Q.1
Which is an acidic refractory?
Q.2
Which of the following consumes the maximum tonnage of refractories annually in an integrated steel plant?
Q.3
Grog
Q.4
Refractories used in/for __________ should have low thermal conductivity.
Q.5
Ferromagnetic ceramic material is not used in the
Q.6
Electrical resistor bars are made of
Q.7
Chrome magnesite brick is not used for lining the
Q.8
With increase in the porosity, thermal spalling resistance of fireclay brick
Q.9
Use of higher percentage of lime for bonding silica bricks, reduces their
Q.10
'Super refractories' are made from pure
Q.11
Pyrometric cone equivalent (PCE) of a refractory is the measure of its
Q.12
Panel test determines the __________ of refractories.
Q.13
Machine moulding of dry mixture of refractories requires a pressure of the order of __________ kg/cm².
Q.14
Ganister is a source of the
Q.15
Faster rate of drying of moulded refractories results in high __________ of refractories.
Q.16
Grog addition in fireclay during brick manufacture is done to
Q.17
The maximum linear expansion of silica bricks during firing is about __________ percent.
Q.18
Si percentage in silica refractories used in the walls of coke oven is about
Q.19
Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to
Q.20
To resist spalling tendency, a refractory should have
Q.21
The largest consumer of refractories is the __________ industry.
Q.22
Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm² ) is __________ °C.
Q.23
Thermal conductivity of refractory bricks
Q.24
Thermal spalling mainly occurs during __________ of furnaces.
Q.25
Chrome magnesite bricks are used in the
Q.26
The highest melting pure oxide (m.p. > 3000°C) is
Q.27
Dolomite bricks have good resistance to attack by
Q.28
Mullite is chemically represented by
Q.29
Refractory materials are never used in the construction of
Q.30
Refractoriness under load (RUL) is the most important property for the refractory bricks
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