Temperatures for the primary crystallization of
Na3AlF6-AlF3-CaF2-KF-LiF-Al2O3 system adopted in aluminum electrolysis
process were determined by thermal analysis. An empirical equation was
derived to describe the liquidus temperatures for the primary
crystallization of this multicomponent electrolyte system: t/?=1011 +
0.7w(AlF3) - 0.232w(AlF3)2 - 7.65w(Al2O3) + 0.523w(Al2O3)2 - 8.96w(LiF) +
0.043w(LiF)2 - 3.32w(KF) - 0.12w(KF)2 - 3.28w(CaF2) +0.037w(CaF2)2 +
0.091w(AlF3)w(LiF) + 0.074w(AlF3)w(KF) + 0.084w(AlF3)w(CaF2) -
0.27w(Al2O3)w(LiF), where w(AlF3) denotes the mass fraction of excess
aluminum fluoride with respect to cryolite. While w(Al2O3) ranges from 2% to
4%, w(LiF), w(KF) and w(CaF2) from 0 to 7%, and the molar ratio of NaF/AlF3
from 2.2 to 3.
A novel hybrid analysis and modeling approach applied to aluminum electrolysis process
