Overview
Hydrometallurgy extracts metals via leach → solvent extraction (SX) → electrowinning (EW). Leach-liquor acidity, organic-to-aqueous ratio in SX, and Cu²⁺ concentration in EW tankhouse electrolyte are the critical control parameters. The framework spans copper (heap-leach SX-EW), cobalt (laterite Co solvent extraction), nickel (HPAL pressure leach) and lithium (brine and spodumene leach) — the heart of the modern non-ferrous and battery-materials industry.
Process challenges
- Leach liquor is strongly acidic (pH < 1) and hot (80-150°C)
- SX phase carries kerosene + extractant — phase boundary detection is hard
- EW electrolyte needs ±0.1 g/L Cu²⁺ precision — directly drives cathode yield
- Brine streams at 200-300 g/L total salts are prone to crystallisation on differential-pressure cells
- Radioactive gauges face strict licensing in remote refineries
Recommended solutions
| Measurement point | Principle | Models |
|---|---|---|
| Leach liquor Cu²⁺ / Ni²⁺ | Ultrasonic sound velocity + T comp | PS7020 |
| SX organic-to-aqueous (O/A) ratio | Optical / microwave | PS7110 / PS7600 |
| EW tankhouse Cu²⁺ | Ultrasonic sound velocity | PS7020 |
| Brine Li concentration | Coriolis / ultrasonic | PS7200 / PS7020 |
| Crystallisation mother liquor | Ultrasonic + scale-resistant | PS7000 |