Refractory Technology Questions

• Presence of MgO in alumino-silicate refractories __________ its refractoriness.
• RUL of refractories depends on the
• Which of these statement is correct?
• Which property of refractories is the most important for top section of the blast furnace?
• Which is not a basic refractory?
• Resistance to slag attack of a refractory
• Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900°C ) use, except
• With increase in the porosity, thermal spalling resistance of fireclay brick
• Magnesite bricks are used in those parts of furnaces, which are
• Spray test determines the __________ of refractories.
• silicon carbide refractories have very low
• Cold crushing strength of ordinary fireclay brick is about 950 kg/cm2 . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm2 .
• Which of the following is not a neutral refractory?
• Silica refractories
• With increase in the alumina content in firebricks, its fusion point (refractoriness)
• Which is not an alumino-silicate refractory?
• Which is required in an insulating refractory?
• __________ nozzles are used in continuous casting of steel,
• Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
• Which is the most stable crystalline form of silica at room temperature?