Treating sludge esp. from blast furnace gas scrubbers - in rotary drum furnace to remove zinc and lead and produce partially reduced iron sinter

摘要

Sludges, from scrubbing of gases from steelworks or esp. blast furnaces, are treated by (a) decanting; (b) mixing with carbon granules while still in a fluid state; and (c) introducing the mixt., still contg. 35-55% water into a drum furnace where it is driled in a counter flow of gas and sintered at 900-1300 degrees C, while Pb and Zn are evaporated and iron oxide are partially reduced. After removal from the furnace and cooling, the product is used as a charge material for iron prodn. The material can be recycled directly to the blast furnace or the sintering machine.