Abstract:The recovery value of neutralized slag in lead-zinc smelting wastewater is high and the treatment difficulty is high. The wet treatment process is the mainstream trend in the future development. According to the characteristics of neutralized slag, a countercurrent acid leaching process was proposed to recover the valuable metals. The influence of different reaction factors on the leaching effect was investigated. The results showed that under the conditions of liquid-solid ratio 3:1, slag-acid ratio 1.67, initial sulfuric acid concentration of 200 g/L, mature sulfuric acid concentration of 98%, room temperature (self-heating leaching) and leaching time of 30 min, the leaching rates of zinc, manganese and germanium in neutralized slag were more than 95%, and the leaching rates of magnesium were more than 85%. The technology can transform calcium in the neutralized slag into gypsum slag product, arsenic into iron arsenate solid arsenic product, and obtain active zinc oxide and basic magnesium carbonate products that can be sold abroad. This technology can provide theoretical basis for green production of Chinese enterprises.