Abstract: Tantalum powders of capacitor grade are provided, containing interacting silicon and phosphorous dopants to effect low D.C. leakage of electrolytic capacitors having anodes made from such powders, with anodic formation at low temperatures (40.degree.-60.degree. C.), consistent with high capacitance.

Abstract: Tantalum powders which have high oxygen, high sodium contents are reclaimed for practical applications by treating said powders with selected fused salt compositions. This process converts normally unleachable sodium metatantalate, recognized herein as a significant source of the powder's content of oxygen and sodium, to leachable forms of oxygen and sodium bearing compounds.The conversion is accomplished by placing the high oxygen, high sodium tantalum powder, containing such metatantalate, in a fused salt bath which has the major portion of its composition equivalent to the final salts composition which would result from a reduction of potassium fluotantalate with sodium metal, under conditions where 90%-95% of required sodium stoichiometry was used and as a minor portion of composition contains small amounts of added potassium fluotantalate. The required amount of potassium fluotantalate is small in relation to the quantity of reclaimable tantalum powder treated by the process; i.e.

Abstract: Metal powders of agglomerated form having a uniform specific surface area for various size fractions thereof in a size spectrum extending from 3 microns to 10 mesh are produced by heating a charge of a salt source of the metal, pre-coated with reducing agent, to initiate an exothermic reduction reaction and continuing application of heat after termination of the exotherm heat output to modify powder size and agitating the reaction charge substantially throughout and further heating periods to maintain homogeneity. The charge may be diluted with inert salts to modify the necessary minimum hold temperature and the properties of resultant powders. The metal may comprise one or more of tantalum, columbium, zirconium, vanadium, hafnium, tungsten, titanium, thorium, chromium, yttrium, rare earths, germanium, manganese, beryllium, boron, iron, nickel and platinum group metals.