How do I lay the refractory brick of a furnace's working lining

Refractory brick lining plays a very important role in blast furnace, but in the production process, the refractory brick lining of furnace wall is gradually eroded by various effects. To prolong the service life of blast furnace, it is necessary to choose and buy refractory brick lining reasonably.

How to make a reasonable choice of refractory brick lining? There are the following references

1、 Furnace throat: bear the impact and wear of human furnace charge. Generally, steel brick or water-cooled steel brick is selected

2、 Upper part of furnace body: the alkali metal and zinc vapor in this part are seriously eroded, coupled with the scouring and wear of falling charge and rising gas flow, dense clay brick with good chemical erosion resistance and wear resistance, three-stage high alumina brick or phosphoric acid impregnated clay brick, that is, phosphorus impregnated clay brick, shall be selected.

3、 Middle and lower part of furnace body and waist: refractory materials resistant to thermal shock, initial slag erosion and erosion shall be selected for the chemical erosion and brick lining of this part. Silicon carbide bricks with good performance shall be selected for large blast furnaces at home and abroad, so as to make the service life reach more than 8 years. However, aluminum carbon bricks can also be used for blast furnaces below 1000m3. Aluminum carbon brick is cheap, which will reduce the cost accordingly.

4、 Bosh: the bosh is scoured by high-temperature gas and slag iron, with high heat flow intensity. Generally, high alumina bricks and aluminum carbon bricks with high fire resistance, high load softening temperature and high bulk density are selected.

5、 Hearth tuyere: this part is the area of oxidation reaction, with a temperature of 1900-2400 ℃. The brick lining is subjected to the thermal stress caused by high temperature, as well as the erosion of high-temperature gas, slag iron erosion, alkali metal erosion and circulating coke. The modern blast furnace uses combined bricks to build the hearth tuyere, which is made of high alumina bricks, corundum mullite bricks, silicon carbide bricks combined with brown corundum and silicon nitride, and also uses hot pressed carbon blocks.

6、 Hearth lower part and bottom: This is the place where the lining of the whole blast furnace is seriously eroded, and its erosion degree determines the service life of the blast furnace. Large blast furnaces will use ceramic cups, staggered biting, etc. they also use high-quality brown corundum bricks, gray corundum bricks, carbon microporous bricks and hot pressed bricks. However, the penetration and dissolution of molten iron on carbon bricks, the chemical erosion of alkali metals on carbon bricks, and the damage of thermal stress on carbon bricks are still important factors threatening the service life of the hearth and bottom.

In short, the production conditions of each part of the blast furnace are different. Therefore, different refractory bricks are selected for different parts to use accordingly, so as to avoid unnecessary trouble caused by the failure of refractory brick lining to meet the requirements.