System and method for treating dust contained in extracted cement kiln combustion gas

Abstract

A treatment system to efficiently remove lead from dust contained in extracted cement kiln combustion gas while reducing facility and running costs. A treatment systemcomprising: a probefor extracting a part of combustion gas, while cooling it, from a kiln exhaust gas passage, which runs from an inlet end of a cement kiln to a bottom cyclone; a classifierfor separating coarse powder from dust contained in the combustion gas extracted by the probe; a wet dust collectorfor collecting dust from the extracted gas containing fine powder discharged from the classifier; and devicesfor feeding sulfurizing agent for sulfurizing lead contained in the kiln exhaust gas to the wet dust collector, and others. From the sulfurizing-agent feedersare preferably added the sulfurizing agents to a circulation liquid tankor a pumpfor circulating slurry. The slurry obtained by the wet dust collectoris separated into froth including lead and tail side slurry including gypsum by a flotation facility