Recovery of zinc from electric-are furnace dust by leaching with aqueous hydrochloric acid, plating of zinc and regeneration of electrolyte

Synopsis Hot hydrochloric acid solutions were used to extract zinc from electric-are furnace dusts containing zinc oxide and zinc ferrite and to minimize iron dissolution. Fresh electric-are furnace dust was used to remove iron from t he filtrate after hot acid leaching. The zinc chloride solutions, purified by activated carbon to remove organics and by metallic zinc powder to remov e cadmium, copper and lead, were electrolysed in electrowinning cells that had a cation-exchange membrane to produce high-purity zinc metal and regene rate hydrochloric acid. The spent electrolyte contained 1-2 M HCl and this was used to leach the residue in the hot acid leaching vessel.