METHOD OF REPROCESSING ZINC- AND IRON OXIDE-CONTAINING RESIDUAL MATERIAL

摘要

This invention describes a method of reprocessing zinc- and iron oxide-containing residual material. Zinc- and iron oxide-containing dust and/or sludge is granulated with water, granules and carbonaceous material are fed to a circulating fluidized bed system, the gas-solids suspension circulated in the circulating fluidized bed system is fed to a second fluidized bed reactor, the solids discharged from the second fluidized bed reactor are recycled to the reactor of the circulating fluidized bed system, 50 to 75% by volume of the oxygen required to gasify the carbonaceous material are fed as fluidizing gas to the reactor of the circulating fluidized bed system and 25 to 50% by volume of said required oxygen are fed as a fluidizing gas and secondary gas to the second fluidized bed reactor, iron oxide-containing material is discharged from the reactor of the circulating fluidized bed system and zinc-containing material is discharged with the exhaust gas from the circulating fluidized bed system.