1. There are differences between special-grade high alumina bricks and ordinary high aluminum bricks in terms of performance, indicators and usage.
The main difference is the intrinsic quality. Special-grade bricks are made of special-grade bauxite raw materials. The AL2O3 content of special-grade raw materials is more than 85% and the density is 2.8g/cm. The AL2O3 of ordinary raw materials is 75% and the density is around 2.6. Therefore, the two raw materials There is a big difference in the density of the products produced.
2. There are differences in compressive strength and wear resistance.
The fire resistance of ordinary bricks is 1780℃. The refractoriness of special grade bricks is 1820℃, and the firing temperature is about 30℃ higher than that of ordinary bricks. The service life of special grade high alumina bricks is twice that of ordinary high aluminum bricks. The crystal phase of high alumina refractory bricks is mainly composed of mullite, glass phase and corundum phase. The higher the aluminum content, the greater the proportion of corundum phase. Therefore, there is also a big difference in compressive strength and wear resistance.
3. The difference between load softening temperature
There is also a difference in load softening temperature between special grade bricks and ordinary bricks. Since the firing temperature differs by about 30°C, the load softening temperature also differs by more than 30°C. Then there is the use temperature. The use temperature of ordinary high alumina bricks is divided into three different grades of high-alumina bricks: three, two and one. The use temperatures are between 1250-1450℃ respectively, while the use temperature of special high alumina refractory bricks is 1500. ℃.
4. Are they strong in slag resistance?
The high-temperature structural strength, thermal shock stability and slag resistance of special-grade bricks are also 1-2 times higher than ordinary high-alumina bricks. Ordinary high-alumina bricks do not have strong slag resistance, while special-grade bricks have strong slag resistance, and their fatigue resistance at high temperatures is particularly strong.
For example, anchor bricks are an example. High aluminum content and good strength are not conducive to use. Anchor bricks with an aluminum content of about 55% have good flexibility. If the aluminum content is too high, the strength will be too high, which will make the castable more likely to crack.
In short, whether it is a special high alumina brick or an ordinary brick, you must understand the performance of each grade to select different grades of high-alumina bricks to meet various temperatures and corrosion conditions.
