yes, very classical i think. seldom people do the work. in our company the normal Ta powders are ok, no problem.
the oxygen is controled below 1500 ppm, generally around 1000 ppm, how much the oxygen in your Ta powders.
the big problem is the capacitor grade Ta, some properties are not stable.
the EBM Ta powder is another kind powder, we also hydride Nb or Ta for other applications.
we also have Nb powders.
we do the whole process, from the Ta and Nb minerals to Ta and Nb oxide, K2TaF7, LiTaO3 and so on.
Nb and Ta powders, Nb alloys, Ta alloys and etc.