Solvent extraction of copper values using dihydroxy azoarenes

In a process for the recovery of copper values from an aqueous solution of copper and iron values, wherein said aqueous solution is contacted with an immiscible solution of an extracting agent in an organic solvent and the resultant mixture is separated into a barren aqueous phase and a pregnant organic phase and copper values are subsequently recovered from the organic phase by treatment with an aqueous acid solution, the improvement which comprises utilizing as the extracting agent 2,2'-dihydroxy azoarenes having the formula:

• Ar - N = N - Ar'
• wherein Ar and Ar' are each selected from the group consisting of ##STR9## wherein each of R, R' and R" is a monovalent radical selected from the group consisting of hydrogen and alkyl groups having 1-20 carbon atoms.