METHOD FOR DETERMINING THE COMPOSITION AND CRYOLITE RATIO OF SOLID SAMPLES OF POTASSIUM-CONTAINING ELECTROLYTE IN ALUMINIUM PRODUCTION BY XRD

摘要

The invention relates to a method for determining the composition and cryolite ratio of a potassium-containing electrolyte, and can be used in nonferrous metallurgy and, more specifically, during in-process monitoring of the composition of an electrolyte by means of quantitative phase analysis by X-ray diffraction. The method involves taking a sample of electrolyte from a bath, grinding the sample, and adding sodium fluoride to the powdered sample in a ratio of 1:2 relative to the mass of the sample. The sample is sintered a temperature 650-750°C for 20-40 minutes. After sintering, the sample is subjected to additional heat treatment at 420-450°C for 15-30 minutes until equilibrium is reached between the crystalline phases resulting from the sintering the sample with sodium fluoride: Na 3 AlF 6 , K 2 NaAlF 6 , CaF 2 , NaF. Analysis of the phase composition of the resultant sample is carried out using quantitative phase analysis by X-ray diffraction and the cryolite ratio and the concentration of fluorides in the initial sample is determined.