M. Ueda et al., INVESTIGATION OF HIGH-TEMPERATURE MOLTEN- SALTS PREDOMINANTLY COMPOSED OF CHLORIDE FOR ALUMINUM-ELECTROREFINING, Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 63(7), 1995, pp. 664-668
For electrorefining of Al from aluminum scraps by using a bipolar elec
trode system, characteristics of BaCl2-NaCl, less-corrosive melts to c
ell materials than fluoride melts, were investigated. Measuring the de
nsities as a function of their compositions showed that melts containi
ng BaCl2 over 50 mol% had higher densities than that of liquid Al (2.3
5 g . cm(-3) at 800 degrees C) and were applicable as a base melt to t
he bipolar electrode system. Next, methods for adding aluminum compone
nts into the BaCl2-NaCl were examined in terms of their solubilities a
nd stabilities. Only by feeding double salts of 40 similar to 43 mol%
AlF3-NaF, a significant concentration of aluminum components was attai
ned in the BaCl2-NaCl. The proposed melt for the bipolar electrode sys
tem is as follows, 10 mol% AlF3 15 mol% NaF-41 mol% BaCl2-34 mol% NaCl
. The low corrosivity of this melt against quartz materials has also b
een confirmed.