Section 01
Overview
Base-metal flotation is the workhorse of global non-ferrous metal production — and the area where small process improvements have outsized economic impact. A 2,000 t/day copper concentrator that improves copper recovery from 87% to 89% generates an additional ~$8 million per year at current metal prices.
Cathay base-metal equipment is engineered for selective flotation: separating chalcopyrite from pyrite, galena from sphalerite, sphalerite from gangue. The mill specification depends on the mineralogy (chalcopyrite-pyrite vs. chalcopyrite-bornite, galena-sphalerite-pyrite vs. galena-only), and Cathay's process team configures the flotation circuit per ore type.
We supply both standalone equipment (ball mill, flotation cell, magnetic separator, thickener) and complete circuit packages. Reference deployments span Andean copper porphyries, Iberian polymetallic sulphides, and African polymetallic vein deposits.
Cathay base-metal equipment is engineered for selective flotation: separating chalcopyrite from pyrite, galena from sphalerite, sphalerite from gangue. The mill specification depends on the mineralogy (chalcopyrite-pyrite vs. chalcopyrite-bornite, galena-sphalerite-pyrite vs. galena-only), and Cathay's process team configures the flotation circuit per ore type.
We supply both standalone equipment (ball mill, flotation cell, magnetic separator, thickener) and complete circuit packages. Reference deployments span Andean copper porphyries, Iberian polymetallic sulphides, and African polymetallic vein deposits.
Section 02
Operational Challenges
**Selectivity vs. recovery.** Aggressive reagent dosing recovers more metal but pulls more gangue into the concentrate, lowering grade. Conservative dosing keeps grade high but loses metal to tailings. Cathay flotation cells include precise air-flow + impeller-speed controls so the operator can navigate this trade-off without circuit reconfiguration.
**Polymetallic separations.** Lead-zinc-copper ores require sequential flotation: depress sphalerite while floating galena, then activate sphalerite for separate recovery. Each stage has different reagent regimes; mill design must accommodate easy reagent introduction at multiple points.
**Pyrite handling.** Pyrite is the dominant gangue sulphide and floats easily with copper, contaminating concentrate. Lime addition for pyrite depression must be controlled tightly — too much depresses copper, too little contaminates concentrate. Our flotation cells include in-cell pH probes as standard.
**Concentrate dewatering.** Smelter contracts penalise wet concentrate (penalty per percentage point above target moisture). Our thickeners + filter presses are sized for the actual concentrate grade, not the ore feed rate — small operations need the same filter press surface area as larger ones if the concentrate is the same.
**Polymetallic separations.** Lead-zinc-copper ores require sequential flotation: depress sphalerite while floating galena, then activate sphalerite for separate recovery. Each stage has different reagent regimes; mill design must accommodate easy reagent introduction at multiple points.
**Pyrite handling.** Pyrite is the dominant gangue sulphide and floats easily with copper, contaminating concentrate. Lime addition for pyrite depression must be controlled tightly — too much depresses copper, too little contaminates concentrate. Our flotation cells include in-cell pH probes as standard.
**Concentrate dewatering.** Smelter contracts penalise wet concentrate (penalty per percentage point above target moisture). Our thickeners + filter presses are sized for the actual concentrate grade, not the ore feed rate — small operations need the same filter press surface area as larger ones if the concentrate is the same.
Section 04
Typical Plant Setup
A representative 1,500 t/day copper-concentrator circuit:
1. **Three-stage crushing** — jaw → cone → cone. Output to 12 mm.
2. **Coarse ore stockpile (5,000 t)** — buffer to enable independent crushing/grinding shift patterns.
3. **SAG mill or rod mill** + **ball mill** (in series) — primary grind to 70% passing 75 microns.
4. **Cyclone cluster** — overflow to flotation, underflow to ball mill (closed circuit).
5. **Copper rougher flotation** (6 × 16 m³ cells) — primary recovery.
6. **Copper cleaner flotation** (4 × 8 m³ cells) — concentrate upgrade.
7. **Cleaner scavenger** (4 × 8 m³ cells) — recover middlings.
8. **Concentrate thickener (30 m diameter)** + **filter press** — dewater to 8-10% moisture for shipment.
9. **Tailings thickener** + tailings pump to TSF.
Total connected power: ~3.8 MW. Site footprint: ~120×60 m for the process plant. Commissioning: 14-20 weeks.
1. **Three-stage crushing** — jaw → cone → cone. Output to 12 mm.
2. **Coarse ore stockpile (5,000 t)** — buffer to enable independent crushing/grinding shift patterns.
3. **SAG mill or rod mill** + **ball mill** (in series) — primary grind to 70% passing 75 microns.
4. **Cyclone cluster** — overflow to flotation, underflow to ball mill (closed circuit).
5. **Copper rougher flotation** (6 × 16 m³ cells) — primary recovery.
6. **Copper cleaner flotation** (4 × 8 m³ cells) — concentrate upgrade.
7. **Cleaner scavenger** (4 × 8 m³ cells) — recover middlings.
8. **Concentrate thickener (30 m diameter)** + **filter press** — dewater to 8-10% moisture for shipment.
9. **Tailings thickener** + tailings pump to TSF.
Total connected power: ~3.8 MW. Site footprint: ~120×60 m for the process plant. Commissioning: 14-20 weeks.