Refractory Technology Thermal conductivity of refractory bricks Decreases with decreases in porosity Increases with the amount of air entrapped in pores Increases with decrease in porosity Is independent of its porosity and is maximum for insulating bricks Decreases with decreases in porosity Increases with the amount of air entrapped in pores Increases with decrease in porosity Is independent of its porosity and is maximum for insulating bricks ANSWER DOWNLOAD EXAMIANS APP
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 Cost Electrical conductivity Fusion point Thermal conductivity Cost Electrical conductivity Fusion point Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity). Graphite Fireclay Carborundum Chromite Graphite Fireclay Carborundum Chromite ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Vacuum steel degassing units are lined with High alumina bricks Graphite blocks Low duty firebricks Silica bricks High alumina bricks Graphite blocks Low duty firebricks Silica bricks ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Silica refractories All of these Have lower thermal conductivity than fireclay bricks Can not be used in the dome of hot blast stoves Crack when subjected to sudden change of temperature All of these Have lower thermal conductivity than fireclay bricks Can not be used in the dome of hot blast stoves Crack when subjected to sudden change of temperature ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the Washing action of metal Corrosion by layer of slag Both A & B Neither A nor B Washing action of metal Corrosion by layer of slag Both A & B Neither A nor B ANSWER DOWNLOAD EXAMIANS APP
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