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

Fireclay bricks is not used for lining the__________________?

A. Cupola
B. Gas producer
C. Bottom of hot metal mixer
D. Roof of open hearth furnace

In panel test for spalling resistance, the average face temperature of panel assembly is maintained at ______________ °C for 24 hours?

A. 700
B. 1000
C. 1600
D. 2000

Which is an acidic refractory ?

A. Magnesite
B. Dolomite
C. Fireclay
D. Chrome magnesite

Which is not an acidic refractory ?

A. Silica
B. Fireclay
C. High alumina refractory
D. Carbon black

Fireclay bricks are used in the__________________?

A. Coke ovens regenerator
B. Outer lining of L.D. converter
C. Hearth bottom of blast furnace
D. Coke oven walls

Fusion point of a basic refractory material is__________________?

A. Reduced by the addition of acid oxides
B. Increased by the addition of acid oxides
C. Not affected by the addition of acid oxides
D. Always less than 1000°C

Thermal conductivity of refractory bricks_________________?

A. Increases with decrease in porosity
B. Decreases with decreases in porosity
C. Is independent of its porosity and is maximum for insulating bricks
D. Increases with the amount of air entrapped in pores

Which form of silica has the highest specific gravity ?

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

Fireclay bricks are not used in the_____________________?

A. Blast furnace
B. Hot blast stove
C. Cupola
D. Wall of coke oven