Research On Improving Dazhou Iron And Steel Group Of 5~# Blast Furnace's Coal Injection

Blast furnace coal injection is a technology that directly inject grinded coal from the blast furnace tuyere to inside during the the process of smelting.It is an important technical means to reduce production costs and improve economic benefits in the metallurgical industry of blast furnace.Dazhou iron and Steel Group has been continuously exploring and testing suitable coal types and reasonable proportions of coal blending,so as to improve the coal injection ratio,reduce the cost of coal injection and achieve greater economic benefits.Semi-coke and dry quenching coke ash as a low-cost solid fuel appropriate amount with blowing coal,can greatly reduce the production cost.This article according to research Dazhou iron and Steel Group existing blowing coal and Semi-coke's grindability,combustibility,explosibility,reactivity draws the following conclusion:(1)Semi-coke reached standard coal for blast furnace injection in Dazhou iron and Steel Group,can be mixed in Da-gang blast furnace,the ratio should be less than or equal to 20%.(2)The reactivity,combustibility and grindability of dry quenching coke ash are poor,but from the point of saving cost and utilizing waste resources,the proportions of 5%are reasonable.(3)The mixed coal experiment scheme(20%coal Semi-coke+45%Hengda coal+30%Ruisheng coal+5%dry quenching dust-ash)is not only has greater economy,but also has better blowing performance.(4)The best combustion efficiency can be achieved in the coal blending scheme of 20%lanzhou pulverized coal+45%Evergrande coal+30%ruishen bituminous coal+5%CDQ dust removal ash under the conditions of particle size composition of-200(60%),moisture content of 1%and oxygen-rich 2-3%.(5)In the process of industrial testing,the economic and technical indicators of5~#blast furnace has been improved greatly,the overall fuel ratio reduces 1.69kg/t,the coke ratio decreased 7.18 kg/t and the coal injection ratio increased 5.48 kg/t.