ABSTRACT
This chapter consists of a bench scale evaluation of solvent extraction separation options for recovery of metals such as chromium, copper, nickel, and zinc from multi-component metal wastes: pickling acids and acid solubilized sludges from the plating, hardware and electrochemical machining metal finishing industries. It utilizes a waste mineral acid and some acid solubilized waste metal sludges. Sequential solvent extraction at low pH with extraction agents effective at low pH is considered a promising approach to achieving efficient recoveries of such metals as chromium, copper, nickel, and zinc from multicomponent acid waste systems. Efficient separation of nickel following iron and copper extractions is quite variable, dependent upon the system. Stripping iron and copper by solvent extraction in a mixed waste system, combined with alternative nickel separations by cation exchange or electrowinning, can provide useful separation options. The extraction agents are predominantly commercial materials with good stability and demonstrated extraction efficiency at low pH.
