3332. Semi-silica bricks compared to silica bricks have
less fusion point.
better spalling resistance.
both (a) and (b).
neither (a) not (b).
✅ The correct answer is option C.
3337. Which is the stable form of silica below 870°C ?
Tridymite
Cristobalite
Quartz
None of these
✅ The correct answer is option C.
3315. Which of the following is not a by-product fuel?
Producer gas
Blast furnace gas
Coke oven gas
Refinery gas
✅ The correct answer is option A.
3305. Fireclay bricks are used in the
furnaces allowed to cool frequently
flues
chimney linings
all (a), (b) and (c)
✅ The correct answer is option D.
3261. Which of the following consumes the maximum tonnage of refractories annually in an integrated steel plant ?
Soaking pits
Ceheating furnace
L.D. converter
Rotary lime kiln
✅ The correct answer is option C.
3266. The average molecular weight of a flue gas having the composition by volume as CO₂ = 25%, O₂ = 25%, N₂ = 50% will be
27.6
23
47.3
42.9
✅ The correct answer is option B.
3270. Resistance to slag attack of a refractory
depends on the nature of slag & refractory.
decreases at higher temperature.
decreases, if defective joints & cracks exist in the refractory.
all (a), (b) and (c).
✅ The correct answer is option D.
3275. A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the
Presence of large quantity of hydrogen in the fuel
Low calorific value of the fuel
High sulphur content in the fuel
Lack of thorough mixing of fuel with air
✅ The correct answer is option D.
3280. A fuel with high heat release rate will
Require smaller combustion chamber
Have high calorific value
Have high adiabatic flame temperature
None of these
✅ The correct answer is option A.
3285. Outer combustion chamber of blast furnace stove is lined with __________ bricks.
fireclay
silica
chrome magnesite
zirconia
✅ The correct answer is option A.