A. Silica
B. Fireclay
C. High alumina refractory
D. Carbon black
Related Mcqs:
- Which is an acidic refractory ?
A. Magnesite
B. Dolomite
C. Fireclay
D. Chrome magnesite - An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture ?
A. Cork
B. Saw dust
C. Sand
D. Chemically prepared foam - A solution having a pH value of 5 is less acidic than the one having a pH value of 2 by a factor of ________________?
A. 3
B. 100
C. 1000
D. None of these - If pH value of an acidic solution is decreased from 5 to 2, then the increase in its hydrogen ion concentration is _____________ times?
A. 10
B. 100
C. 1000
D. 10000 - Thermal conductivity of refractory bricks____________________?
A. Increases with decrease in porosity
B. Decreases with decreases in porosity
C. Is independent of its porosity and is maximum for insulating bricks
D. Increases with the amount of air entrapped in pores - Water content in ground refractory material to be shaped into bricks by hand moulding is about _____________ percent?
A. 5
B. 20
C. 40
D. 55 - 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. - High porosity refractory bricks have________________?
A. Poor resistance to the penetration of molten slag, metal & flue gases
B. Poor heat conductivity & low strength
C. Better thermal spalling resistance
D. All A., B. and C. - Test piece for determination of RUL of a refractory is heated in a/an__________________?
A. Oxidising atmosphere
B. Reducing atmosphere
C. Electric furnace
D. Neutral atmosphere - Fusion point of a basic refractory material is________________?
A. Reduced by the addition of acid oxides
B. Increased by the addition of acid oxides
C. Not affected by the addition of acid oxides
D. Always less than 1000°C
