China Nonferrous Metallurgy

Guangxi is an important production base of electrolytic manganese dioxide and titanium dioxide in China. The treatment of electrolytic manganese slag and titanium alum slag has always been a difficult problem restricting the development of the two industries.Since the ferrous sulfate of titanium alum slag can be used as a reducing agent to leach MnO2 from electrolytic manganese slag, the manganese leaching test of electrolytic manganese slag in sulfuric acid system was carried out in this study. The effects of the ratio of electrolytic manganese slag to titanium alum slag, leaching temperature, sulfuric acid concentration, leaching time and solid-liquid ratio on the leaching rate of manganese were investigated, and the leaching reaction kinetics was analyzed. The results showed that under the conditions of mass ratio of electrolytic manganese slag to green alum slag 10∶1.0, leaching temperature 50℃, sulfuric acid concentration 1.0mol/L, leaching time 1.0h and solid-liquid ratio 1∶15g/m, the leaching rate of manganese reached 98.67%. The apparent activation energy of the reaction was 40.49kJ/mol, which indicated that the leaching was controlled by internal diffusion-interfacial reaction. The macroscopic kinetic equation of manganese leaching process was also determined according to the linear fitting results. This study provides a reference for the recovery of manganese from electrolytic manganese slag and the resource utilization of electrolytic manganese slag and titanium alum slag, and has practical significance for the reduction and disposal of solid waste.