Each claim states how it is known and cites its evidence.
EstablishedCaWO4
Reported for this deposit
General principle, shown here for context — not an observation about this record.
Scheelite is calcium tungstate, CaWO4, which the tungsten-skarn review gives when it names the mineral and when it explains that tungsten's Swedish-derived name came from scheelite, the calcium tungstate.
- assertion basis: SOURCE_REPORTED
- generality: GENERAL_PRINCIPLE
- definition basis: The formula as written in the review; no separate mineralogical authority was consulted for it in this phase.
Evidence support: Supported by the cited evidence · one source
Evidence: Foucaud 2020 · Peer-reviewed
Establishedselectivity against calcium salts, unresolved; contradictory results on phosphate depressants
Reported for this deposit
General principle, shown here for context — not an observation about this record.
The difficulty in floating scheelite is one of SELECTIVITY rather than of floatability. A review states that skarn gangue includes calcium salts — fluorite, apatite and calcite — whose surface properties resemble scheelite's, that most reagents fail to give good global selectivity in favour of scheelite against them, and that the froth flotation of scheelite therefore remains in the twenty-first century a strong scientific, industrial and technical challenge. The review also records that published results on phosphate derivatives as depressants are contradictory, some authors using them to depress calcite and fluorite and others to depress apatite.
- assertion basis: SOURCE_REPORTED
- generality: GENERAL_PRINCIPLE
- definition basis: The review's own characterisation of the problem and of the state of the reagent literature.
- assumption: A class-level statement about scheelite skarn flotation. It describes a scientific difficulty and says nothing about the economics of any operation, and the contradiction in the reagent literature is preserved rather than resolved here.
Evidence support: Supported by the cited evidence · one source
Evidence: Foucaud 2020 · Peer-reviewed
Establishedmagnetic unsuitable; gravity lossy at fine liberation; flotation by default since the 1930s
Reported for this deposit
General principle, shown here for context — not an observation about this record.
A review of tungsten skarn processing states that scheelite's own properties rule out two routes and force a third. It is diamagnetic, as are most of its gangue minerals, so magnetic separation is usually unsuitable. Its specific gravity of 6.1 invites gravity separation, but skarn ores display fine liberation sizes at which classical gravity apparatus is poorly efficient, and scheelite's tendency to form particles below ten micrometres increases the losses further. Consequently, the review states, scheelite has traditionally been beneficiated by froth flotation since the 1930s.
- assertion basis: SOURCE_REPORTED
- generality: GENERAL_PRINCIPLE
- definition basis: A class-level statement about a mineral's separation behaviour, made by a review of the deposit type.
- assumption: This is about scheelite skarn ores as a class. It is not a statement about any particular deposit's plant, and no route may be attached to a named deposit on the strength of it.
Evidence support: Supported by the cited evidence · one source
Evidence: Foucaud 2020 · Peer-reviewed