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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 As 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 AsO 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. [ABSTRACT FROM AUTHOR]

We developed a novel method for comprehensive treatment of copper smelting dust (CSD) and arsenic sulfide residue (ASR) using three processes: leaching CSD by sulfuric acid, Cu precipitation with ASR, and FeSO 4 ·7H 2 O/O 2 co-oxidizing and precipitating As. The novel method not only realizes the recovery of valuable metals from dust, but also removes and solidifies As in CSD and ASR in the form of scorodite to achieve harmless treatment. With sulfuric acid as leaching agent, the leaching efficiencies of Cu, Zn and As reached 87.23%, 93.07% and 95.21%, respectively, under the optimum conditions. Subsequently, Cu in CSD leaching solution was precipitated in the form of CuS by ASR, and the Cu precipitation percentage reached 97.39% and 94.86 wt. % of As in ASR entered the solution under the optimum conditions. Finally, FeSO 4 ·7H 2 O/O 2 was used to co-oxidize As(III) and simultaneously precipitate the As in the form of scorodite. The oxidation percentage and precipitation percentage of arsenic reached 98.73% and 96.77%, respectively. The leaching concentration of As in the arsenic precipitate residue (APR) was only 0.17 mg/L in the toxicity characteristic leaching procedure (TCLP). The arsenic precipitate solution can be directly used to recover Zn. [ABSTRACT FROM AUTHOR]