Investigation of applicability to hydrometallurgical studies of photochemical oxidation technology

The dissolution behaviors of metals from two different solid materials, sphalerite concentrate and copper slag, were investigated with photochemical reactions. Photochemical reactors are prevalently used in disinfection and the removal of various pollutants, and it is a new approach to adapt them to hydrometallurgy applications and examine the process. Experiments were run intermittently with a quartz glass jacket in a glass reactor, by submerging UV lamps and using a glass tube as an air supply distributed under the reactor. The behaviors of UVA, UVB, UVC, and VUV light at different wavelengths and powers in a leaching solution were examined. All experiments were conducted comparatively in the presence and absence of UV lamps under identical conditions. The adaptation of the radical formation mechanism to the leaching environment and its usability in leaching by creating an oxidative solution medium were investigated. The effects of the UV wavelength, UV power, air supply rate, acid concentration, leaching temperature, leaching time, and solid-liquid ratio on metal dissolution were analyzed. To understand the dissolution mechanism better, leaching kinetics were examined in the presence and absence of UV light. The distribution of ray intensity on the cross-section of the reactor under different conditions was measured, and the UV dose and electrical energy consumption in the optimum conditions for metal recovery were calculated. The metal dissolution behaviors during leaching in the photoreactor systems with UV light were more effective than those in the systems without UV light in cases of both copper slag and sphalerite concentrate Keywords: Leaching, Sphalerite Concentrate, Copper Production Slags, Photochemical Oxidation, Ultraviolet Lamp, Oxidative Radical