Refining of tantalum and tantalum scrap with carbon
AssigneeH.C. Starck GmbH
InventorsRobert A Dorvel, Leonid N. Shekhter, Ross W. Simon
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Abstract
Tantalum scrap of high oxygen content is recovered and processed to metallurgical grade tantalum by fine participation. Blending with carbon or other appropriate solid reducing agent, melting in a plasma furnace (20) at about tantalum melt temperature while suppressing partial pressure of tantalum oxide gas to minimize tantalum loss of the process.
Claims24
The method of refining high oxygen sources of refractory metal(s) comprising the step of intermixing a solid reducing agent the refractory metal(s) and heating the metal(s) with the intermixed solid reducing agent with at a temperature at or above melting point of the metal while suppressing partial pressure of oxides of the refractory metal through maintenance of an elevated pressure environment to produce a refined refractory metal, the process being controlled so that only a portion of the intermixed reducing agent and source material melts at a time while the oxide of solid adjacent source material is reduced before melting as well as during its eventual melting, the process being further controlled to effect substantial oxygen, nitrogen removal while suppressing carbide formation and over 90% by weight of the refractory metal of the source is recovered.
The method of refining high oxygen sources of refractory metal(s) comprising the step of intermixing a solid reducing agent with the refractory metal(s) and heating the metal(s) with the intermixed solid reducing agent at 1000-3000° C. while suppressing partial pressure of oxides of the refractory metal through maintenance of an elevated pressure environment to produce a refined refractory metal, the process being controlled so that only a portion of the intermixed reducing agent and source material melts at a time while the oxide of solid adjacent source material is reduced before melting as well as during its eventual melting, the process being further controlled to effect substantial oxygen, nitrogen removal while suppressing carbide formation and over 90% by weight of the refractory metal of the source is recovered.
Dependencies are inferred from the claim text.