Preparation of Niobium Metal Powder by Two-Stage Magnesium Vapor Reduction of Niobium Pentoxide

Table 2

Chemical analysis of magnesium vapor reduced niobium powders (in ppm).

Element	Niobium pentoxide	1st stage niobium powder	After 2nd stage niobium powder
Ni	<20	35	35
W	420	550	555
Ta	925	1150	1160
Co	<20	<20	<20
Cr	<20	<20	<20
Mn	<10	<10	<5
Mg	<20	1200	925
O	—	8%	6500
Fe	<20	<20	<20