Abstract：In the attempt to reduce the proportion of high-quality coking coals (rich coal and coking coal) and increase the proportion of gas coal for low-expense coke-making, coke-making experiments using high-proportion gas coal were conducted in a 2 kg laboratory coke oven in term of raw materials including two types of gas coal, rich coal and coking coal, one kind of lean coal, and original pulverized coal modifier. The experimental results show that coke quality indexes worsened when the contents of high-quality coking coal and gas coal were lower than 50% and greater than 35%, respectively. The coke reactivity index (CRI) is more than 36%, and the coke strength after reaction index (CSR) is less than 50%, which cannot meet the requirements of medium and large blast furnaces. However, under the action of the modifier, when the high-quality coking coal was gradually replaced by gas coal in coke-making, the thermal strength indexes of the modified coke were significantly improved. Although the ratio of gas coal in coal blending was increased to 45% and the ratio of high-quality coking coal was reduced to 40%, the modified coke with CRI less than 30% and CSR more than 58% can still be produced. Combined SEM, XRD and Raman, the analysis results about the difference on the microscopic layer of coke show that adding high-proportion gas coal will increase the amount and size of void in coke and the content of amorphous carbon, and decrease the volume and density of microcrystal units, resulting in the increase of reactivity of coke and the decrease of coke strength after reaction. By adding the modifier, the modified coke′s properties dramatically improved and the distributions of microstructures and components of modified coke with high proportion of gas coal were closed to the level of coke produced with high proportion of high-quality coking coal. Eventually, industrial experiments proved the possibility of adding 45% gas coal to produce high-quality coke under the premise of using the modifier, which is a new method to save high-quality coking coal and reduce the cost of coal blending.
武强, 朱子宗, 王瑛栋, 孙灿, 樊锦涛. 配加大剂量气煤改质炼焦[J]. 钢铁, 2021, 56(11): 30-38.
WU Qiang, ZHU Zi-zong, WANG Ying-dong, SUN Can, FAN Jin-tao. Production of coke by modifying coal blending with high proportion of gas coal[J]. Iron and Steel, 2021, 56(11): 30-38.
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2021, Vol. 56 
