Refractory Technology Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900°C ) use, except Electrical conductivity Fusion point Cost Thermal conductivity Electrical conductivity Fusion point Cost Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology SiO₂ percentage in firebrick is about 80-85 55-60 35-40 >94 80-85 55-60 35-40 >94 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material? Water Plaster of paris Aluminium phosphate Lime Water Plaster of paris Aluminium phosphate Lime ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology With increase in the alumina content, the refractoriness of high alumina refractories Increases May increase or decrease Decreases Remains same Increases May increase or decrease Decreases Remains same ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Which one contains maximum percentage of Al2O₃ ? Sillimanite Magnesite Firebrick Aluminous firebrick Sillimanite Magnesite Firebrick Aluminous firebrick ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Graphite or carbon refractories Exhibit high shrinkage on thermal treatment Should be used in neutral or reducing atmosphere Exihibit wetting characteristics Are not resistant to corrosion by slag Exhibit high shrinkage on thermal treatment Should be used in neutral or reducing atmosphere Exihibit wetting characteristics Are not resistant to corrosion by slag ANSWER DOWNLOAD EXAMIANS APP
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