Machine moulding of dry mixture of refractories requires a pressure of the order of _____________ kg/cm2?

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

Carbon bricks are not used in the lining of the_________________?

A. Combustion chamber of blast furnace stoves
B. Electric furnaces
C. Highly chemical resistant equipments
D. Blast furnace hearth

Grog addition in fireclay during brick manufacture is done to_________________?

A. Reduce its shrinkage on heating
B. Impart greater spalling resistance
C. Enhance the strength of fired refractories
D. All A., B. and C.

Which of the following does not occur during firing/burning of refractories ?

A. Removal of water of hydration
B. Vitrification
C. Decrease in crushing strength
D. Development of stable mineral form

Conversion of silica mineral to Cristobalite is accompanied by reduction in its ____________________?

A. Volume
B. Specific gravity
C. Both A. & B.
D. Neither A. nor B.

Magnesite chrome bricks are used in the___________________?

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

Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material ?

A. Aluminium phosphate
B. Water
C. Lime
D. Plaster of Paris

Periclase is___________________?

A. Crystalline form of MgO
B. MgCO3
C. ZrSO4
D. Amorphous magnesite

RUL of refractories depends on the _____________________?

A. Chemical composition
B. Physical structure
C. Presence of impurities like iron & alkali
D. All A., B. and C.

Which one contains maximum percentage of Al2O3 ?

A. Firebrick
B. Sillimanite
C. Magnesite
D. Aluminous firebrick