Haig V Vartanian DeceasedHudson, MA

4141720, Feb 27, 1979

May 16, 1978

5/906150

Haig Vartanian - Newton MA

NRC, Inc. - Newton MA

B22F 900

75 05BB

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. , the weight ratio of tantalum powder to be treated to tantalum contained in the added potassium fluotantalate (K. sub. 2 TaF. sub.

4067736, Jan 10, 1978

Jun 4, 1976

5/693002

Haig Vartanian - Newton MA

NRC, Inc. - Newton MA

B22F 900

75251

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.

3992192, Nov 16, 1976

Jul 1, 1974

5/484780

Haig Vartanian - Newton MA

B22F 900

75 5B

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.