Fundamentals of Chlorination of Lead Oxide Using Magnesium Chloride

Zinc-and lead-containing waste materials such as steel mill electric arc furnace dust are mainly processed by the Waelz process (volatilisation of zinc under reducing conditions). However, the removal of the element lead is not completely. It remains partly as water-soluble compounds in the Waelz slag in the order of magnitude of 3 mass-% which prevents the use in road construction. - Starting from the idea lead can be volatilised by using an additional chlorinating agent like magnesium chloride first principle investigations with pure model substances PbO and MgCl 2 were made. Thereby, the formation and volatilisation of PbCl 2 is assumed, because of its high vapor pressure. Besides the favorable thermodynamic conditions using MgCl 2 as chlorinating agent the reaction kinetics are of special interest. Volatilisation experiments in the temperature range of 800 °C to 1000 °C showed promising results.