Alkaline electro- hydrometallurgical process for Zn extraction from electric arc furnace dust

摘要

The process of the invention produces fine Zinc powder 33 of high purity from electric-arc furnace (EAF dust) dust 1 through the conventional lixiviation 3, cementation 10 and electro-deposition 26 stages, but including improvements, modifications and new operations which minimize water consumption, avoid generation of liquid wastes and also minimize both the generation of particulate and gaseous emissions, thus reducing environmental pollution to levels lower than those permitted by law. The fine particle size gof the Zinc powder is achieved by the use of a non conventional electrodeposition equipment, which eliminates the gaseous pollution. Other elements that contribute to the above are equipments and operational practices especially included to produce such effect, both, in transportation and lixiviation of the powder, and in the purification of zincate solution. Finally, an equipment and operation for washing and drying of Zinc powder is set forth.