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Sulphur 417 Mar-Apr 2025

19 March 2025

Metso launches sustainable new copper leaching process

FINLAND

Metso launches sustainable new copper leaching process

Metso has launched its new Cu POX leaching process for the copper extraction industry. The company says that, as ore compositions change due to depletion of deposits and increasing environmental and efficiency demands, this solution not only maximises copper recovery but also reduces environmental impact.

The Cu POX process is a hydrometallurgical method for the treatment of copper sulphide concentrates at lower capacities. The heart of the process is Metso’s proprietary OKTOP® autoclave unit, where copper concentrate is oxidised under high pressure and temperature. This results in a copper-bearing pregnant leach solution to be further treated in solvent extraction and electrowinning processes, where copper is recovered as high-purity LME Grade A cathodes.

“Copper sulphide minerals require specialized leaching conditions to achieve high recovery rates. Metso’s Cu POX leaching uses 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 minimizes environmental impact by reducing emissions and optimising the use of resources through, for example, closed loop process steps reducing the use of water,” says Petteri Pesonen, Technology Manager, Copper Hydrometallurgy at Metso.

The scalable Cu POX process accommodates various capacities and raw material compositions. The predesigned process and equipment package enables fast ramp-up to production and integrates seamlessly with solvent extraction and electrowinning (SX/EW) infrastructure. The Cu POX plant can also be implemented to improve existing heap leaching – SX/EW operations to complete depleting heap leaching pregnant leach solution production. In all cases, Metso can provide end-to-end service, from batch tests, modelling and pilot tests to engineering, equipment deliveries and plant commissioning, and training, as well as services, spare parts and digital solutions to optimise continuous process and plant performance.

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