The quality of high alumina bricks is mainly distinguished from appearance, physical and chemical indicators, sound, weight and other aspects. This is a problem that needs to be considered when purchasing high aluminum bricks.
1. Appearance
The surface of high alumina refractory bricks is smooth to the naked eye, the color is beige, the four sides are flat, there are no broken corners and cracks, and there are few black spots. The color will be different according to the content of alumina. The higher the alumina content, the whiter the color will be. The black spots on the surface of high-alumina bricks are mainly formed during the calcination of ferric oxide. If the black spots appear in a large area, it means that the ferric oxide content of the brick is too high, which indicates that there is a problem with its ratio, which will affect the service life of the brick.
2. Sound
When two bricks are hit, the sound of high-quality high alumina bricks is crisp and not dull.
3. Weight
According to the weight specification, the weight of the first-grade high alumina fire brick is about 4.4 kg, the weight of the second-grade high-alumina brick is about 4.0 kg, the weight of the third-grade high-alumina refractory brick is about 3.7 kg, and the weight of the special-grade high-alumina brick is about 4.8 kg. The fluctuation of 0.1-0.2 kg is within the normal error range. In addition to the above common weights, the weight of high-alumina bricks will also vary with the different alumina content of the bricks. When distinguishing between first-grade, second-grade, third-grade, and special-grade high-alumina refractory bricks, it is still necessary to look at the alumina content. Of course, there is definitely a difference in weight between them.
4. Physical and chemical indicators
The most effective indicator of the quality of high-alumina bricks is its physical and chemical indicators, such as the strength, volume density, reburning line change, load softening degree, etc. of refractory bricks. Generally speaking, there are some differences between the physical and chemical indicators of first-grade, second-grade, third-grade, and special-grade high-alumina bricks, and they are definitely used in different occasions during use.
The quality of high alumina bricks affects the service life of high-temperature kilns, so you must be careful when purchasing them, and use different high-alumina bricks in different parts, because the working temperatures of various parts in the high-temperature kiln are different, so when using them, you must also choose different types of high-alumina bricks according to the different temperatures, so as to ensure the long-term and stable use of the high-temperature kiln.
