In the blast furnace, high-alumina refractory bricks are mainly used in the following key positions to meet the needs of complex working conditions such as high temperature, chemical erosion and mechanical wear in different regions:

I. Middle and upper part of furnace body

High-alumina refractory bricks are mainly used in the middle and upper part of blast furnace body, and this area is greatly rubbed by hot air and burden, which requires refractory materials to have good wear resistance and spalling resistance. High alumina brick has high fire resistance (up to 1750℃), which can effectively resist high temperature and chemical erosion.

II. Furnace belly

The temperature in the belly of the furnace is high, and the air flow temperature can reach 1600℃~1650℃, and it is eroded by slag, alkali metal and material. Therefore, high-alumina refractory bricks are usually used in the furnace belly, and their good alkali resistance and slag resistance can effectively prolong the service life.

III. tuyere combined refractory brick

Tuyere area is one of the most serious parts of blast furnace in temperature and erosion. High alumina refractory bricks are widely used in tuyere composite bricks because of their excellent corrosion resistance and wear resistance. In addition, in order to further improve the performance, some blast furnaces will also use silicon carbide bricks or corundum bricks in the tuyere area.

IV. Furnace throat

The throat of the furnace mainly bears the direct impact and friction of the burden, and the airflow erosion is relatively light. Therefore, the furnace throat generally adopts high-density high-alumina refractory bricks or wear-resistant cast steel protective plates (furnace throat steel bricks). The wear resistance and impact resistance of high alumina brick can effectively protect the throat of the furnace.

V. Hot blast stove

The hot blast stove of blast furnace is the key equipment to improve the efficiency of blast furnace, and the working temperature is usually between 1200℃ and 1300℃. High alumina refractory bricks are widely used in the upper and top checker bricks of hot blast stoves because of their thermal shock resistance, volume stability, creep deformation resistance and high thermal conductivity.

VI. Other parts

High-alumina refractory bricks are also used in other high-temperature parts of blast furnace, such as furnace bottom and hearth, which require refractory materials with good corrosion resistance and high-temperature stability.

VII. Summary

The application of high-alumina refractory bricks in blast furnace is mainly concentrated in the middle and upper part of furnace body, furnace belly, tuyere combined brick, furnace throat and hot blast stove. Its high refractoriness, corrosion resistance, wear resistance and spalling resistance make it an ideal choice for blast furnace refractories, which can effectively prolong the service life of blast furnace and improve production efficiency.