Advantage of Pulverized Coal
Replacing increasingly scarce and expensive metallurgical coke with low-cost coal reduces the proportion of coke used, which greatly reduces the cost of blast furnace ironmaking. Blast furnace coal injection can also be used as a means to adjust the condition of the blast furnace, improve the working state of the furnace body and make the blast furnace stable operation. At the same time, the injection of pulverized coal will reduce the combustion temperature before the tuyere, and the main reasons for the reduction of the combustion temperature are: after the blast furnace pulverized coal powder is injected, the amount of gas increases, and the heating of the gas requires heat; the heat introduced by the injected pulverized coal is low, and coke enters In the tuyere area, it has been fully heated to 1450-1500°C, and the temperature of the pulverized coal injection does not exceed 100°C; the decomposition of the hydrocarbons in the pulverized coal needs to absorb heat, which has created a blast furnace to increase the gentle oxygen-rich blast condition. The content of hydrogen in injected coal powder is more than that of coke. Hydrogen can improve the reducing ability and penetration diffusion ability of coal gas, which is beneficial to the reduction of ore and the improvement of blast furnace operation index. The injection of pulverized coal replaced part of the coke, which not only eased the tight supply and demand of coking coal, but also reduced the investment and construction of coking facilities, and reduced the environmental pollution caused by coking production.
Blast furnace coal injection has become the core development trend for the optimization of the process structure of the ironmaking system and the change in energy structure. Its development has strengthened the competitiveness of the blast furnace ironmaking process and the new non-blast furnace ironmaking process, eased the pressure on ironmaking production from resources, investment, cost, energy, environment, transportation and other aspects, laying the foundation for the continued development of coal injection basis.