Refractory Technology Porosity of silica bricks varies from __________ percent. 20 to 30 60 to 75 5 to 10 45 to 60 20 to 30 60 to 75 5 to 10 45 to 60 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Mullite is chemically represented by Al2O₃ . 2SiO₂ 2Al2O₃ . 3SiO₂ 3Al2O₃ . 2SiO₂ Al2O₃ . SiO₂ Al2O₃ . 2SiO₂ 2Al2O₃ . 3SiO₂ 3Al2O₃ . 2SiO₂ Al2O₃ . SiO₂ ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Carborundum used for making crucibles for melting non-ferrous metals is chemically Silicon nitride Silicon carbide Zirconium sulphate Crystalline magnesia Silicon nitride Silicon carbide Zirconium sulphate Crystalline magnesia ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the Nuclear reactors, missiles & space crafts Hearth of the blast furnace Roof of electric furnaces Insulation of high temperature furnaces Nuclear reactors, missiles & space crafts Hearth of the blast furnace Roof of electric furnaces Insulation of high temperature furnaces ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Addition of grog in fireclay brick during its manufacture is advantageous, because it results in Less shrinkage in heating, decreased apparent porosity & increased specific gravity All of these Less addition of water to get a workable plasticity & lesser time required for drying the raw refractories and hence increased rate of production High strength & thermal spalling resistance Less shrinkage in heating, decreased apparent porosity & increased specific gravity All of these Less addition of water to get a workable plasticity & lesser time required for drying the raw refractories and hence increased rate of production High strength & thermal spalling resistance 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