Relationship between the particle size and the crystalline phases amount of an aluminum dross

Abstract

The Rietveld method was used in order to determine the amount of crystalline phases present in aluminum dross with particle size less than 3.35 mm. Initially, the dross was separated in four granulometric fractions by screening. Two samples of each granulometric size were obtained by means of quartering and homogenization. Each sample was grounded and subsequently analyzed by X-ray diffraction in order to identify and quantify the crystalline phases present in the dross. Metallic aluminum, aluminum oxide, spinel, defect spinel, diaoyudaoite and aluminum nitride were identified and then quantified by the Rietveld method. In order to observe the dependence of the particle size with the amount of each phase, statistical analyses was done by means of analyses of variance (ANOVA). The coefficient of determination R2 was greater than 94% for all phases except for the NaAl11O17 phase. Thus, the amount of each crystalline phase is satisfactory explained by particle size.