Refractory Technology Carborundum used for making crucibles for melting non-ferrous metals is chemically Zirconium sulphate Crystalline magnesia Silicon carbide Silicon nitride Zirconium sulphate Crystalline magnesia Silicon carbide Silicon nitride ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Spalling resistance of a refractory can not be increased by Making it denser Increasing its porosity Decreasing its thermal co-efficient of expansion Using a coarser grog during its manufacture Making it denser Increasing its porosity Decreasing its thermal co-efficient of expansion Using a coarser grog during its manufacture ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Fusion point of an acidic refractory material is Not affected by the addition of basic oxides Increased by the addition of basic oxides Not affected by the addition of basic oxides Reduced by the addition of basic oxides Not affected by the addition of basic oxides Increased by the addition of basic oxides Not affected by the addition of basic oxides Reduced by the addition of basic oxides ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm² ) is __________ °C. >2000 1000 500 >1350 >2000 1000 500 >1350 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Chromite refractories are used in Both A & B Neither A nor B Between acid & basic linings in basic open hearth furnaces to prevent their chemical action with each other Bottom of soaking pits Both A & B Neither A nor B Between acid & basic linings in basic open hearth furnaces to prevent their chemical action with each other Bottom of soaking pits ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Carbon refractories 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 Have extremely low thermal & electrical conductivities Do not burn/oxidise, when exposed to air on heating ANSWER DOWNLOAD EXAMIANS APP
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