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In the present paper,novel sidewall materials for aluminum reduction cell were prepared in air using magnesia and magnetite as starting materials. The sintering behaviors of the specimens were investigated by means of X- ray diffraction( XRD) and scanning electron microscope( SEM). And corrosion tests in a Na_3 AlF_6- AlF_3- K_3 AlF_6 bath were conducted to evaluate the electrolyte corrosion resistance. The results show that the Fe_3O_4 phase is transformed into Fe_2O_3 at high temperatures,which in turn reacts with the MgO added to form MgFe_2O_4 spinel. And with increasing the MgO content from 0 to 30 mass%,densification of the specimens decreases mainly due to larger volume expansion resulting from formation of more Mg Fe_2O_4. The corrosion tests show that corrosion layers are produced in all the MgO added specimens. However,for specimens containing Mg Fe_2O_4 phase only,Mg( Al,Fe)_2O_4composite spinel layers are also generated,which remarkably improve the corrosion resistance of the specimens.
In the present paper, novel sidewall materials for aluminum reduction cells were prepared in air using magnesia and magnetite as starting materials. The sintering behaviors of the specimens were investigated by means of X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the Fe_3O_4 phase is transformed into Fe_2O_3 at high temperatures, which in turn reacts with the MgO added to form MgFe_2O_4 spinel. And corrosion tests in a Na_3 AlF_6-AlF_3_K_3 AlF_6 bath were conducted to evaluate the electrolyte corrosion resistance. And with increasing the MgO content from 0 to 30 mass%, densification of the specimens decreases mainly due to larger volume expansion resulting from formation of more Mg Fe_2O_4. However, for specimens containing Mg Fe 2 O 4 phase only, Mg (Al, Fe) 2 O 4 composite spinel layers are also generated, which remarkably improve the corrosion resistance of t he specimens.