Reduction of valuable metal loss in copper anode slime process

To reduce the leaching loss of valuable metal and Tellurium in the process of separating copper from copper anode slime after sulphate calcinations, water leaching copper is utilized to replace acid leaching copper. The effects of sodium chloride dosage, reaction temperature, reaction time and liquid-solid ratio on the leaching rate of copper, silver and tellurium were mainly investigated. The results show that the optimum conditions for the process of water leaching and separating copper from the deimpregnated slag are as follows: the adding of deselenide residue sodium chloride 9 %, reaction temperature 30 C, the liquid-solid ratio 4:1, stirring reaction 2 h. The recovery rate of copper is 94.17 %, while the leaching loss of silver and tellurium is reduced to 0.08 % and 2.39 %, respectively when the above optimal conditions are applied to the workshop expansion test. The percentage of gold and silver quality increased from 0.24 % and 10.64% to 0.62 % and 17.85 % respectively.