Recovery of copper, cobalt, nickel, cadmium, zinc and bismuth from electrolytic copper solution

An electrolytic Copper Solution (ECS) was electrolyzed using platinum electrodes. Copper was obtained in solid form. In order to precipitate Cd(II), Bi(III), As(III), Sb(III) and the rest of the Cu(II) ions, $H_2S$ gas was passed through the remaining solution. The remaining solution was evaporated to obtain metal sulphates. The sample containing metal sulphates was roasted at temperatures between 550 and 800 °C. Cobalt, nickel and zinc in the solid sample remained in the form of metal sulphates, while the iron in the sample.was converted into Fe2Û3. This solid sample was dissolved in water and filtered in order to crystallize the $NiSO_4$. As a result of crystallization, a maximum yield of 86.2 % was obtained. The solid containing metal sulphides (CuS, CdS, $Bi_2S_3$ and $Sb_2S_3$) was roasted at 600° C for 3 hours. The roasted sample was dissolved in water and filtered. It was determined that the conversion of CuS into $CuSO_4$ occurred, together with the conversion of CdS and $Bi_2S_3$ into CdO and $Bi_2S_3$. The samples containing CdO and $Bi_2S_3$ were then leached with 0.5 M $H_2SO_4$ solution at 50° C for one hour. The extraction yield was 97%.