Material
Penouta niobium–tantalum leach liquor
The mixed liquor produced by leaching Penouta tin slag in hydrofluoric and sulphuric acid, carrying niobium and tantalum together. A mixed intermediate: at this point neither element is a product, and the whole difficulty of the route is that they are chemically alike enough to travel together.
Classification
- material class
- INTERMEDIATE
- physical form
- SOLUTION
How this record is known
- 1
- Settled consensus
- Cited as the accepted position of the discipline.
1 of 1 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.
What Lithoen records
Each claim states how it is known and cites its evidence.
EstablishedSeparation by selective stripping after co-extraction. Niobium stripped with NH4F 0.3 mol/L and NH3 0.1 mol/L; tantalum with NH4F 1.1 mol/L and NH3 0.4 mol/L; both at unit aqueous-to-organic ratio, 25 degrees Celsius. Separation factor defined as the ratio of distribution ratios.
Measured at this deposit
Niobium and tantalum were taken apart from one leach liquor into two separately identified products: liquid–liquid extraction with Cyanex 923 loaded both, and two different stripping solutions — a weaker fluoride-ammonia solution for niobium and a stronger, more alkaline one for tantalum — recovered them separately.
- assertion basis: SUBJECT_MEASURED
Evidence support: Supported by the cited evidence · one source
Evidence: Rodríguez 2020 · Peer-reviewed
Record last updated 2026-09-11. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.