Chrome magnesite bricks are_________________?

Related Mcqs:

1. 10 to 30% magnesite is added to Chromite to produce chrome-magnesite refractories. Magnesite addition is mainly done to improve the _____________ of Chromite?

   A. Spalling resistance
   B. Refractoriness
   C. Crushing strength
   D. Resistance to slag

2. Chrome magnesite bricks are used in the_________________?

   A. Side walls of soaking pits and arc furnaces
   B. Copper melting furnaces & converters
   C. Burner block of glass tanks
   D. All A., B. and C.

3. Magnesite chrome bricks are used in the___________________?

   A. Roof lining of basic open hearth & other basic furnaces
   B. Reheating furnaces
   C. Soaking pits
   D. All A., B. and C.

4. Chrome magnesite is not used in the ____________________?

   A. Inner lining of L.D. converter
   B. Aluminium melting furnaces
   C. Wear out lining of steel melting furnaces
   D. All A., and B. and C.

5. Chrome magnesite brick is not used for lining the___________________?

   A. Hearth of soaking pits
   B. Bottom hearth of reheating furnace
   C. Coke oven regenerator
   D. Burning zone of limestone rotary kilns

6. Rotary kilns meant for calcination of limestone are lined with chrome magnesite in ______________ zone?

   A. Preheating
   B. Cooling
   C. Burning
   D. All the above

7. Magnesite chrome refractories____________________?

   A. Have better spalling resistance than chrome magnesite refractories
   B. Have very low thermal co-efficient of expansion
   C. Are not at all resistant to the corrosive action of iron oxide
   D. Have very low (50 kg/cm2) cold crushing strength (C.C.S.), and cannot be used in metalcase
   form

8. Which of the following impurities reduces the refractoriness of magnesite bricks ?

   A. Al2O3
   B. CaO
   C. SiO2
   D. All A., B. & C.

9. Magnesite bricks are used in those parts of furnaces, which are __________________?

   A. Subjected to temperature fluctuation
   B. Required to resist corrosive basic slag
   C. Subjected to high load
   D. None of these

10. Maximum apparent porosity of magnesite bricks is about _____________ percent?

    A. 8
    B. 24
    C. 44
    D. 58