NOUFERROUS METALLURGICAL EQUIPMENT

In order to solve the problems of low leaching rate and safety and environmental protection in the current process of indium extraction from lead-bearing soot, a new process of indium recovery from lead-bearing soot by two-stage mixed acid leaching with full-wet process was proposed.The effects of sulfuric acid concentration, liquid-solid ratio, reaction time and different sulfuric acid initial acid concentration on indium leaching rate during lead-bearing soot leaching were studied.The results indicated that the leaching process conditions were as follows: a liquid-solid ratio of 8∶1, sulfuric acid concentration of 150g/L, hydrochloric acid concentration of40g/L, reaction temperature of 90℃, and a reaction time of 4h. The conditions for the two-stage leaching process were as follows: a liquid-solid ratio of 4∶1, initial sulfuric acid concentration of 300g/L, initial hydrochloric acid concentration of40g/L, reaction temperature at 90℃ with an indium leaching rate at 81.18%, leaching residue containing indium at 0.25%, and low-acid leaching liquid output meeting the purification process requirements. Following the industrial implementation of the lead-soot two-stage mixed acid leaching process, there is a potential increase in crude indium production by approximately 3.63 tons per year and an associated rise in economic benefits by about 5.5361 million yuan, demonstrating significant potential for widespread application.