2013 Volume 53 Issue 9 Pages 1523-1528
For the purpose of reducing specific coke breeze consumption, we examined the influence which the morphology of coke breeze and pseudo-particles structure have on sintering quality. As a means to control the morphology of coke breeze in pseudo-particles, we delayed the timing of coke breeze addition in granulation process of sintering materials. As a result, when we added more coke breeze in the latter stage of granulation, we noticed that granulating property as well as permeability were improved. Also, much of coke breeze stayed on the surface layer of pseudo-particles or in free particle, which led to improved quality and burn through speed (abbreviated as BTS).
When we added the entire charge of coke breeze in the latter stage, combustion quality of coke breeze was improved. However, conduction and accumulation of heat turned down, which resulted in deteriorating yield due to the exhaust heat loss.
Therefore, we searched for a ratio of the second-stage addition favorable for improving yield by making a higher raw material bed.
With the second-stage addition at 50%, we were able to build a higher raw material bed through improvement in sinter quality and permeability, while maintaining good BTS. As a result, expanded area in the sintering bed with temperature at 1200°C or higher led to liquid phase growth, which finally enabled the reduction in coke breeze consumption without causing deterioration in both yield and shutter index.