China Nonferrous Metallurgy

In order to reduce the unit consumption of zinc powder in the purification process and improve the quality of electrowinning feed, Yunxi Wenshan Zinc Indium Smelting Co. Ltd. conducted a test on Co removal from the primary purified solution by using antimony trioxide method, and analyzed the test results. In the test, better process parameters obtained are: agitation speed of 400r/min, temperature of 85~90℃, Sb-Co ratio of 0.2~0.25, zinc powder of 2.5~3.0g/L, pH value of 4.5 and reaction lasting 2~2.5h. Under such conditions, the Co content in the solution can be reduced to below 0.4mg/L and the quality of electrowinning feed is improved, creating a good condition for the downstream process. Meanwhile, the good process control in the secondary purification has guaranteed a lower unit consumption of zinc powder and played a positive guiding role in stabilizing production, reducing cost and increasing efficiency.