Refractory Technology What is Thoria? Thoria Has high resistance to basic slags Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock All of these Which is expensive & radioactive, is used in crucibles for melting high purity metals Thoria Has high resistance to basic slags Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock All of these Which is expensive & radioactive, is used in crucibles for melting high purity metals ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Spalling resistance of a refractory can not be increased by 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 Making it denser Increasing its porosity ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Magnesite refractories are generally not used in the Electric furnace walls Steel melting furnace Open hearth furnace Burning zone of cement kilns Electric furnace walls Steel melting furnace Open hearth furnace Burning zone of cement kilns ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Zirconia refractories are not used in Making sheaths for thermocouple High frequency induction furnaces in the form of inductors Lining high temperature ceramic kilns Furnaces subjected to fluctuating temperature Making sheaths for thermocouple High frequency induction furnaces in the form of inductors Lining high temperature ceramic kilns Furnaces subjected to fluctuating temperature ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Fusion point of an acidic refractory material is Reduced by the addition of basic oxides Increased by the addition of basic oxides Not affected by the addition of basic oxides Not affected by the addition of basic oxides Reduced by the addition of basic oxides Increased by the addition of basic oxides Not affected by the addition of basic oxides Not affected by the addition of basic oxides ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Magnesite refractories have low resistance to Disintegration on sudden change of temperature Attack by basic slag Abrasion Both B and C Disintegration on sudden change of temperature Attack by basic slag Abrasion Both B and C ANSWER DOWNLOAD EXAMIANS APP
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