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Chemical Engineering :: Refractory Technology

  1. Porosity of silica bricks varies from __________ percent.

  2. A.
    5 to 10
    B.
    20 to 30
    C.
    45 to 60
    D.
    60 to 75

  3. Colour of fireclay bricks is

  4. A.
    light buff to reddish buff
    B.
    yellow
    C.
    black
    D.
    none of these

  5. Rate of slag attack on refractories increases with rise in temperature due to the

  6. A.
    decreased viscosity of slag.
    B.
    increased thermal conductivity of brick.
    C.
    oxidising condition in the furnace.
    D.
    none of these.

  7. Which of the following is not a high alumina refractory material ?

  8. A.
    Kyanite
    B.
    Sillimanite
    C.
    Diaspore
    D.
    Periclase

  9. Magnesite chrome bricks are used in the

  10. A.
    roof lining of basic open hearth & other basic furnaces.
    B.
    reheating furnaces.
    C.
    soaking pits.
    D.
    all (a), (b) and (c).

  11. Mullite is chemically represented by

  12. A.
    Al2O3 . 2SiO2
    B.
    3Al2O3 . 2SiO2
    C.
    Al2O3 . SiO2
    D.
    2Al2O3 . 3SiO2

  13. __________ bricks are used in the burning zone of a cement rotary kiln.

  14. A.
    High alumina
    B.
    Fireclay
    C.
    Thoria
    D.
    Silicon carbide

  15. Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be

  16. A.
    oxidising
    B.
    neutral
    C.
    either (a) or (b)
    D.
    neither (a) nor (b)

  17. Roof of a basic open hearth furnace is lined with __________ bricks.

  18. A.
    silica
    B.
    fireclay
    C.
    dolomite
    D.
    magnesite

  19. High alumina refractories are used in the

  20. A.
    dome of blast furnace stoves.
    B.
    electric arc furnace roof.
    C.
    glass melting furnaces.
    D.
    all (a), (b) and (c).