What is the best way to reduce Tantalum oxide powder/chippings to Tantalum?

I've heard that using molten salts in an inert atmosphere works, although I have found no definitive evidence so far. Any advice is welcomeWhat is the best way to reduce Tantalum oxide powder/chippings to Tantalum?
The tantalum oxide is converted to a salt, K2TaF7, potassium fluorotantalate. The Ta has an oxidation state of +5 here. Now if you melt the salt and pump in pure sodium, the sodium Na gives electrons to the Ta so it gets reduced from Ta +5 to Ta, which is a pure gray metal. The Na goes to Na+ which becomes part of the salt matrix. When the solution cools you have something that looks like granite. Crushing and washing away all the salts and rinsing in water leaves pure Ta. You need inert atm because the molten Na will burn in air.