Solvent extraction of metals from acidic solutions with quaternary ammonium salts of hydrogen ion exchange agents

The process of extracting divalent metal values from an aqueous acidic solution thereof comprising contacting said solution with a solution of a quaternary ammonium salt of a hydrogen ion exchange agent in an essentially water-immiscible organic solvent to extract at least a portion of the said divalent metal values into the organic phase, separating the loaded organic phaase from the aqueous phase and stripping the divalent metal values from the loaded organic phase by contacting same with an aqueous acidic stripping medium, said divalent metal values being capable of being extracted from an aqueous acidic solution thereof, said quaternary ammonium salt of the hydrogen ion exchange agent having the formula QL where Q is a quaternary ammonium cation and L is the deprotonated moiety or anion of the hydrogen ion exchange agent and said quaternary ammonium cation having the formula ##STR10## where R.sub.1 is a hydrocarbon radical of 6 to 24 carbon atoms and R.sub.2, R.sub.3 and R.sub.4 are hydrocarbon radicals of 1 to 24 carbon atoms.