A. Very high thermal conductivity
B. High co-efficient of expansion upto this temperature
C. High thermal diffusivity
D. Low refractoriness
Related Mcqs:
- Semi-silica bricks compared to silica bricks have_______________?
A. Less fusion point
B. Better spalling resistance
C. Both A. and B.
D. Neither A. not B. - With increase in the porosity, thermal spalling resistance of fireclay brick___________________?
A. Increases
B. Decreases
C. Remain same
D. May increase or decrease - Spalling resistance of a refractory cannot be increased by ____________________?
A. Increasing its porosity
B. Using a coarser grog during its manufacture
C. Decreasing its thermal co-efficient of expansion
D. Making it denser - In panel test for spalling resistance, the average face temperature of panel assembly is maintained at ______________ °C for 24 hours?
A. 700
B. 1000
C. 1600
D. 2000 - Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material ?
A. Aluminium phosphate
B. Water
C. Lime
D. Plaster of Paris - Porosity of silica bricks varies from ______________ percent?
A. 5 to 10
B. 20 to 30
C. 45 to 60
D. 60 to 75 - Use of higher percentage of lime for bonding silica bricks, reduces their__________________?
A. Strength
B. Abrasion resistance
C. Both A. & B.
D. Neither A. nor B. - The maximum linear expansion of silica bricks during firing is about ______________ percent?
A. 0.5
B. 1
C. 2
D. 3.5 - Silica bricks are never used for lining the____________________?
A. Beehive coke ovens
B. By-product coke ovens
C. Dome of blast furnace stoves
D. Roof of open hearth furnace - Which is the stable form of silica below 870°C ?
A. Tridymite
B. Cristobalite
C. Quartz
D. None of these
