1.Product introduction
The blast furnace is made of steel plate for the shell, the shell lined with refractory bricks. The body of the blast furnace from top to bottom is divided into furnace throat, furnace body, furnace waist, furnace belly, furnace cylinder 5 parts. Due to the advantages of good technical and economic indicators, simple process, large production capacity, high labor productivity and low energy consumption, this method of iron production accounts for the majority of the world’s total iron production.
The main product of blast furnace smelting is pig iron, and by-product blast furnace slag and blast furnace gas.
2. Refractory materials for blast furnace
1. The furnace throat part, the temperature is 400~500℃, here can use dense clay bricks, high alumina bricks, clay castables/spray coating etc. for masonry.
2. The body part is the more important part of the blast furnace, which is used for heating, reducing and slagging of the furnace charge. The temperature of the middle part of the furnace body is 400~800℃, the middle and upper part of this part uses clay bricks, high alumina bricks, phosphate clay bricks, high alumina bricks. The lower part of the furnace body uses clay bricks, high alumina bricks, corundum bricks, silicon carbide bricks for masonry.
3. Furnace abdominal position, the furnace lining is seriously eroded by iron slag. Here the upper temperature up to 1400 ~ 1600 ℃, the lower 1600 ~ 1650 ℃. Here should be used to resist slag erosion strong, resistant to scouring and abrasion of refractory materials. Furnace belly bit can use low porosity clay brick, high alumina brick, graphite brick, silicon carbide brick, corundum brick, etc. for masonry.
4. The furnace cylinder is the bearing part of the molten iron and slag, the highest temperature in the wind mouth area in 1700 ~ 2000 ℃, the furnace bottom temperature in 1450 ~ 1500 ℃. Furnace cylinder air outlet area can use corundum mullite brick, brown corundum brick for masonry. The contact hot surface of slag iron uses corundum mullite bricks, brown corundum bricks, brown corundum prefabricated blocks. The bottom of the furnace uses graphite and semi-graphite carbon bricks for masonry.
In addition the blast furnace out of the iron ditch parts can use clay bricks, silicon carbide bricks, graphite bricks, electrofused corundum castables, silicon carbide castables. Low cement high alumina castables are used for the ditch cover, and low cement corundum castables are used for the slag skimmer part.