A method comprising reacting an aluminum mineral polymorph or a gallium mineral polymorph with an acid at an aluminum metal to acid molar ratio or gallium metal to acid molar ratio sufficient to produce M.sub.13 nanoscale clusters, M nano-agglomerates, or a M.sub.13 slurry, wherein M is Al or Ga.

A method comprising reacting an aluminum mineral polymorph or a gallium mineral polymorph with an acid at an aluminum metal to acid molar ratio or gallium metal to acid molar ratio sufficient to produce M.sub.13 nanoscale clusters, M nano-agglomerates, or a M.sub.13 slurry, wherein M is Al or Ga.

Aluminum chloride is separated from a silane mixture containing aluminum chloride by reacting the aluminum chloride with a compound reactive therewith which forms an ionic liquid or solid, and separating the ionic liquid or solid from the now-purified silane.

A method comprising reacting an aluminum mineral polymorph or a gallium mineral polymorph with an acid at an aluminum metal to acid molar ratio or gallium metal to acid molar ratio sufficient to produce M.sub.13 nanoscale clusters, M nano-agglomerates, or a M.sub.13 slurry, wherein M is Al or Ga.

A method comprising reacting an aluminum mineral polymorph or a gallium mineral polymorph with an acid at an aluminum metal to acid molar ratio or gallium metal to acid molar ratio sufficient to produce M.sub.13 nanoscale clusters, M nano-agglomerates, or a M.sub.13 slurry, wherein M is Al or Ga.

A method comprises reacting an aluminum feedstock with an acid in the presence of water to provide an aluminum salt solution comprising an aluminum salt in water, wherein the aluminum salt comprises a reaction product of the acid and aluminum, and spray roasting the aluminum salt solution at a temperature of at least about 450 C. to provide an aluminum oxide powder, wherein the spray roasting is performed in a furnace lined with a refractory comprising alumina that is at least about 99.2% purity alumina, and wherein the aluminum oxide powder is 99.2% pure aluminum oxide or greater.

A method comprises reacting an aluminum feedstock with an acid in the presence of water to provide an aluminum salt solution comprising an aluminum salt in water, wherein the aluminum salt comprises a reaction product of the acid and aluminum, and spray roasting the aluminum salt solution at a temperature of at least about 450 C. to provide an aluminum oxide powder, wherein the spray roasting is performed in a furnace lined with a refractory comprising alumina that is at least about 99.2% purity alumina, and wherein the aluminum oxide powder is 99.2% pure aluminum oxide or greater.

Methods for recovering a metal from a metal-containing material are provided. In embodiments, such a method comprises exposing a metal-containing material to a leaching solution comprising a solvent and a binoxalate, a tetraoxalate, or a combination thereof, under conditions to provide a leachate comprising a soluble metal oxalate; inducing precipitation of a metal-containing precipitate comprising the metal of the soluble metal oxalate from the leachate; and recovering the metal-containing precipitate.

Methods for recovering a metal from a metal-containing material are provided. In embodiments, such a method comprises exposing a metal-containing material to a leaching solution comprising a solvent and a binoxalate, a tetraoxalate, or a combination thereof, under conditions to provide a leachate comprising a soluble metal oxalate; inducing precipitation of a metal-containing precipitate comprising the metal of the soluble metal oxalate from the leachate; and recovering the metal-containing precipitate.

A process for producing high purity alumina (HPA) or high purity aluminium salts from an aluminium-bearing material, such as is disclosed. An aluminium-bearing solution is first obtained by either dissolving or leaching the aluminium-bearing material. Aluminium is then selectively extracted by liquid-liquid or liquid-solid extraction to obtain an aluminium-enriched liquid or aluminium-enriched solid phase. Minor metal impurities still remaining in the aluminium-enriched liquid or solid phase are removed by scrubbing the aluminium-enriched liquid or aluminium-loaded ion exchange resin with an aqueous solution thereby producing a metal impurity-depleted aluminium-enriched liquid or metal impurity-depleted aluminium enriched solid phase. Aluminium is then stripped from the scrubbed liquid or solid phases with an acidic aqueous solution to produce an aluminium-enriched aqueous solution. High purity aluminium salts may be crystallised from said solution. Alternatively, the pH of said solution may be raised to precipitate an aluminium precipitate, such as Al(OH)3, which is then calcined to produce HPA.