Selective Recovery of Copper from Industrial Sludge by Integrated Sulfuric Leaching and Electrodeposition

Abstract

The metal-containing sludge generated from the printed circuit boards (PCBs) manufacturing has been recycled as a secondary resource of copper (Cu) rather than being treated as a hazardous solid waste. However, it should consider the complexity of processing and using of oxidizing or precipitation agents to dissolve and separate Cu from other impurities, especially iron (Fe). This study has combined the dissolution and separation step in one stage by integrated acid leaching and electrodeposition to simplify the recovery process, while maintaining the high efficiency of separation. The chemistry of acid leaching and electrodeposition of the metals demonstrated that the metals (Cu and Fe) in the sludge sample were dissolved in the H2SO4 electrolyte, and Cu could be selectively deposited on the cathode based on the different potential conditions to reduce it on the cathode. The important factors affecting the deposition of Cu were investigated, finding the optimal conditions (current density 15 mA/cm2, H2SO4 100 g/L, Cu 20 g/L, at 45 °C, and for 6 h) which could completely recover Cu from the electrolyte in a selective manner. The obtained copper product possessed a high purity of >99% with adequately uniform morphology and an acceptable consumption of energy (1.7 kWh/kg). It is an effective and simple approach to reclaim the value metal copper from the industrial waste in one single stage of integrated extraction and refining.

Mapping Recyclability of Industrial Waste for Anthropogenic Circularity: A Circular Economy Approach

“…We perform a thorough analysis of the literature based on National Statistical Bureau of China, Sohu, and Chinese papers to collect the chemical compositions of 11 industrial waste types: iron and steel slag, , stainless steel slag, red mud, copper slag, , copper tailings, − iron tailings, , gold tailings, , oily sludge, copper sludge, coal fly ash, and spent petroleum catalysts for the measurement. Besides, we also collected some industrial waste samples from the copper smelting industry in Shandong and Taishan gypsum plants in China.…”

The Role of Electrochemistry and Electrochemical Technology in Environmental Protection, a review

“…Numerous research projects have recently focused on using electrochemical technology for environmental cleanup [7][8][9][10][11][12][13]. Toxic metals utilized in the extensively used electrodeposition (ED), electrowinning (EW), and electrorecovery (ER) processes are cathodically deposited during electrolytic procedures [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Also, hazardous organic molecules are electro-oxidized and degraded either directly on the anode surface or through oxidants produced on the anode or the cathode surface.…”

“…By utilizing insoluble anodes during electrowinning, various metals that are found in industrial wastewaters can be electro recovered [38 -49]. The feeding electrochemical cell and electrolyte are the metal-containing waste solutions [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Metals recovered through electrolysis are equally pure (virgin) plating materials.…”

Management of selected waste generated during cable production

“…Waste wire strands and cables are recycled and managed (Xie et al 2009 ; Liao et al 2019 ; Trinh et al 2021 ). The waste generated during the production of cable insulation is interesting.…”