| 摘要 |
PROBLEM TO BE SOLVED: To raise the ratio of non- or slightly caking coal used in a chambertype coke oven without detriment to the product quality by compounding non- or slightly caking coal pulverized to a particle size smaller than that of caking coal. SOLUTION: Non- or slightly caking coal is compounded with caking coal to give coal for coke making. Preferably, at least 80% of non- or slightly caking coal has a particle size of 2 mm or lower; and at least 70 % of caking coal has a particle size of 3 mm or lower. The degradation in the coke strength due to non- or slightly caking coal is caused by cracks derived from insufficient adhesion between non- or slightly caking coal and caking coal and by cracks derived from too large air bubbles occurring in non- or slightly caking coal particles. By decreasing the particle size of non- or slightly caking coal, the occurrence of coarse air bubbles is prevented, removing the factor for decreasing coke strength; and the uniformity is increased, increasing the contact area between non- or slightly caking coal and caking coal to increase the adhesive strength. When the caking property of caking coal is enough, the contact area increases as the particle size of non- or slightly caking coal decreases, increasing the adhesive strength. Thus, the coke production cost is reduced and the range of selecting coal for coke making is widened.
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