Recycling process for electric arc furnace dust containing zinc ferrite

摘要

The present invention relates to a method of recovering high purity hydrochloric acid and metal zinc by treating an electric arc furnace (EAF) dust generated in an electric furnace steelmaking solution with a hydrochloric acid solution.;In the present invention, zinc is selectively leached while minimizing leaching of iron, and iron precipitates in the form of FeOOH and Fe ₂ O ₃ , and high temperature 37g / l-74g / l hydrochloric acid (HCl) and 104g / l -270g / l. Zinc chloride (ZnCl ₂ ) leaching solution is used. When hot leached, fresh dust is applied to remove the leached iron. This zinc chloride solution is purified using activated carbon and metal zinc, and then high purity metal zinc and hydrochloric acid are obtained in an electrodeposition cell equipped with a cation exchange membrane. Zinc can be obtained with a current efficiency of 90% or more by carrying out electrodeposition at 40 ° C. or lower in a solution having a zinc concentration of 50-130 g / l. In the range of anode current density of 300-1000 A / m ² and membrane current density of 750-2000 A / m ² , the loss of hydrochloric acid is less than 2% and the energy is less than 5.0 kWh / kg-Zn during electrodeposition. The effluent obtained after electrodeposition is a hydrochloric acid concentration of 1-2 N, which is suitable for leaching solids from neutral leaching at high temperatures.