Category: Refractory Technology

A. 3Al2O3.2SiO2
B. Al2O3
C. ZrSO4
D. ThO2

A. Are not resistant to the action of basic slags
B. Combine with salts (e.g. chlorides sulphates etc.) & bases (e.g. lime, magnesia etc.) forming
fusible aluminates silicates etc
C. Shrink during firing
D. All A., B. and C.

A. High thermal conductivity
B. Low porosity
C. Both A. and B.
D. Neither A. nor B.

A. Quartz
B. Cristobalite
C. Tridymite
D. All have the same specific gravity

A. Less fusion point
B. Better spalling resistance
C. Both A. and B.
D. Neither A. not B.

A. Fireclay
B. Carborundum
C. Graphite
D. Chromite

A. Roof lining of basic open hearth & other basic furnaces
B. Reheating furnaces
C. Soaking pits
D. All A., B. and C.

A. Have better spalling resistance than chrome magnesite refractories
B. Have very low thermal co-efficient of expansion
C. Are not at all resistant to the corrosive action of iron oxide
D. Have very low (50 kg/cm2) cold crushing strength (C.C.S.), and cannot be used in metalcase
form

A. 5 to 10
B. 20 to 30
C. 45 to 60
D. 60 to 75

A. 1520
B. 1630
C. 1670
D. 1730