Abstract: The present disclosure relates to processes for recovering rare earth elements from various materials. The processes can comprise leaching the at least one material with at least one acid so as to obtain a leachate comprising at least one metal ion and 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 metal 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.

Abstract: There are provided processes for preparing alumina. These processes can comprise leaching an aluminum-containing material with HCl so as to obtain a leachate comprising aluminum ions and a solid, and separating said solid from said leachate; reacting said leachate with HCl so as to obtain a liquid and a precipitate comprising said aluminum ions in the form of AlCl3, and separating said precipitate from said liquid; and heating said precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced. These processes can also be used for preparing various other products such as hematite, MgO, silica and oxides of various metals, sulphates and chlorides of various metals, as well as rare earth elements, rare metals and aluminum.

Abstract: There are provided processes for preparing various products from various materials. For example, such processes are effective for extracting various metals from various materials, thereby allowing for preparing products such as aluminum chloride, alumina, titanium chloride and titanium oxide. These processes can comprise leaching the starting material with HCl so as to obtain a leachate and a solid. The solid can be treated so as to substantially selectively extract titanium therefrom while the leachate can be treated so as to substantially selectively recover a first metal chloride therefrom.

Abstract: 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.

Abstract: There are provided processes for preparing various products from various materials. For example, such processes are effective for extracting titanium and various other metals from various materials, thereby allowing for preparing products such as titanium chloride and titanium oxide. These processes can comprise leaching the starting material with HCl so as to obtain a leachate and a solid. The solid can be treated so as to substantially selectively extract titanium therefrom while the leachate can be treated so as to substantially selectively recover a first metal chloride therefrom.

Abstract: There are provided methods for preparing hematite. For example, the method can comprise reacting a basic aqueous composition comprising the iron and the aluminum with hematite under conditions suitable for at least partially converting the iron into hematite under the form of a precipitate, thereby obtaining a liquid phase and a solid phase; and separating the liquid phase from the solid phase.

Abstract: 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.

Abstract: There are provided processes for treating fly ash. For example, the processes can comprise leaching fly ash with HCl so as to obtain a leachate comprising aluminum ions and a solid, and separating the solid from the leachate; reacting the leachate with HCl so as to obtain a liquid and a precipitate comprising the aluminum ions in the form of AlCl3, and separating the precipitate from the liquid; and heating the precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced.

Abstract: The present description relates to an anode arrangement for use in an electrolysis production of metals comprising an anode having a hollow body comprising a cavity, the body having at least one gas outlet connected in flow communication with the cavity. A gas inlet is connected in fluid flow communication with the cavity of the anode, the gas inlet being connectable to a source of hydrogen gas for feeding hydrogen gas into the cavity of the anode. The anode arrangement also comprises an electrical connector and a hydrogen chloride (HCl) recuperator surrounding at least a portion of the anode for recovering HCl gas released through the at least one gas outlet at an outer surface of the anode during electrolysis.

Abstract: There are provided processes for treating fly ash. For example, the processes can comprise leaching fly ash with HCl so as to obtain a leachate comprising aluminum ions and a solid, and separating the solid from the leachate; reacting the leachate with HCl so as to obtain a liquid and a precipitate comprising the aluminum ions in the form of AlCl3, and separating the precipitate from the liquid; and heating the precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced.

Abstract: 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.

Abstract: There are provided methods for separating iron ions from aluminum ions. For example, the methods can comprise providing a basic aqueous composition comprising said iron ions and said aluminum ions and having a pH of about 10.5 to about 13 and a temperature of about 50 ° C. to about 150 ° C.; reacting said basic aqueous composition with hematite so as to promote, catalyze and/or enhance formation of hematite and to obtain a liquid phase comprising said aluminum ions and a solid phase comprising said so-formed hematite generated with said iron ions; and separating said liquid phase from said solid phase.

Abstract: 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 TiO2, SiO2 etc.

Abstract: It is described a process for extracting magnesium from magnesium-bearing materials comprising the steps of leaching the magnesium-bearing material with HCl as to obtain a leachate comprising the magnesium in solution and a solid form; purify said leachate to produce magnesium chloride and electrolysing the magnesium chloride producing magnesium metal.

Abstract: There are provided processes for preparing various products from various materials. For example, such processes are effective for extracting titanium and various other metals from various materials, thereby allowing for preparing products such as titanium chloride and titanium oxide. These processes can comprise leaching the starting material with HCl so as to obtain a leachate and a solid. The solid can be treated so as to substantially selectively extract titanium therefrom while the leachate can be treated so as to substantially selectively recover a first metal chloride therefrom.

Abstract: 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 TiO2, SiO2 etc.

Abstract: There are provided processes for treating fly ash. For example, the processes can comprise leaching fly ash with HCl so as to obtain a leachate comprising aluminum ions and a solid, and separating the solid from the leachate; reacting the leachate with HCl so as to obtain a liquid and a precipitate comprising the aluminum ions in the form of AlCl3, and separating the precipitate from the liquid; and heating the precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced.

Abstract: The present disclosure relates to processes for recovering rare earth elements from various materials. The processes can comprise leaching the at least one material with at least one acid so as to obtain a leachate comprising at least one metal ion and 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 metal 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.

Abstract: 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 TiO2, SiO2 etc.

Abstract: There are provided methods for preparing hematite. For example, the method can comprise reacting a basic aqueous composition comprising the iron and the aluminum with hematite under conditions suitable for at least partially converting the iron into hematite under the form of a precipitate, thereby obtaining a liquid phase and a solid phase; and separating the liquid phase from the solid phase.