The increasing demand for zinc and a range of zinc-related metals (for example: lead; indium; tin; cadmium; and copper) in the Russian Federation cannot be satisfied by the existing production plants due to the lack of raw materials. At the same time, ferrous and non-ferrous metallurgy and the chemical industry have accumulated hundreds of millions of tons of zinc wastes (falling into the hazard categories 2 to 4), the processing of which could not only make up the raw material base, but also improve the environmental situation. In the world, over 85% of ferrous dust is recycled using the Waelz process. The Waeltz process is used for distilling separation of elements under reducing conditions. In this study, a block diagram for production of the following elements from industrial wastes is proposed: zinc, cadmium and indium in form of massive metals; zinc and indium in the form of fine powders; and clinker as a raw material for cement production. The technical and scientific details of this new process have been patented in the Russian Federation and abroad. For the first time, the following operations have been implemented with the use of large-sized Waelz kilns: vapour-oxidized Waeltz treatment of polymetallic wastes; recycling of heat from gases and solid products with generation of process fumes; and implementation of alternative flux (dolomite) and alternative fuel (petroleum coke).
Keywords: Waelz process, industrial wastes, heat recycling, vapour-oxidized Waelz processing
Physical and Chemical Fundamentals and Technical Solutions for Recovery of Non-ferrous and Rare Metals from Industrial Wastes