Category: Refractory Technology

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

A. crack when subjected to sudden change of temperature
B. Cannot be used in the dome of hot blast stoves
C. Have lower thermal conductivity than fireclay bricks
D. All A., B. and C.

A. Wetting characteristics
B. Refractoriness
C. Thermal conductivity
D. Both B. and C.

A. Hearth of the blast furnace
B. Nuclear reactors, missiles & space crafts
C. Insulation of high temperature furnaces
D. Roof of electric furnaces

A. 10
B. 100
C. 500
D. 1000

A. Refractoriness
B. Melting point
C. Rate at which a fluid will pass through the pores
D. Expansion during heating

A. Sand & coke is the main raw material for the manufacture of silicon carbide
B. Carbon refractories cannot be used in the furnaces operating under reducing conditions
C. Mullite can be obtained by the heating of alusite, kyanite or sillimanite
D. Silica occurs in nature in all cellular, amorphous or crystalline form

A. Low co-efficient of thermal expansion
B. Poor thermal spalling resistance
C. Tendency to expand unduly high during firing
D. Very high cost

A. Tar bonded dolomite bricks
B. Fireclay bricks
C. Mullite bricks
D. Magnesite bricks

A. Increases with rise in service temperature
B. Decreases with rise in service temperature
C. Is unaffected with change in service temperature
D. Decreases with increase in porosity