METHOD FOR PROCESSING ZINC AND LEAD-CONTAINING RESIDUES FROM THE STEEL INDUSTRY WITH REGARD TO METALLURGICAL PROCESSING

摘要

According to the instant invention fine and very fine granular zinc- and lead-containing oxidic byproducts are mixed with thermally inert additives and are hot briquetted with caking coal as a binder at a temperature of 490 DEG +/-40 DEG C. using sufficient carbon to reduce all of the metallic components in the byproducts. Then this mixture is briquetted and heated to more than 700 DEG C. and is maintained at this high temperature for a predetermined time to reduce, that is deoxidize, most of the oxidic components of the briquets, especially zinc, lead, and iron oxides. When the byproducts are not dry, which is standard with a wet scrubbing system for cleaning stack gases, the resultant slurry must be dried before it can be treated according to this invention. The carbon according to the invention is added as fine-granular caking coal in portions of at least 20% by weight. Preferably the portion is between 25% and 35% and up to 40%.