JOHN FINLAY MINING中文JOHN FINLAY MINING中文From laboratory dense-medium test work to a 300,000 t/a beneficiation plant with a 10-year operating contract — commissioned July 2026.
We ran dense medium cyclone separability tests across multiple fluorite ore grades to fix the optimal feed size window (0.5–10 mm). The client endorsed the results and awarded us the full chain: a 300,000 t/a fluorite beneficiation plant built entirely by our team, with a signed 10-year whole-plant operating contract.
| Product | Yield % | Grade % | Recovery % |
|---|---|---|---|
| Concentrate | 47.59 | 84.74 | 95.22 |
| Rejects | 52.41 | 3.86 | 4.78 |
| Feed | 100 | 42.35 | 100 |
Fluorite (CaF₂ 3.18 g/cm³) separates cleanly from quartz-calcite gangue in a centrifugal dense-medium field. Rejecting more than half the run-of-mine mass before grinding cuts milling and flotation cost dramatically, with only 0.1 m³/t of fully recycled water.
The samples came from a Mongolian fluorite district where run-of-mine grades vary widely between ore zones. Fluorite occurs as coarse-liberated crystals in a quartz–calcite host, which is close to ideal for density separation: liberation happens at crusher sizes, well before grinding. We tested several grade classes to establish how robust the cut would be across the life-of-mine blend, and fixed 0.5–10 mm as the optimum feed window.
The enrichment ratio is 2.0 (42.35% → 84.74% CaF₂) at a concentrate yield of 47.59%. More than half the feed — 52.41% — leaves the plant as coarse rejects carrying only 4.78% of the fluorite. The concentrate clears the metallurgical-grade threshold (CaF₂ ≥ 80%) straight out of a single density stage, with no grinding and no reagents; upgrading to acid-grade (≥97%) needs only a much smaller flotation circuit fed by this pre-concentrate.
| Item | Value |
|---|---|
| Feed size fraction | 0.5–10mm |
| Separator | Pressurized two-product dense medium cyclone |
| Medium | Ferrosilicon + magnetite powder, closed-circuit recovery |
| Density control | In-line density gauge with automatic water/medium make-up loop |
| Value mineral density | Fluorite: 3.18 g/cm³ |
| Gangue density | Quartz, calcite: 2.65–2.71 g/cm³ |
| Process water | 0.1 m³/t, fully recirculated |
| Medium drainage | Sieve bends + drain-and-rinse screens |
The ore was first wet-screened to remove the −0.5 mm slimes (evaluated separately for flotation). The 0.5–10mm fraction was fed to a ferrosilicon/magnetite suspension; a density-gradient series located the optimum cut density, after which the sample was passed once through a pressurized two-product cyclone. Products were drained on sieve bends, rinsed on drain-and-rinse screens, dewatered, sampled and assayed to compute yield, grade and recovery. Dilute medium was recovered by magnetic separation and densified back to the correct-medium sump under closed-loop density control.
The plant that grew from this campaign follows the test flowsheet at industrial scale: crushing and screening, dense medium cyclone separation of 0.5–10 mm, medium recovery in closed circuit, and dry coarse rejects stacked without a tailings pond. Because we operate the plant ourselves under a 10-year contract, the guarantees behind these numbers are ours to keep — grade, recovery and medium consumption are contractual, not aspirational.
Market context: Mongolia & Central Asia operations
Q: What recovery did dense medium separation achieve on this fluorite ore?
A: 95.22% of the CaF₂ reported to an 84.74% concentrate while 52.41% of the mass was rejected (0.5–10 mm feed).
Q: Will this work on my fluorite deposit?
A: Density separation depends on liberation size and density contrast, not on locality. A one-tonne representative sample answers the question definitively — washability results within 24 hours of sample receipt.
Send ~1 tonne of representative ore — washability results within 24 hours of sample receipt.
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