DETERMINATION OF ALUMINUM OXIDE CONCENTRATION IN MOLTEN CRYOLITE-ALUMINA

摘要

A method is developed for determining alumina concentration in molten cryolite-alumina. The divergence between alumina concentration values, determined by the proposed method and by leaching AlCl_3, is on average 1.5 wt. % Al_2O_3. It is established that the electrolyte melting temperature depends to a considerable extent on the current melt alumina concentration. Values are determined of specific influence coefficients for the content of AlF_3, CaF_2, MgF_2, LiF, and Al_2O_3 in electrolyte on melt liquidus temperature. The method makes it possible to exclude errors connected with the residual insoluble alumina content within an electrolyte sample, due to the use of a device providing operational and precise determination of data required for calculating alumina concentration.