The refractoriness and thermal shock resistance of any material is deeply related to the crystalline and amorphous phases present. In 1969, H. M. Rietveld developed a software that provides the complete characterization of single or multiphase materials. For nearly thirty years, since it was developed, the Rietveld Method has not been extensively used in quantitative analysis of natural raw material. This study has the objective to use this methodology along with other ones, in order to quantify the amorphous phase in refractory bauxites, considering its facilities and drawbacks. Four techniques were chosen to determine the vitreous phase in refractories raw materials, using the Rietveld method as theoretical basis. The fifth technique, named chemical dissolution in fluorydric acid, was used as a comparison method. The results illustrated that, despite the efforts, none of the techniques studied can be applied as a fast and reliable method to determine the amorphous content in refractories.
raw-materials; refractories; chemical characterization
