A process for alumina and carbonate production from aluminium rich materials with integrated CO.sub.2 utilization, comprising: comminuting and leaching Al-rich materials in concentrated HCl; separating unreacted material from metal chloride solution; separating Al.sup.3+ from solution by crystallization of AlCl.sub.3.6H.sub.2O; calcination of AlCl.sub.3.6H.sub.2O with HCl recovery; precipitation of metal carbonates from CO.sub.2; regeneration of HCl and extractive amines; the Al.sup.3+ separation the facilitated by increasing HCl concentration; the calcination being performed in two steps, one in the range 400 and 600? C. to generate a HCl-rich gas and one above 600? C. to produce Al.sub.2O.sub.3; for precipitating metal carbonates, mixing the metal chloride solution with an organic solution containing a selected amine and contacting the mixture with a CO.sub.2-containing gas, thereby also extracting HCl by formation of an ammonium chloride salt complex; processing thermally or chemically the organic solution to regenerate the amine for recirculation.

A process for alumina and carbonate production from aluminium rich materials with integrated CO.sub.2 utilization, comprising: comminuting and leaching Al-rich materials in concentrated HCl; separating unreacted material from metal chloride solution; separating Al.sup.3+ from solution by crystallization of AlCl.sub.3.6H.sub.2O; calcination of AlCl.sub.3.6H.sub.2O with HCl recovery; precipitation of metal carbonates from CO.sub.2; regeneration of HCl and extractive amines; the Al.sup.3+ separation the facilitated by increasing HCl concentration; the calcination being performed in two steps, one in the range 400 and 600? C. to generate a HCl-rich gas and one above 600? C. to produce Al.sub.2O.sub.3; for precipitating metal carbonates, mixing the metal chloride solution with an organic solution containing a selected amine and contacting the mixture with a CO.sub.2-containing gas, thereby also extracting HCl by formation of an ammonium chloride salt complex; processing thermally or chemically the organic solution to regenerate the amine for recirculation.

A process for extracting values from a leach residue from lithium extraction comprising:

(a) mixing the leach residue with a chloride containing compound to form a first mixture;

(b) calcining the first mixture to form a calcined mixture rich in calcium aluminosilicate and a hydrochloric acid containing off gas;

(c) acid leaching the calcined mixture to form an aluminium bearing liquor and a silicon rich solid residue;

(d) recovering values selected from the group consisting of aluminium compounds, silicon compounds and compounds containing silicon and aluminium.

A process for extracting values from a leach residue from lithium extraction comprising:

(a) mixing the leach residue with a chloride containing compound to form a first mixture;

(b) calcining the first mixture to form a calcined mixture rich in calcium aluminosilicate and a hydrochloric acid containing off gas;

(c) acid leaching the calcined mixture to form an aluminium bearing liquor and a silicon rich solid residue;

(d) recovering values selected from the group consisting of aluminium compounds, silicon compounds and compounds containing silicon and aluminium.

Aspects of the invention include a method of producing a cement material comprising step of: first reacting a calcium-bearing starting material with a first acid to produce an aqueous first calcium salt; second reacting the aqueous first calcium salt with a second acid to produce a solid second calcium salt; wherein the second acid is different from the first acid and the second calcium salt is different from the first calcium salt; and thermally treating the second calcium salt to produce a first cement material. Preferably, but not necessarily, during the second reacting step, reaction between the first calcium salt and the second acid regenerates the first acid.

Aspects of the invention include a method of producing a cement material comprising step of: first reacting a calcium-bearing starting material with a first acid to produce an aqueous first calcium salt; second reacting the aqueous first calcium salt with a second acid to produce a solid second calcium salt; wherein the second acid is different from the first acid and the second calcium salt is different from the first calcium salt; and thermally treating the second calcium salt to produce a first cement material. Preferably, but not necessarily, during the second reacting step, reaction between the first calcium salt and the second acid regenerates the first acid.

A method comprising (a) reacting aluminum metal with an acid in the presence of water to provide a first aluminum salt solution comprising an aluminum salt in water, wherein the aluminum salt comprises a reaction product of the acid and the aluminum metal, (b) heating the first aluminum salt solution to provide a mother liquor and solid aluminum salt, (c) optionally, separating the solid aluminum salt from the mother liquor, (d) optionally, dissolving at least a portion of the separated solid aluminum salt with water to provide a second aluminum salt solution, (e) spray roasting the first, or second (if produced), aluminum salt solution to provide an aluminum oxide powder, and (f) washing the aluminum oxide powder, wherein the washed aluminum oxide powder comprises less than about 30 ppmw total metallic and alkyl impurities.

Aluminum chlorohydrate products include particles of aluminum chlorohydrate, in fractured crystal form, the particles having a basicity in the range of about 50% to about 85.6%, a bulk density of 40 to 65 pounds per cubic foot, and a mean particle size in the range of about 10 microns to about 15 microns. The particles may also have a surface area to weight ratio of about 295 to about 705 m.sup.2/kg, inclusive of both endpoints and all numerical values therebetween, where the ratio is measured by laser diffraction. Methods of producing such products are also disclosed.

Aluminum chlorohydrate products include particles of aluminum chlorohydrate, in fractured crystal form, the particles having a basicity in the range of about 50% to about 85.6%, a bulk density of 40 to 65 pounds per cubic foot, and a mean particle size in the range of about 10 microns to about 15 microns. The particles may also have a surface area to weight ratio of about 295 to about 705 m.sup.2/kg, inclusive of both endpoints and all numerical values therebetween, where the ratio is measured by laser diffraction. Methods of producing such products are also disclosed.

A method comprising contacting high-purity acid, high-purity aluminum, and high-purity water to form a first solution in a heated non-contaminating vessel, wherein the aluminum is employed in at least a stoichiometric amount relative to the acid, heating the first solution in a non-contaminating container, to provide a mother liquor and solid aluminum salts, separating the solid aluminum salts from the mother liquor, heating the solid aluminum salts in a non-contaminating crucible, to provide alpha aluminum oxide, and, optionally, washing the alpha aluminum oxide with high-purity water after some or all of the heating of the solid aluminum salts to provide the alpha aluminum oxide.