Study On Optimization Of Blast Furnace Coal Injection Structure Under Low Grade Raw Material Condition

Blast furnace coal injection has good economic and social benefit, which is the key technology that changing the energy structure for blast furnace, and an effective energy saving measures. The blast furnace takes coal instead of coke, it can ease the shortage of coking coal resources and reduce the cost of pig iron.In this paper, a steel 2500m3 blast furnace coal blending structure was the research object. Firstly, basted on the economic technology index of blast furnace, such as pulverized coal combustion rate, fuel ratio, cost of molten iron, theoretical combustion temperature, bosh gas volume and furnace condition, several aspects to determine the economic coal ratio of a steel plant 2500m3 blast furnace under the condition of low grade and high slag ratio; Secondly, from blast furnace spray blowing coal properties, analyzing of the composition and performance of bituminous coal, anthracite, The ratio of economy bituminous and anthracite for a steel plant 2500m3 blast furnace was searched and optimized. At the same time, for the 2500m3 blast furnace in a steel plant, management innovation, optimize the operation of the blast furnace were carried out, the economic and technical indicators of the blast furnace were then improved, the cost of iron was reduced, to guide significance to the actual production, and provide valuable experience for the same industry.The main conclusions are as follows:1. The economic coal ratio of 2500m3 blast furnace for A steel was 150-170kg/t-Fe.2. The coal-to-coke replacement ratios of coal blending ratio structure as "anthracite 70%+bituminous coal 30%" and "100% anthracite" were increased by 0.076 and 0.143 times than " anthracite 50%+bituminite 50%", coal to coke replacement ratio is high, the more conducive to lowering coke ratio in blast furnace;3.The coke ratios of coal blending ratio structure as "anthracite 70%+bituminous coal 30%" and " 100% anthracite" were decreased by 1.155kg/t 20.816kg/t than " anthracite 50%+ bituminite 50%"; and the fuel ratio were decreased by 13.087kg/t and 23.997kg/t.4. In some steels, under existing spray blowing coal purchasing conditions, without Sichuan quality coal, anthracite injection was the most economical.