Carbonization Behaviors of Slightly-and Non-caking Coals

Abstract

Morphological changes and caking properties during the carbonization of eight slightly-and non-caking coals (SNCC) were studied in their single and co-carbonization with a caking coal to evaluate them as a blending component. The coals were classified according to their petrographic analyses and coking properties into four categories (1) high rank (2) low rank (3) high inert content (4) weathered.
The morphological examination revealed that vitrinites of their reflectance ranging 0.58 to 2.04% Ro except for weathered ones exhibited softening whatsoever in the carbonization. The fluidity of blended coal was estimated from the amouts of vitrinite of this range and inert, allowing the estimation of coke strength.
It is noted that the carbonization above 200°c developed fissures in the most grains of non-fusible vitrinites in low ranking SNCC due to large amount of volatile matter, which reduced the strength of cokes obtained by the co-carbonization. Such vitrinites should be carefully distinguished from inerts of low volatile content at their blenging.