An indication of degree of firing in silica brick is its____________________?

Related Mcqs:

1. The maximum linear expansion of silica bricks during firing is about ______________ percent?

   A. 0.5
   B. 1
   C. 2
   D. 3.5

2. Semi-silica bricks compared to silica bricks have_______________?

   A. Less fusion point
   B. Better spalling resistance
   C. Both A. and B.
   D. Neither A. not B.

3. Firing of refractory brick is done to __________________?

   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.

4. Refractoriness of a typical silica brick corresponds to Segar cone number, ’32’, which is equivalent to a temperature of _____________ °C?

   A. 1380
   B. 1520
   C. 1710
   D. 1915

5. Addition of zircon to silica refractory brick improves its_____________________?

   A. Crushing strength
   B. Resistance to slag attack
   C. Both A. and B.
   D. Neither A. nor B.

6. Spalling of a refractory means its____________________?

   A. Softening
   B. Fracture due to uneven expansion at high temperature
   C. Resistance to compressive loads
   D. Resistance to chemical action of gases and molten fluxes

7. Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as ______________ percent?

   A. 10
   B. 15
   C. 20
   D. 30

8. Which of the following does not occur during firing/burning of refractories ?

   A. Removal of water of hydration
   B. Vitrification
   C. Decrease in crushing strength
   D. Development of stable mineral form

9. Firing temperature of magnesite bricks is about _____________ °C?

   A. 800-1000
   B. 1000-1200
   C. 1600-1800
   D. 2400-2600

10. Firing temperature is minimum (1250-1400 °C) for _______________ bricks?

    A. Fireclay
    B. Direct bonded basic
    C. Silica
    D. Magnesite