Refractory Technology __________ of carbon blocks in the hearth of blast furnace helps in avoiding skull formation, when it becomes cold. Low porosity Non-wetting characteristics High thermal conductivity High density Low porosity Non-wetting characteristics High thermal conductivity High density ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology What is Thoria? Which is expensive & radioactive, is used in crucibles for melting high purity metals Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock Thoria Has high resistance to basic slags All of these Which is expensive & radioactive, is used in crucibles for melting high purity metals Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock Thoria Has high resistance to basic slags All of these ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Which of the following does not occur during firing/burning of refractories? Vitrification Development of stable mineral form Removal of water of hydration Decrease in crushing strength Vitrification Development of stable mineral form Removal of water of hydration Decrease in crushing strength ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Carbon refractories Have extremely low thermal & electrical conductivities Do not resist temperature fluctuations Do not burn/oxidise, when exposed to air on heating Are not attacked by slags, as they are not wetted by melts Have extremely low thermal & electrical conductivities Do not resist temperature fluctuations Do not burn/oxidise, when exposed to air on heating Are not attacked by slags, as they are not wetted by melts ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Natural silica All of these Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes Is not stable at high temperature Mainly contains quartz All of these Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes Is not stable at high temperature Mainly contains quartz ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Roof of a basic open hearth furnace is lined with __________ bricks. Fireclay Silica Dolomite Magnesite Fireclay Silica Dolomite Magnesite ANSWER DOWNLOAD EXAMIANS APP
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