The Research of Copper Leaching from the Waste Computer Mainboards

In this study, a new hydrometallurgical recovery technology of leaching copper from waste computer mainboards (WCM) has been presented using ammonia-ammonium chloride buffering solution as leachant and hydrogen peroxide solution ( AR, 30% w/w) as oxidant. The influences of aqueous ammonia concentration, ammonium chloride concentration, dose of hydrogen peroxide, reaction temperature and leaching time were investigated experimentally. The results indicated that increasing reaction temperature by externally heating appeared to be negligible effect on the recovery efficiency of copper and other factors were considerable contribution to copper recovery. It was favorable for copper recovery when solid-liquid ratio was 1:30, under the condition of 50 ml NH₄OH(l:l), 20ml NH₄Cl(2.0 mol/L), 6 ml H₂O₂ solution, 2 h leaching time and at room temperature(298K). The best dissolution rate of copper reached about 98% in this favorably experimental condition, which suggested this technological viability of copper recovery. On the basis of practice, this recycling was an environment-friendly and energy-saving recycling technology and expected to be a great potential.