Fusion temperature of pure silica (SiO2) is _______________ °C?

Related Mcqs:

1. 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.

2. SiO2 percentage in firebrick is about____________________?

   A. 35-40
   B. 55-60
   C. 80-85
   D. > 94

3. Sillimanite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in________________?

   A. Pottery furnace
   B. Glass melting furnace
   C. Crucibles
   D. Gas retorts

4. Which one contains minimum percentage of SiO2 ?

   A. Firebrick
   B. Sillimanite
   C. Semi-silica
   D. Aluminous firebrick

5. Refractoriness/fusion points of ‘Superduty’ refractories is _______________ °C?

   A. 1520-1630
   B. 1630-1670
   C. > 1730
   D. > 2000

6. Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for _____________ bricks?

   A. Fireclay
   B. Silica
   C. Dolomite
   D. Very low alumina

7. Which is the most stable crystalline form of silica at room temperature ?

   A. Quartz
   B. Cristobalite
   C. Tridymite
   D. None of these

8. Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material ?

   A. Aluminium phosphate
   B. Water
   C. Lime
   D. Plaster of Paris

9. 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

10. Pure oxide refractories are generally monocrystalline in nature and are self bonded _______________ bricks are generally used as moderator in nuclear reactors?

    A. Beryllia
    B. Carborundum
    C. Corundum
    D. Thoria