Al2O3
CaO
SiO2
all (a), (b) & (c)
✅ The correct answer is option D.
Refractory Technology MCQs
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
fireclay
silicon carbide
corrundum
siliceous fireclay
✅ The correct answer is option B.
Porosity of fireclay refractories is __________ percent.
5-Oct
Oct-25
25-35
35-50
✅ The correct answer is option B.
Carborundum used for making crucibles for melting non-ferrous metals is chemically
silicon carbide
silicon nitride
crystalline magnesia
zirconium sulphate
✅ The correct answer is option A.
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Cristobalite
Tridymite
Quartz
None of these
✅ The correct answer is option A.
Firing of refractory brick is done to
dehydrate the dried refractory.
develop stable mineral forms in them.
form ceramic bonds necessary for development of high crushing strength in the finished product.
all (a), (b) and (c).
✅ The correct answer is option D.
Which of the following has the lowest electrical resistivity ?
Graphite
Fireclay
Alumina
Zircon
✅ The correct answer is option A.
Carbon refractory blocks
are wetted by molten iron.
are used in the hearth of blast furnace.
are acidic in nature.
all (a), (b) and (c).
✅ The correct answer is option B.
Which brick undergoes maximum shrinkage on drying ?
Tar bonded dolomite bricks
Fireclay bricks
Magnesite bricks
Chromite bricks
✅ The correct answer is option B.
Chrome magnesite bricks are
acidic in nature.
neutral in nature.
having higher RUL than silica bricks.
made by mixing 30% chromite and 70% periclase.
✅ The correct answer is option C.