Mullite is chemically represented by_________________?

Related Mcqs:

1. Chemically, mullite refractories is____________________?

   A. 3Al2O3.2SiO2
   B. Al2O3
   C. ZrSO4
   D. ThO2

2. ‘Spinel’, a refractory mineral is chemically represented as____________________?

   A. MgAl2O4
   B. MgAl2O3
   C. MgSO4
   D. MgAl2O3.2H2O

3. Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the_________________?

   A. Washing action of metal
   B. Corrosion by layer of slag
   C. Both A. & B.
   D. Neither A. nor B.

4. Hot face insulating linings of high purity alumina fused mullite are used, where_________________?

   A. Very high temperatures are involved
   B. Highly reducing conditions are involved
   C. Presence of iron or silica is harmful
   D. All A., B. and C.

5. Roof of a basic open hearth furnace is lined with ______________ bricks?

   A. Silica
   B. Fireclay
   C. Dolomite
   D. Magnesite

6. _____________ is not a single oxide-refractory?

   A. Zirconia
   B. Silicon carbide
   C. Magnesia
   D. None of these

7. Pyrometric cone equivalent (PCE) value (Segar cone) of ‘Superduty refractories’ is more than 33 which corresponds to a temperature of _____________ °C?

   A. 1520
   B. 1630
   C. 1670
   D. 1730

8. Chromite refractories are used in_______________?

   A. Bottom of soaking pits
   B. Between acid & basic linings in basic open hearth furnaces to prevent their chemical action
   with each other
   C. Both A. & B.
   D. Neither A. and B.

9. Which is not a high alumina refractory ?

   A. Mullite
   B. Corundum
   C. Bauxite
   D. Dolomite

10. Dilatometer is used for the determination of ______________ of refractories?

    A. Modulus of rupture
    B. Permanent linear change
    C. Resistance to CO attack
    D. RUL