Influence of iron ore quality on blast furnace smelting

Influence of iron ore quality on blast furnace smelting

1) Influence of iron ore grade

Iron ore grade refers to the iron content of iron ore. high iron content of iron ore is conducive to reducing coke ratio of blast furnace and increasing production. Domestic experience parameters: 1% increase in grade, 2% decrease in coke ratio and 3% increase in output. This is due to the decrease of iron content in iron ore, the increase of gangue quantity, the increase of flux quantity and slag quantity, and the multiple of slag quantity increase is greater than that of iron content decrease. Therefore, the higher the iron ore grade is, the better the blast furnace smelting requires.

For limonite and siderite, the requirement of iron content can be reduced properly, because limonite and siderite decompose crystal water and volatilize CO2 under high temperature, and the iron grade is relatively improved.

2) The influence of gangue chemical composition

The chemical composition of gangue has a great influence on the smelting value of iron ore. because the gangue and coke ash of most ores are acidic, there is more Cao in the iron ore. The amount of limestone (quicklime powder) added during sintering can be less or not, which has a high smelting value and the iron content of ore can be reduced. In iron ore, SiO2 is lower, SiO2 is more, limestone (quicklime powder) consumption is large, sintering grade is reduced, and the ore grade into the furnace is also reduced, resulting in the increase of coke ratio and the decrease of output. In the same grade iron ore, if the content of SiO2 is different, its smelting value is also different.

When MgO in iron ore is high, the amount of dolomite powder added in sintering will be reduced. Appropriate amount of MgO can improve the fluidity, desulfurization capacity and stability of blast furnace slag. The high content of MgO in iron ore is of high smelting value.

To learn more about pellet powder, please contact pellet powder manufacturer!