Sodium has a melting point slightly below 100 degrees Celsius. Magnesium has a melting point of 650 Celsius. I don't know the exact temperature that sodium will

Sodium has a melting point slightly below 100 degrees Celsius. Magnesium has a melting point of 650 Celsius. I don't know the exact temperature that sodium will have in the Natrium reactor, but in the French Phenix reactor it was about 560 Celsius. But that's the highest one. The temperature at the bottom of the sodium pool is most likely much lower. In any case, much, much lower than the "freezing" point of magnesium, which will particulate. So, I imagine it can be filtered by a sieve made of steel, not much different than the sieve in my kitchen to filter my tea.