China Nonferrous Metallurgy

In order to comprehensively recover valuable metals from zinc smelting fuel dust and electrolytic waste liquid, a synergistic treatment experiment of zinc smelting electrolytic waste liquid and oxygen pressure leaching zinc smelting fuel dust was researched, zinc and magnesium precipitation products were obtained through a process of leaching, neutralization of zinc precipitation with sodium carbonate, and neutralization of magnesium precipitation with sodium hydroxide, indium-rich slag and by-product lead silver slag were obtained through two-stage leaching, extraction-stripping and indium neutralization-precipitation，and the experimental conditions were optimized. The results show that the liquid-solid ratio is 4∶1, the leaching temperature is 80℃, and the leaching time is 75minutes. under these conditions, the zinc leaching rate can reach 78.69%, while the indium leaching rate is only 8.4%; the optimal endpoint pH range for zinc magnesium separation is 6.86 to 7.80; the endpoint pH value is 1.08, the liquid-solid ratio is 3∶1, the leaching temperature is 75℃, and the leaching time is 10h, which is the optimal process conditions for two-stage leaching,under these conditions, the leaching rate of indium can reach 86.84%, which can provide new ideas for open circuit impurity removal and comprehensive recovery of valuable metals in zinc smelting plants.