Silica bricks mainly consists of quartz and tridymite, Fang Shiying and a small amount of residual glassy phase composed of acidic refractories.
Silica brick for an acid-proof material, has good corrosion resistance to acidic residues, refractoriness of up to 1640~1670℃, volume relatively stable long-term use at high temperatures. Mineral composed primarily of silica bricks to tridymite and cristobalite, and small amounts of quartz and glass. Tridymite, Fang Shiying and residual quartz crystal at low temperatures, large changes in size, poor thermal stability of silica brick in low temperatures. During use, 800 ℃ the following slow heating and cooling, in order to avoid cracks. So it would not be appropriate to 800 degrees centigrade furnaces for temperatures below provided it on. The nature and process of silica bricks with closely related to crystalline transformation of SiO2, therefore, specific gravity is an important quality indicator of silica brick. General requirements below 2.38, high quality silica brick under 2.35. The proportion of small, reflecting brick tridymite and cristobalite in quantity, residual quartz is very low, thus the residual linear expansion of small, less decline in strength.
The raw material for the manufacture of silica brick of silica. Silica SiO2 content of the raw material, the higher the higher the refractoriness. Most harmful impurities in Al2O3 and K2O, Na2O, they severely reduce refractoriness of refractory products. Silica bricks with silica SiO2 content is not less than 96% as raw material, join the mineralizer (such as iron scale, lime milk) and Binder (such as molasses, sulphite pulp wastewater), mixed practice, forming, drying and firing processes.
Application:
Mainly used for lianjiaolu of coking Chamber and Firebox walls, steel regenerator and sediment room with open hearth coke ovens, silicon glass melting furnaces, refractory brick and ceramic kiln furnace arch and other weight-bearing parts. Also used for hot air furnace and acid open hearth furnace high temperature bearing parts.
