Experimental investigation for self-propagating aluminum thermal reduction of hafnia

The experiment of self-propagating aluminum thermal reduction of hafnia was investigated with the X-ray diffraction (XRD), scanning electron microscope (SEM) and chemical analysis. The results show that hafnia can be reduced when the heat of reaction per unit mass is greater than 3000 kJ/kg and the separation of slag-metal is good after adding the calcium oxide. The results of XRD analysis show that reduced product is Al₃Hf mainly. The results of SEM/energy disperse spectroscopy (EDS) show that metal product, which is composed of Al₃Hf phase and Al phase, is lamellar and irregular arrangement. The chemical analysis results show that the oxygen content of the metal is as low as 0.20% and the hafnium content is up to 41.20%. (authors)