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.

The present disclosure relates to processes for recovering rare earth elements from an aluminum-bearing material. The processes can comprise leaching the aluminum-bearing material with an acid so as to obtain a leachate comprising at least one aluminum ion, at least one iron ion, at least one rare earth element, and a solid, and separating the leachate from the solid. The processes can also comprise substantially selectively removing at least one of the at least one aluminum ion and the at least one iron ion from the leachate and optionally obtaining a precipitate. The processes can also comprise substantially selectively removing the at least one rare earth element from the leachate and/or the precipitate.

The present disclosure relates to processes for recovering rare earth elements from an aluminum-bearing material. The processes can comprise leaching the aluminum-bearing material with an acid so as to obtain a leachate comprising at least one aluminum ion, at least one iron ion, at least one rare earth element, and a solid, and separating the leachate from the solid. The processes can also comprise substantially selectively removing at least one of the at least one aluminum ion and the at least one iron ion from the leachate and optionally obtaining a precipitate. The processes can also comprise substantially selectively removing the at least one rare earth element from the leachate and/or the precipitate.

Methods and composition are provided for deriving cement and/or supplementary cementitious materials, such as pozzolans, from one or more non-limestone materials, such as one or more non-limestone rocks and/or minerals. The non-limestone materials, e.g., non-limestone rocks and/or minerals, are processed in a manner that a desired product, e.g., cement and/or supplementary cementitious material, is produced.

There are provided processes for treating red mud. For example, the processes can comprise leaching red mud with HCl so as to obtain a leachate comprising ions of a first metal (for example aluminum) and a solid, and separating said solid from said leachate. Several other metals can be extracted from the leachate (Fe, Ni, Co, Mg, rare earth elements, rare metals, etc.). Various other components can be extracted from solid such as TiO.sub.2, SiO.sub.2 etc.

There are provided processes for treating red mud. For example, the processes can comprise leaching red mud with HCl so as to obtain a leachate comprising ions of a first metal (for example aluminum) and a solid, and separating said solid from said leachate. Several other metals can be extracted from the leachate (Fe, Ni, Co, Mg, rare earth elements, rare metals, etc.). Various other components can be extracted from solid such as TiO.sub.2, SiO.sub.2 etc.

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 HCI; 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 HCI; 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.

There are provided processes for purifying aluminum ions. Such processes comprise precipitating the aluminum ions under the form of Al(OH).sub.3 at a first pH range; converting Al(OH).sub.3 into AlCl.sub.3 by reacting Al(OH).sub.3 with HCl and precipitating said AlCl.sub.3; and heating the AlCl.sub.3 under conditions effective for converting AlCl.sub.3 into Al.sub.2O.sub.3 and optionally recovering gaseous HCl so-produced. The processes can also comprise converting alumina into aluminum.

A process for producing alumina and a lithium salt comprising the steps of: (a) calcining an alpha spodumene ore or concentrate to produce beta spodumene; and (b) (I) leaching beta spodumene from the calcining step (a) with an alkaline solution under pressure; or (II) sulphating beta spodumene with at least sodium sulphate and leaching said sulphated beta spodumene to produce a lithium containing solution and a zeolitic residue. The lithium containing solution is treated to provide a purified lithium salt and said zeolitic residue is treated to provide high purity alumina.