Q.1
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
Q.2
Spalling resistance of a refractory can not be increased by
Q.3
Hollow refractory bricks are made by
Q.4
Which property of refractories is the most important for top section of the blast furnace?
Q.5
Carbon bricks are not used in the lining of the
Q.6
Zirconia refractories are not used in
Q.7
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Q.8
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Q.9
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
Q.10
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Q.11
Permeability of bricks is a measure of the
Q.12
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Q.13
Cold crushing strength of refractories depends upon its
Q.14
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Q.15
Which one contains maximum percentage of Al2O₃ ?
Q.16
Which brick undergoes maximum shrinkage on drying?
Q.17
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
Q.18
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Q.19
Which of the following is not a neutral refractory?
Q.20
Which is not an acidic refractory?
Q.21
Hot face insulating linings of high purity alumina fused mullite are used, where
Q.22
With increase in the alumina content in firebricks, its fusion point (refractoriness)
Q.23
Magnesite bricks have poor resistance to attack by __________ slag.
Q.24
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
Q.25
Addition of zircon to silica refractory brick improves its
Q.26
__________ is not a single oxiderefractory.
Q.27
Roof of a basic open hearth furnace is lined with __________ bricks.
Q.28
Bauxite calcining rotary kilns are lined with __________ bricks.
Q.29
Lower part of hot metal mixer are lined with __________ bricks.
Q.30
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
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