- (A) Mainly contains quartz
- (B) Is not stable at high temperature
- (C) Transforms to other allotropic forms i.e. Tridymite and Cristobalite involving very high volume changes
- (D) All
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- (A) 500
- (B) 1000
- (C) >1350
- (D) >2000
- (A) Do not burn/oxidise, when exposed to air on heating
- (B) Are not attacked by slags, as they are not wetted by melts
- (C) Do not resist temperature fluctuations
- (D) Have extremely low thermal & electrical conductivities
- (A) Basic
- (B) Neutral
- (C) High alumina
- (D) Insulating
- (A) Silica
- (B) Periclase
- (C) Lime
- (D) None of these
- (A) At the hearth bottom of the furnace on which stock is placed
- (B) Used for furnace insulation
- (C) Used in the roof of the furnace
- (D) None of these
- (A) Firebricks
- (B) Silica bricks
- (C) Silicon carbide bricks
- (D) Sillimanite
- (A) Soaking pit
- (B) Blast furnace
- (C) L.
- (D) converter
- (A) Carbides
- (B) Oxides
- (C) Borides
- (D) Nitrides
- (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
