Chemical Engineering - Refractory Technology

6. 

Which is the most stable crystalline form of silica at room temperature ?

A. Quartz
B. Cristobalite
C. Tridymite
D. None of these

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.

7. 

Silica refractories

A. crack when subjected to sudden change of temperature.
B. can not be used in the dome of hot blast stoves.
C. have lower thermal conductivity than fireclay bricks.
D. all (a), (b) and (c)

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.

8. 

PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.

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

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

9. 

Which of the following is not an acidic refractory ?

A. Silica bricks
B. Fireclay bricks
C. Bauxite bricks
D. Magnesia bricks

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

10. 

Insulating refractories should have

A. high porosity
B. low thermal conductivity
C. both (a) and (b)
D. neither (a) not (b)

Answer: Option B

Explanation:

No answer description available for this question. Let us discuss.