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.

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.

The present disclosure is directed to novel functionalized ionic liquids (ILs) that are used, for example, for enhanced recovery and separation of rare earth elements from aqueous solutions. The liquids and processes disclosed herein lead to greater separation efficiency, increased stability of separation materials, increased selectivity, and a reduced amount of waste materials.

The present disclosure is directed to novel functionalized ionic liquids (ILs) that are used, for example, for enhanced recovery and separation of rare earth elements from aqueous solutions. The liquids and processes disclosed herein lead to greater separation efficiency, increased stability of separation materials, increased selectivity, and a reduced amount of waste materials.

Methods for removing an oxyanion from an aqueous source containing said oxyanion, comprising contacting said aqueous source with an aqueous-insoluble hydrophobic solution containing an oxyanion extractant compound dissolved in an aqueous-insoluble hydrophobic solvent to result in formation of an oxyanion salt of said extractant compound and extraction of said oxyanion salt into said aqueous-insoluble hydrophobic solution, wherein said extraction results in an extraction affinity (D) of said oxyanion of at least 1, wherein D is the concentration ratio of said oxyanion in the organic phase divided by the concentration of said oxyanion in the aqueous phase; wherein said extractant compound has the following composition: ##STR00001##
wherein at least one of R.sup.1-R.sup.10 is or contains a hydrocarbon (R) group containing at least 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms.

A process of isolating samarium from a hydrophilic composition comprises nitrate ions, europium and samarium, by reducing europium(III) to europium(II) in this hydrophilic composition, and by extracting the samarium with a water-immiscible organic phase comprising an ionic liquid comprising nitrate anions.

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.

The present disclosure is directed to novel functionalized ionic liquids (ILs) that are used, for example, for enhanced recovery and separation of rare earth elements from aqueous solutions. The liquids and processes disclosed herein lead to greater separation efficiency, increased stability of separation materials, increased selectivity, and a reduced amount of waste materials.

Methods for removing an oxyanion from an aqueous source containing said oxyanion, comprising contacting said aqueous source with an aqueous-insoluble hydrophobic solution containing an oxyanion extractant compound dissolved in an aqueous-insoluble hydrophobic solvent to result in formation of an oxyanion salt of said extractant compound and extraction of said oxyanion salt into said aqueous-insoluble hydrophobic solution, wherein said extraction results in an extraction affinity (D) of said oxyanion of at least 1, wherein D is the concentration ratio of said oxyanion in the organic phase divided by the concentration of said oxyanion in the aqueous phase; wherein said extractant compound has the following composition:

##STR00001##

wherein at least one of R.sup.1-R.sup.10 is or contains a hydrocarbon (R) group containing at least 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms.