Analytical appro­ aches in the development of industry standard specimens of aluminum production electrolyte

Abstract

A combination of the methods of X-ray phase and X-ray spectral analyzes is used at domestic aluminum plants for operational technological control of the composition of cooled electrolytes. In this case, standard samples of chemical and phase composition are used to calibrate measuring instruments. The synthesis of standard samples from simple components is impossible due to the inadequacy of their microcrystalline structure to real electrolyte samples. Therefore, it is necessary to develop standard samples directly from the material of real electrolytes with a reliably established quantitative chemical and mineralogical phase composition. We managed to develop a set of 30 standard samples of aluminum-produced electrolyte using electrolytes taken from the electrolysis baths of various plants; some of the samples were doped with so­dium, aluminum, calcium, and magnesium fluorides to expand the range of compositions. A metrological certification of the set with the status of "Industry standard samples" was performed based on the data of interlaboratory analysis according to the methods of X-ray control used at the plants and according to the well-known Rietveld X-ray phase method for determining the quantitative phase composition. The set has been successfully implemented at seven RUSAL plants.