE Solvent Extraction (SX) separation
and re-leaching
of rare earth elements and/or rare metals oxalates.
[00345] Water of very high quality, demineralized or nano, at the rate of 100
tph was
added to the strip solution and washing of precipitates.
[00346] Oxalic acid as di-hydrate at a rate of 0.2 tph was added and
contributes to the
rare earth elements and rare metals oxalates precipitation. NaOH or Mg0H at a
rate of
0.5 tph can be used as a neutralization agent.
[00347] DEHPA SX organic solution at the rate of 500 g/h was used as active
reagent in
rare earth elements separation while TBP SX organic solution at the rate of 5
kg/h is used
as the active reagent for gallium recovery and yttrium separation. Finally, a
kerosene
diluent was used at the rate of approximately 2 kg/h in all SX section.
Calcination occurs in
an electric rotary furnace via indirect heating to convert contents to REE203
(oxides form)
and maintain product purity.
[00348] Results of various tests made regarding stage 108 are shown in Table
6.
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Table 6.
One line divided in subsections (5) to isolate the following elements using
solvent
extraction:
= Ga203
= Y203
= Sc203
= Eu203 + Er203 + Dy203
= Ce203 + Nd203 + Pr203
Equivalent output
166.14 kg/h
I___earths oxides
Projected production as per pilot testing
results
Incoming Final extraction individual
Feed
(_kg/h) (kg/h)
Ga203 __ 15.66 11.98
Sc203 9.06 8.11
Y203 22.56 20.22
La203 32.24 25.67
Ce203 61.37 51.82
____________ 8.08 6.18
I Nd203 ____________ 30.3 27.24
r Sm203 5.7 4.51
Eu203 1.06 0.95
r-Gd203 4.5 4.06
Dy203 3.9 3.55
___________________ ---
Er203 2.1 1.86
Total 196.55 166.14
Global yield: 84.53%
[00349] Alternatively, stage 108 can be carried out as described in
VVO/2012/126092
and/or VVO/2012/149642.
[00350] The solution after stages '108 and 109 contained mainly MgC12, NaCI,
KC1, CaCl2,
FeCl2/FeC13, and AlC13 (traces), and then undergoes the 111 stage.Na, K, Ca
that follows
the MgO can be extracted in stage 110 by crystallization in a specific order;
Na first,
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followed by K, and then Ca. This technique can be employed for example in the
Israeli
Dead Sea salt processing plant to produce MgO and remove alkali from the raw
material.
HCI regeneration
[00351] Alkali (Na, K), once crystallized, was sent and processed in the
alkali hydrochloric
acid regeneration plant 110 for recovering highly concentrated hydrochloric
acid (HCI). The
process chosen for the conversion can generate value-added products
[00352] Various options are available to convert NaCI and KCI with intent of
recovering
HCI. One example can be to contact them with highly concentrated sulfuric acid
(H2SO4),
which generates sodium sulphate (Na2SO4) and potassium sulfate (K2SO4),
respectively,
and regenerates HCI at a concentration above 90% wt. Another example, is the
use of a
sodium and potassium chloride brine solution as the feed material to adapted
small chlor-
alkali electrolysis cells. In this latter case, common bases (NaOH and KOH)
and bleach
(NaOCI and KOCI) are produced. The electrolysis of both NaCI and KCI brine is
done in
different cells where the current is adjusted to meet the required chemical
reaction. In both
cases, it is a two-step process in which the brine is submitted to high
current and base
(NaOH or KOH) is produced with chlorine (Cl2) and hydrogen (H2). H2 and Cl2
are then
submitted to a common flame where highly concentrated acid in gas (100% wt.)
phase is
produced and can be used directly in the crystallization stage 104, or to
crystallization
stages requiring dry highly concentrated acid.
Magnesium oxide
[00353] The reduced flow, which was substantially free of most elements (for
example
AICI3, FeCI3, REE-CI, NaCl, KCI) and rich in MgCl2, was then submitted to the
magnesium
oxides plant 111. In the MgO, pyrohydrolysis of MgC12 and any other leftover
impurities
were converted into oxide while regenerating acid, The first step was a pre-
evaporator/crystallizer stage in which calcium is removed and converted into
gypsum
(CaSO4-2H20) by a simple chemical reaction with sulfuric acid, for which
separation of MgO
is required. This increases the capacity of MgO roasting and also energy
consumption
slightly, while substantially recovering HCI. The next step was the specific
pyrohydrolysis of
MgO concentrated solution by spray roasting. Two (2) main products were
generated; MgO
that was further treated and HCI (about 18% wt.), which was either recycled
back to the
upstream leaching stage 102 or to the hydrochloric acid purification plant
(107) The MgO-
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product derived from the spray roaster can require further washing,
purification, and finally
calcining depending on the quality targeted. The purification and calcining
can comprise a
washing-hydration step and standard calcining step.
[00354] The MgO from the spray roaster is highly chemically active and was
directly
charged into a water tank where it reacts with water to form magnesium
hydroxide, which
has poor solubility in water. The remaining traces of chlorides, like MgCl2,
NaCI, dissolved
in water. The Mg(OH)2 suspension, after settling in a thickener, was forwarded
to vacuum
drum filters, which remove the remaining water. The cleaned Mg(OH)2 is then
forwarded
into a calcination reactor where it is exposed to high temperatures in a
vertical multi-stage
furnace. Water from hydration is released and allows the transformation of the
Mg(OH)2 to
MgO and water. At this point, the magnesium oxide was of high purity (>99%).
HCI purification
[00355] The hydrochloric acid purification stage 107 is effective for
purifying HCI
regenerated from different sectors (for example 105, 106, 111) and to increase
its purity for
crystallization, whereas dry highly concentrated acid (> 90% wt.) can be used
as the
sparging agent. Stage 107 also allowed for controlling the concentration of
the acid going
back to stage 102 (about 22 to about 32% wt.) and allows total acid and water
balance.
Total plant water balance is performed mainly by reusing wash water as
absorption
medium, as quench agent or as dissolution medium at the crystallization
stages.
For example, HCI purification can be carried out as shown in Figs. 4 and 5.
[00356] For example, purification can be carried out by means of a membrane
distillation
process. The membrane distillation process applied here occurs when two
aqueous liquids
with different temperatures are separated through a hydrophobic membrane. The
driving
force of the process was supplied by the partial pressure vapour difference
caused by the
temperature gradient between these solutions. Vapour travels from the warm to
the cold
side. Without wishing to be bound to such a theory, the separation mechanism
was based
on the vapour/liquid equilibrium of the HCl/water liquid mixture. Practical
application of such
a technology has been applied to HCl/water, H2SO4/water systems and also on
large
commercial scales on aqueous solution of sodium chloride with the purpose of
obtaining
potable water from seawater and nano water production. Therefore membrane
distillation
was a separation process based on evaporation through a porous hydrophobic
membrane.
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The process was performed at about 60 C and was effective to recover heat from
the 104
and 102 stage with an internal water circulation loop, in order to maintain a
constant
incoming temperature to the membranes. For example, eight membranes of 300,000
m2
equivalent surface area can be used per membrane to obtain a concentration of
HCI well
above the azeotropic point (i.e. > 36%) of the 750 m3/h and final 90%
concentration is
then obtained through pressure distillation (rectification column).
[00357] Purification of HCI by processing thus regenerated acid through
hydrophobic
membrane and separating water from HCI; therefore increasing HCI concentration
up to
about 36% (above azeotropic point) and therefore allowing with a single stage
of
rectification through a pressure stripping column to obtain >90% in gaseous
phase, for
crystallization stage (sparging); and therefore controlling acid concentration
into
crystallization stages up to 30-35 %(aq).
[00358] As indicated stage 107 was operated at about 60 C and heat input
provided by
heat recovery from stages 102 to 110. Rectification column was operated at
about 140 C
in the reboiler part. Net energy requirement was neutral (negative in fact at -
3.5 Gj/t A1203)
since both systems were in equilibrium and in balance.
[00359] For example, the acid purification can be carried out by using
adsorption
technology over an activated alumina bed. In continuous mode, at least two
adsorption
columns are required to achieve either adsorption in one of them and
regeneration in the
other one. Regeneration can be performed by feeding in counter-current a hot
or
depressurized gas. This technology will result in a purified gas at 100% wt.
[00360] For example, the acid purification can be made by using calcium
chloride as
entrainer of water. A lean hydrochloric acid solution is contacted with a
strong calcium
chloride solution through a column. The water is then removed from the
hydrochloric acid
solution and 99.9% gaseous HCI comes out of the process. Cooling water and
cryogenic
coolant is used to condense water traces in the HCI. The weak CaCl2 solution
is
concentrated by an evaporator that ensures the recuperation of calcium
chloride.
Depending on the impurities in the incoming HCI solution feed to the column,
some metals
can contaminate the calcium chloride concentrated solution. A precipitation
with Ca(OH)2
and a filtration allows the removal of those impurities. The column can
operate for example
at 0.5 barg. This technology can allow for the recuperation of 98% of the HCI.
¨i
ty
tdr
C
Composition, Slaw 101 Stage 10,2 Stage 105 Stage
105 V Stage 107 Stage 108 TOTAL PRODUCF.D FP-
t=J
(% wt) Yield (%) Yield (%) Yield (%) Yield
( %) tpy Yield (%) Yield (%) ield (%) Yield (%) -.1
¨
c.i7
r.
.
r_
Main constituents
*
-.I
--.1
0
tN3
99.997% _ __ _ ...
--
- 99.997%
oe
9503% - .....
,... ... 95.03% 0
ai
FE _ 100.00% ._ 9165% --
-- --- 92.65% cn
c
4 -- 93.998% --- - 4756 9164%
- - 9164% irr-
Ca --- 99.938% _ - -- -
-- -- 9818% o
o-
Na - 99.998% __ _ ... ._
92.76% ai 0
5
K - loan __ -- _ ___
_ -- 93.97% (1) o
l0
Others ind . 420 - -- - --
- - -.
a
(J.)
REAM =- 99.80% - 9232% - --
-- 84,67% 84.67%
o cn
co
53-i3
n.)
=.
cn Sy-Products
5 n.)
o
NaOH -- ... -- 65,555
-- - -- - up
ol
i
Na0O - -- -- 9,2E8
- - - - a)
it
KON -- __ ..- ---
73,211 - ... - 73
a
1
n.)
600 _ _. ._
... _ _ o -4
a)
CaSO4 -- -- - - 46,837
- - ... -- -- (nu4
(i)
D-
o
Reactants
*
D
H2SO4 CI - __. "-- - 19,204
-- -- -- -
5'
Fresh HO M-UP - -- - - - - -
59.75% ... 93,75% -71 't
(5
n
_
Total _ 9855% 95.03%
256,419 9164% 59.75% _ 8467% a)
>
¨
c..J
,.:.---
c-.--,
--oc
c,.i
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[00361] Tables 8 to 26 show results obtained concerning the products made in
accordance with the process shown in Fig. 6 in comparison with standard of the
industry.
Table 8.
Chemical composition of obtained alumina
Element % Weight* Standard used in
industry
A1203 99.938 __________________________ 98.35 min
Fe203 0.0033 0.0100
S102 0.0032 0.0150
TiO2 0.0003 0.0030
V205 0.0008 0.0020
ZnO 0.0005 0.0030
Cr203 0.0003 N/A
MgO 0.0090 N/A
MnO 0.0002 N/A
P205 0.0039 0.0010
Cu 0.0030 __________ N/A _____
Ca 0.0020 0.0030
Na 0.0190 0.4000
0.0053 0.0150
Li 0.0009 N/A
Ba <0.00001 0.0000
Th <0000001 0.0000
< 0.000001 0.0000
Free or Not detectable 0.0000
LO1 <1.0000 ___________ <1.0000
[00362] P205 removal technique can include, for example, after leaching,
phosphorous
precipitation using zirconium sulphate. It can be provided, for example, in a
solution heated
at 80 to about 90 C or about 85 to about 95 C, under vacuum.
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Table 9.
Physical properties of obtained alumina
Standard used in
Property Orbite Alumina industry
PSD < 20pm 5-10% N/A
PSD < 45pm 10-12% <10%
PSD > 75pm 50-60% N/A
SSA (m2/g) 60-85 60-80
Att. Index 10-12% <10% __
a A1203 2-5% <7-9%
Table 10.
Chemical composition of obtained hematite
Element % Weight
Fe203 > 99.5%
tyl drolysable elements <0.2%
Table 11.
Physical properties of obtained hematite*
_______ Property _______ Orbite hematite
PSDmean 25-35 pm
Density (bulk) 2000-3000 kg/m3
Humidity after filtration ________ <10%
* Material can be produced as brickets
Table 12.
¨ Chemical composition of obtained silica
Element % Weigtlt
Si02 >99.7
A1203 <0.25%
M_gO 0.1%
Fe203 0.1%
CaO 0.01%
Na20 ________________________ <0.1%
K20 <0.1%
Note: Product may have unbleached cellulose fiber filter aid. Cellulose wood
flour.
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Table 13.
Physical properties of obtained silica
Property ___________________ Orbite silica
PSDmean 10-20yrn
___ Specific surface area 34 mz/g
Density (bulk) __________ 2000-2500 k./m3
Humidity after filtration <30%
Table 14.
Purity of obtained rare earth element oxides
Element Purity (%)
Ga203
Sc203
Y203
La203
Ce203
Pr203 ________
r¨ >99/0
Nd203 ________
Sm203
_ _
Eu203
Gd203 _______________
P12_03
Er203
Physical properties of obtained REE-0/RM-0
Property Orbite REE-0/RM-0
PS Dmean 2-30 pm __
________ Density 5500-13000 ki/m3
LOI __________________________ <1%
Table 15.
Chemical composition of obtained MgO
Element Typical _______ Specification
70g0 99.0k 98.35min
CaO ____________________ 0.0020 0.83
Si02 0.0000 0.20 max
_______________________ B203 0.0000 0.02 max
A1203 0.0300 0.12 max
Fe203 0.0160 _________ 0.57 max
Mn02 ___________________ <0.14 _________ 0.14 max
Iii. IiiLOI 1 _______________ 0.7% < 1%
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Table 16.
Physical properties of obtained MgO
Property Orbite M.0
PS Dmean 10 pm __
_______ Density N/A
LOI 650 kg_/m3
Table 17.
Chemical composition of obtained NaOH
Element % Weight
Sodium hydroxide 32%
__________________________________ Water 68%
Table 18.
Physical properties of obtained NaOH
Sodium hydroxide
Property
__________________________________ (NaOH)
Ph&cal state __ Liquid
Vapour pressure 1 4 mmHg
Viscosity > 1
L Boiling point 100 C
Melting point 0 C
t Specific 9ravity 1.0
Table 19.
Chemical composition of obtained sodium
h =ochlorite (bleach)
Element ___________________________ % Weight
Sodium hypochlorite 12%
Sodium hydroxide <1%
_________________________________ Water > 80%
Table 20
Physical properties of obtained Na0C1
Sodium hypochlorite
Property
(Na0C11
Physical state Liquid
Vapour pressure 1.6 kPa
Viscosity N/A
Boilin_g point 100 C
_______________ Melting point -3 C
L Specific_vavit_y_ 1.2
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Table 21.
Chemical composition of obtained potassium
hydroxide
Element % Weight
Potassium hydroxide ______________ 32%
Water 68%
Table 22.
Physical properties of obtained potassium hydroxide
_______ Property KOH
Physical state Liquid
Vapour pressure 17.5 mmHg
Viscosity ________________________ N/A
Boiling point 100 C
Melting point N/A
Specific gravily 1.18
Table 23.
Chemical composition of obtained potassium
______________ hypochlorite (1_<OCI)
Element % Weight
Potassium hypochlorite __________ 12%
Potassium hydroxide < 1%
Water > 80%
Table 24.
Physical properties of obtained potassium
hypochlorite __________________________
Pro=ert KOCI
Physical state Liquid
______________ Vapour pressure N/A
_______ Viscosity N/A
Boiling point 103 C
Melting point N/A ___
Specific gravity
_
Table 25.
Chemical composition of obtained calcium sulphate
dihydrate
Element % Wei=ht
Calcium sulphate 100%
dihydrate
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Table 26.
Physical properties of obtained calcium sulphate
dehydrate
Property _______________ Orbite CaSO4-2H20 __
Physical state Solid
Specific gravity 2.32
[00363] In order to demonstrate the versatility of the processes of the
present
disclosure, several other tests have been made so as to shown that these
processes can
be applied to various sources of starting material.
Example 6
[00364] Another starting material has been used for preparing acidic
compositions
comprising various components. In fact, a material that is a concentrate of
rare earth
elements and rare metals (particularly rich in zirconium) has been tested.
Table 27 shows
the results carried out on such a starting material using a similar process as
shown in Figs.
1, 3, 6, 7, 13 and 14 and as detailed in Examples 1, 2 and 5. It can thus be
inferred from
the results shown in Table 27 that the various components present in the
leaching (various
metals such as aluminum, iron, magnesium as well as rare earth elements and
rare metals)
can be extracted from the obtained leaching composition and that they can
eventually be
isolated by the processes of the present disclosure such as, for example,
those presented
in Examples 1, 2 and 5.
Example 7
[00365] Other tests have been made in a similar manner as described in
Example 6.
In the present example, carbonatite has been used as a starting material. (see
Table 28
below).
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Table 27. Tests made on a zirconium rich material.
Raw material Composition Average
Extraction 0 All Orbite
measure measured for rate process
and/or testing (% measured recovery
(%)
evaluated (% wt.) (ALP) (%)
wt.) .
A1203 6.12 6.12 89.65 86.97
Fe203 15.80 15.80 99.50 97.51
Si02 36.00 36.00 0.000 99.997
MgO 3.08 3.08 99.75 92.66
Na20 1.13 1.13 99.50 99.50
K20 2.12 2.12 99.50 99.50
CaO 6.10 6.10 99.50 99.00
S total 0.22 0.22 100.00
F 1.98 1.98 99.50 99.00
TiO2 0.13 0.13 0.000 99.03
V205 0.00 0.00 98.00 96.04
P205 1.10 1.10 98.00 96.04
MnO 0.43 0.43 98.00 96.04
Zr02 12.43 12.43 22.70 20.43
Cr203 0.00 0.00 0.00 0.00
Ce203 3.05 3.045 97.31 92.98
La203 1.34 1.337 99.55 92.68
Nd203 1.55 1.551 98.40 94.79
Pr203 0.37 0.375 99.75 97.52
Sm203 0.15 0.151 88.75 84.80
Dy203 0.09 0.089 80.35 76.77
Er203 0.03 0.030 72.60 69.37
Eu203 0.03 0.027 85.57 81.76
Gd203 0.21 0.205 82.85 79.16
Ho203 0.01 0.013 77.10 73.67
Lu203 0.00 0.003 60.15 57.47
Tb203 0.02 0.022 78.05 74.58
Th 0.02 0.022 88.10 84.18
Tm203 0.00 0.004 66.85 63.88
U 0.01 0.014 81.90 78.26
Y203 0.30 0.300 72.70 69.46
Yb203 0.02 0.023 62.80 60.01
Ga203 0.02 0.016 96.90 92.59
Sc203 0.00 0.003 95.00 90.77
LOI (inc. water) 6.122023973 6.12
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Table 28. Tests made on carbonatite
Raw material Composition Average Extraction 0 All
Orbite
measure and/or measured for rate process
evaluated (% testing (% measured recovery (%)
wt.) wt.) (ALP) (%)
A1203 0.70 0.70 84.31 81.61
Fe203 11.22 11.22 94.14 92.15
Si02 2.11 2.11 0.00003 99.997
MgO 6.50 6.500 100 96.25
Na20 0.07 0.07 92.54 90.55
K20 0.18 0.181 37.33 37.33
CaO 16.51 16.51 100 98.00
TiO2 0.00 0.000 0.00000 100.000
V205 0.00 0.000 0 100.000
P20, 0.00 0.000 0 100.000
MnO 0.00 0.000 0 100.000
Zr02 0.00 0.000 0 100.000
Cr203 0.00 0.000 0 100.000
Ce203 1.19 1.195 64.04 61.190
La203 0.46 0.463 63.86 61.018
Nd203 0.45 0.448 81.46 77.835
Pr203 0.14 0.142 67.59 64.582
Sm203 0.03 0.033 65.32 62.413
Dy203 0.00 0.000 78.12 74.644
Er203 0.00 0.000 86.15 82.316
Eu203 0.01 0.007 66.45 63.493
Gd203 0.01 0.013 54.46 52.037
Ho203 0.00 0.000 83.12 79.421
Lu203 0.00 0.000 88.86 84.906
Tb203 0.00 0.001 41.42 39.577
Th 0.06 0.065
Tm203 0.00 0.000 90.70 86.664
U 0.01 0.007
Y203 0.00 0.000 84.68 80.912
Yb203 0.00 0.000 85.11 81.323
Ga203 0.00 0.000 0 0.000
Sc203 0.00 0.000 0 0.000
LOI (inc. 60.33
water)
[00366] It can
thus be inferred from the results shown in Table 28 that the various
metals, rare earth elements and rare metals extracted present in the obtained
leaching
composition can eventually be isolated by the processes of the present
disclosure such
as, for example, those presented in Examples 1, 2 and 5.
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[00367]The process shown in Fig. 8 is similar to the process of Fig.1, with
the exception
that in Fig. 8, the term "aluminum" is replaced by a "first metal". The person
skilled in the
art would thus understand that in accordance with the present disclosure, the
processes
can also encompass recovering various other products and using various types
of
material as starting material. The first metal can be chosen from Al, Fe, Ti,
Zn, Ni, Co,
Mg, Li, Mn, Cu, Au, Ag, Pd, Pt. and mixtures thereof etc. Such a process can
thus be
used for recovering various other metals than aluminum. Thus, the first metal
will be
precipitated as a chloride in stage 4 and eventually converted into an oxide.
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[00368] In fact, the person skilled in the art would understand that by
replacing in Figs. 1,
3, 6 and 7' the term "aluminum" with the expression "first metal" the
processes shown in
these figures can be used to obtain various other products than alumina and
also used for
treating various different starting material. Thus, the first metal can be
recovered as a
chloride (as it is the case for aluminum chlorides in the processes of Figs.
1, 3, 6, 7, 13 and
14) and all the other stages of these processes can thus be carried out (when
applicable)
depending on the nature of the starting material used.
[00369] In step 4, the first metal chloride can be precipitated or
crystallized. In fact, the
first metal can be removed from the leachate in various manner. For example, a
precipitating agent can be added or HCI (for example gaseous) can be reacted
with the
liquid obtained from step 3 so as to cause precipitation and/or crytallization
of the first metal
chloride. Alternatively, the temperature of the leachate can be controlled so
as to
substantially selectively cause precipitation of the first metal chloride.
[00370] As previously indicated, the processes of the present disclosure can
be efficient
for treating material comprising Al, Fe, Ti, Zn, Ni, Co, Mg, Li, Mn, Cu, Au,
Ag, Pd, Pt.
[00371] For example, when treating a material that comprises, for example, Mg
and Fe,
the material can be leached for example by using HCI. Then, while the mixture
(comprising
a solid and a liquid) so obtained is still hot, it can be treated so as to
separate the solid from
the solid (for example by means of a solid/liquid separation). That will be
effective for
removing solids such as Si and optionally others such as Ti. Thus, the liquid
can be cooled
down to a temperature of about 5 to about 70 C, about 10 to about 60 C,
about 10 to
about 50 C, about 10 to about 40 C, or about 15 to about 30 C so as to
substantially
selectively precipitate or crystalize magnesium (for example as MgC12 (first
metal chloride in
Fig. 8)), as shown in 4 of such a figure.. Then, the first metal chloride can
be converted as
shown in 5 so as to obtain the first metal oxide. The iron can then be treated
as in 6 of Fig.
8. The remainder of the process shown in Fig. 8 (stages 6 to 10) being as
described
previously for Fig. 1.
[00372] Other examples of processes for treating material comprising magnesium
and
iron can be as shown in Figs. 13 and 14. The processes of Figs. 13 and 14 are
similar to
the processes of Figs. 1 and 3, respectively. The main differences reside in
steps 20 and 21
of Figs. 13 and 14.
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[00373] In these two examples of Figs. 13 and 14 aluminum is also treated. In
fact, as it
can be seen in stages 20 and 21 of Figs. 13 and 14, Mg, Fe and Al, the
material can be
leached for example by using HCI. Then, while the mixture (comprising a solid
and a liquid)
so obtained is still hot, it can be treated so as to separate the solid from
the liquid (for
example by means of a solid/liquid separation (see stage 3)). That will be
effective for
removing solids such as Si and optionally others such as Ti. Thus, the liquid
can be cooled
down to a temperature of about 5 to about 70 C, about 10 to about 60 C,
about 10 to
about 50 C, about 10 to about 40 C, or about 15 to about 30 C so as to
substantially
selectively precipitate or crystalize magnesium (for example as MgC12 (see
stage 20 in Figs.
13 and 14)). Then, magnesium chloride can be converted into magnesium oxide as
shown
in 21 of Figs. 13 and 14. HCI can then be recovered and treated as previously
indicated
The remainder of the process shown in Fig. 13 (stages 4 to 10) are as
described previously
for Fig. 1 and the remainder of the process shown in Fig. 14 (stages 4 to 10)
are as
described previously for Fig. 3.
[00374] As previously indicated, magnesium can be firstly removed from the
leachate and
then aluminum can be removed as shown in Figs. 13 and 14. Alternatively,
aluminum can
be firstly removed from the leachate and then magnesium can be removed. In
such a case,
steps 20 and 21 of Figs. 13 and 14 would be disposed between steps 4 and 6.
[00375] As another example, a mixture Ni/Co of a low concentration in the feed
(0.5 ¨
2.0% wt) can be leached with HCI according to Fig. 9. For example, leaching
can be carried
out by using HCI having a concentration of about 18 to about 32 wt % in a
first reactor then,
by using HCI having concentration of about 90 to about 95 % (gaseous) in a
second
reactor; and by optionally using HCI having concentration of about 90 to about
95 %
(gaseous) in an optional third reactor. Then selective crystallization with
HCI bubbling,
solubility of chlorides (cobalt chloride vs nickel chloride) is distinct based
on HCI
concentration. Hexahydrate chloride can then be processed (produced) and fed
for
example to standard spray roaster 600-640 C or fluid bed in view of producing
oxides. HCI
can therefore be regenerated, sent to closed loop acid purification where it
is dried. Excess
HCI can also be absorbed at its isotropic point and be used to solvent
extraction or
leaching. For example, nickel or cobalt chloride can thus replace aluminum
chloride in Figs.
1, 3, 6, 7, 13 and 14. After the leaching, shown in Fig. 9, the leachate can
thus be treated
as the leachate described in the processes described in the present disclosure
and those of
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Figs. 1, 3, 6, 7, 13 and 14, with the exception that instead of aluminum
chloride, nickel
chloride or cobalt chloride will be treated.
[00376] A similar approach can be adopted when using a starting material that
contains
Mg and Li. Leaching can be carried out as shown in Fig. 9 and selective
precipitation of LiCI
over MgCl2 or selective precipitation of MgC12 over LiCI by injecting HCI (for
example
gaseous HCI) can be done. Na can be removed by crystallisation first. K can
then be
removed by crystallisation Moreover, for further purification, LiCI and MgC12
can be
separated by difference of solubility and/or crystallization in water.
[00377] For example, platinum and palladium can also be treated similarly.
Moreover,
their separation can also be accomplished with ion exchange: selective
crystallization in
HCI is possible and can be temperature sensitive.
[00378] Figs, 10A and 10B show methods for separating Si from Ti. For example,
when
using an ore as starting material, leaching can be carried out in the presence
of C12
(optionally in the presence of carbon) so as to maintain Ti under the form of
TiC14 since in
remains in solution (fluid) while Si remains solid (Si02). Then, Ti (such as
TiCI4) can be
heated so as to be converted into Ti02. For example, it can be injected into a
plasma torch
for being purified.
[00379] Such a method for purifying Si and Ti can be used in all the processes
of the
present disclosure when there is a need for separating these two entities. See
stage 13 in
Figs. 1, 3, 6, 7, 13 and 14 and stage 113 in Fig. 7.
[00380] The processes shown in Figs. 11A, 11B, 12A and 12B are processes that
can be
useful for treating various materials that comprise, for example, Mg and other
metals such
as Ni and/or Co. These materials can also comprise other metals such as
aluminum, iron
etc. The processes of Figs. 11A, 11B, 12A and 12B are similar, with the
exception that
magnesium remains in solution after step 204 in Fig. 11A, while magnesium is
precipitated
after step 304 in Fig. 12A.
[00381] Certain steps carried out in the processes of Figs. 11A, 11B, 12A and
12 are
similar to the steps of other processes described in the present disclosure.
[00382] For example, steps 201 and 301 are similar to step 101 of Figs. 6 and
7.
Moreover, steps 202 and 302 of Figs. 11 and 12 are similar to step 102 of
Figs. 6 and 7.
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[00383] Steps 203 and 303 of Figs. 11 and 12 are similar to step 103 of Figs.
6 and 7.
[00384] Steps 213 and 313 of Figs. 11 and 12 are similar to step 113 of Fig.
7. With
respect to steps 214 and 314, TiO2 can eventually be purified by means of a
plasma torch.
[00385] Eventually, CaSO4 = 2H20 (gypsum) can be produced as detailed in steps
223
and 323. Finally, pursuant to steps 224, 324, 225 and 325 Na2SO4 and K2SO4 can
be
produced.
[00386] With respects to steps 213 and 313, TiO2 can be converted into TiCl2
and/or TiCI4
so as to solubilize the titanium. For example, this can be done by reacting
TiO2 optionally
with Cl2 and carbon (C) (see Figs. 10A and 10B. Therefore, Si02 and titanium
can be
separated from one another since Si02 remains solid while titanium will be
solubilized. For
example, steps 213, 313, 214 and 314 can be carried out as detailed in Fig.
10.
[00387] Such processes are also efficient for achieving whole recovery of HCI.
[00388] Pursuant to Ni and/or Co precipitation (steps 212 and 312) LiOH can be
precipitated and eventually washed in steps 208 and 308. Then, a further
leaching can be
carried out in steps 209 and 309 so as to extract further metals. For example,
if the starting
material to be used in the processes of Figs. 11 and 12 contains aluminum,
steps 210 and
310 can be carried out so as to precipitate AlC13. Such a step (210 or 310) is
similar to step
104 carried out in Figs. 6 and 7. In an analogous manner, steps 205 and 305 of
Figs. 11
and 12 are similar to step 105 of Figs. 6 and 7. Steps 206 and 306 of Figs. 11
and 12 are
similar to step 106 of Figs. 6 and 7. HCI purification carried out in steps
215 and 315 is
similar to step 107 carried out in Figs. 6 and 7. As it can be seen in Figs.
216 and 316, HCI
is thus regenerated.
[00389] Alternatively, pursuant to step 209, and depending on the composition
of the
starting material used for the processes of Figs. 11 and 12, steps 210 and 310
can be
omitted or bypassed. Therefore, if substantially no aluminum is comprised
within the
starting material, or if the content in aluminum is considerably low after
step 209, step 249
can be carried out. The same also applied to step 309 and 349 of Fig. 12.
Then, pursuant
to steps 249 and 349 of Figs. 11 and 12 in which a mixture of various metal
chlorides are
obtained, calcination can be carried out in steps 217 and 317 so as to
eventually obtain a
mixture of various metal oxides.
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[00390]
Impurities obtained in steps 210 and 310 can be crystallized in steps 218
and 318. By doing so, NaCI (steps 219 and 319) and KCI (steps 221 and 321) can
be
crystallized. An electrolysis of NaCI (steps 220 and 320) and KCI (steps 222
and 322)
can be carried out as previously indicated in the present disclosure.
Example 8
[00391] Tests
have been made for treating a magnesium-containing material as
starting material. The magnesium-containing material was serpentine (asbestos)
obtained from Black Lake, Quebec, Canada. Tables 29 to 31 below shows results
obtained when leaching such a material with HCI. The serpentine ore was
leached with
a 30 `)/0 molar excess of HCI at a temperature of about 150 to about 160 C.
Table 29. Tests made on serpentine
Asbestos 1 Asbestos 2 Asbestos 3 Asbestos 4
Mass In 880 800 1000 820
Mass Out 3.34 250 325 323
35% 45% 45% 45%
*
.4J Fe Na K i Mg Ca Ti SI
rntal % 1,38 3,62 0,25 0,34 18,1 059 0,03
20,3
, compound kg 12.144 31,855 2,2 2,992 159,29
5192 0.264 178,64
i' Cake 1,87 1,11 0,33 0,3 6,49 0,15 0,01
34,8
kg 4,05977 2,40991 0,71E43 0,5513 14,08979 0,34736
0,02171 75,5508
_o
,
% 67% 92% 67% 78% 91% 93% 92% 58%
recovery
1-1 q.ai ,:. 0,49 3,5E 0,03 0,04 23,5 0,13
0,0.1 16,7
(NI compound kg 3,92 28,48 0,24 0,32 188 1,04
0,08 133,6
0,59 0,47 0,02 0,01 2,88 0,05 0,007 39,2
VI Cake
Ci kg 0,81125 0,64625 0,0275 0,01375 3,96
0,06875 0,009625 52,525
.o
79% 98% 89% 9.6% 98% 93% 88% 61%
IC covery
.0,58 4,13 0,15 0,08 22,3 0,23 .0,01 17,3
m compound kg 5,8 41,3 1,6 0,8 223 2,3 0,1
173
0
9% 0,06 .0,44 0,01 0,01 3,71 0,02 0,01 34,3 I
, Cake
c_. kg 0,10725 0,7965 0,017875 0,017875
5,845125 0,03575 0,017875 61,31125
_o
Y'le:d N 98% 98% 99% 98% 97% 98% 82% 65%
recovery ___________________________________________________ ,
flita,' ,,,. 0,31 5,54 0,01 0,01 22,9 0,03
0.01 15,4
, compound kg 2,542 45,429 0,082 0,082 197,78
0,246 0,082 126,28
g Cake % 1,14 0,37 0,41 0,23 2,5 0,2 0,005
37,1 I
Ci kg 2,02521 0,557305 0,728365 0,409595 4,44125 0,3553
0,0088825 65,90815
m
20% 99% -788% -398% 98% -44% 89% 48%
recovery
!
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Table 30. Chemical Composition of Serpentine
Components Concentration measured
and/or evaluated ( /0 wt.)
A1203 0.59-2.61
Fe203 5.09-7.92
Si02 32.94-43.43
MgO 30.01-38.97
Na20 0.04-0.337
K20 0.012-0.41
CaO 0.04-0.83
TiO2 0.017-0.050
\./205 0.00
P205 0.00
MnO 0.005-0.080
Zr0 0.0000
0.00
Co 0.0000
Cr 0.076-0.101
Cd 0.0000
Zn 0.0000
Ni 0.0000
Cu 0.0000
Pb 0.0000
As 0.0000
Ga203 0.0000
Sc203 0.0000
R e203 0.00000
LOI(Jic. water) 15.0-20.0
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[00392] Table 31. Leaching of Serpentine - Recovery Yields
Components Leaching extraction rate
(%)
A1203 81.34
Fe203 96.70
S102 0.00003
MgO 96.01
Na20 84.96
K20 90.57
CaO 95.05
TiO2 0.00002
V205 0.00
P20, 0.00
MnO 0.00
Zr0 0.00
0.00
Co 0.00
Cr 0.00
Cd 0.00
Zn 0.00
Ni 0.00
Cu 0.00
Pb 0.00
As 0.00
[00393] The results of Tables 29 to 31 thus show that the processes of Figs.
11 to 14 can
be carried out with success.
[00394] It was also observed that when obtaining such a leachate by leaching
serpentine
with HCI, it was possible to substantially selectively precipitate some metals
by controlling
certain parameters. In fact, it was found that magnesium chloride has a very
low solubility
as compared with other chlorides (such as AlC13, FeCl3, CaCl2, NaCI, KCI,
MnCl2, etc.), for
example when the leachate is at a temperature of about 10 to about 60 C,
about 10 to
about 40 C, about 15 to about 30 C, about 15 to about 25 C or about 20 C
(see Figs. 16
and 17). Therefore, one possible way among others of removing magnesium
chloride in a
substantially selective manner was to leach serpentine and remove the
unleached solid
while the mixture of solid and leachate is still hot. Then, when the solid is
removed, the
leachate can be cooled down so as to substantially selectively precipitate
magnesium
chloride.
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[00395] Moreover, it was observed, during tests made, that when the leachate
has a
concentration in HCI of about 16 to about 20 %, about 1710 about 18 %, or
about 17.5 % by
weight, MgCl2 was selectively precipitated over FeCI3 (see Fig. 15). It was
also observed
that magnesium chloride can have a low solubility at a temperature of about 15
to about 30
C, about 15 to about 25 C or about 20 C (see Figs. 16 and 17).
[00396] The process shown in Fig. 18 is similar to the process shown in Fig.
1. The main
difference resides in the fact that in the process of Fig. 18 comprises stages
25 and 26
instead of stage 5 of Fig. 1. In fact, in Fig. 18, the process comprises,
after crystallization of
AlC13, to convert AlC13 into Al(OH)3 before calcining the latter product into
A1203. For
example conversion of AlC13 into Al(OH)3 can be carried out by reacting AlC13
with a base
(for example KOH or NaOH). Calcination of Al(OH)3 into A1203 can be carried
out at high
temperature such as about 800 to about 1200 C or about 1000 to about 1200 C.
[00397] In fact, in the processes and the methods of the present disclosure,
calcination of
A1C13 can be replaced by calcination of Al(OH)3, as shown in Fig. 18 (see the
differences
between the processes of Fig. 1 and Fig. 18). For example, stages 25 and 26
can replace
stage 5 of various processes and methods such as shown in Figs. 3, 8, 13 and
14 or stage
106 of Figs. 6 and 7.
[00398] The processes of the present disclosure provide a plurality of
important
advantages and distinction over the known processes.
[00399] The processes of the present disclosure provide fully continuous and
economical
solutions that can successfully extract alumina from various type of materials
while
providing ultra pure secondary products of high added value including highly
concentrated
rare earth elements and rare metals. The technology described in the present
disclosure
allows for an innovative amount of total acid recovery and also for a ultra
high concentration
of recovered acid. When combing it to the fact that combined with a semi-
continuous
leaching approach that favors very high extraction yields and allows a
specific method of
crystallization of the aluminum chloride and concentration of other value
added elements
These processes also allow for preparing aluminum with such a produced
alumina.
[00400] Specifically through the type of equipment used (for example
vertical roller mill)
and its specific operation, raw material grinding, drying and classifying can
be applicable to
various kinds of material hardness (furnace slag for example), various types
of humidity (up
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to 30%) and incoming particle sizes. The particle size established provides
the advantage,
at the leaching stage, of allowing optimal contact between the minerals and
the acid and
then allowing faster kinetics of reaction. Particles size employed reduces
drastically the
abrasion issue and allows for the use of a simplified metallurgy/lining when
in contact with
hydrochloric acid.
[00401] A further advantage of the processes of the present disclosure is the
combined
high temperature and high incoming hydrochloric acid concentration. Combined
with a
semi continuous operation where the free HCI driving force is used
systematically, iron and
aluminum extraction yields do respectively reach 100% and 98% in less than
about 40 %
of the reference time of a basic batch process. Another advantage of higher
HCI
concentration than the concentration at azeotropic point is the potential of
capacity
increase. Again a higher HCI concentration than the concentration of HCI at
the azeotropic
point and the semi-continuous approach represent a substantial advance in the
art. The
same also applies for continuous leaching.
[00402] Another advantage in that technique used for the mother liquor
separation from
the silica after the leaching stage countercurrent wash, is that band filters
provide ultra pure
silica with expected purity exceeding 96%.
[00403] The crystallization of AlC13 into AlC13 = 6H20 using dried, cleaned
and highly
concentrated gaseous HCI as the sparging agent allows for a pure aluminum
chloride
hexahydrate with only few parts per million of iron and other impurities. A
minimal number
of stages are required to allow proper crystal growth.
[00404] The direct interconnection with the calcination of AlC13 = 61-120 into
A1203 which
does produce very high concentration of gas allows the exact adjustment in
continuous of
the HCI concentration within the crystallizer and thus proper control of the
crystal growth
and crystallization process.
[00405] The applicants have now discovered fully integrated and continuous
processes
with substantially total hydrochloric acid recovery for the extraction of
alumina and other
value added products from various materials that contain aluminum (clay,
bauxite,
aluminosilicate materials, slag, red mud, fly ashes etc.) containing aluminum.
In fact, the
processes allows for the production of substantially pure alumina and other
value added
products purified such as purified silica, pure hematite, pure other minerals
(ex: magnesium
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oxide) and rare earth elements products. In addition, the processes do not
require thermal
pre-treatment before the acid leach operation. Acid leach is carried out using
semi-
continuous techniques with high pressure and temperature conditions and very
high
regenerated hydrochloric acid concentration. In addition, the processes do not
generate any
residues not sellable, thus eliminating harmful residues to environment like
in the case of
alkaline processes.
[00406] The advantage of the high temperature calcination stage, in addition
for allowing
to control the a-form of alumina required, is effective for providing a
concentration of
hydrochloric acid in the aqueous form (>38%) that is higher than the
concentration of HCI at
the azeotropic point and thus providing a higher incoming HCI concentration to
the leaching
stage. The calcination stage hydrochloric acid network can be interconnected
to two (2)
crystallization systems and by pressure regulation excess HCI can be being
absorbed at
the highest possible aqueous concentration. The advantage of having a
hexahydrate
chloride with low moisture content (< 2%) incoming feed allows for a
continuous basis to
recover acid at a concentration that is higher than the azeotropic
concentration. This HCI
balance and double usage into three (3) common parts of the processes and
above
azeotropic point is a substantial advance in the art.
[00407] Another advantage is the use of the incoming chemistry (ferric
chloride) to the
iron oxide and hydrochloric acid recovery unit where all excess heat load from
any
calcination part, pyrohydrolysis and leaching part is being recovered to
preconcentrate the
mother liquor in metal chloride, thus allowing, at very low temperature, the
hydrolysis of the
ferric chloride in the form of very pure hematite and the acid regeneration at
the same
concentration than at its azeotropic point.
[00408] A further major advantage of the instant process at the ferric
chloride hydrolysis
step is the possibility to concentrate rare earth elements in form of
chlorides at very high
concentration within the hydrolyser reactor through an internal loop between
hydrolyzer and
crystallization. The advantage in that the processes of the present disclosure
benefit from
the various steps where gradual concentration ratios are applied. Thus, at
this stage, in
addition to an internal concentration loop, having the silica, the aluminum,
the iron and
having in equilibrium a solution close to saturation (large amount of water
evaporated, no
presence of free hydrochloric acid) allows for taking rare earth elements and
non-
hydrolysable elements in parts per million into the incoming feed and to
concentrate them In
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high percentage directly at the hydrolyser after ferric chloride removal
Purification of the
specific oxides (RE-0) can then be performed using various techniques when in
percentage levels. The advantage is doubled here: concentration at very high
level of rare
earth elements using integrated process stages and most importantly the
approach
prevents from having the main stream (very diluted) of spent acid after the
leaching step
with the risk of contaminating the main aluminum chloride stream and thus
affecting yields
in A1203. Another important improvement of the art is that on top of being
fully integrated,
selective removal of components allows for the concentration of rare earth
elements to
relatively high concentration (percentages).
[00409] Another advantage of the process is again a selective crystallization
of MgCl2
through the sparging of HCI from either the alumina calcination step or the
magnesium
oxide direct calcination where in both cases highly concentrated acid both in
gaseous
phase or in aqueous form are being generated. As previously indicated, Mg(OH)2
can also
be obtained. As per aluminum chloride specific crystallization, the direct
interconnection
with the calcination reactor, the HC1 gas very high concentration (about 85 to
about 95 %,
about 90 to 95 % or about 90 % by weight) allows for exact adjustment in
continuous of the
crystallizer based on quality of magnesium oxide targeted. Should this process
step (MgO
production or other value added metal oxide) be required based on incoming
process feed
chemistry, the rare earth elements extraction point then be done after this
additional step;
the advantage being the extra concentration effect applied.
[00410] The pyrohydrolysis allows for the final conversion of any remaining
chloride and
the production of refined oxides that can be used (in case of clay as starting
material) as a
fertilizer and allowing the processing of large amount of wash water from the
processes
with the recovery hydrochloric acid in close loop at the azeotropic point for
the leaching
step. The advantage of this last step is related to the fact that it does
totally close the
process loop in terms of acid recovery and the insurance that no residues
harmful to the
environment are being generated while processing any type of raw material, as
previously
described.
[00411] A major contribution to the art is that the proposed fully integrated
processes of
the present disclosure is really allowing, among others, the processing of
bauxite in an
economic way while generating no red mud or harmful residues. In addition to
the fact of
being applicable to other natural of raw materials (any suitable aluminum-
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material or aluminous ores), the fact of using hydrochloric acid total
recovery and a global
concentration that is higher than the concentration at the azeotropic point
(for example
about 21% to about 38%), the selective extraction of value added secondary
products and
compliance (while remaining highly competitive on transformation cost) with
environmental
requirements, represent major advantages in the art.
[00412] It was thus demonstrated that the present disclosure provides fully
integrated
processes for the preparation of pure aluminum oxide using a hydrochloric acid
treatment
while producing high purity and high quality products (minerals) and
extracting rare earth
elements and rare metals.
[00413] With respect to the above-mentioned examples 1 to 5, the person
skilled in the
art will also understand that depending on the starting material used (for
example, clays,
argillite, bauxite, kaolin, serpentine, kyanite nepheline, aluminosilicate
materials, mudstone,
beryl, cryolite, garnet, spinel, niccolite, kamacite, taenite, limonite,
garnierite, laterite,
pentlandite, smithsonite, warikahnite, sphalerite, chalcopyrite, chalcocite,
covellite, bornite,
tetrahedrite, malachite, azurite, cuprite, chrysocolla, ecandrewsite,
geikielite, pyrophanite,
ilmenite, red mud, slag, fly ashes, industrial refractory materials etc.,)
some parameters
might need to be adjusted consequently. In fact, for example, certain
parameters such as
reaction time, concentration, temperature may vary in accordance with the
reactivity of the
selected starting material.
[00414] The scope of the claims should not be limited by specific embodiments
and
examples provided in the disclosure, but should be given the broadest
interpretation
consistent with the disclosure as a whole.
86