Section 01
Overview
Gold processing rewards precision: an extra one or two percentage points of recovery on a 200 t/day mill is the difference between a profitable operation and one that closes inside a year. The technical challenge is mineralogical — every gold deposit is different, and the equipment specification that delivered 92% recovery at one site may deliver 78% at another two kilometres away.
Cathay's gold-processing equipment line is built around four recovery pathways: **gravity** (for free gold), **flotation** (for sulphide-associated gold), **cyanidation** (for refractory ores), and **combinations** of the three. The mill specification follows the mineralogy, not the other way around.
We commission gold plants from 30 t/day artisan-scale operations in West Africa to 500 t/day industrial concentrators in Central Asia. Every commissioning includes a gold-balance audit at 30, 60, and 90 days to verify recovery hits the design target.
Cathay's gold-processing equipment line is built around four recovery pathways: **gravity** (for free gold), **flotation** (for sulphide-associated gold), **cyanidation** (for refractory ores), and **combinations** of the three. The mill specification follows the mineralogy, not the other way around.
We commission gold plants from 30 t/day artisan-scale operations in West Africa to 500 t/day industrial concentrators in Central Asia. Every commissioning includes a gold-balance audit at 30, 60, and 90 days to verify recovery hits the design target.
Section 02
Operational Challenges
**Mineralogical variation.** Free gold liberates cleanly; sulphide-locked gold needs grinding to passing-200-mesh before flotation can attack it; refractory gold (gold in pyrite/arsenopyrite) needs roasting or pressure oxidation upstream of cyanidation. Equipment chosen for the wrong liberation regime under-recovers by 15–30%.
**Reagent cost.** Cyanide, flotation collectors, and frothers can represent 20–35% of operating cost. Mill specification (residence time, slurry density, pH control) directly drives reagent consumption — a poorly-spec'd ball mill increases reagent dose to compensate for inadequate liberation.
**Security.** Gold concentrate is a high-value, portable theft target. Cathay equipment ships with sealed-discharge concentrators, locked sample ports, and secured launder geometry — design choices that matter at the plant operator level, not just the engineering specification.
**Tailings management.** Gold tailings often contain residual cyanide or sulphide gangue. Our process design includes dewatering and detoxification equipment so the operator can meet downstream environmental compliance without retrofit.
**Reagent cost.** Cyanide, flotation collectors, and frothers can represent 20–35% of operating cost. Mill specification (residence time, slurry density, pH control) directly drives reagent consumption — a poorly-spec'd ball mill increases reagent dose to compensate for inadequate liberation.
**Security.** Gold concentrate is a high-value, portable theft target. Cathay equipment ships with sealed-discharge concentrators, locked sample ports, and secured launder geometry — design choices that matter at the plant operator level, not just the engineering specification.
**Tailings management.** Gold tailings often contain residual cyanide or sulphide gangue. Our process design includes dewatering and detoxification equipment so the operator can meet downstream environmental compliance without retrofit.
Section 04
Typical Plant Setup
A representative 100 t/day gold-processing plant:
1. **Primary jaw crusher (PE-400×600)** + **secondary cone crusher** — ROM to 15 mm feed.
2. **Vibrating screen** — closed-circuit return of oversize.
3. **Ball mill (1.5×3 m)** in closed circuit with **hydrocyclone** — grinds to 70% passing 75 microns.
4. **Centrifugal concentrator** on cyclone underflow — captures 65% of free gold before flotation.
5. **Sub-aeration flotation cells** (6 cells × 6 m³) — rougher + scavenger circuit.
6. **Shaking tables** on concentrator concentrate — final gravity upgrade.
7. **Thickener + filter press** on tailings — dewatering before tailings storage.
8. **Sample turret + assay lab** — composite sampling at three circuit points.
Total connected power: ~480 kW. Site footprint: ~60×30 m for the process building. Commissioning: 10-14 weeks including gold-balance audit at 30 days.
1. **Primary jaw crusher (PE-400×600)** + **secondary cone crusher** — ROM to 15 mm feed.
2. **Vibrating screen** — closed-circuit return of oversize.
3. **Ball mill (1.5×3 m)** in closed circuit with **hydrocyclone** — grinds to 70% passing 75 microns.
4. **Centrifugal concentrator** on cyclone underflow — captures 65% of free gold before flotation.
5. **Sub-aeration flotation cells** (6 cells × 6 m³) — rougher + scavenger circuit.
6. **Shaking tables** on concentrator concentrate — final gravity upgrade.
7. **Thickener + filter press** on tailings — dewatering before tailings storage.
8. **Sample turret + assay lab** — composite sampling at three circuit points.
Total connected power: ~480 kW. Site footprint: ~60×30 m for the process building. Commissioning: 10-14 weeks including gold-balance audit at 30 days.