DENSIFICATION AND MECHANICAL PROPERTIES OF REACTION SINTERED Al_2O_3-MgO-CaO REFRACTORY

摘要

For the purpose to reduce the high cost and heat storage loss of Al_2O_3-MgO bricks used as ladle linings, Al_2O_3-MgO-CaO bricks with lower theoretical density were fabricated and the densification behavior as well as mechanical property of this refractory was investigated. With addition of CaO, the initial sintering temperature of Al_2O_3-MgO refractory was decreased from 1300 to 1100°C associated with the expansive formation of CA2, and the compressive strength was also enhanced owing to the formation of bond linkage between CA_6 and spinel. At high temperature, brick with 4% CaO content showed poor sinterability with high porosity because of the formation of platelet structure of CA_6 grains, whereas brick with 8% CaO content was well sintered with higher relative density but lower bulk density than Al_2O_3-MgO brick, indicating that the densification as well as lightweight of Al_2O_3-MgO refractory was effectively promoted.