2023 Volume 63 Issue 9 Pages 1459-1466
Recently, the environment has indicated an increase in the price of coking coal. Thus, in order to produce high strength coke at a low production cost, the application of blending technology to various types of coal is required. Coal dilatation is an important factor in determining coke strength. It is well known that the dilation values of blended coal containing semi-soft coking coals does not match with the weighted average value of coking coal and semi-soft coking coal; it denotes a value lower than the weighted average value. Therefore, in this study, to develop and apply coal blending technology to various types of semi-soft coal, we investigated the inhibitory influence of kind and particle size of semi-soft coking coals on the dilatation of hard coking coal.
Subsequently, we observed that the inhibitory effect was stronger when the specific dilatation volume of the blended coal was low. This is because when the semi-soft coking coal was resolidified, the specific dilatation volume of the semi-soft coking coal or/and hard coking coal was minimal. Additionally, the inhibitory influence was further increased by the decrease in the grain size of the semi-soft coking coal. These results suggest that the inhibitory influence on the dilatation of hard coking coal is dominated by the pore structure of the semi-coke derived from the semi-soft coking coal.
