‘Super refractories’ are made from pure____________________?

Related Mcqs:

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

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

2. Because of its very high refractoriness of the order of __________ °C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns ?

   A. 1800 B. 2200 C. 2400 D. 2700...

3. Porosity is induced in insulating refractories by adding________________?

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

4. Magnesite refractories are generally not used in the___________________?

   A. Electric furnace walls B. Steel melting furnace C. Open hearth furnace D. Burning zone of cement kilns...

5. Cold crushing strength of refractories depends upon its_________________?

   A. Composition B. Texture C. Firing temperature D. All A., B. and C....

6. 10 to 30% magnesite is added to Chromite to produce chrome-magnesite refractories. Magnesite addition is mainly done to improve the _____________ of Chromite?

   A. Spalling resistance B. Refractoriness C. Crushing strength D. Resistance to slag...

7. Furnace atmosphere for softening temperature determination of refractories (in which Seger Cones are placed) should be __________________?

   A. Oxidising B. Neutral C. Either A. or B. D. Neither A. nor B....

8. Spray test determines the _____________ of refractories?

   A. Resistance to slag penetration B. Resistance to CO attack C. RUL D. Permanent linear change...

9. Fireclay refractories have __________________?

   A. Low co-efficient of thermal expansion B. Poor thermal spalling resistance C. Tendency to expand unduly high during firing D. Very high cost...

10. With decrease in porosity, the ______________ of the refractories decreases?

    A. Strength B. Thermal conductivity C. Spalling resistance D. None of these...