Technology Development On Copper Recovery From Waste Printed Circuit Boards By Electrolysis Process

Printed circuit boards are an essential part of almost all of the electronic products. Amount of waste printed circuit boards (WPCBs) increased sharply with the increase of waste electrical and electronic equipment. WPCBs contain lots of valuable resources together with plenty of hazardous materials, which are considered as an attractive secondary resource but an environmental contaminant. To implement the e-waste pollution control, it is extremely important to develop efficient and low cost technologies for WPCBs reutilization. Therefore, the electrolysis process for recycling of copper from WPCBs was proposed in the present study. In the study, the concentrated metal scraps, obtained by the mechanical process for WPCBs recycling, were pressed as the anode, which was directly electrolyzed to produce copper powders. And the slurry electrolysis process was used to recovery copper from WPCBs. In addition, the electrochemical behavior of slurry electrolysis was analysed. The results were significant in scientific and practical value, and the following creative results have been achieved:1. The results of electrolytic copper powders showed:under the optimum conditions (50 g/L CuSO4-5H2O,40 g/L NaCl,118 g/L H2SO4,80 mA/cm2 for 3 h), the purity of deposited copper was 98.06%and the mean particle size was 9.35 ?m, current efficiency was 98.12%. The results indicated that the process is effective for copper recovery from concentrated WPCB metal scraps.2. The results of slurry electrolysis showed:under the optimum conditions (30 g/L CuSO4·5H2O,40 g/L NaCl,170 g/L H2SO4,0.6 A,0.3g WPCBs, for 9 h), the copper recovery rate was 97.42%. It is believed that the slurry electrolysis process is effective for copper recovery from WPCBs. The process also recovery other metals such as Zn, Pb,Ni, Fe, Al, Sn, the highest total metal recovery rate was 97.35%. It showed that the slurry electrolysis process is effective for metal recovery from WPCBs.3. The results of electrochemical study showed:the cyclic voltammetric of anode showed the oxidation potential was 0.7 V; the cyclic voltammetric of cathode showed the reduction potential was 0.9 V. The result of constant current showed that the deposition potential in reality is greater than the theoretical deposition potential. The deposition potential increased with the increase of electrolysis time.