Abstract:The main study object is the lead-zinc mixed concentrate obtained by the secondary beneficiation of tailings, aiming at the characteristics of high lead content and low iron content. The effects of oxygen pressure leaching of different zinc sulfide concentrates were compared, and the oxygen pressure leaching behavior of high lead and low iron zinc sulfide concentrates was analyzed. The results show that the low iron zinc concentrate needs to add 5 g/L iron to transfer oxygen in the second stage, the leaching rate of zinc is more than 99%, and the leaching rate of copper is about 90%. Most of the iron enter into the leachate with zinc in the form of divalent iron, and a small part enter into the residue. It exists in the form of pyrite with a small amount of iron oxide; Lead, silver and silicon are basically precipitated into the residue and enriched in the residue. The leaching residue can realize the recovery of valuable metals such as lead and silver, and the sulfur in the concentrate is mainly in the form of elemental sulfur. In the two-stage oxygen pressure countercurrent leaching, copper in the second stage leaching solution will precipitate into the first stage residue, which will accumulate in the system until equilibrium. The final residue contains 0.16% copper, and the first stage leaching solution contains 1.00 g/L copper, which has high recovery value.