logo

CuriousTab

CuriousTab

Discussion


Home Chemical Engineering Refractory Technology Comments

  • Question
  • Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.


  • Options
  • A. 770
  • B. 570
  • C. 270
  • D. 70

  • Correct Answer
  • 270 


  • Refractory Technology problems


    Search Results


    • 1. Maximum alumina content in high alumina refractory can be as high as __________ percent.

    • Options
    • A. 30
    • B. 50
    • C. 70
    • D. 90
    • Discuss
    • 2. Firing of refractory brick is done to

    • Options
    • A. dehydrate the dried refractory.
    • B. develop stable mineral forms in them.
    • C. form ceramic bonds necessary for development of high crushing strength in the finished product.
    • D. all (a), (b) and (c).
    • Discuss
    • 3. Which is the stable form of silica below 870°C?

    • Options
    • A. Tridymite
    • B. Cristobalite
    • C. Quartz
    • D. None of these
    • Discuss
    • 4. Chemically, mullite refractories is

    • Options
    • A. 3Al2O3.2SiO2
    • B. Al2O3
    • C. ZrSO4
    • D. ThO2
    • Discuss
    • 5. Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.

    • Options
    • A. 1380
    • B. 1520
    • C. 1710
    • D. 1915
    • Discuss
    • 6. Firing temperature of magnesite bricks is about __________ °C.

    • Options
    • A. 800-1000
    • B. 1000-1200
    • C. 1600-1800
    • D. 2400-2600
    • Discuss
    • 7. Fireclay bricks are used in the

    • Options
    • A. coke ovens regenerator.
    • B. outer lining of L.D. converter.
    • C. hearth bottom of blast furnace.
    • D. coke oven walls.
    • Discuss
    • 8. Panel test determines the __________ of refractories.

    • Options
    • A. fusion point
    • B. spalling resistance
    • C. slag penetration resistance
    • D. refractoriness under load (RUL)
    • Discuss
    • 9. Vacuum steel degassing units are lined with

    • Options
    • A. silica bricks
    • B. low duty firebricks
    • C. high alumina bricks
    • D. graphite blocks
    • Discuss
    • 10. Fusion point of a basic refractory material is

    • Options
    • A. reduced by the addition of acid oxides.
    • B. increased by the addition of acid oxides.
    • C. not affected by the addition of acid oxides.
    • D. always less than 1000°C.
    • Discuss


    Comments

    There are no comments.

Enter a new Comment