Patent · US Expired

Process for the recovery of tantalum values

US4495158A · kind A · utility

6Cited by
4References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 29, 1984
Grant dateJan 22, 1985
Priority date
Expiry dateFeb 29, 2004

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC22B34/24
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Tantalum is recovered from an impure source containing niobium, tungsten, titanium, iron, and other impurities by a process comprising mixing the impure source with an alkali metal carbonate, drying the resulting mixture, heating the dried mixture to convert the tungsten to a soluble form, leaching to solubilize the tungsten, digesting the resulting leached solids containing tantalum in hydrochloric acid to solubilize iron values and a portion of the titanium values, dissolving the leached solids containing tantalum values in hydrofluoric acid, adjusting the pH of the resulting solution to form a first tantalum precipitate, dissolving the first tantalum precipitate in oxalic acid adjusting the pH to form a second tantalum precipitate, dissolving and digesting the second tantalum precipitate in hydrochloric acid solution to form a third tantalum precipitate of high purity.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.