All types of raw materials used in aluminum production, are finely dispersed structures, which cause dusting during manufacturing operations, which leads to the formation of substandard raw material deposits. Their turnover in primary production contributes to the deterioration of techno-economic parameters of the process. Alumina dust samples werea collected with a mark of 16,0 meters on aluminum smelters in Russia, in the process of various technologies application. While in the upper layers alumina absorbss moisture, fluorides, and carbon. Penetration of fluoride in the amount of alumina particles depends of the crystallographic characteristics of the grains. At high stratification of the particles, fluorides are evenly distributed on the surface, and in the bulk of the particles. Mostly solid fluorides penetrate into cracks and deformation of the grains of alumina and hydrogen fluoride is adsorbed on the surface with the formation of aluminum fluoride. Alumina dust produced by the company operating for a long time with the cryolite ratio 2,2-2,35, contains a large amount of silicon. Silicon compound coat grain acicular alumina film.
