3056. Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
chrome or magnesite
silicon carbide
silica
lowduty fireclay
✅ The correct answer is option A.
3061. Roof of a basic open hearth furnace is lined with __________ bricks.
silica
fireclay
dolomite
magnesite
✅ The correct answer is option A.
3028. __________ nozzles are used in continuous casting of steel,
Zircon
Thoria
Carborundum
Beryllia
✅ The correct answer is option A.
3033. Zircon refractories have
low co-efficient of expansion.
high RUL (1600°C) and refractoriness (> 2000°C).
high spalling resistance.
all (a), (b) and (c).
✅ The correct answer is option D.
3039. Segar cones are used for the determination of __________ of refractories.
softening temperature
spalling resistance
electrical conductivity
resistance to slag attack
✅ The correct answer is option A.
3043. 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.
3048. Test piece for determination of RUL of a refractory is heated in a/an
oxidising atmosphere
reducing atmosphere
electric furnace
neutral atmosphere
✅ The correct answer is option C.
3052. The linear thermal expansion of __________ bricks upto 1000 °C is very low of the order of ≤ 0.5 percent.
fireclay
silica
magnesite
corundum
✅ The correct answer is option A.
3057. High density refractory bricks have lower
spalling resistance.
thermal conductivity.
fusion point.
slag penetration resistance.
✅ The correct answer is option A.
3062. Chemically, mullite refractories is
3Al2O3.2SiO2
Al2O3
ZrSO4
ThO2
✅ The correct answer is option A.