Rare earth fluorides, metals and slag have strong chemical activity, so the crucible material used must be resistant to corrosion by halogens and their compounds at high temperatures and does not interact with rare earth metals. It can be used for a long time in inert atmosphere.
Below we list the chemical stability of different crucible materials to rare earth metals and halides.
It is relatively stable at 1200 ℃. It was used in the village of RECl3-KCl molten salt electrolyzer.
Stable within 1000℃
Can be used up to 1250 ℃
High purity zirconia
No higher than 1700 ℃, stable in vacuum and inert atmosphere
Alumina, Silicon Oxide
Reacts with molten metal at high temperatures
Stable in vacuum and inert gas before 1700 ℃, but it has obvious effect with scandium and lutetium
1% -2% dissolved in rare earth metal at 1500 ℃ in vacuum and inert gas paper
Stable before 1400 ℃ in inert gas
Slowly corroded at high temperature in an inert atmosphere, but stable to halides
Slow action on rare earth metals, but stable to halides
Stable to cerium at high temperature and halide at 1000 ℃
Titanium nitride (70%) + titanium oxide (30%)