Q.1
Which is the most stable crystalline form of silica at room temperature?
Q.2
Fireclay refractories
Q.3
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Q.4
Which is the stable form of silica below 870°C ?
Q.5
Porosity of fireclay refractories is __________ percent.
Q.6
Cold crushing strength of a refractory does not depend upon its
Q.7
Refractory bricks having lower porosity have
Q.8
Fireclay bricks is not used for lining the
Q.9
Chrome magnesite is not used in the
Q.10
Magnesite bricks are used in those parts of furnaces, which are
Q.11
Carbon refractories are exclusively used in the
Q.12
Fireclay refractories have
Q.13
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Q.14
Cermets are
Q.15
Which is the stable form of silica upto 1470°C ?
Q.16
Firing temperature of magnesite bricks is about __________ °C.
Q.17
Maximum safe working temperature for fireclay bricks is about __________ °C.
Q.18
Vacuum steel degassing units are lined with
Q.19
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Q.20
Colour of fireclay bricks is
Q.21
Semi-silica bricks compared to silica bricks have
Q.22
Silicon carbide refractories are used in the
Q.23
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Q.24
Insulating refractories should have
Q.25
Which is not a basic refractory?
Q.26
Chrome magnesite bricks are
Q.27
Chemically, mullite refractories is
Q.28
Carbon refractories
Q.29
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Q.30
Magnesite refractories have low resistance to
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