METHOD FOR WORKING UP ZINC-AND LEAD-BEARING STEEL PLANT RESIDUES

摘要

Zinc- and lead-containing residues from metallurgical plants are reprocessed by heat treatment in a circulating fluidized bed system. Most of the heat demand is met by the combustion of solid carbon in the fluidized bed reactor of the circulating fluidized bed system. A reducing fluidizing gas, substantially free of oxygen, is fed to the bottom of the fluidized bed reactor. 5-30% of the solid carbon content in the fluidized bed in the fluidized bed reactor bottom is adjusted, which is fed into its upper part with an oxygen-containing gas, and CO ₂ is formed at a rate such that zinc metal is not reoxidized. . All solids are subsequently released and removed from the recycled suspension in the recycle cyclone. The gas is cooled to a temperature where the zinc metal is oxidized to ZnO. Dusty zinc and lead compounds are removed from the gas.