High alumina refractory materials are the most widely used material type in the refractory industry. High alumina belongs to the aluminum silicate series. Its high alumina refractory bricks, high alumina amorphous materials, etc. can be used in thermal kilns in downstream industries such as steel, cement, glass, and nonferrous metals. In our country, high-alumina refractory bricks are basically made from natural high-alumina bauxite clinker and partially bound clay.
Among high-alumina refractory bricks, two indicators are very important. This is also the most prominent advantage of high-alumina refractory bricks compared with clay refractory bricks. Even though we are most concerned about the refractory degree and High load softening temperature.
1. Refractory resistance
The refractory degree of high alumina refractory bricks fluctuates widely, generally between 1770 and 2000°C. It is mainly affected by the Al2O3 content and increases as the Al2O3 content in the product increases. At the same time, the refractoriness is also affected by the content and type of impurities, and is related to the mineral structure of the product.
2. Load softening temperature
The softening deformation temperature of high alumina refractory bricks under load is greater than 1400°C, and increases with the increase of Al2O3 content. For products with an Al2O3 content of less than 71.8%, the load softening temperature depends on the quantity ratio of mullite and liquid phase, and increases with the increase in the quantity of mullite. The quantity and nature of the liquid phase have a significant impact on the load softening point.
When the Al2O3 content is 71.8% to 90%, it is a mullite or corundum product. As the Al2O3 content increases, the glass phase volume basically remains unchanged. Although corundum increases, mullite decreases, so the softening temperature under load does not increase. Significantly. After the Al2O3 content exceeds 90%, as the Al2O3 content increases, the number of glass phases decreases and the load softening temperature increases significantly, rising from 1630°C at 90% Al2O3 to 1900°C at 100% Al2O3. The relationship between Al2O3 content and load softening temperature.
