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Home Chemical Engineering Refractory Technology Comments

  • Question
  • Test piece for determination of RUL of a refractory is heated in a/an


  • Options
  • A. oxidising atmosphere
  • B. reducing atmosphere
  • C. electric furnace
  • D. neutral atmosphere

  • Correct Answer
  • electric furnace 


  • Refractory Technology problems


    Search Results


    • 1. Refractoriness/fusion points of 'superduty' refractories is __________ °C.

    • Options
    • A. 1520-1630
    • B. 1630-1670
    • C. > 1730
    • D. > 2000
    • Discuss
    • 2. Hot metal runner in blast furnace are lined with __________ bricks.

    • Options
    • A. silica
    • B. carborundum
    • C. fireclay
    • D. magnesite
    • Discuss
    • 3. Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.

    • Options
    • A. 1520
    • B. 1630
    • C. 1670
    • D. 1730
    • Discuss
    • 4. Thoria

    • Options
    • A. has high fusion temperature (> 3000°C) but poor resistance to thermal shock.
    • B. has high resistance to basic slags.
    • C. which is expensive & radioactive, is used in crucibles for melting high purity metals.
    • D. all (a), (b) and (c).
    • Discuss
    • 5. Quartz is

    • Options
    • A. stable form of silica upto 870°C.
    • B. converted to tridymite on firing between 870 to 1470°C.
    • C. transformed to crystoballite on heating above 1470°C.
    • D. all (a), (b) and (c).
    • Discuss
    • 6. Chromite refractories

    • Options
    • A. are bonded with lime and clay.
    • B. (free from silica) have better thermal fatigue resistance than silica and magnesite refractories.
    • C. are resistant to basic slag.
    • D. all (a), (b) and (c).
    • Discuss
    • 7. Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called

    • Options
    • A. spalling resistance.
    • B. refractoriness.
    • C. refractoriness under load (RUL).
    • D. none of these.
    • Discuss
    • 8. High porosity refractory bricks have

    • Options
    • A. poor resistance to the peneration of molten slag, metal & flue gases.
    • B. poor heat conductivity & low strength.
    • C. better thermal spalling resistance.
    • D. all (a), (b) and (c).
    • Discuss
    • 9. Which is the stable form of silica between 1470°C and the melting point 1713°C?

    • Options
    • A. Cristobalite
    • B. Tridymite
    • C. Quartz
    • D. None of these
    • Discuss
    • 10. Fireclay bricks are not used in the

    • Options
    • A. beehive coke oven.
    • B. by-product coke oven walls.
    • C. combustion chamber of B.F. stoves.
    • D. coke oven regenerators.
    • Discuss


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