Extraction Technology Of Valuable Metals From Tin Flue Dust By Hydrometallurgical Process

Based on hot tinning line in the process of tin plating, tin flue dust was used as the raw material treated with hydrochloric acid leaching-hydrolysis precipitation; tin was separated from impurities such as copper, zinc. In addition, the process of spraying flue dust was simulated.The fundamental generation mechanism analysis of tin phase, zinc phase and copper phase of tin flue dust was studied according to the composition of tin fule dust, soldering flux and hot tinning line in the process control conditions of tin plating. The ways of reducing occurrence rate of tin flue dust are decreasing the concentration of HC1, NH4Cl and zinc compounds.The optimization conditions on treatment of tin flue dust were studied. In the process of hydrochloric acid leaching, the optimum conditions are hydrochloric acid concentration of125g/L, leaching temperature of75℃, liquid-solid ratio of5:1, leaching time of100minute, the leaching rates of Sn, Zn and Cu are97.36%,99.03%and99.98%, separately. In the process of hydrolysis precipitation to obtain SnO2, the optimum conditions are pH of1.25, temperature of30℃,99.9%of Sn was precipited with Na2CO3in the leaching solution. In the whole processes, the direct the recovery of Sn is97.26%.Independent simulated spaying flue dust system was designed. Water is used as eluting agent. After spraying the flue dust, the residual flue dust can achieve discharge standards. The overall of figures, tables and inferences are21,15,55, respectively.