An investigation of copper and selenium recovery from copper anode slimes

In this study, an alternative method was investigated for the recovery of copper and selenium from copper anode slimes, supplied from Sarkuysan Co. in Turkey. The proposed process was composed of two hydrometallurgical steps; decopperization in H₂SO₄ medium and dissolution of selenium into NaOH solution. The effects of oxygen flow rate and solution temperature on the decopperization of anode slimes were examined in H ₂SO₄ medium and copper recovery was achieved with an efficiency of 94%. The X-ray diffraction (XRD) analysis revealed Cu ₂Se as a remaining phase of copper in anode slimes after the decopperization process. Following the decopperization stage, anode slimes were treated with NaOH solution in order to dissolve selenium. The influences of NaOH concentration, temperature and various types of oxidants on selenium dissolution were inspected. The uniqueness of this technique is that it provides to have an efficiency of selenium recovery as high as 86.8% in an alkaline solution (4 M NaOH) under atmospheric conditions without requiring an autoclave.