A. 3Al2O3.2SiO2
B. Al2O3
C. ZrSO4
D. ThO2
Related Mcqs:
- Mullite is chemically represented by_________________?
A. Al2O3. 2SiO2
B. 3Al2O3. 2SiO2
C. Al2O3. SiO2
D. 2Al2O3. 3SiO2 - Faster rate of drying of moulded refractories results in high _____________ of refractories?
A. Green strength
B. Voids
C. Shrinkage
D. Both B. and C. - Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the_________________?
A. Washing action of metal
B. Corrosion by layer of slag
C. Both A. & B.
D. Neither A. nor B. - Hot face insulating linings of high purity alumina fused mullite are used, where_________________?
A. Very high temperatures are involved
B. Highly reducing conditions are involved
C. Presence of iron or silica is harmful
D. All A., B. and C. - ‘Spinel’, a refractory mineral is chemically represented as____________________?
A. MgAl2O4
B. MgAl2O3
C. MgSO4
D. MgAl2O3.2H2O - Si percentage in silica refractories used in the walls of coke oven is about______________________?
A. 45
B. 60
C. 80
D. 95 - Magnesite refractories are generally not used in the___________________?
A. Electric furnace walls
B. Steel melting furnace
C. Open hearth furnace
D. Burning zone of cement kilns - Cold crushing strength of refractories depends upon its_________________?
A. Composition
B. Texture
C. Firing temperature
D. All A., B. and C. - 10 to 30% magnesite is added to Chromite to produce chrome-magnesite refractories. Magnesite addition is mainly done to improve the _____________ of Chromite?
A. Spalling resistance
B. Refractoriness
C. Crushing strength
D. Resistance to slag - PCE value (Segar cone) of Superduty refractories is more than 33, which is equivalent to a temperature of ____________ °C?
A. 1520
B. 1630
C. 1670
D. 1730
