The use of bauxite in blast furnace is mainly reflected in the following aspects:

I. Blast furnace lining materials

Bauxite is one of the main raw materials for manufacturing refractory bricks for blast furnace lining. High alumina refractory bricks have high refractoriness (up to about 1780℃) and good corrosion resistance, and can withstand the corrosion of high temperature slag and gas in blast furnace. The Al₂O₃ content of high-alumina bricks is usually more than 48%, and its main mineral components include corundum and mullite, which give refractory bricks excellent high-temperature properties.

II. Repair of blast furnace taphole

High alumina castable is often used to repair the taphole of blast furnace. This castable takes bauxite as the main raw material, which has excellent high temperature performance and corrosion resistance, high strength after construction, high temperature resistance and slag resistance. High-alumina castable has good thermal shock resistance, and can withstand rapid temperature changes without cracking and peeling.

III. Application of hot blast stove

Bauxite is also used to make high alumina bricks for hot blast stoves. The Al₂O₃ content of this brick is not less than 48%, and it has good fire resistance and corrosion resistance, which can effectively improve the service life of the hot blast stove.

IV. Unformed refractories

Bauxite clinker can be processed into unshaped refractory materials, such as refractory castable and paint spraying. These materials have good construction performance and can meet the construction requirements of complex shapes and parts in blast furnace. High-alumina castable is widely used in the lining and taphole of blast furnace, which can resist the corrosion of high-temperature molten metal.

V. Slag treatment

Bauxite can effectively combine slag, promote its fluidity and separability, and make the tapping and slag tapping process of blast furnace smoother.

VI. Economy and durability

Although the initial investment of bauxite is high, its durability and long service life can effectively reduce the maintenance and replacement cost of blast furnace.

To sum up, the use of bauxite in blast furnace mainly includes the manufacture of high-alumina refractory bricks and high-alumina castables, as well as its application in furnace lining, taphole repair and hot blast stove. Its excellent high temperature resistance, corrosion resistance and thermal shock resistance make it an indispensable refractory for blast furnace.