Refractory Technology Questions MCQs


refractory technology Questions

Total Questions : 220

Page 1 of 11 pages
Question 1. Highest melting (m.p = 3070°C) oxide refractory is
  1.    Alumina
  2.    Thoria
  3.    Zirconia
  4.    Magnesia
Answer: Option B
Question 2. Fusion point of an acidic refractory material is
  1.    Increased by the addition of basic oxides
  2.    Reduced by the addition of basic oxides
  3.    Not affected by the addition of basic oxides
  4.    Not affected by the addition of basic oxides
Answer: Option B
Question 3. Which of the following is not a high alumina refractory material?
  1.    Kyanite
  2.    Sillimanite
  3.    Diaspore
  4.    Periclase
Answer: Option D
Question 4. Magnesite refractories are generally not used in the
  1.    Electric furnace walls
  2.    Steel melting furnace
  3.    Open hearth furnace
  4.    Burning zone of cement kilns
Answer: Option B
Question 5. Silica bricks are never used for lining the
  1.    Beehive coke ovens
  2.    By-product coke ovens
  3.    Dome of blast furnace stoves
  4.    Roof of open hearth furnace
Answer: Option A
Question 6. Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
  1.    450
  2.    250
  3.    150
  4.    65
Answer: Option D
Question 7. Magnesite chrome bricks are used in the
  1.    Roof lining of basic open hearth & other basic furnaces
  2.    Reheating furnaces
  3.    Soaking pits
  4.    All of the above
Answer: Option D
Question 8. Which of the following bricks has the most close values of RUL and PCE?
  1.    Silica bricks
  2.    Fireclay bricks
  3.    High alumina bricks
  4.    Tar dolomite bricks
Answer: Option A
Question 9. __________ is the measure of the strength of refractory under the combined effect of temperature & load.
  1.    Porosity
  2.    RUL
  3.    Specific gravity
  4.    Thermal conductivity
Answer: Option B
Question 10. An indication of degree of firing in silica brick is its
  1.    Specific gravity
  2.    Fusion point
  3.    RUL
  4.    None of these
Answer: Option A
Question 11. Hot face insulating linings of high purity alumina fused mullite are used, where
  1.    Very high temperatures are involved
  2.    Highly reducing conditions are involved
  3.    Presence of iron or silica is harmful
  4.    All of the above
Answer: Option D
Question 12. With increase in the alumina content in firebricks, its fusion point (refractoriness)
  1.    Decreases linearly
  2.    Remains unchanged
  3.    Increases
  4.    Decreases
Answer: Option C
Question 13. Which is required in an insulating refractory?
  1.    High thermal conductivity
  2.    Low porosity
  3.    Both A & B
  4.    Neither A nor B
Answer: Option D
Question 14. Roof of a basic electric furnace is made of __________ bricks.
  1.    Superduty fireclay
  2.    Silica
  3.    Chromite
  4.    None of these
Answer: Option B
Question 15. Mixing of ground refractory material and water is done in a __________ mill.
  1.    Pug
  2.    Ball
  3.    Tube
  4.    Rod
Answer: Option A
Question 16. Which of the following is not a neutral refractory?
  1.    Silicon carbide
  2.    Magnesite
  3.    Chromite
  4.    Graphite
Answer: Option B
Question 17. Which is not an acidic refractory?
  1.    Silica
  2.    Fireclay
  3.    High alumina refractory
  4.    Carbon black
Answer: Option D
Question 18. Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
  1.    Segar cones
  2.    Muffles for muffle furnaces
  3.    Insulating bricks
  4.    Crucibles used for melting of high purity metals
Answer: Option D
Question 19. Outer combustion chamber of blast furnace stove is lined with __________ bricks.
  1.    Fireclay
  2.    Silica
  3.    Chrome magnesite
  4.    Zirconia
Answer: Option A
Question 20. Hot metal runner in blast furnace are lined with __________ bricks.
  1.    Silica
  2.    Carborundum
  3.    Fireclay
  4.    Magnesite
Answer: Option C