Related Mcqs:

1. Skull is not formed on the carbon blocks in the hearth of a blast furnace, when it becomes cold, because of its_______________?

   A. Non-wetting characteristic
   B. High thermal conductivity
   C. High crushing strength
   D. None of these

2. Hot blast main (carrying air at 1000°C) in blast furnace are lined with ______________ bricks?

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

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

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

4. Bottom of basic open hearth furnace are constructed of__________________?

   A. Dead burnt magnesite ramming mass
   B. Porous fireclay bricks
   C. Semi-silica bricks
   D. Silicon carbide bricks

5. Carbon refractory blocks ___________________?

   A. Are wetted by molten iron
   B. Are used in the hearth of blast furnace
   C. Are acidic in nature
   D. All A., B. and C.

6. Outer combustion chamber of blast furnace stove is lined with _____________ bricks?

   A. Fireclay
   B. Silica
   C. Chrome magnesite
   D. Zirconia

7. 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 A., B. and C.

8. Because of its very high refractoriness of the order of __________ °C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns ?

   A. 1800
   B. 2200
   C. 2400
   D. 2700

9. 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.

10. 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?

    A. 450
    B. 250
    C. 150
    D. 65