Si percentage in silica refractories used in the walls of coke oven is about______________________?

Related Mcqs:

1. 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....

2. With increase in the density of silica refractories, its_______________?

   A. Resistance to slag attack increases B. Spalling resistance reduces C. Both A. and B. D. Neither A. nor B....

3. 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...

4. Faster rate of drying of moulded refractories results in high _____________ of refractories?

   A. Green strength B. Voids C. Shrinkage D. Both B. and C....

5. 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....

6. An indication of degree of firing in silica brick is its____________________?

   A. Specific gravity B. Fusion point C. RUL D. None of these...

7. Porosity of silica bricks varies from ______________ percent?

   A. 5 to 10 B. 20 to 30 C. 45 to 60 D. 60 to 75...

8. 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...

9. 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...

10. Which form of silica has the highest specific gravity ?

    A. Quartz B. Cristobalite C. Tridymite D. All have the same specific gravity...