Refractory Technology Mcqs for Chemical - Set 2

1)   Roof of a basic open hearth furnace is lined with ______________ bricks?

a. Silica
b. Fireclay
c. Dolomite
d. Magnesite
Answer  Explanation 

ANSWER: Silica

Explanation:
No explanation is available for this question!


2)   Chrome magnesite bricks are used in the_________________?

a. Side walls of soaking pits and arc furnaces
b. Copper melting furnaces & converters
c. Burner block of glass tanks
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


3)   Refractory materials are never used in the construction of _________________?

a. Segar cones
b. Orton cones
c. Pressure vessels
d. Ovens & retorts
Answer  Explanation 

ANSWER: Pressure vessels

Explanation:
No explanation is available for this question!


4)   Graphite or carbon refractories______________________?

a. Exhibit wetting characteristics
b. Should be used in neutral or reducing atmosphere
c. Exhibit high shrinkage on thermal treatment
d. Are not resistant to corrosion by slag
Answer  Explanation 

ANSWER: Should be used in neutral or reducing atmosphere

Explanation:
No explanation is available for this question!


5)   Zirconia refractory_________________?

a. Does not react with basic slags
b. Is produced from baddeleyite
c. Cannot be used as an insulator
d. Has poor electrical conductivity at high temperature
Answer  Explanation 

ANSWER: Is produced from baddeleyite

Explanation:
No explanation is available for this question!


6)   Carbon refractories have very high __________________?

a. Wetting characteristics
b. Refractoriness
c. Thermal conductivity
d. Both B. and C.
Answer  Explanation 

ANSWER: Both B. and C.

Explanation:
No explanation is available for this question!


7)   An ideal refractory should have high__________________?

a. Spalling rate
b. Fusion point
c. Shrinkage ability
d. None of these
Answer  Explanation 

ANSWER: Fusion point

Explanation:
No explanation is available for this question!


8)   Fusion point of an acidic refractory material is________________?

a. Increased by the addition of basic oxides
b. Reduced by the addition of basic oxides
c. Not affected by the addition of basic oxides
d. Always more than 2500°C
Answer  Explanation 

ANSWER: Reduced by the addition of basic oxides

Explanation:
No explanation is available for this question!


9)   Segar cones are used for the determination of ____________ of refractories?

a. Softening temperature
b. Spalling resistance
c. Electrical conductivity
d. Resistance to slag attack
Answer  Explanation 

ANSWER: Softening temperature

Explanation:
No explanation is available for this question!


10)   Porosity is induced in insulating refractories by adding________________?

a. Powdered naphthalene
b. Ammonium chloride/sulphate
c. Calcium phosphate
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


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

a. 10
b. 100
c. 500
d. 1000
Answer  Explanation 

ANSWER: 1000

Explanation:
No explanation is available for this question!


12)   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
Answer  Explanation 

ANSWER: Combustion chamber of blast furnace stoves

Explanation:
No explanation is available for this question!


13)   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.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


14)   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
Answer  Explanation 

ANSWER: Decrease in crushing strength

Explanation:
No explanation is available for this question!


15)   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.
Answer  Explanation 

ANSWER: Specific gravity

Explanation:
No explanation is available for this question!


16)   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.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


17)   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
Answer  Explanation 

ANSWER: Water

Explanation:
No explanation is available for this question!


18)   Periclase is___________________?

a. Crystalline form of MgO
b. MgCO3
c. ZrSO4
d. Amorphous magnesite
Answer  Explanation 

ANSWER: Crystalline form of MgO

Explanation:
No explanation is available for this question!


19)   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.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


20)   Which one contains maximum percentage of Al2O3 ?

a. Firebrick
b. Sillimanite
c. Magnesite
d. Aluminous firebrick
Answer  Explanation 

ANSWER: Sillimanite

Explanation:
No explanation is available for this question!