A. Attack by basic slag
B. Abrasion
C. Disintegration on sudden change of temperature
D. Both B. and C.
Related Mcqs:
- 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 - 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 - Magnesite refractories are used for the construction of those furnaces, which are________________?
A. Not required to resist the corrosive action of basic slag
B. Not subjected to fluctuation in temperature
C. Used for raising & maintaining high temperature
D. Both B. and C. - Faster rate of drying of moulded refractories results in high _____________ of refractories?
A. Green strength
B. Voids
C. Shrinkage
D. Both B. and C. - Magnesite bricks have poor resistance to attack by _____________ slag?
A. Lime
B. Basic
C. Acid
D. None of these - Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to__________________?
A. Thermal spalling
B. Slag attack
C. Fusion under load
D. CO attack - Silicon carbide refractories have very low ___________________?
A. Refractoriness (< 1700°C)
B. Thermal conductivity
C. Resistance to thermal shock
D. None of these - Except _____________, all other refractories are bad conductors of electricity (i.e, have low electrical conductivity)?
A. Fireclay
B. Carborundum
C. Graphite
D. Chromite - Rotary kilns meant for calcination of limestone are lined with chrome magnesite in ______________ zone?
A. Preheating
B. Cooling
C. Burning
D. All the above - Magnesite bricks are used in those parts of furnaces, which are __________________?
A. Subjected to temperature fluctuation
B. Required to resist corrosive basic slag
C. Subjected to high load
D. None of these
