Vaporization of Alumina

There is a detailed discussion of the vaporization behavior of alumina and other oxides in [29]. The main vapor species over alumina are Al, AlO, Al2O, and AlO2, depending on the temperature and oxidizing or reducing conditions in the surrounding atmosphere. Under reducing conditions Al and Al2O are predominant; in 0.2 bar O2, both AlO and AlO2 are the main species [30].

Two examples of quantitative data of vapor pressure as a function of temperature are given in Table 15.

The boiling temperature of alumina at one atm pressure is about 3,530°C with a heat of vaporization of about 1,900kJ mol-1 at 25°C [2], when compared with the melting temperature of 2,054°C, and a heat of fusion of about 109 kJ mol-1 at 25°C [31].