2014 Volume 54 Issue 11 Pages 2446-2453
Oil sand bitumen and hypercoal are examined as a caking additives to the mixture of strongly coking coal and non-slightly coking coal. Samples were coked, then their strength, crystallinity of the carbon structure, and an anisotropic microstructure were measured. Oil sand bitumen addition enhanced strength, but 15% addition caused a strength decline because of the formation of large pores and cracks. Hypercoal addition increased strength with increased its content. Correlation was observed between increased strength and the crystallinity of a carbon structure or the anisotropic microstructure. Results suggest that mutual melting occurred between a coal blend and a caking additive. Then the caking additive took a carbon structure with high crystallinity by coking, achieved a function as a binder material that connects coal-particle interfaces, and ultimately enhanced strength.