What is the performance of silica refractories developed today?
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Silica refractory material is SiO2 content of more than 65%, Al2O3 is less than 30% of an acidic refractory. Including silica brick, special silica brick, quartz glass and its products. Made of clay, kaolin or pyrophyllite with low Al2O3 content. Quartz variants are contained in the raw materials and products. The expansion caused during the sintering process can counteract the partial shrinkage. The slight expansion produced during use can improve the integrity of the masonry and reduce the infiltration of slag along the brick joints. At the same time can also form a layer of brick surface SiO2 content, viscosity of the glaze closed surface pores, to prevent the infiltration of slag to improve the slag resistance. Can be used for glass kilns, steel ladle and iron furnace and other thermal equipment.
Features
Silica products are acidic refractory materials, strong resistance to acidic slag, but strongly corroded by alkaline slag, easily destroyed by the inclusion of Al203, K2O, Na2O and other oxides, and good for CaO, FeO, Fe203 and other oxides Resistant. The deformation temperature of silica brick is high, fluctuating between 1640 ~ 1680 ℃, which is close to the melting point (1670 ℃, 1723 ℃) of tridymite and cristobalite. The residual expansion ensures the masonry body has good air tightness and structural strength.
The biggest drawback
Silicone refractory low thermal shock resistance, refractoriness is not high.
Application areas
Mainly used for coke oven, glass furnace, acid steelmaking furnace.
