Patent ID: 7993613

Claim:
A water-immiscible extraction reagent formulation comprising an extractant reagent consisting of: (a) one or more aldoxime extractants, (b) optionally, one or more ketoxime extractants, and (c) one or more branched-chain ether equilibrium modifiers, in a molar ratio of branched-chain ether equilibrium modifier(s) to extractant reagent effective to provide a net copper transfer greater than that achieved in the absence of such modifier(s), wherein said branched-chain ether equilibrium modifiers are selected from the group consisting of compounds of Formula (I): wherein R 1 , R 2 , and R 3 , independently, represent a saturated or unsaturated, straight or branched C 1 -C 6 alkyl group, hydrogen, a C 5 -C 6 cycloalkyl group, or a phenyl group; and R 4 represents a saturated or unsaturated, straight-chain C 1 -C 20 alkyl group, with the proviso that, if any one of R 1 , R 2 , or R 3 is hydrogen, then the other two must be the same C 1 -C 6 alkyl group or each a different C 1 -C 6 alkyl group, or one of the other two may be a C 5 -C 6 cycloalkyl group or a phenyl group, and with the further proviso that the total number of carbon atoms in each branched-chain ether equilibrium modifier is 8-24.