Treatment of Waste Copper Electrolytes Using Insoluble and Soluble Anodes

Abstract

The use of copper anodes with non standard content of impurities for the treatment of waste, sulphur acid solutions that came as a result of the industrial process of electrolytic copper refining was investigated. Those solutions contain the high content of copper, nickel and arsine, and because of that, the copper anodes with high content of Ni, Pb, Sn and Sb were prepared. Examination the effect of high impurities content as well as the influence of the solution temperature on the anodes behaviour during the electrolytic process under the conditions that are the same as the industrial was the aim of this work. Obtained results clearly indicate that tested anodes could be used for the refined during the electrorefining process. Dissolution of copper anodes was not stoppage after the first appearance of the passivation region for A1 and A2 anodes while appearance of passivation for A3 anode, for test duration of 72 h, was not registered. The start time of the first passivation appearance is shorter in the case of the anode with high content of all impurities, anode A1. The first passivation occurrence was detected on higher temperature after about 29 h from the test starts. The change of chemical composition of electrolyte was monitored during electrolysis. Concentration of nickel in the working electrolyte at the end of process is increased and it corresponds to the Ni content in anodes. The copper and arsenic concentrations are decreased during the process. Arsenic passes into the anode slime, while the copper is deposited on the cathode and also passed in the slime. After the process is finished, obtained solution could be used for the nickel recover using the electrochemically or chemically methods.