50-100
100-150
200-400
500-1000
✅ The correct answer is option C.
Refractory Technology MCQs
silicon carbide refractories have very low
refractoriness (< 1700°C).
thermal conductivity.
resistance to thermal shock.
none of these.
✅ The correct answer is option D.
Silica bricks have low spalling resistance below 600°C, due to its
very high thermal conductivity.
high co-efficient of expansion upto this temperature.
high thermal diffusivity.
low refractoriness.
✅ The correct answer is option B.
The maximum linear expansion of silica bricks during firing is about __________ percent.
0.5
1
2
3.5
✅ The correct answer is option D.
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
80 and 20
20 and 80
50 and 50
60 and 40
✅ The correct answer is option A.
SiO2 percentage in firebrick is about
35-40
55-60
80-85
>94
✅ The correct answer is option B.
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves ?
High refractoriness.
High resistance to spalling.
High strength and density.
All (a), (b) and (c).
✅ The correct answer is option A.
Rate of slag attack on refractories increases with rise in temperature due to the
decreased viscosity of slag.
increased thermal conductivity of brick.
oxidising condition in the furnace.
none of these.
✅ The correct answer is option A.
Zirconia refractory
does not react with basic slags.
is produced from baddeleyite.
can not be used as an insulator.
has poor electrical conductivity at high temperature.
✅ The correct answer is option B.
Use of higher percentage of lime for bonding silica bricks, reduces their
strength
abrasion resistance
both (a) & (b)
neither (a) nor (b)
✅ The correct answer is option C.