Properties and structural optimisation of pulverised coal for blast furnace injection.

The properties and structural optimisation of mixed pulverised coals were studied for blast furnace injection on the basis of known properties of the injecting coals: melting properties of coal ash, Hardgrove grindability index, ignition point, combustion rate, length of back-fire of explosion, and reactivity. Bituminous coal from Loudi was mixed with four types of anthracite (Yongcheng, Guiyang, Jinzhushan and Laiyang) and the properties of the mixed pulverised coals were investigated. The mixed coals were found to display lower ignition points and explosibility, together with improved combustibility and grindability. After adoption of mixed Loudi/Laiyang coal injection into a blast furnace operated by Jiangxi Xinyu Iron and Steel Co., China, the ignition point and explosibility of coals decreased while the combustion rate and grindability increased. Coal combustion and the permeability of the furnace were both improved by adopting mixed pulverised coal injection. The injecting coal ratio went up to more than 150 kg/t, and the economic and technical indices, as well as the productivity, were all improved.
The properties and structural optimisation of mixed pulverised coals were studied for blast furnace injection on the basis of known properties of the injecting coals: melting properties of coal ash, Hardgrove grindability index, ignition point, combustion rate, length of back-fire of explosion, and reactivity. Bituminous coal from Loudi was mixed with four types of anthracite (Yongcheng, Guiyang, Jinzhushan and Laiyang) and the properties of the mixed pulverised coals were investigated. The mixed coals were found to display lower ignition points and explosibility, together with improved combustibility and grindability. After adoption of mixed Loudi/Laiyang coal injection into a blast furnace operated by Jiangxi Xinyu Iron and Steel Co., China, the ignition point and explosibility of coals decreased while the combustion rate and grindability increased. Coal combustion and the permeability of the furnace were both improved by adopting mixed pulverised coal injection. The injecting coal ratio went up to more than 150 kg/t, and the economic and technical indices, as well as the productivity, were all improved.