Recovery of Gold and Silver from Tin-Rich Slag

摘要

To extract gold and silver from a copper anode slime with about 15 tin in a plant using the traditional pyrometallurgy-electrorefining technique, the recovery is only 90. The rest of the gold and silver is lost in the slag which contains mainly SnO2, PbO, and Sb2O3In the present work, a process is developed to recover the gold and silver further. The slag is mixed with NaCl, NaOH and/or Na2CO3, and roasted at 400#xB0;C #x223C; 800#xB0;C to obtain calcine containing water soluble salts of tin and antimony. After leaching with water, the residue consisting of PbO, Au, and Ag is sent back to extract gold and silver with current techniques in the plant. Tin and antimony in the liquor are also recovered separately.