A. At the hearth bottom of the furnace on which stock is placed
B. Used for furnace insulation
C. Used in the roof of the furnace
D. None of these
Related Mcqs:
- . Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm2) is ______________ °C?
A. 500
B. 1000
C. >1350
D. >2000 - Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for _____________ bricks?
A. Fireclay
B. Silica
C. Dolomite
D. Very low alumina - 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 - 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 - High refractoriness of refractory bricks means, that it has a________________?
A. High spalling resistance
B. Low spalling resistance
C. High resistance to fusion
D. Low porosity - 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 - ___________________ is the measure of the strength of refractory under the combined effect of temperature & load ?
A. Porosity
B. RUL
C. Specific gravity
D. Thermal conductivity - Which of the following bricks has the most close values of RUL and PCE ?
A. Silica bricks
B. Fireclay bricks
C. High alumina bricks
D. Tar dolomite bricks - RUL of refractories depends on the _____________________?
A. Chemical composition
B. Physical structure
C. Presence of impurities like iron & alkali
D. All A., B. and C. - 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
