Micromorphology and safety properties of meager coal and meager-lean coal for blast furnace injection

Four types of meager coal and meager-lean coal and one type of high-quality anthracite are selected based on the safety requirements of blast furnace coal injection. The analysis of the organic macerals and inorganic macerals, and the chemical composition of the selected coal samples indicate that the four types of meager coal and meager-lean coal have low volatilization, low ash content, and low sulfur. These qualities are suitable for blast furnace injection and high-quality anthracite. The grindability test was conducted on the four types of meager coal and meager-lean coal, and anthracite mixed coal samples. The results indicate that the mixture of meager coal and meager-lean coal is beneficial to improve the grindability of pulverized coal. The explosive test revealed that the selected coal samples were non-explosive or weak explosive coal samples. When the mixing ratio of meager coal and meager-lean coal was less than 40%, the mixed coal powder would not explode during the blowing process. The minimum ignition temperature test determined the minimum ignition temperatures of the four types of meager coal and meager-lean coal, and anthracite as 326, 313, 310, 315, and 393℃, respectively.