Study on the mechanism of copper and arsenic separation in copper smelting acidic solution by arsenic sulfide residue

A large amount of acidic solution containing arsenic and copper is produced in the hydrometallurgical treatment process of arsenic-containing solid waste in copper smelting. It is necessary to develop an economical and efficient separation technology of arsenic and copper from the solution. In this paper, according to the difference of solubility product between As2S3 2 S 3 and CuS, arsenic sulfide residue (ASR) was used as copper precipitant to realize the efficient separation of copper and arsenic in acidic solution, so as to achieve the purpose of "treating waste with waste". It is found that the copper precipitation reaction is a more sensitive reaction. With the increase of temperature and time, the precipitation efficiency of copper first increases and then decreases, mainly because CuS will react with AsO43-in 4 3- in the solution, and then re-dissolution occurs. With the increase of pH value, As and Fe precipitate, resulting in incomplete separation of Cu and As. Under the optimum conditions, the precipitation efficiencies of Cu, Sb, Cd, Fe and Zn reached 97.39 %, 46.31 %, 2.04 %, 2.59 % and 0.65 %, respectively. The content of Cu in the precipitated residue reaches 50.47 wt%. The precipitated residue can be used as raw material for copper smelting.