Chemical titration method for Determination of Concentration of REO in Rare Earth Fluoride Melts

Abstract

Abstract. In the present study, chemical titration method for determination of concentration of REO in REF 3 -LiF-RE 2 O 3 melts was investigated. The melts with the composition of 40mol%REF 3 -60mol%LiF (RE=La and Nd) was taken as object for illustrating the measurement of concentration and solubility of REO by the chemical titration method. Then the changing of REO concentration in 40mol%REF 3 -60mol%LiF melts with electrolytic time in practical electrolysis production was studied. The concentration of REO decreases with the electrolytic time, and rate of the decreasing also declines with the electrolytic time. And the reasonable time interval for REO addition was recommended defining as 1.75 h which is very close to the empirical value 2 h, This would also illustrate the reliability of chemical titration method on determination of concentration of REO in the melts.