A CLEAN ROUTE FOR RECYCLING TIN FROM THE SILVER SEPARATED RESIDUE

摘要

Silver separated residue (SSR) is rich in valuable tin. SSR is the residue that copper anodic mud after de-coppering, de-golding, and de-silvering processes, containing 50~60wt% SnO2, 10~20wt% PbSO4, 10~20wt% Sb2O5. According to its composition and crystal structure, we have developed a clean route for recycling tin from SSR. In this article, by using SSR as raw material, was recovered by the following clean processes, low temperature alkaline smelting method with NaOH, leaching, purification and concentration. This clean route is a closed-loop system by reusing the tail liquid. Moreover, Tin recovery rate can reach up to 95% in optimal the molar ratio of reactants, alkaline smelting temperature and time, concentration of Na2SnO3 solution. This study shows that this method has broad application prospects with great advantages, such as high recycling rate, environmental protection and economy.