The Choice of Refractory Brick Furnace Lining in Different Parts of Blast Furnace

The blast furnace is currently the main smelting equipment, which has the characteristics of simple public welfare and high production capacity. The refractory brick furnace lined in a blast furnace to occupy an important position. However, during the production process, due to the role of various functions, the inner lining of the fire-resistant brick of the furnace wall was gradually eroded. Therefore, to extend the service life of the high-temperature furnace, it is necessary to reasonably choose the refractory brick furnace. The selection method for the refractory bricks of each part is as follows:

1. The stove and throat are mainly impacted and worn by the furnace material. Generally, steel bricks or water-cooled steel bricks are used.

2. When using a thin-walled structure in modern large blast furnaces, chemical erosion, and abrasion resistance should be selected. Among them, high-density clay bricks are most suitable to replace bricks.

3. Its destruction mechanism is mainly the heat shake peeling, high-temperature gas erosion, the precipitation of alkaline metals, zinc, and carbon, and the chemical erosion of the initial residue. The brick lining should be used to resist the refractory material with heat shock, residual slag erosion, and anti-erosion. The practice has proved that no matter how good the refractory material is, it must be eroded. Only when the balance (about half of the original thickness) can stabilize. This time is about 3 years. Sintering aluminum carbon bricks with good performance (much cheaper) can also achieve this. Therefore, the 1000M3 and below blast furnaces can be aluminum-carbon bricks.

4. The main cause of stove-abdominal damage is the erosion of high-temperature gas and slag iron. The heat flow of this part is very high, and any refractory material cannot resist refractory materials for a long time. The use of refractory materials for this part is not long (1 to 2 months long, 2 to 3 weeks). Generally, refractory materials with high fire resistance, high load soften temperature, and high capacity, such as high aluminum bricks, aluminum carbon bricks, etc.

5. Furnace air outlet area. The area is the only oxide reaction area in the blast furnace, with a high temperature of 1900 to 2400 ° C. The thermal stress caused by high-temperature and high-temperature gas erosion, slag iron erosion, alkaline metal erosion, and circulating coke erosion can cause damage to bricks. The modern blast furnace uses a composite brick stove-tank air outlet area. The material is high aluminum, rigid jade, Mo Lai stone, brown corundum jade, silicon container, and silicon carbide, and can also be used for hot-pressing carbon blocks.

6. In areas where the blast furnace lining is severe, the degree of erosion has always been the basis for determining the service life of the first generation of blast furnaces. In the early days, because there was no cooling, most of the blast furnace bottoms used a single ceramic refractory material. Therefore, the main cause of damage is the floating bottom tiles caused by the masonry cracks and iron water infiltration caused by thermal stress, while the penetration and corrosion of the carbon bricks of the iron water, the chemical erosion of alkaline metals on carbon bricks, thermal stress on carbon brick to carbon bricks Destruction, CO2 and H2O oxidation of carbon bricks is still an important factor that threatens the life of the bottom and the use of the furnace cylinder.

The production conditions of each part of the blast furnace are different, so different regions need to choose different refractory materials to use correspondingly to avoid problems such as unnecessary trouble and fire resistance materials.