High Alumina Bricks are a kind of refractory bricks for sale in RS Company, whose main component is Al2O3. High Alumina Bricks have lots of different properties due to its different uses, such as high strength, high refractoriness, acid and washing erosion resistance, good thermal stability and so on. High Alumina Brick is mainly used for masonry blast furnace, hot-air furnace, electric furnace, reverberatory furnace, etc. As a leading manufacturer, RS refractory Manufacturer adheres to the idea “product quality as life, enterprise honesty as the foundation“. After more than ten years of development, has been winning the trust and praise from customers at home and abroad. Therefore, RS refractory materials are with high quality at low price. Welcome to contact us for free quotation/price list.
High alumina brick usually refers to the aluminum silicate refractory material Whose Al2O3 content is above 48%. As a neutral refractory brick with an alumina content above 48%, High-alumina bricks are shaped and calcined from bauxite or other high-alumina raw materials.
Characteristics of High Alumina Brick
The high-soft, low-creep high-alumina bricks are high-grade refractory materials made of fused corundum,fused mullite and the super bauxite. High Alumina Bricks possess the following characteristics:
Good thermal stability
High refractoriness, more than 1770℃
Good thermal shock resistance and Good thermal conductivity
High temperature creep is small
Wear and spalling resistance, and chemical resistance
High Alumina Bricks are mainly used for masonry blast furnace, hot-air furnace, electric furnace, reverberatory furnace, blast furnace, rotary kiln lining. In addition, high-alumina bricks are widely used as refrigerated lattice bricks for plug heads for gating systems, nozzle bricks, open hearth furnaces.
According to different Al2O3 contents, High Alumina Bricks can be classified into Three Grades in China.
Grade I : High Alumina Brick has Al2O3 content above 75%.
Grade II : High Alumina Brick has Al2O3 content about 60~75%.
Grade III : High Alumina Brick has Al2O3 content about 48~60%.
In addition, High Alumina Bricks can also be classified according to its mineral composition, generally divided into the following five categories:Low mullite（including Sillimanite）, mullite（48%～71.8%）, mullite-corundum, corundum-mullite（71.8%～95%） and corundum（95%～100%）.
High Alumina Bricks Composition
High alumina brick is made of high-quality bauxite clicker as starting material by sgaping at high pressure and sintering at high temperature. The following are the high alumina bricks content:
Alumina: above 48%
Clinker: up to 90-95%
Raw materials:bauxite, corundum, and clay
Production technology: crushing, mixing, molding, drying, firing, inspecting, and packing.
High alumina brick has high thermal stability, good slag-resistance, and their refractoriness is above 1770°C.
Besides, High Alumina Brick has the advantages of high temperature creep, strong erosion resistance, good thermal shock resistance, etc. This kind of refractory bricks are suitable for large and medium-sized hot blast stoves. Because of the higher Al2O3 proportion, the chemical properties of high alumina bricks are close to neutral refractory, which is resistant to acid and alkaline slag erosion.
High Alumina Bricks Manufacturing Process
The production process of high-alumina bricks is similar to that of multi-clinker clay bricks. The difference is that the proportion of clinker in the ingredients is relatively high, nearly up to 90~95%. The clinker must be sorted and sieved to remove iron before crushing and the sintering temperature is more higher. For example, Grade I & II High Alumina Bricks can be fired in the high temperature of 1500~1600℃ in the tunnel kiln. In production, the method of forming a mixture of smut and mud particles is usually adopted to improve the grain structure characteristics of the high-alumina bricks, thereby improving their thermal shock resistance.
When it comes to high alimina bricks, we always think of fireclay bricks. But high alumina brick usually are better than fireclay. Why? Maybe the next chart can tell you something.
Comparision Between High Alumina Index and Fireclay Brick Index
Items/Brands
High aluminum brick
Clay brick
RS-GL-65
RS-GL-55
RS-GL-48
RS-ZGN-42
RS-GN-42
AL2O3, % ≥
65
55
48
42
42
Fe2O3, % ≤
2
2
2
1.6
1.7
Apparent Porosity(%) ≤
19
19
18
15
16
Cold Crushing Strength ≥
58.8
58.8
49
58.8
49
Bulk Density(g/cm*) ≥
2.6
2.5
2.4
2.3
2.2
Efractoriness ≥
1790
1770
1750
1750
1750
Permanent Linear Change
0~-0.2
0~-0.2
0~-0.2
0~-0.2
0~-0.3
1500℃*2h
1450℃*2h
0.2MPa Refractoriness Under Load ≥
1500
1480
1450
1450
1430
The difference between high-alumina brick and fireclay brick is that the content of Al2O3 is different, and the AL2O3 of fireclay brick is between 30% and 48%, but the Al2O3 of high alumina brick is above 48%. The slag resistance of high alumina brick also increase with the increase of Al2O3 content. Compared with fire clay bricks, the high alumina bricks have good performance and long service life. The price of high-alumina bricks is higher than that of fire clay bricks.
China is rich in high-alumina vanadium resources, which has excellent quality in texture. According to different resource conditions and product requirements, the following types of raw materials of high alumina bricks can be used:
High-alumina bauxite mainly composed of hydrous alumino-oxygen minerals
(one water aluminum, aluminum trihydrate, etc)
Sillimanite mineral (Kyanite, Andalusite, Sillimanite)
Synthetic raw materials
High Alumina Bricks Application
As neutral refractories, High-alumina bricks have strong resistance to acidic and alkaline slags, have high-temperature mechanical strength and high refractoriness, and are slightly inferior in resistance to quenching and hot-heating than clay bricks, and have a higher cost than clay bricks. High alumina bricks are mainly used for the furnace bottom of the soaking furnace, the lower furnace wall, the furnace wall of the continuous heating furnace, the ceiling, the bottom of the furnace and the burner brick.
Now Rongsheng have professional sales team, senior professional technicians and complete manufacturing and testing equipment with continuous innovation and development. Our products are popular in the whole country and have been exported to Vietnam, India, Korea, Russia, Pakistan, Iran,etc. Welcome to contact us for high quality bricks in RS at a low price!
