Žáruvzdorné cihly s vysokým obsahem oxidu hlinitého

High alumina refractory bricks are a kind of alumina-silicate refractory material with a content of alumina oxide of more than 48%. It is calcined and formed by the raw material of bauxite or the material with a high content of AL2O3. High thermal stability, the refractoriness is more than 1770℃. Good slag resistance, used for the liner of masonry steel-making electric stoves, glass furnaces, and cement revolvers.

If the Al₂Ó₃ content of High alumina refractory brick is higher than 90%, it is called corundum brick. Due to different resources, the standards of different countries are not completely consistent. For example, in European countries, the lower limit of Al₂Ó₃ content for high alumina refractories is 42%. In China, Al₂Ó₃ content in high alumina brick is generally divided into three grades: Grade I – Al₂Ó₃ content > 75%; grade II – Al₂Ó₃ content is 60-75%; grade III – Al₂Ó₃ content is 48-60%.

High Alumina Refractory Brick Physical and Chemical Index

Položka		Properties
		RS-80	RS-75	RS-65	RS-55	RS-48
Al2O3(%)		80	≥75	≥65	≥55	≥48
Žáruvzdornost(°C )		≥1790	≥1790	≥1790	≥1770	≥1750
Bulk density(g/cm3)		2.65	2.5	2.45	2.4	2.3
Softening temperature under load(°C )		1530	≥1520	≥1500	≥1470	≥1420
Reheating Linear changes Rate (%)	1500°CX2H	0.1	0.1	0.1	0.1	0.1
	1450°CX2H	-0.4	-0.4	-0.4	-0.4	-0.4
Apparent porosity (%)		22	≤23	≤23	≤22	≤22
Cold crushing strength (Mpa)		55	≥50	≥ 45	≥ 40	≥35

Advantages of high alumina bricks

1. Strong high-temperature resistance: The main component of high alumina bricks is alumina, so they have extremely high-temperature resistance and can usually withstand temperatures above 1500 degrees Celsius.
2. Dobrá odolnost proti korozi: High alumina bricks have strong resistance to chemical corrosion such as acid and alkali, so they are often used in environments in contact with corrosive media, such as the metallurgical industry, glass industry, atd.
3. Strong thermal shock resistance: Due to its unique composition and structure, high alumina bricks have good thermal shock resistance and can withstand rapid changes in temperature.
4. Low thermal conductivity: Compared with other refractory materials, high alumina bricks have low thermal conductivity, which makes them advantageous in some special industrial applications, such as thermal insulation layers inside high-temperature kilns.
5. Vysoká pevnost: High alumina bricks have high compressive strength and can withstand large mechanical stress.
6. Good volume stability: High alumina bricks are not prone to significant volume changes in high-temperature environments, which makes them widely used in industrial furnaces and other occasions.
7. Strong wear resistance: High alumina bricks have high surface hardness and have strong resistance to the friction and impact of some particulate materials.
8. Not easily contaminated: The surface of high alumina bricks is not easily contaminated, which makes them widely used in some industrial fields that require high product purity.

The difference between heavy high alumina bricks and lightweight high alumina bricks

1. Different production processes

2. Different volume densities

3. Different refractory temperatures

4. Different parts of use

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