Characterization Of Coking Coal Maceral And Its Influence On Coking Properties

To study the influence of maceral on the performance of coking coal, and quantitatively experess the decisive factors (such as Maceral and quality of colloid et al) of coking performance, the proximate and processing property analyses, such as Arnu-Audibert's dilatometer, Colloid layer index and caking index of different metamorphic degrees of bituminous coal were conducted. The average maxima reflectance (Remax) of vitrinite and coal maceral were measured by metallographic microscope. The simulating coking process of different metamorphic degrees of coals and the colloidal-forming process were observed by the heating stage, which visualized the coking process in different melting phase. The cold strengths and thermal properties of 8 kinds of coke were also tested by the laboratory coking test. At the same time, the optical textures of coke were measured. The correlation between the macerals of coking coals and the optical textures was investigated systematically.The results show that the metamorphic grade could be presented subtlely by the Remax distribution. The coking properties and Remax of coking coals has a certain correlation. The coke quality index has a close relationship to the Remax distribution range, maceral, the Ratio between Reactive Component and Inert Component. The optical microstructures of eight kinds of coking coals are different. A certain relationship between the optical structure of coke and its maceral exist. The vitrinites which its reflectance is less than 0.8 is changed into isotropic after coking, with the reflectance between 1.4-2.0 turned into fusain and fragment, flake and pyrolysis carbon. Fusain and fragment mainly transformed from inert ingredients such as fusinite. In the optical microstructure of coke, the more contents of coarse grain and anisotropic components of the coke have, the better quality and higher thermal strength of coke are.