A. Oxidising
B. Neutral
C. Either A. or B.
D. Neither A. nor B.
Related Mcqs:
- Segar cones are used for the determination of ____________ of refractories?
A. Softening temperature
B. Spalling resistance
C. Electrical conductivity
D. Resistance to slag attack - 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 - Dilatometer is used for the determination of ______________ of refractories?
A. Modulus of rupture
B. Permanent linear change
C. Resistance to CO attack
D. RUL - Faster rate of drying of moulded refractories results in high _____________ of refractories?
A. Green strength
B. Voids
C. Shrinkage
D. Both B. and C. - Carbon refractories have very high __________________?
A. Wetting characteristics
B. Refractoriness
C. Thermal conductivity
D. Both B. and C. - 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 - Pyrometric cone equivalent (PCE) value (Segar cone) of ‘Superduty refractories’ is more than 33 which corresponds to a temperature of _____________ °C?
A. 1520
B. 1630
C. 1670
D. 1730 - Rate of slag attack on refractories increases with rise in temperature due to the___________________?
A. Decreased viscosity of slag
B. Increased thermal conductivity of brick
C. Oxidising condition in the furnace
D. None of these - PCE value (Segar cone) of Superduty refractories is more than 33, which is equivalent to a temperature of ____________ °C?
A. 1520
B. 1630
C. 1670
D. 1730 - Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage ?
A. Tar bonded dolomite bricks
B. Fireclay bricks
C. Mullite bricks
D. Magnesite bricks
