A. Carbides
B. Oxides
C. Borides
D. Nitrides
Related Mcqs:
- Faster rate of drying of moulded refractories results in high _____________ of refractories?
A. Green strength
B. Voids
C. Shrinkage
D. Both B. and C. - 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 - Porosity is induced in insulating refractories by adding________________?
A. Powdered naphthalene
B. Ammonium chloride/sulphate
C. Calcium phosphate
D. All A., B. and C. - 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 - Cold crushing strength of refractories depends upon its_________________?
A. Composition
B. Texture
C. Firing temperature
D. All A., B. and C. - 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 - 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. - Spray test determines the _____________ of refractories?
A. Resistance to slag penetration
B. Resistance to CO attack
C. RUL
D. Permanent linear change - 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 - With decrease in porosity, the ______________ of the refractories decreases?
A. Strength
B. Thermal conductivity
C. Spalling resistance
D. None of these
