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

The technology for granulating coke breeze by centrifugal rolling type pelletizer, which is operated at a Froude number (Fr) 10(2) times mor e than an ordinary drum mixer, and the effect of granulated coke breez e on sintering operation, granulation of raw mix and quality of sinter were quantitatively studied by use of sinter pot and NAGOYA No.2 sint er plant. The following results were obtained: (1) In the granulation test of coke breeze, the centrifugal rolling type pelletizer can not o nly granulate fine coke breeze but also penetrate ultra fine coke part icles into a coarser coke, while preventing the granulated particles f rom becoming excessively coarse. (2) In the pot test and the sinter pl ant test, it was clarified that granulated coke breeze becomes the nuc leus in quasi particles of raw mix and then promotes the granulation o f other raw materials in the sintering process of iron ores. In additi on, this new technology was confirmed to be able to decrease the NOx e mission by reducing the fine portion in coke breeze. The addition oi q uick lime reduces the NOx emissions further. It was also clarified tha t the reducibility of sinter was improved.