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  • Question
  • Magnesite refractories are generally not used in the


  • Options
  • A. electric furnace walls.
  • B. steel melting furnace.
  • C. open hearth furnace.
  • D. burning zone of cement kilns.

  • Correct Answer
  • steel melting furnace. 


  • Refractory Technology problems


    Search Results


    • 1. Refractories used in/for __________ should have low thermal conductivity.

    • Options
    • A. coke ovens
    • B. insulation
    • C. regenerators
    • D. muffle furnaces
    • Discuss
    • 2. Bottom of basic open hearth furnace are constructed of

    • Options
    • A. dead burnt magnesite ramming mass.
    • B. porous fireclay bricks.
    • C. semi-silica bricks.
    • D. silicon carbide bricks.
    • Discuss
    • 3. Natural silica

    • Options
    • A. mainly contains quartz.
    • B. is not stable at high temperature.
    • C. transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes.
    • D. all (a), (b) and (c).
    • Discuss
    • 4. The highest melting pure oxide (m.p. > 3000°C)is

    • Options
    • A. thoria
    • B. alumina
    • C. beryllia
    • D. zirconia
    • Discuss
    • 5. __________ is not a single oxiderefractory.

    • Options
    • A. Zirconia
    • B. Silicon carbide
    • C. Magnesia
    • D. None of these
    • Discuss
    • 6. Carborundum used for making crucibles for melting non-ferrous metals is chemically

    • Options
    • A. silicon carbide
    • B. silicon nitride
    • C. crystalline magnesia
    • D. zirconium sulphate
    • Discuss
    • 7. Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to

    • Options
    • A. thermal spalling
    • B. slag attack
    • C. fusion under load
    • D. CO attack
    • Discuss
    • 8. Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.

    • Options
    • A. 80 and 20
    • B. 20 and 80
    • C. 50 and 50
    • D. 60 and 40
    • Discuss
    • 9. Refractory bricks with lower permeability is produced by using

    • Options
    • A. higher firing temperature.
    • B. higher moulding pressure.
    • C. finer grog size.
    • D. all (a), (b) and (c).
    • Discuss
    • 10. Which is not a natural insulating material?

    • Options
    • A. Diatomaceous earth/kieselgur
    • B. Asbestos
    • C. Vermiculite
    • D. None of these
    • Discuss


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