High-alumina bricks have a wide range of applications, but in lime kilns, they are mainly used for masonry high-temperature zones and firing zones.
High alumina bricks use bauxite clinker as the main raw material, which is Al2O3>55%, multi-level particle ratio, supplemented by special additives, high pressure molding, high temperature firing, is a refractory product used for masonry blast furnace lining .
They are divided into four grades according to the content of Al2O3: super bricks have an Al2O3 content of more than 80%; first-grade bricks have an Al2O3 content of 75%-80%; second-gradebricks have an Al2O3 content of 65% -75%; the third-grade brick is Al2O3 content of 55%-60%;
1. Refractoriness
The refractoriness of high-alumina bricks is higher than that of clay bricks and semi-silica bricks, reaching 1750~1790℃, which belongs to advanced refractory materials.
2. Load softening temperature
Because of the high Al2O3 in high alumina products, less impurities and less fusible glass body, the softening temperature under load is higher than that of clay bricks, but because mullite crystals do not form a network structure, the softening temperature under load is still lower than that of silica bricks.
3. Slag resistance
There are more Al2O3 in high alumina bricks, which are close to neutral refractory materials, and can resist the erosion of acidic slag and alkaline slag.
High-alumina thermal insulation bricks are used for thermal insulation layers or layers generally used in industrial kilns, and are not in contact with slag and molten material. Lightweight mullite bricks have excellent performance and can be used for the thermal insulation layer of industrial kilns in metallurgy, petrochemical, building materials, ceramics and other industries, as well as for the working layer in contact with the flame, and the temperature should not be higher than 1450 ℃. Lightweight high-alumina bricks are generally used for thermal insulation layers and parts without strong high-temperature melt erosion and erosion. For example, the temperature should not be higher than 1350°C when in contact with the melt.
There are many specifications and sizes of lightweight high-alumina bricks, such as the common standard size T-3, wedge-shaped bricks, arch bricks, arc-shaped bricks, etc., as well as some special-shaped products. When making lightweight high-alumina bricks of different sizes The selection of pressing brick moulds is different, such as irregular special-shaped lightweight high-aluminum products, it is necessary to redesign the pressing brick moulds for reproduction.
