A. Chemical composition
B. Physical structure
C. Presence of impurities like iron & alkali
D. All A., B. and C.
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. - Which of the following bricks has the most close values of RUL and PCE ?
A. Silica bricks
B. Fireclay bricks
C. High alumina bricks
D. Tar dolomite bricks - Test piece for determination of RUL of a refractory is heated in a/an____________________?
A. Oxidising atmosphere
B. Reducing atmosphere
C. Electric furnace
D. Neutral atmosphere - Refractoriness under load (RUL) is the most important property for the refractory bricks_________________?
A. At the hearth bottom of the furnace on which stock is placed
B. Used for furnace insulation
C. Used in the roof of the furnace
D. None of these - . Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm2) is ______________ °C?
A. 500
B. 1000
C. >1350
D. >2000 - Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for _____________ bricks?
A. Fireclay
B. Silica
C. Dolomite
D. Very low alumina - Cold crushing strength of refractories depends upon its_________________?
A. Composition
B. Texture
C. Firing temperature
D. All A., B. and C. - Which of the following does not occur during firing/burning of refractories ?
A. Removal of water of hydration
B. Vitrification
C. Decrease in crushing strength
D. Development of stable mineral form - Magnesite refractories have low resistance to___________________?
A. Attack by basic slag
B. Abrasion
C. Disintegration on sudden change of temperature
D. Both B. and C. - Pure oxide refractories are generally monocrystalline in nature and are self bonded _______________ bricks are generally used as moderator in nuclear reactors?
A. Beryllia
B. Carborundum
C. Corundum
D. Thoria
