Process for treating metallic dust, substantially oxidized waste, in particular galvanizing dust and / or steel mill smoke

摘要

A method of treating metallic dust (A), preferably oxidized waste, particularly galvanizing dust, and/or steelworks smoke (B), is characterized in that it comprises: a) at least one acid-leaching step (1) with hydrochloric acid or exhausted acid in conditions such as to bring the metals contained in the dust into solution; b) an oxidation step (4) carried out on the leaching solution to convert and precipitate the iron in the trivalent state; c) a step (9) for the cementation of the metallic impurities, carried out on the solution coming from step b) after the separation of the insoluble residue, the cementation step (9) being carried out by the addition of zinc powder and copper chloride and possibly antimony trioxide to bring about precipitation of the metals more noble than zinc in the electrochemical series; d) an electrolysis step (14) carried out on the electrolyte coming from the cementation step (9) to produce electrolytic zinc and gaseous chlorine. IMAGE