A. Silicon carbide
B. Silicon nitride
C. Crystalline magnesia
D. Zirconium sulphate
Related Mcqs:
- 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 ?
A. Cost
B. Electrical conductivity
C. Thermal conductivity
D. Fusion point - Which is the stable form of silica between 1470°C and the melting point 1713°C ?
A. Cristobalite
B. Tridymite
C. Quartz
D. None of these - The highest melting pure oxide (m.p. > 3000°C)is___________________?
A. Thoria
B. Alumina
C. Beryllia
D. Zirconia - Highest melting (m.p = 3070°C) oxide refractory is__________________?
A. Alumina
B. Thoria
C. Zirconia
D. Magnesia - Chrome magnesite is not used in the ____________________?
A. Inner lining of L.D. converter
B. Aluminium melting furnaces
C. Wear out lining of steel melting furnaces
D. All A., and B. and C. - Firing of refractory brick is done to __________________?
A. Dehydrate the dried refractory
B. Develop stable mineral forms in them
C. Form ceramic bonds necessary for development of high crushing strength in the finished
product
D. All A., B. and C. - Firing temperature is minimum (1250-1400 °C) for _______________ bricks?
A. Fireclay
B. Direct bonded basic
C. Silica
D. Magnesite - Faster rate of drying of moulded refractories results in high _____________ of refractories?
A. Green strength
B. Voids
C. Shrinkage
D. Both B. and C. - Which of the following bricks should not be used, if the furnace is to be used intermittently ?
A. Firebricks
B. Silica bricks
C. Silicon carbide bricks
D. Sillimanite - Spray test determines the _____________ of refractories?
A. Resistance to slag penetration
B. Resistance to CO attack
C. RUL
D. Permanent linear change
