Metso has introduced the Cu POX leaching solution, a new hydrometallurgical process to enhance copper sulphide leaching efficiency and environmental sustainability.
The Cu POX leaching solution aims to boost copper recovery while mitigating environmental impact, while addressing the challenges posed by changing ore compositions and the depletion of deposits.
Central to the Metso Cu POX process is the proprietary OKTOP Autoclave unit, which oxidises copper concentrate under high pressure and temperature.
This generates a copper-bearing pregnant leach solution (PLS) that undergoes further processing through solvent extraction and electrowinning (SX-EW), producing high-purity London Metal Exchange (LME) Grade A cathodes.
Metso Copper Hydrometallurgy technology manager Petteri Pesonen said: “Copper sulphide minerals require specialised leaching conditions to achieve high recovery rates.
“Metso’s Cu POX leaching utilises high-temperature oxidation to convert sulphide sulphur into sulphate and sulphuric acid, ensuring efficient copper dissolution. This technology offers a high-performance solution with high, up to 99%, copper recovery rates, ensuring maximum extraction of valuable metals from the ore.
“The process also minimises environmental impact by reducing emissions and optimising the use of resources through, for example, closed loop process steps reducing the use of water.”
According to the company, the Cu POX process is flexible and scalable and can accommodate different capacities and raw material compositions.
Its pre-designed setup allows quick production ramp-up and integrates with SX-EW infrastructure.
The technology can also enhance heap leaching operations by supplementing PLS production as resources deplete.
Metso said it offers comprehensive support throughout the implementation of the Cu POX process, including batch tests, engineering, equipment supply, modelling, pilot tests, plant commissioning and training.
The company also provides ongoing services, spare parts and digital solutions to optimise plant performance.
In September 2024, Metso secured a contract with Barrick Gold for the supply of key process equipment for the Lumwana copper project in Zambia.
The contract includes the provision of grinding, flotation, thickening, feeding and filtration systems.
