A method for extracting a rare earth metal from a mixture of one or more rare earth metals, said method comprising contacting an acidic solution of the rare earth metal with a composition which comprises an ionic liquid to form an aqueous phase and a non-aqueous phase into which the rare earth metal has been selectively extracted; recovering the rare earth metal from the non-aqueous phase; and processing the recovered rare earth metal into a rare earth metal oxide.

A process (10) for the treatment of a lithium containing material (12), the process comprising the steps of: (i) Preparing a process solution from the lithium containing material (12); (ii) Passing the process solution from step (i) to a series of impurity removal steps, one of which is an HCl sparging step 58, thereby providing a substantially purified lithium chloride solution; and (iii) Passing the purified lithium chloride solution of step (ii) to an electrolysis step (70) thereby producing a lithium hydroxide solution. An additional step in which the lithium hydroxide solution produced in step (iii) is carbonated by passing compressed carbon dioxide (88) through the solution, thereby producing a lithium carbonate precipitate, is also disclosed.

A process (10) for the treatment of a lithium containing material (12), the process comprising the steps of: (i) Preparing a process solution from the lithium containing material (12); (ii) Passing the process solution from step (i) to a series of impurity removal steps, one of which is an HCl sparging step 58, thereby providing a substantially purified lithium chloride solution; and (iii) Passing the purified lithium chloride solution of step (ii) to an electrolysis step (70) thereby producing a lithium hydroxide solution. An additional step in which the lithium hydroxide solution produced in step (iii) is carbonated by passing compressed carbon dioxide (88) through the solution, thereby producing a lithium carbonate precipitate, is also disclosed.

An object of the present invention is to recover a minor metal and/or rare-earth metal. The present invention provides a method for recovering a minor metal and/or rare-earth metal from a post-chlorination residue in titanium smelting. The minor metal and/or rare-earth metal is one or more metal selected from the group consisting of Sc, V, Nb, Zr, Y, La, Ce, Pr, and Nd.

A method for extracting rare earth elements (REEs) from a REE hyperaccumulator, including: subjecting the REE hyperaccumulator to microwave-assisted digestion to obtain a REE extract; subjecting the REE extract to absorption with a chelating resin and elution to obtain a purified REE solution; and subjecting the purified REE solution to precipitation and calcination to obtain high-purity rare earth compound.

A method for extracting rare earth elements (REEs) from a REE hyperaccumulator, including: subjecting the REE hyperaccumulator to microwave-assisted digestion to obtain a REE extract; subjecting the REE extract to absorption with a chelating resin and elution to obtain a purified REE solution; and subjecting the purified REE solution to precipitation and calcination to obtain high-purity rare earth compound.

The present invention provides a process for metallurgy and separating a rare earth concentrate using a combination method, the process including: treating the rare earth concentrate containing bastnaesite by using a method including roasting under an atmosphere, leaching with hydrochloric acids, and roasting with a sulfuric acid, wherein stepping acid leaching with low-concentration hydrochloric acids is controlled during the leaching with the hydrochloric acids so as to obtain a rare earth solution with a high concentration (150-250 g/L REO), such that a leaching rate of Ce reaches 60% or more, and the content of F.sup.− in a leaching liquor is reduced by aging; and rare earth is further recovered from a leach residue by roasting with the sulfuric acid and leaching with water, and the total yield of the rare earth reaches 95% or more.

The present invention provides a process for metallurgy and separating a rare earth concentrate using a combination method, the process including: treating the rare earth concentrate containing bastnaesite by using a method including roasting under an atmosphere, leaching with hydrochloric acids, and roasting with a sulfuric acid, wherein stepping acid leaching with low-concentration hydrochloric acids is controlled during the leaching with the hydrochloric acids so as to obtain a rare earth solution with a high concentration (150-250 g/L REO), such that a leaching rate of Ce reaches 60% or more, and the content of F.sup.− in a leaching liquor is reduced by aging; and rare earth is further recovered from a leach residue by roasting with the sulfuric acid and leaching with water, and the total yield of the rare earth reaches 95% or more.

The present invention is related to a method for producing lithium chloride aqueous solution and a method for producing lithium carbonate, and comprises introducing calcium chloride into a slurry containing a solvent and lithium phosphate; and obtaining a precipitate of chloroapatite which is an poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.

The present invention is related to a method for producing lithium chloride aqueous solution and a method for producing lithium carbonate, and comprises introducing calcium chloride into a slurry containing a solvent and lithium phosphate; and obtaining a precipitate of chloroapatite which is an poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.