2004 年 90 巻 9 号 p. 743-750
We have recently presented a new coal solvent extraction method that enhances the extraction yield dramatically. The method extracts coal using a flowing stream of a non-polar solvent such as tetralin under 10 MPa at 350°C. The extract yield reached 65 to 80% for bituminous coals at 350°C, and the extract was separated into about 25 to 40% of soluble fraction at room temperature (soluble) and about 40% of solid fraction which precipitated from the extract at room temperature (deposit). It was found that the soluble and the deposit were almost free from inorganic materials. In this paper we clarified by the thermomechanical analyses that the extracts had remarkable fusibility when heated. To utilize the characteristics of the extract, we investigated the possibility to produce metallurgical coke from slightly caking or non-caking coal by carbonizing it with the extract (5 to 1 mixing ratio). The carbonized material obtained by the co-carbonization was much harder than that prepared from coal itself even in the case of non-caking coal, indicating the possibility of producing metallurgical cokes from only slightly caking coals or non-caking coals. We also succeeded in preparing mesophase from the extract. This suggested the possibility of utilizing the extract as a feedstock of high performance carbon materials.