A. Poor resistance to the penetration of molten slag, metal & flue gases
B. Poor heat conductivity & low strength
C. Better thermal spalling resistance
D. All A., B. and C.
Related Mcqs:
- Refractory bricks having lower porosity have_________________________?
A. High insulating properties
B. Low heat capacity
C. Low thermal conductivity
D. Greater strength - High density refractory bricks have lower__________________?
A. Spalling resistance
B. Thermal conductivity
C. Fusion point
D. Slag penetration resistance - High refractoriness of refractory bricks means, that it has a________________?
A. High spalling resistance
B. Low spalling resistance
C. High resistance to fusion
D. Low porosity - High alumina refractory compared to fireclay bricks have____________________?
A. Less load bearing capacity
B. Less resistance to slag attack
C. Low refractoriness
D. High resistance to thermal shock and creep - Porosity of silica bricks varies from ______________ percent?
A. 5 to 10
B. 20 to 30
C. 45 to 60
D. 60 to 75 - Maximum apparent porosity of magnesite bricks is about _____________ percent?
A. 8
B. 24
C. 44
D. 58 - 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 - Hollow refractory bricks are made by___________________?
A. Slip casting
B. Hand moulding
C. pressing/machine moulding
D. Extrusion - Water content in ground refractory material to be shaped into bricks by hand moulding is about ______________ percent?
A. 5
B. 20
C. 40
D. 55 - 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.
