We all know that high alumina bricks are divided into three grades according to the content of Al2O3: Grade I (Al2O3>75%); Grade II (Al2O3 is 60%~75%); Grade III (Al2O3 is 48%~60%). According to the mineral composition can be divided into: low mullite (including sillimanite) and mullite (Al2O3 is 48% ~ 71.8%), mullite – corundum and corundum – mullite (Al2O3 is 71.8%~95%), corundum (Al2O3 is 95%~1), etc. The 70 Alumina Fire Brick is belong to the Grade II high alumina bricks.
In general, Grade II high alumina bricks are based on aluminum content. However, the price of Grade II 70 Alumina Fire Brick depend not only on the amount of aluminum, but also on physical and chemical properties such as bulk density, porosity, and line change of refractory bricks. Because the bulk density of the Grade II high-alumina bricks produced by different high-aluminum brick manufacturers is also different, the bulk density of the Grade II high-aluminum bricks produced by some manufacturers is 2.4g/cm3, 2.6g/cm3, and the bulk density has different effects. The weight of the high aluminum brick, it also affects the use of thermal equipment.
With the increase of Al2O3 content in high alumina bricks, the amount of mullite and corundum components also increases, the glass phase decreases correspondingly, and the fire resistance and density of high alumina refractory bricks also increase. When the Al2O3 content in the high alumina brick is less than 71.8%, the high temperature stable crystal phase in the high alumina refractory brick is mullite and increases with the addition of Al2O3 content. For high alumina refractory bricks with Al2O3 content above 71.8%, the high temperature stable crystal phase is mullite and corundum. With the increase of 71.8% content, the amount of corundum increases, mullite decreases, and the high temperature performance of Grade II 70 Alumina Fire Brick is correspondingly improved.
High alumina bricks are made of bismuth bauxite with white mud and other additives. According to the different formulas, it can be divided into special high aluminum brick, first grade high aluminum brick, second grade high aluminum brick, third grade high aluminum brick, low creep high aluminum brick, anti-flaking high aluminum brick and so on. The high alumina brick has a refractoriness of about 1770 ° C and a load softening temperature of 1420 ° C to 1550 ° C. The chemical properties of high-aluminum bricks tend to be neutral, so acid-resistant and alkaline slag have good erosion, high strength, good wear resistance, excellent erosion resistance and thermal shock stability. At present, it is mainly used for masonry blast furnaces, hot blast stoves, reverberatory furnaces, tunnel kiln, non-ferrous smelting kiln, electric furnace top, steel drum, cement kiln, glass kiln regenerator lattice brick and chemical industry kiln.
Rongsheng refractory manufacturer 70 Alumina Fire Brick products have the advantages of low temperature creep, strong corrosion resistance and good thermal shock resistance. They are suitable for large and medium-sized cfb boilers. If you are in need of 70 Alumina Fire Brick, please contact us. We will give you back as soon as possible.
