Refractory Technology Which is the stable form of silica between 1470°C and the melting point 1713°C ? None of these Tridymite Quartz Cristobalite None of these Tridymite Quartz Cristobalite ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Addition of grog in fireclay brick during its manufacture is advantageous, because it results in High strength & thermal spalling resistance All of these Less addition of water to get a workable plasticity & lesser time required for drying the raw refractories and hence increased rate of production Less shrinkage in heating, decreased apparent porosity & increased specific gravity High strength & thermal spalling resistance All of these Less addition of water to get a workable plasticity & lesser time required for drying the raw refractories and hence increased rate of production Less shrinkage in heating, decreased apparent porosity & increased specific gravity ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C. 1520 1730 1630 1670 1520 1730 1630 1670 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Crushing strength of a refractory Increases with rise in service temperature Decreases with increase in porosity Is unaffected with change in service temperature Decreases with rise in service temperature Increases with rise in service temperature Decreases with increase in porosity Is unaffected with change in service temperature Decreases with rise in service temperature ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology SiO₂ percentage in firebrick is about 55-60 35-40 >94 80-85 55-60 35-40 >94 80-85 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Magnesite chrome refractories Have very low (50 kg/cm² ) cold crushing strength (C.C.S.), and can not be used in metalcase form Have very low thermal co-efficient of expansion Are not at all resistant to the corrosive action of iron oxide Have better spalling resistance than chrome magnesite refractories Have very low (50 kg/cm² ) cold crushing strength (C.C.S.), and can not be used in metalcase form Have very low thermal co-efficient of expansion Are not at all resistant to the corrosive action of iron oxide Have better spalling resistance than chrome magnesite refractories ANSWER DOWNLOAD EXAMIANS APP
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