Controlled Electrodeposition of Uniform Copper Powder from Hydrochloric Acid Solutions

Recovery of copper from hydrochloric acid solution is of significant importance for the heavy-metal pollution protection and valuable metal resources utilization. In order to overcome the drawbacks of low current efficiency and contaminated deposits in conventional electrochemical recovery, a controlled electrodeposition process was first developed using low-cost stainless steel cathodes. It has been demonstrated that mass transport has a facilitating effect for the copper electrodeposition in HCl media, thus a cylinder turbulent cell equipped larger surface area cathode was used. 93.6% copper was successfully extracted with a current efficiency of 89.4%, and the impurity of CuCl was completely eliminated. This indicated the low efficiency chloride-mediated pathway was avoided and the regular 2e reduction to metallic copper was greatly improved. Besides, more uniform and fine powder was obtained, which could be readily flushed and collected from the cell with water. This controlled electrodeposition may serve as a promising alternative to overcome the disadvantages of existing metal recovery and water purification. (C) 2017 The Electrochemical Society. All rights reserved.