Refractory Technology Fireclay refractories have Low co-efficient of thermal expansion Poor thermal spalling resistance Very high cost Tendency to expand unduly high during firing Low co-efficient of thermal expansion Poor thermal spalling resistance Very high cost Tendency to expand unduly high during firing ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Magnesite refractories are generally not used in the Open hearth furnace Burning zone of cement kilns Steel melting furnace Electric furnace walls Open hearth furnace Burning zone of cement kilns Steel melting furnace Electric furnace walls ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Carbon refractories Have extremely low thermal & electrical conductivities Do not burn/oxidise, when exposed to air on heating Do not resist temperature fluctuations Are not attacked by slags, as they are not wetted by melts Have extremely low thermal & electrical conductivities Do not burn/oxidise, when exposed to air on heating Do not resist temperature fluctuations Are not attacked by slags, as they are not wetted by melts ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C. 570 770 70 270 570 770 70 270 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity). Carborundum Fireclay Graphite Chromite Carborundum Fireclay Graphite Chromite ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Conversion of silica mineral to cristobalite is accompanied by reduction in its Neither A nor B Specific gravity Both A & B Volume Neither A nor B Specific gravity Both A & B Volume ANSWER DOWNLOAD EXAMIANS APP
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