Abstract
While high strength coke is required for the high productivity of blast furnace, price of coking coal has been increasing. High accuracy of coke strength (drum index) estimation based on the degradation mechanism and on the physical propertyof coke is necessary to achieve cost reduction of raw coal by avoiding the excess coke strength.
In this paper, the behavior of fine coke generation during the drum test was investigated considering coke breakage mechanism. Change in fine generation rate, its Weibull analysis and size distribution of fines was examined. Coke fines after drum test was divided into following three classes;
(1) Under 0.5 mm fines generated by compressive breakage of coke matrix.
(2) 6 to 15 mm fines generated by volume breakage induced by cracks and defects in coke lump.
(3) 0.5 to 6 mm fines influenced by both compressive breakage and volume breakage.
Also, amount of these fines were related to the coke and coal properties. Amountof 0.5 mm under fine and Brinell hardness, which represents strength of coke matrix, had good correlation. On the other hand, volume breakage was influenced by the volatile matter content and fluidity of raw coal.
