JOHN FINLAY MINING中文JOHN FINLAY MINING中文Oxide copper at 1.03% Cu upgraded to 2.32% at 81.2% recovery — letter of intent signed, preliminary design and estimate delivered.
| Product | Yield % | Grade % | Recovery % |
|---|---|---|---|
| Concentrate | 36.04 | 2.32 | 81.18 |
| Rejects | 63.96 | 0.30 | 18.82 |
| Feed | 100.00 | 1.03 | 100.00 |
Rejecting 64% of mass before grinding more than doubles effective plant capacity per tonne milled and cuts power and water demand — decisive in DRC conditions where both are constrained.
The sample was an oxide copper ore from the DRC Copperbelt, dominated by malachite in a siliceous host. Oxide ores are awkward for conventional sulphide flotation and often head for leaching — which makes coarse pre-rejection doubly valuable: every barren tonne removed is a tonne that never consumes acid, and haulage in Copperbelt logistics is a major cost line.
The enrichment ratio is 2.25 (1.03% → 2.32% Cu) at 36.04% yield: nearly two thirds of the mass (63.96%) is rejected at 0.30% Cu, taking 18.82% of the copper with it. That metal loss is a deliberate trade — at coarse sizes, some copper always sits in composite particles — and the exchange buys a 2.8× reduction in downstream tonnage per tonne of copper. Whether the optimum cut sits here or at a lighter density is an economic choice we model against acid price, power cost and haul distance.
| Item | Value |
|---|---|
| Feed size fraction | 0.5–8mm |
| 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 | Malachite & Cu oxides: 3.9–4.0 g/cm³ |
| Gangue density | Siliceous gangue: 2.6–2.7 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 0.5–8mm 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 campaign closed with a letter of intent, a preliminary plant design and a cost estimate. For DRC conditions the design logic is: reject at the mine, truck only pre-concentrate, and size the leach or flotation plant for 36% of the mined tonnage. Power demand — the scarcest resource on the Copperbelt — falls in almost direct proportion.
Market context: Copperbelt beneficiation — Zambia & DRC
Q: What recovery did dense medium separation achieve on this copper ore?
A: 81.18% Cu recovery into a 2.32% concentrate, with 63.96% of mass rejected at 0.30% Cu (0.5–8 mm).
Q: Will this work on my copper 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.
Contact us