Refractory Technology Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C. 70 770 570 270 70 770 570 270 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Natural silica Mainly contains quartz All of these Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes Is not stable at high temperature Mainly contains quartz All of these Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes Is not stable at high temperature ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Thermal conductivity of refractory bricks Is independent of its porosity and is maximum for insulating bricks Increases with decrease in porosity Decreases with decreases in porosity Increases with the amount of air entrapped in pores Is independent of its porosity and is maximum for insulating bricks Increases with decrease in porosity Decreases with decreases in porosity Increases with the amount of air entrapped in pores ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C. 1670 1520 1730 1630 1670 1520 1730 1630 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology High thermal conductivity of a refractory material is not important, when it is to be used in the Recuperators Muffle furnace Coke oven regenarators Blast furnace Recuperators Muffle furnace Coke oven regenarators Blast furnace ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Mullite is chemically represented by 3Al2O₃ . 2SiO₂ 2Al2O₃ . 3SiO₂ Al2O₃ . SiO₂ Al2O₃ . 2SiO₂ 3Al2O₃ . 2SiO₂ 2Al2O₃ . 3SiO₂ Al2O₃ . SiO₂ Al2O₃ . 2SiO₂ ANSWER DOWNLOAD EXAMIANS APP