Recovery of metal values from process residues
US5437848A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1992 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | Jul 10, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for recovering metal and acid values from a source material containing metallic fluorides comprises digesting the source material in sulfuric acid to form a slurry, separating a fluoride containing solid phase and a metal containing first liquid phase. The solid phase is subjected to pyrohydrolysis, sulfuric and hydrofluoric acids are recovered, and the first liquid phase is processed to recover the metal values by solvent extraction or ion exchanges. The tantalum values are extracted from the first liquid aqueous phase by a water immiscible organic extractant such as methylisobutyl ketone to form a first liquid organic phase containing tantalum and a second liquid aqueous phase. The tantalum is stripped from the first organic phase using water. The process includes the additional steps of heating the separated solid phase from about ambient temperature to an elevated temperature in the presence of water vapor to evolve sulfuric acid and render the gangue chemically inert. When the source material contains uranium the digestion step reduces the amount of gangue present in the radioactive source. The process can include the additional steps of removing uranium from the sec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.