Abstract: This invention relates to producing aluminum by electrolysis of a melt and can be used in the process control of an electrolyte composition by quantitative X-ray phase analysis (XRD) of potassium-containing electrolyte with calcium or calcium and magnesium additives. A quantitative XRD method is employed for analyzing doped samples of crystallized bath samples taken from baths. A weighted ground bath sample is mixed with a weighted quantity of sodium fluoride at a ratio, for example, 1:2 by weight. The weighted quantities are mixed and placed in a furnace (650-750° C. for 20-40 minutes) to dissolve sodium fluoride in the sample and recrystallize the sample with the desired phase composition. The doped sample is placed in a furnace (420-450° C) and held for 15-30 minutes. The doped sample is removed from the furnace and allowed to air cool. The phase composition of the doped sample is analyzed by any quantitative X-ray phase method.

Abstract: This invention relates to the field of nonferrous metallurgy, and in particular, to producing aluminum by the electrolysis of a melt and can be used in the process control of an electrolyte composition by quantitative X-ray phase analysis (XRD) of potassium-containing electrolyte with calcium or calcium and magnesium additives. The method is as follows. A quantitative XRD method is employed for analyzing doped samples of crystallized bath samples taken from baths. For this purpose, a weighted ground bath sample is mixed with a weighted quantity of sodium fluoride at a ratio, for example, 1:2 by weight of the sample. The weighted quantities are mixed and placed in a furnace heated to 650-750° C. for 20-40 minutes to dissolve sodium fluoride in the sample and recrystallize the sample with the desired phase composition. Then the doped sample is placed in a furnace heated to a temperature of 420-450° C. and held there for 15-30 minutes. The doped sample is then removed from the furnace and allowed to air cool.