Chemical Engineering - Refractory Technology
Exercise :: Refractory Technology - Section 2
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:
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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:
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8. |
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C. |
Answer: Option D
Explanation:
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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:
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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:
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