1. 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.
Refractory Technology MCQs
2. Which is not a high alumina refractory ?
Mullite
Corrundum
Bauxite
Dolomite
✅ The correct answer is option D.
3. 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.
4. 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.
5. Hollow refractory bricks are made by
slip casting
hand moulding
pressing/machine moulding
extrusion
✅ The correct answer is option A.
6. Spalling tendency of refractories is reduced by increasing its
porosity
specific gravity
thermal conductivity
strength
✅ The correct answer is option A.
7. 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.
8. Refractory bricks having lower porosity have
high insulating properties
low heat capacity
low thermal conductivity
greater strength
✅ The correct answer is option D.
9. To resist spalling tendency, a refractory should have
greater diffusivity.
low specific heat.
low thermal co-efficient of expansion.
all (a), (b) and (c).
✅ The correct answer is option D.
10. Spray test determines the __________ of refractories.
resistance to slag penetration
resistance to CO attack
RUL
permanent linear change
✅ The correct answer is option A.