Experimental Study on Improving Codmium Leaching Rate in Acid Leaching Treatment of Cadmium-Containing Soot
There is a small amount of cadmium in the materials in the lead smelting system,and most of the cadmium enters the soot after smelting in the smelting furnace,and the soot contains about 10%~20%cadmium.In this study,cadmium was leached by acid leaching,and the leach residue was re-turned to lead smelting system.Sponge cadmium was prepared by adding zinc powder to cadmium-rich solution,and zinc was recovered by electrodeposition system after replacement.The effects of sulfuric acid acidity,reaction temperature,reaction time,liquid-solid ratio and stirring speed on the leaching rate of cadmium and zinc were investigated.The results show that under the condition of sulfuric acid acidity of 50 g/L,the liquid-solid ratio of 5∶1,the temperature of 50 ℃,reaction time of 2.0 h,the stirring speed of 70 r/min,the cadmium leaching rate of cadmium-containing soot is 95.24%,cadmium leaching effect is good.Using the above optimum test conditions,the production practice shows that the leaching rate of cadmium and zinc in cadmium ash are stable above 95%,and the purity of cadmium in sponge is above 95%.