Performance analysis of corundum brick

1. Fire resistance of corundum brick

It can be seen from the binary phase diagram of Al2O3 - Cr2O3 that Al2O3 and Cr2O3 can form a continuous solid solution without eutectic. Therefore, the addition of Cr2O3 to the high-purity corundum material, regardless of the amount of addition, not only does not reduce the fire resistance of the material, but also improves the fire resistance of the material. The refractory degree (>1790 °C) and the load softening temperature (>1700 °C) of chrome corundum bricks are superior to those of high purity corundum products.

 

2, the strength of corundum brick

The normal temperature compressive strength of high-purity corundum bricks is generally 70-100 MPa, and the normal-temperature compressive strength of high-performance chrome corundum bricks is generally >150 MPa, and its strength is significantly higher than that of corundum bricks. This is because the Al2O3-Cr2O3 solid solution is formed between the particles and the particles, between the particles and the fine powder, between the fine powder and the fine powder during the firing process, and the solid solution connects the particles and the fine powder like a bridge. Together, the strength of the material is greatly increased.

 

3. Thermal shock stability

According to the data, Cr2O3 is added to corundum. When the content of Cr2O3 is 10%-66%, the thermal shock stability of the material decreases with the increase of Cr2O3 content, that is, the chrome corundum brick with low Cr2O3 content has good thermal shock resistance. Chrome corundum brick with high Cr2O3 content.

 

4, resistance to slag erosion

Solubility of various refractory oxides in molten cinder: The solubility of Cr2O3 in coal gasifier slag (SiO2-CaO) and various glass melts is much less than that of other oxide materials. Therefore, Cr2O3 or Cr2O3-containing refractories have good corrosion resistance to steel slag, colored smelting slag, coal gasifier slag, oil gasification slag and various glass melts. The viscosity of the liquid phase formed by the reaction of the Cr2O3 melt or Cr2O3 with the slag is greater than that of the other low-melting materials, which effectively prevents the slag from penetrating into the interior of the brick body along the capillary pores, thereby avoiding structural spalling due to the formation of the metamorphic layer.

Used in the steel industry, the chrome corundum material has more than doubled the service life of the corundum material, such as ladle permeable bricks; in the non-ferrous smelting industry, the wear resistance and erosion resistance of corundum bricks are significantly better than other bricks; In the black industry, the use of chrome corundum bricks is twice as long as the corundum bricks used under the same conditions. The AK-type chrome corundum brick produced is used in the carbon black reaction furnace of the carbon black plant, and its service life has exceeded that of corundum brick. In the petrochemical industry, long-term high temperature (1350 ~ 1450 °C), high pressure (3.1 to 8.53 MPa), strong reducing atmosphere (CO + H2 + CH4) and gas flow rate in gasifiers of large and medium-sized fertilizer plants Large (about 10 m·s-1), the erosion and damage to the lining refractory material is more serious, so the lining refractory material is more demanding. High-performance corundum bricks have high density and high strength, and are more resistant to airflow than corundum bricks and have better wear resistance. The introduction of Cr2O3 in corundum bricks changes the intrinsic quality of the products, so that the erosion resistance and permeability resistance of the bricks are significantly improved. The use of corundum bricks on the gasifier can improve the service life of the gasifier.