Modifying Optical Texture of the Coke from Miike Coal

Abstract

Modifying optical texture of the coke from Miike coal of powdered form, which gave, singly carbonized, an isotropic coke, was investigated by applying the variable carbonization conditions, a carbonization catalyst and co-carbonization with some hydrocarbons and pitches. A rapid tempetature-rise was favourable to develop fine mosaic texture in a rather limited area of the coke. Aluminum chloride was effective to carbonize carbonecious materials, the degree of anisotropic development in the produced coke being influenced by the amount of the catalyst. Pyrene showed little modification ability as a co-carbonizing partner, whereas hydropyrene was a powerful agent to produce fine to coarse mosaic texture according to mixing ratio of 0.5 or 2.0 (mole ratio), respectively, although the former compound was not carbonized singly. Acenaphthylene and decacyclene which gave, singly carbonized, flow texture were also effective, the latter agent being quite powerful probably because of its high coke yield. Co-carbonization of hydrocarbons assisted by aluminum chloride could be effective to develop better anisotropy from fine to flow texture according to the amount of aluminum chloride and the hydrocarbons. Co-carbonization activities of several residual oils were also examined. Some of them are quite powerful to develop the flow texture by the mixing ratio of 1 to 2. The development of anisotropic texture from the fusible coal is discussed from the viewpoint of carbonization mechanism where the mesophase formation is possibly influenced by the heating rate, the catalyst, and the co-carbonizing partners.