Discussion and application of geological evaluation index of scarce coal injected into blast furnace

Coal injected into blast furnace can reduce the use of coke, is an important technical measure to reduce the production cost and improve the economic benefit of modern blast furnace. From the influential factors of quality of coal injected into blast furnace and on the basis of evaluation of quality of high-quality coal and scarce coal, the geological evaluation indexes and the grading parameters of scarce coal injected into blast furnace were discussed. The evaluation indexes of coal quality for blast furnace are divided into process index and economic index. Process index is the key index to determine whether coal can be used in blast furnace injection process. Economic index mainly affects the cost of blast furnace injection process. According to the characteristics of coal resources in China, anthracite, lean coal and meager-lean coal are the rare coal for blast furnace. Combined with the evaluation standard of "high quality coal" in coal geological exploration, it is proposed that ash, sulfur and phosphorus are the key indexes for geological evaluation of scarce coal for blast furnace, it is required that the ash mass fraction is less than 12.00%, the total sulfur mass fraction less than 1.00% and the phosphor mass fraction less than 0.03%. Using these indexes, the coal quality evaluation and resource division of typical mining areas of anthracite, lean coal and meager-lean coal in China are carried out. It is proposed that Yongcheng, Xishan, Yangquan, Lu'an, Erdaoling and Rujigou mining areas are the main distribution areas of scarce blast furnace coal, and the remaining resources of scarce blast furnace coal are 10.7 billion tons. It provides a basis for the rational exploitation and full utilization of the coal injected into blast furnace in China.