Treatment of high arsenic content lead copper matte by a pressure oxidative leaching combined with cyclone and vertical electro-deposition method

In this work, pyrite was first used to precipitate arsenic in lead copper matte as the form of FeAsO4 during pressure oxidative leaching process. Initial content of arsenic in lead copper matte is of 7.92 wt%, and concentration of arsenic in leaching liquid can be less than 0.25 g·L−1 when the dosage of pyrite reaches 10 g. Leaching time, liquid-to-solid ratio, oxygen partial pressure, temperature, sulfuric acid concentration, agitation speed, and sodium lignosulfonate content were systematically studied and optimized during pressure oxidative leaching process, and the optimized conditions for pressure oxidative leaching are: leaching time 2 h, liquid-to-solid ratio 5:1, oxygen partial pressure 1.2 MPa, temperature 150 °C, sulfuric acid 200 g·L−1, agitation speed 500 r·min−1, sodium lignosulfonate 4 g. A cyclone and vertical electro-deposition method is introduced to treat the above optimized leaching solution. This method is first applied for leaching solution which is obtained from lead copper matte. After having the cyclone and vertical electro-deposition step finished, cathode copper can be greater than 99.00%.