Al2O3-SiO2 series refractory materials
Al2O3-SiO2 series refractories mainly include silica refractory, aluminum silicate refractory and corundum refractory. Silica refractory contains at least 93% SiO2, it is main products of acidic refractory. Main products of silica refractory are fired silica bricks and bulk silica refractory.
Silica bricks are composed of tridymite, cristobalite, residual quartz and glass phase. Silica bricks belong to acidic refratoires, so they have strong resistance to acidic slag corrosion. Besides, silica bricks have good high temperature strength, won’t deform in long term application, RUL is similar to refractoriness, usually between 2620~1660℃. Silica bricks are mainly used to construct coke furnace, glass furnaces, ceramics kilns, refractory material kilns, hot blast furnace load supporting part and so on.
Aluminum silicate refractory main compositions are Al2O3 and SiO2. According to Al2O3 content, aluminum silicate refractories are classified into semi silica bricks and bulk material, fireclay bricks and bulk material, high alumina bricks and bulk material. Semi silica refractory is further classified into semi silica bricks and agalmatolite bricks. Semi silica bricks are suitable for glass kiln, steel ladle, heating furnace, soaking pit, copula and so on. Agalmatolite bricks are also called pyrophyllite bricks, and they are mainly used to line steel ladle inner linings.
Fireclay bricks mineral compositions are mullite, glass phase, cristobalite and quartz. Fireclay bricks are usually used in blast furnaces, hot blast furnaces, heating furnaces, power boilers, lime kilns , rotary kilns, glass furnace, ceramics kilns and refractory material kilns.
High alumina refractory mineral compositions are corundum, mullite and glass phase. High alumina bricks are mainly produced by sintering method, fused cast high alumina bricks, unfired high alumina bricks and monolithic high alumina refractory. High alumina bricks are widely used in steel industry, nonferrous metals industry and other industries.
Sillimanite bricks raw materials are sillimanite family minerals, in which Al2O3/SiO2 ratio is about 1. Sillimanite and andalusite have good volume stability during calcining, so they don’t need to be pre-sintered. Sillimanite bricks have homogeneous composition distribution and very good high temperature performance.
Mullite bricks are high alumina based refractory in which mullite is main mineral phase. Main raw materials of mullite bricks are high alumina bauxite clinker. High temperature performance of mullite bricks are decided by Al2O3 content and the distribution of mullite phase and glass phase.
Corundum bricks contains at least 90% of Al2O3. The main mineral phase of corundum bricks is corundum. Sintered Al2O3 or fused corundum are usually used as raw materials of corundum bricks.