Insulating refractories should have_______________?

Related Mcqs:

1. Porosity is induced in insulating refractories by adding________________?

   A. Powdered naphthalene B. Ammonium chloride/sulphate C. Calcium phosphate D. All A., B. and C....

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

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

3. 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....

4. Hot face insulating linings of high purity alumina fused mullite are used, where_________________?

   A. Very high temperatures are involved B. Highly reducing conditions are involved C. Presence of iron or silica is harmful D. All A., B. and C....

5. Which is required in an insulating refractory ?

   A. High thermal conductivity B. Low porosity C. Both A. and B. D. Neither A. nor B....

6. Which is not a natural insulating material ?

   A. Diatomaceous earth/kieselgur B. Asbestos C. Vermiculite D. None of these...

7. Carbon refractories are exclusively used in the_________________?

   A. Hearth of blast furnace B. Walls of coke oven C. Regenerators of coke oven D. Side wall of soaking pits...

8. Machine moulding of dry mixture of refractories requires a pressure of the order of _____________ kg/cm2?

   A. 10 B. 100 C. 500 D. 1000...

9. 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....

10. Chemically, mullite refractories is____________________?

    A. 3Al2O3.2SiO2 B. Al2O3 C. ZrSO4 D. ThO2...