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 Thermal conductivity Cost Electrical conductivity Fusion point Thermal conductivity Cost Electrical conductivity Fusion point ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture? Saw dust Chemically prepared foam Sand Cork Saw dust Chemically prepared foam Sand Cork ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Periclase is MgCO₃ Crystalline form of MgO ZrSO₄ Amorphous magnesite MgCO₃ Crystalline form of MgO ZrSO₄ Amorphous magnesite ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the Neither A nor B Both A & B Washing action of metal Corrosion by layer of slag Neither A nor B Both A & B Washing action of metal Corrosion by layer of slag ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology With increase in the density of silica refractories, its Both A & B Resistance to slag attack increases Spalling resistance reduces Neither A nor B Both A & B Resistance to slag attack increases Spalling resistance reduces Neither A nor B 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 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 All of these Less shrinkage in heating, decreased apparent porosity & increased specific gravity 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 All of these ANSWER DOWNLOAD EXAMIANS APP