Method and plant for manufacturing cement clinker

Abstract

Described is a method for manufacturing cement clinker by which method cement raw meal is preheated and burned in a plant comprising a cyclone preheater () and a kiln (). The method is peculiar in that that at least a portion of the raw meal is extracted from the cyclone preheater (), that this raw meal is introduced into a separate unit () in which it is given a retention time under oxidating conditions provided by means of a gas stream for forming SO2 and for expelling organic carbon, that the formed SO2 and the expelled organic carbon are subsequently discharged from the separate unit () entrained in the gas stream for further treatment in a subsequent process stage, and that the raw meal is reintroduced into the cyclone preheater (). Hereby is obtained an effective reduction of the VOC, CO as well as the SO2 emission without necessitating utilization of additional energy for heating. By giving the extracted and partially preheated raw meal a retention time under oxidating conditions separate from the cyclone preheater it is obtained that sulphide will oxidate into SO2 and that organic carbon is expelled from the raw meal, so that the thus formed SO2 and the thus expelled organic carbon can be entrained in a separate, relatively small gas stream and subjected to subsequent treatment in the optimum manner.