Fireclay refractories___________________?
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. Spalling resistance
B. Refractoriness
C. Refractoriness under load (RUL)
D. None of these
Refractoriness/fusion points of ‘Superduty’ refractories is _____________ °C?
A. 1520-1630
B. 1630-1670
C. > 1730
D. > 2000
With increase in the porosity, thermal spalling resistance of fireclay brick_______________?
A. Increases
B. Decreases
C. Remain same
D. May increase or decrease
A. Stable form of silica upto 870°C
B. Converted to Tridymite on firing between 870 to 1470°C
C. Transformed to Cristobalite on heating above 1470°C
D. All A., B. and C.
A. Beryllia
B. Carborundum
C. Corundum
D. Thoria