Leaching Effects of Metal from Electroplating Sludge under Phosphate Participation in Hydrochloric Acid Medium

In recent years, with the rapid development of the electroplating industry, electroplating sludge has reached much attention. Electroplating sludge contains heavy metals such as nickel, copper, cadmium and chromium. To avoid releasing metal into the environment, removal of heavy metals from the electroplating industry is highly desired. In this study, effects of leaching metal from electroplating sludge under phosphate participation in hydrochloric acid medium were measured. The effects of the amount of hydrochloric acid, phosphoric acid concentration, temperature, and liquid to solid ratio along with leaching time were investigated and measured using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Using the optimized conditions of 1.5 mol/L hydrochloric and phosphoric acid concentration, liquid to solid ration 10:1 and temperature 40 ̊C, actual electroplating sludge was treated. The leaching rate of copper was measured as high as to 80.6% under optimal conditions.