Collective Recovery of Copper and Silver from Secondary Copper Electrolytic Refining Slimes. Part 1.

In this study, the effect of copper and silver low-temperature leaching from secondary copper electrolytic refining slime with the sulfuric acid solution was investigated. Herein, the relevance of copper and silver collective recovery from secondary copper electrolytic refining slime was verified at the initial stage of their processing. Additionally, characterization of the secondary copper electrolytic refining slime sample was explored in detail. It was found that the main phases are PbSO4 (25.0%), SnO2 (20.0%), and BaSO4 (13.1%), and copper (9.62%) was distributed between its conventional phases (Cu2O and Cu2Se) and complex compounds (CuPbSO4(OH)2, Cu5(SO4)2(OH)6·4H2O). Moreover, silver (5.6%) was in metallic form by 73.2%, while the remaining amount is in AgCl, Ag2Se, and Ag2Te compounds. The formation enthalpies of the new phases (CuPbSO4(OH)2, Cu5(SO4)2(OH)6∙4H2O) were calculated at their crystalline structures based on the electronegativity concept. Thermodynamic analysis of the slime–H2SO4 and slime–H2SO4–H2O2 systems was conducted to substantiate the probability and conditions of the slime component low-temperature hydrometallurgical opening because of the odd qualitative or quantitative slime composition. Technological studies confirmed the possibility of copper and silver collective leaching with the sulfuric acid solution in the presence of an oxidant at > 95% and > 23%, respectively. [ABSTRACT FROM AUTHOR]