A. Beryllia
B. Carborundum
C. Corundum
D. Thoria
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. - A metal oxide is reduced by heating it in a stream of hydrogen. After complete reduction, it is found that 3.15 gm of the oxide has yielded 1.05 gm of the metal. It may be inferred that the ____________________?
A. Atomic weight of the metal is 4
B. Equivalent weight of the metal is 4
C. Atomic weight of the metal is 2
D. Equivalent weight of the metal is 8 - The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. The temperature at which the above mixture will exert a pressure of one standard atm. is___________________?
A. Less than 100°C
B. 100°C
C. Between 100 and 110°C
D. 110.6°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 - Refractories used in/for ______________ should have low thermal conductivity?
A. Coke ovens
B. Insulation
C. Regenerators
D. Muffle furnaces - Panel test determines the ______________ of refractories?
A. Fusion point
B. Spalling resistance
C. Slag penetration resistance
D. Refractoriness under load (RUL) - Presence of MgO in alumino-silicate refractories ______________ its refractoriness ?
A. Increases
B. Lowers
C. Does not affect
D. Either A. or B.; depends on its quantity - Hot metal runner in blast furnace are lined with ______________ bricks?
A. Silica
B. Carborundum
C. Fireclay
D. Magnesite - Roof of a basic electric furnace is made of ______________ bricks?
A. Superduty fireclay
B. Silica
C. Chromite
D. None of these - Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of ______________ °C?
A. 770
B. 570
C. 270
D. 70
