Method of Making Iron Ore Pellets with a Carbon Core by Disc Pelletizer

抄録

The pellet making method was studied for production of iron ore pellets with a carbon core. The pellets are to be fired in a sintering machine to produce sintered ores containing carbonaceous material. This new raw material for the blast furnace will have advantages such as high reducibility and low slag generation. In this study, pellet making tests were performed using laboratory and pilot scale disc pelletizers with 3 to 5 mm coke breeze, concentrated iron ores and additives in order to construct a method for producing pellets with a carbon core. Scaling-up of the method was considered with four discs with diameters of 0.6, 1.2, 2.0 and 3.5 m. As a result, it was found that there were two strategies for producing pellets with a carbon core at high yield: supplying a suitable level of water with a small droplet size, and spraying water in a specific area where the coke breeze flows on the surface of the contents in the disc. This study demonstrated that iron ore pellets with a carbon core can be obtained at a yield of more than 90% by using the disc pelletizer with the 3.5 m diameter. It was also estimated that a production capacity of 70 t/h can be expected with a 7.5 m diameter disc for commercial scale operation. This achievement of constructing a method for producing pellets with a carbon core was a breakthrough which overcame one of the technical hurdles for the development of sintered ores containing carbonaceous material.