Processing of a Waste Stream for Separation and Recovery of Copper and Zinc

Abstract

Solvent extraction studies of copper and zinc have been carried out using Cyanex 272 and LIX 984N separately from a model waste stream of brass pickling. Various parameters for the extraction and separation of copper and zinc such as effect of pH, extractant concentration, phase ratio etc. have been optimized. The results show that extraction of copper and zinc from solution after acid extraction increased with increase in pH and their pH0.5 values were found to be 3.5 and 4.6, and 2.5 and 5.5 with Cyanex 272 and LIX 984N, respectively; LIX 984N showed greater selectivity for copper compared to zinc. By McCabe Thiele diagram number of stages required for the counter current extraction of copper and zinc has been determined for each of the solvents. The stripping study showed that 1 mol/L H2SO4 was sufficient to strip metal ions from both the extractants. An attempt was made to prepare high value products such as copper powder and zinc oxide from the loaded or stripped solution which could be imminently suitable for various P/M and other applications