Method for the production of tantalum powder using reclaimed scrap as source material

Abstract

A process for obtaining tantalum powder from tantalum containing scrap material is provided. The process includes selecting source material, such as from sintered anodes for capacitors, hydriding the source material, milling to desired particle size and surface area, dehydriding, deoxidizing, agglomerating, sifting, and acid treating to obtain tantalum powder of a desired size and purity.

1 . A method for producing tantalum powder from tantalum containing source material comprising the steps of:
 hydriding the source material;   crushing and milling the hydrided source material to form a powder;   dehydriding and agglomerate the powder to form agglomerates;   deoxidize the agglomerated powder; and,   optionally crushing and sifting the agglomerates to a desired particle size.   
     
     
         2 . The method of  claim 1  further comprising the step of acid treating the deoxidized crushed agglomerated powder. 
     
     
         3 . The method of  claim 1  further comprising the step of crushing and sifting the deoxidized crushed agglomerated powder to a desired particle size. 
     
     
         4 . The method of  claim 1  further comprising the step of treating the scrap material to remove contaminates prior to the step of hydriding the scrap material. 
     
     
         5 . The method of  claim 1  wherein the step of crushing and milling the hydrided scrap form a powder with a surface area between about 0.5 and 2.0 m 2 /g. 
     
     
         6 . The method of  claim 1  wherein agglomerates are formed of about 100 microns. 
     
     
         7 . The method of  claim 1  further comprising the step of crushing and sifting the agglomerates prior to the step of deoxidizing the agglomerates. 
     
     
         8 . The method of  claim 1  wherein the step of deoxidizing the agglomerated powder is performed by mixing the agglomerates with Magnesium metal and heating under an inert gas. 
     
     
         9 . The method of  claim 1  where the tantalum containing source material is tantalum scrap comprising one or more of Tantalum capacitor anodes and manufacturing scrap from sheet and wire. 
     
     
         10 . The method of  claim 1  further comprising the step of identifying impurities in the source material prior to the step of hydriding the source material. 
     
     
         11 . The method of  claim 1  further comprising the step of removing impurities prior to the step of hydriding the source material. 
     
     
         12 . The method of  claim 11  further wherein the impurities are removed by acid treating the source material. 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . The method of  claim 2  further comprising the steps of rinsing the acid treated anodes to remove acid residue and drying the rinsed anodes. 
     
     
         17 . The method of  claim 1  further wherein the capacitor anode contains a oxide film and further comprising the step of removing the oxide layer by heating with Mg at sufficient temperature and time to at least partially remove the oxide layer before the step of hydriding. 
     
     
         18 . The method of  claim 1  further comprising the initial steps of sampling the source material to determine initial contamination levels and treating the source material to remove contamination. 
     
     
         19 . The method of  claim 18  wherein the treating the source material is done by acid leaching the source material.