TECHNOLOGY FOR GRANULATING COKE BREEZE BY CENTRIFUGAL ROLLING TYPE PELLETIZER AND EFFECT OF GRANULATED COKE BREEZE ON SINTERING OPERATION

Coke breeze was granulated by a centrifugal rolling type pelletizer wh ich was operated at a froude number (Fr) that is more than 10(2) times that for the conventional drum mixer. The effects of the coke breeze granulated by this new technology on the sintering operation, the gran ulation of raw mix for sintering, and the quality of sinter were quant itatively studied through sintering pot test and plant test at Nagoya No. 2 Sintering Plant. As a result, the following findings were obtain ed: (1) In the coke breeze granulation rest, the centrifugal rolling t ype pelletizer could not only granulate fine coke breeze but also caus e ultra-fine coke particles to penetrate into coarser particles, while preventing the granulated particles from becoming excessively coarse. (2) In the sintering pot test and sintering plant test, it was clarif ied that granulated coke breeze became the nuclei of quasi-particles o f the raw mix for sintering acid then promoted the granulation of othe r raw materials in the iron ore sintering process. (3) It was confirme d that this new technology could decrease NOx emissions by reducing th e ratio of fine particles in coke breeze. NOx emissions could be furth er reduced by the addition of quick lime. It was also clarified that t he reducibility of sinter was improved.