Elaboration du réfractaire de l’oxyde de magnésium de haute pureté extrait de la dolomie

Abstract

The sintering of magnesia of high purity (99.75 %) is made generally only at high temperatures more than 1600°C. To decrease the sintering temperature, the powders of material must undergo preliminary treatment such as the reduction of the size of grains, the temperature of calcination, the pressure of pelleting, etc. In this work, we have operated on the optimization of all these factors. We found that in the temperature 800°C, the morphology of grains is transformed totally to pass of a shape of leaf of an average size of 10 μm in a spherical shape of an average size of 0.1μm only. This mode of treatment of the powder has allows to reach the theoretical density of caking of the oxide of magnesium which is worth 3.58 g / cm3 in a lower temperature at 1500°C.