A. Cristobalite
B. Tridymite
C. Quartz
D. None of these
Which is the stable form of silica between 1470°C and the melting point 1713°C ? Read More »
Refractory Technology A. 1150
B. 1300
C. 1450
D. 1550
Maximum safe working temperature for fireclay bricks is about __________ °C? Read More »
Refractory Technology A. Non-wetting characteristic
B. High thermal conductivity
C. High crushing strength
D. None of these
A. Carbides
B. Oxides
C. Borides
D. Nitrides
‘Super refractories’ are made from pure____________________? Read More »
Refractory Technology 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
Magnesite chrome refractories____________________? Read More »
Refractory Technology A. Strength
B. Abrasion resistance
C. Both A. & B.
D. Neither A. nor B.
A. Less shrinkage in heating, decreased apparent porosity & increased specific gravity
B. High strength & thermal spalling resistance
C. Less addition of water to get a workable plasticity & lesser time required for drying the raw
refractories and hence increased rate of production
D. All A., B. and C.
A. Spalling resistance
B. Fusion point
C. Resistance to slag penetration
D. Resistance to carbon monoxide attack
Pyrometric cone equivalent (PCE) of a refractory is the measure of its_________________? Read More »
Refractory Technology A. Obtaining monolithic working faces
B. Repairing construction of various furnace parts
C. Both A. & B.
D. Neither A. nor B.
Ramming masses are used for____________________? Read More »
Refractory Technology A. Oxidising
B. Neutral
C. Either A. or B.
D. Neither A. nor B.
