A. CaO
B. MgO
C. Al2O3
D. SiO2
Related Mcqs:
- Periclase is___________________?
A. Crystalline form of MgO
B. MgCO3
C. ZrSO4
D. Amorphous magnesite - Sillimanite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in________________?
A. Pottery furnace
B. Glass melting furnace
C. Crucibles
D. Gas retorts - Maximum water percentage in refractory mix meant for hand moulding may be as high as _____________ percent?
A. 2-3
B. 5-7
C. 7-12
D. 14-20 - Mixing of ground refractory material and water is done in a ______________ mill?
A. Pug
B. Ball
C. Tube
D. Rod - Test piece for determination of RUL of a refractory is heated in a/an____________________?
A. Oxidising atmosphere
B. Reducing atmosphere
C. Electric furnace
D. Neutral atmosphere - Spalling resistance of a refractory cannot be increased by ____________________?
A. Increasing its porosity
B. Using a coarser grog during its manufacture
C. Decreasing its thermal co-efficient of expansion
D. Making it denser - Pyrometric cone equivalent (PCE) of a refractory is the measure of its_________________?
A. Spalling resistance
B. Fusion point
C. Resistance to slag penetration
D. Resistance to carbon monoxide attack - Highest melting (m.p = 3070°C) oxide refractory is__________________?
A. Alumina
B. Thoria
C. Zirconia
D. Magnesia - Refractory bricks with lower permeability is produced by using __________________?
A. Higher firing temperature
B. Higher moulding pressure
C. Finer grog size
D. All A., B. and C. - Thermal conductivity of refractory bricks_________________?
A. Increases with decrease in porosity
B. Decreases with decreases in porosity
C. Is independent of its porosity and is maximum for insulating bricks
D. Increases with the amount of air entrapped in pores
