Which is the stable form of silica upto 1470°C ?

A. Quartz
B. Cristobalite
C. Tridymite
D. None of these

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...
Which is the most stable crystalline form of silica at room temperature ?
A. Quartz B. Cristobalite C. Tridymite D. None of these...
Which is the stable form of silica below 870°C ?
A. Tridymite B. Cristobalite C. Quartz D. None of these...
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....
Which form of silica has the highest specific gravity ?
A. Quartz B. Cristobalite C. Tridymite D. All have the same specific gravity...
An indication of degree of firing in silica brick is its____________________?
A. Specific gravity B. Fusion point C. RUL D. None of these...
Silica refractories are not used in _________________?
A. Coke oven walls B. Beehive coke ovens C. Dome and upper portion of B.F. stoves D. Open hearth furnace roof...
Porosity of silica bricks varies from ______________ percent?
A. 5 to 10 B. 20 to 30 C. 45 to 60 D. 60 to 75...
Silica bricks have low spalling resistance below 600°C, due to its________________?
A. Very high thermal conductivity B. High co-efficient of expansion upto this temperature C. High thermal diffusivity D. Low refractoriness...
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....