Practice of reasonable coal injection for blast furnaces in Ansteel

In order to reduce the cost of ironmaking through coal injection improvement,a series of measures to enhance the result of coal injection were taken,such as increasing the ratio of bituminous coal in blended pulverized coal,controlling pulverized coal size,decreasing coal ash content and adding combustion catalyst,etc.Moreover,blast furnace operations were also improved,including the application of quality burden and coke,rational burden distribution with central coke charge,proper opening peripheral gas flow to improve the pemeability of burden column,controlling hearth temperature and increasing top pressure.In the conditions of high blast temperature and oxygen enrichment,the replacement ratio of coal injection was kept in a higher level.As a result,both coke rate and fuel rate of the blast furnaces were reduced.