High Kinetic Processing of EAF dust and a new hydrometallurgical recycling scheme

The Simoloyer® (high kinetic horizontal rotary bail-mill) is used to break technical electric arc furnace (EAF) dust particles down to 1 μm in size which fastens and completes the solution of zinc ferrite and magnetite in strong HCl. The better soluble oxides of Zn, Pb and other metals can be leached with ambient 2n HCl with fewer contents of iron salts. A new separation scheme is developed and executed with a mixture of 200 g each of EAF dusts of five suppliers. After separation of lead, iron, and copper/cadmium fractions for further use, a 96.9 % recovery of the easily soluble zinc as carbonate and sulfide is obtained. This is ambient temperature hydrometallurgy with recovery of the cheap leaching agent HCl. The same separation scheme would be applicable after the complete leaching with constant boiling HCl that includes the zinc ferrite content. The new processes show promise for industrial application.