Q.1
Magnesite chrome bricks are used in the
Q.2
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
Q.3
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Q.4
Which is required in an insulating refractory?
Q.5
Mixing of ground refractory material and water is done in a __________ mill.
Q.6
Roof of a basic electric furnace is made of __________ bricks.
Q.7
Highest melting (m.p = 3070°C) oxide refractory is
Q.8
Fusion point of an acidic refractory material is
Q.9
Which of the following bricks has the most close values of RUL and PCE?
Q.10
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
Q.11
Hot metal runner in blast furnace are lined with __________ bricks.
Q.12
Which of the following is not a high alumina refractory material?
Q.13
Magnesite refractories are generally not used in the
Q.14
Silica bricks are never used for lining the
Q.15
An indication of degree of firing in silica brick is its
Q.16
Pick out the wrong statement.
Q.17
High refractorinness of refractory bricks means, that it has a
Q.18
An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture?
Q.19
Cold crushing strength of fireclay bricks is about __________ kgf/cm².
Q.20
Maximum apparent porosity of magnesite bricks is about __________ percent.
Q.21
Quartz is
Q.22
Tar dolomite bricks are used in the
Q.23
Chromite refractories are used in
Q.24
Segar cones are used for the determination of __________ of refractories.
Q.25
Which of the following does not occur during firing/burning of refractories?
Q.26
Rate of slag attack on refractories increases with rise in temperature due to the
Q.27
Pick out the wrong statement.
Q.28
Refractory castables are used for
Q.29
Silliminite (Al2O₃.SiO₂) refractory, which is a neutral refractory, is not used in
Q.30
Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900°C ) use, except
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