The study on the shortcut approach for cooperative disposal of arsenic-rich copper dust and waste acid to prepare high-purity copper

Abstract

The copper dust derived from the double-flash copper smelting process contains high level of arsenic with almost zero positive potential impurities. This study explores a new process for the preparation of high-purity copper through selective leaching of arsenic-rich copper dust with waste acid-purification-electrodeposition. Furthermore, the study also explores the causes and solutions for recurrent occurrence of excessive Hg impurity content. The results indicate that, the high-purity copper that meets standard 6 N (China) requirements and exhibits smooth surface, dense crystallization, and uniform color can be obtained under the optimal conditions of 200 A/m2 current density, electrolyte sulfuric acid concentration of 120 g/L, additive dosage of 120 g/t·Cu, electrolysis temperature of 50 °C, electrode spacing of 45 mm, endpoint Cu2+ concentration of 30.50 g/L, with C1 used as active adsorbent to purify the electrolyte. The current efficiency can be up to 99.65 %, with average tank voltage of 1.87 V and electrical energy consumption of 1582.93 kW h/t⋅Cu. There will be good environmental and economic benefits with this process of co-disposal and high-value recovery of arsenic-rich copper dust and waste acid.