Refractory Technology

Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of________________? A. FireclayB. Silicon carbide C. Corundum D. Siliceous fireclay

Pure oxide refractories are generally monocrystalline in nature and are self bonded _______________ bricks are generally used as moderator in nuclear reactors? A. Beryllia B. Carborundum C. Corundum D. Thoria

Refractory bricks with lower permeability is produced by using __________________? A. Higher firing temperature B. Higher moulding pressure C. Finer grog sizeD. All A., B. and C.

Addition of zircon to silica refractory brick improves its_____________________? A. Crushing strengthB. Resistance to slag attack C. Both A. and B. D. Neither A. nor B.

Bottom of basic open hearth furnace are constructed of__________________? A. Dead burnt magnesite ramming mass B. Porous fireclay bricks C. Semi-silica bricks D. Silicon carbide bricks

Fusion temperature of pure silica (SiO2) is _______________ °C? A. 1350B. 1715 C. 2570 D. 2800

Porosity of fireclay refractories is _______________ percent? A. 5-10B. 10-25 C. 25-35 D. 35-50

High alumina refractory compared to fireclay bricks have____________________? A. Less load bearing capacity B. Less resistance to slag attack C. Low refractorinessD. High resistance to thermal shock and creep

Mullite is chemically represented by_________________? A. Al2O3. 2SiO2B. 3Al2O3. 2SiO2 C. Al2O3. SiO2 D. 2Al2O3. 3SiO2

Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as _____________ percent? A. 55 B. 70 C. 80D. 90