Methods for removing chloride ions to manufacture zinc from arc melting dust

Abstract

In this work, we review literature sources to identify an industrial-scale technology for manufacturing cathode zinc from technogenic chlorine-containing raw materials of a complex chemical composition, in particular, from arc melting dust. The conducted review of Russian and foreign publications was used to search for a method of purifying process solutions with a high concentration of chloride ions produced by hydrometallurgical processing of technogenic arc melting dusts. It was found that the existing purification methods are associated with substantial limitations, including strict requirements for the acidity of the treated solution, low efficiency of treatment, secondary contamination of the medium by released chloride ions, and the high cost of reagents or equipment. Approaches to reducing the chlorine content in the initial dust and dechlorination of process solutions based on principles of sedimentation, ion exchange, sorption, and oxidation are described. In addition, we analyzed information published on chlorine removal from process effluents and solutions of various nature. Industrially-implemented and recently-reported laboratory methods of solution dechlorination were compared in terms of their feasibility, economic efficiency, and extent of chloride ion removal. It was concluded that the disadvantages of existing methods for processing technogenic chlorine-containing raw materials of arc melting can be eliminated by developing large, stable, and cheap hydride technologies based on principles of extraction, ion exchange, and sedimentation.