China Nonferrous Metallurgy

In the actual production process of recovering waste platinum catalysts using the total dissolution method, there are still insoluble deposits, resulting in secondary pollution and waste of platinum group resources. In this study, insoluble particles were crushed and finely ground, and about 300 mesh powders were calcined. The obtained powders were then leached in the HCl-DCEA system to investigate the effects of reaction time, reaction temperature, liquid-solid ratio, hydrochloric acid concentration, and DCEA concentration on platinum leaching rate. Significant factors such as liquid-solid ratio, hydrochloric acid concentration, and DCEA concentration were selected for response surface optimization experiments. The results indicate that the significant order of influence on platinum leaching rate is DCEA concentration＞liquid-solid ratio≈hydrochloric acid concentration; The optimized process conditions are leaching time of 2hours, leaching temperature of 70℃, liquid-solid ratio of 6∶1, hydrochloric acid concentration of 2.35mol/L, and DCEA concentration of 0.09mol/L. Under these conditions, the waste platinum catalyst is recovered and treated, with a total recovery rate of 99.64%.