- A. Slip casting
- B. Hand moulding
- C. Pressing/machine moulding
- D. Extrusion
Refractory Technology
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Hollow refractory bricks are made by_____.
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Highest melting (m.p = 3070°C) oxide refractory is_____.
- A. Alumina
- B. Thoria
- C. Zirconia
- D. Magnesia
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Porosity is induced in insulating refractories by adding_____.
- A. Powdered naphthalene
- B. Ammonium chloride/sulphate
- C. Calcium phosphate
- D. All of the above
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Which of the following is not a neutral refractory?
- A. Silicon carbide
- B. Magnesite
- C. Chromite
- D. Graphite
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Which one expands on heating?
- A. Silica bricks
- B. Fireclay bricks
- C. Both A & B
- D. Neither A nor B
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An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture?
- A. Cork
- B. Saw dust
- C. Sand
- D. Chemically prepared foam
-
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
- A. High refractoriness
- B. High resistance to spalling
- C. High strength and density
- D. All of the above
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Firing temperature of magnesite bricks is about _____ °C.
- A. 800-1000
- B. 1000-1200
- C. 1600-1800
- D. 2400-2600
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Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage?
- A. Tar bonded dolomite bricks
- B. Fireclay bricks
- C. Mullite bricks
- D. Magnesite bricks
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Fireclay bricks are never used in the_____.
- A. Beehive oven
- B. Coke oven walls
- C. Zinc roaster
- D. Lead blast furnace