Abstract:A new process to extract valuable metals from bag dust was studied. Arsenic was removed by roasting with sodium carbonate and water-washing. Effects of dosage of sodium carbonate, roasting temperature and roasting time on arsenic removal were investigated. The results show that arsenic in washed slag is only 0.15% with removal rate of 99.85% and loss rate of zinc and copper is only 0.5% under the conditions including bag dust of 50 g, sodium carbonate dosage of 25 g, roasting at 600 ℃ for 2 h. Leaching rate of zinc and copper from water-washing residue is 98.53% and 97.65% respectively under the optimum conditions including concentration of sulfuric acid of 1.23 mol/L, leaching temperature of 90 ℃, and leaching time of 1.5 h. Zinc and copper can be separated by adding excess sodium hydroxide. Lead and tin in leaching slag can be received as Pb-Sn alloy by reduction smelting with carbon addition.