【China Aluminum Industry Network】 1. Ordinary high-alumina brick The main mineral composition of the refractory brick is Yinglai stone, corundum and glass phase. As the content of Al2O3 in the product increases, the mullite and corundum increase, and the glass phase decreases accordingly. , The product's refractoriness and high temperature performance increase. Ordinary high-alumina bricks have a series of superior fire resistance than clay bricks. They are a kind of material with good application effect and widely used, and are widely used in various thermal kiln furnaces. Compared with clay bricks, it can effectively improve the service life of kilns.
2. Compared with common high-alumina bricks, the high-alkali soft high-alumina bricks are different from the ordinary high-alumina bricks in that they differ in the matrix part and the binder part: in addition to the addition of Sanshi concentrate, the matrix part is close to the chemical composition after burning. To the theoretical composition of the stone, reasonable introduction of high-aluminum materials, such as corundum powder, high-alumina corundum powder, etc.; selection of high-quality ball clay binders, depending on the variety of different clay composite binder, or mullite binding agent. Through the above method, the load softening temperature of the high alumina brick can be increased by about 50 to 70°C.
3. Low creep high alumina bricks improve the creep resistance of high alumina bricks by using so-called unbalanced reactions. That is, according to the use temperature of the kiln, three-stone mineral, activated alumina, etc. are added to the matrix to make the composition of the matrix close to or completely composed of mullite, because the mullitization of the matrix will increase the mullite content of the material. Reduce the glass phase, while the excellent mechanical and thermal properties of mullite are conducive to the improvement of the high temperature performance of the material. In order to completely complete the matrix, control of Al2O3/SiO2 is the key. Low creep high alumina bricks are widely used in hot blast furnaces, blast furnaces and other thermal kiln furnaces.
4. Phosphate-bonded high-alumina brick phosphate-bonded high-alumina brick is mainly composed of dense special-grade or first-grade high-alumina bauxite clinker. Phosphate solution or aluminum phosphate solution is used as a binding agent, after semi-dry-press molding Chemically bonded refractory bricks, which are heat-treated at 400-600°C. It belongs to non-fired bricks. In order to avoid large shrinkage of the products during use, it is generally required to introduce heating and expansive raw materials, such as blue stone and silica. Compared with ceramic fired high-alumina bricks, its anti-peeling performance is better, but its lower load softening temperature, poor corrosion resistance, so delays to add a small amount of fused alumina, mullite, etc. to strengthen Matrix. Phosphate bonded high-alumina bricks are widely used in cement kiln, electric furnace top and other furnace parts.
5. Micro-expanded high-alumina brick The brick is mainly made of high-alumina bauxite as the main stock material, adding three stone concentrates, and made according to the production process of high-alumina bricks. In order to make suitable expansion of high-alumina bricks during use, the key is to select three-stone concentrates and their grain sizes, and control the firing temperature so that the selected three-stone minerals will be partially molasses, and the remaining three-stone minerals, and the remaining three-stone minerals. Further mullitization (one or two mullitization) during use, with volume expansion. The three-stone mineral selected is preferably a composite material. Due to the different decomposition temperatures of Sanshi minerals, there are also differences in the expansion produced by mullite. Using this feature, high-alumina bricks have corresponding expansion effects due to different operating temperatures, and the extrusion of brick joints improves the overall compactness of the lining, thereby improving the resistance of the brick to slag penetration.
