Question 1

When is metal fiber reinforcement used in castable refractory?

Options :

A : Only when extra strength is required

B : Only when added in the field

C : For all monolithic hot face castable refractory materials

D : Only when specified by the owner

Answer: D

Question 2

Which of the following is a correct condition for gunned material test panels used for CCS and PLC testing?

Options :

A : Test panels must be 24 in. Ã— 24 in. Ã— 6 in. thick and shot vertically.

B : The minimum gunned thickness shall be 2 in., with a tolerance of ±0.25 in.

C : A vibrating screed must be used during panel finishing.

D : Test panels must be dried at 400°F (204°C) for 6 hours before specimen extraction.

Answer: B

Question 3

Cristobalite is an important constituent of

Options :

A : Alumina bricks

B : Silica brick

C : Magnesia brick

D : Insulating brick

Answer: B

Question 4

For air-setting phosphate bonded, erosion – resistant refractories mixing , the mixer’s paddles and bowls shall be

Options :

A : Aluminium

B : Steel

C : Carbon

D : None of the above

Answer: B

Question 5

Throughout a period of at least 24 hours, test specimens for air-setting, phosphate-bonded castable refractories are:

Options :

A : air cured, covered.

B : heat cured, uncovered.

C : air cured, uncovered.

D : heat cured, covered.

Answer: C