2956. Silliminite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in
pottery furnace
glass melting furnace
crucibles
gas retorts
✅ The correct answer is option D.
2961. Which is not a high alumina refractory ?
Mullite
Corrundum
Bauxite
Dolomite
✅ The correct answer is option D.
2966. Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
bakelite impregnated or fused periclase
silica
semi-silica
fireclay
✅ The correct answer is option A.
2971. Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
hearth of the blast furnace.
nuclear reactors, missiles & space crafts.
insulation of high temperature furnaces.
roof of electric furnaces.
✅ The correct answer is option B.
2977. Hollow refractory bricks are made by
slip casting
hand moulding
pressing/machine moulding
extrusion
✅ The correct answer is option A.
2982. Spalling tendency of refractories is reduced by increasing its
porosity
specific gravity
thermal conductivity
strength
✅ The correct answer is option A.
2947. Which of the following bricks should not be used, if the furnace is to be used intermit-tantly ?
Firebricks
Silica bricks
Silicon carbide bricks
Sillimanite
✅ The correct answer is option B.
2914. Washing of coal
Reduces its ash & sulphur content
Improves its coking properties
Increase the fusion point of its ash by removing chlorine compounds
All of the above
✅ The correct answer is option D.
2909. Soft coke is not
Produced by low temperature carbonisation of coal
A domestic fuel
Used in blast furnaces
None of these
✅ The correct answer is option C.
2915. Pulverised coal used in boiler firing need not have
Less moisture content
High fusion point of its ash
High bulk density
Lower ash content
✅ The correct answer is option B.