Systems and methods for selective recovery of metals from ion exchange resins

A method of selectively recovering a first metal from an ion exchange resin, comprising:

• contacting a non-polar fluid and an extractant with the ion exchange resin, the first metal, and a second metal, wherein at least one of the first metal and the second metal are bound to the ion exchange resin, wherein the ion exchange resin comprises a plurality of functional groups having a proton dissociation constant of greater than or equal to 10−5 and less than or equal to 104;
• and
• selectively eluting the first metal from the ion exchange resin into the non-polar fluid such that a ratio of the first metal to the second metal in the non-polar fluid is greater than a ratio of the first metal to the second metal bound to the ion exchange resin,
• wherein the extractant comprises a phosphoric acid, a phosphoric acid ester that serves as a source of a proton and/or serves as a source of an anion, a phosphonic acid, a phosphinic acid, a monothiophosphinic acid, and/or a dithiophosphinic acid, and
• wherein the ion exchange resin is a macroporous resin that comprises pores that resist solvent swelling.

A method of selectively recovering a first metal from an ion exchange resin, comprising:

• contacting a non-polar fluid and an extractant with the ion exchange resin, the first metal, and a second metal, wherein at least one of the first metal and the second metal are bound to the ion exchange resin, wherein the ion exchange resin comprises a plurality of functional groups having a proton dissociation constant of greater than or equal to 10−5 and less than or equal to 104;
• and
• selectively eluting the first metal from the ion exchange resin into the non-polar fluid such that a ratio of the first metal to the second metal in the non-polar fluid is greater than a ratio of the first metal to the second metal bound to the ion exchange resin,
• wherein the extractant comprises a phosphoric acid, a phosphoric acid ester that serves as a source of a proton and/or serves as a source of an anion, a phosphonic acid, a phosphinic acid, a monothiophosphinic acid, and/or a dithiophosphinic acid, and
• wherein the ion exchange resin comprises a solid phase having rigid, minimally-swelling macropores.