Technology for producing pure lead-free zinc oxide from electric arc furnace (EAF) dust

An economical and environmentally advantageous two stages method with efficient recovery of pure lead-free zinc oxide from electric arc furnace dust in parallel with clinker containing iron and carbon production for easy return to the iron smelting furnace was described. At the first stage, the electric arc furnace dust was mixed with a mixture of chloride salts and sintered at various temperatures to lead removing. In the second stage, the clinker after the first sintering stage was mixed with carbonaceous agent and sintered again to obtain pure lead-free zinc oxide. The clinker after the second sintering stage, containing iron and carbon, can be sent to the main iron production. Laboratory-scale measurements with electric arc furnace dust from one of the Kazakhstan metallurgical ferrous plants show that process allows receive lead-free zinc oxide with the total impurity content is 0.06–0.07 mass%, and the lead content is 0.001 mass%. Based on the laboratory studies carried out, a technological scheme for the two-stage processing of electric arc dust was developed to produce marketable products. The environmental benefit of the method is to reduce emissions of harmful substances into the environment associated with the recycling of electric arc furnace dust. In addition, the process allows to recycle production waste and reduce the consumption of natural resources.