Metso introduces new copper sulfide leaching process

Metso has announced the launch of its Cu POX leaching process to address the needs of the copper extraction industry.

As ore compositions change due to depletion of deposits and increasing environmental and efficiency demands, this cutting-edge solution not only maximizes copper recovery but also reduces environmental impact, Metso said on Wednesday.

The Cu POX process is a proven hydrometallurgical method for the treatment of copper sulfide concentrates at lower capacities. The heart of this process is Metso’s proprietary OKTOP autoclave unit, where copper concentrate is oxidized under high pressure and temperature to produce a copper-bearing pregnant leach solution (PLS).

The PLS would be further treated in solvent extraction and electrowinning processes, from which copper is recovered as high-purity LME Grade A cathodes.

“Copper sulfide minerals require specialized leaching conditions to achieve high recovery rates. Metso’s Cu POX leaching utilizes high-temperature oxidation to convert sulfide sulfur into sulfate and sulfuric acid, ensuring efficient copper dissolution,” stated Petteri Pesonen, technology manager, copper hydrometallurgy.

“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 optimizing the use of resources through, for example, closed loop process steps reducing the use of water,” Pesonen added.

According to Metso, the Cu POX process can accommodate various capacities and raw material compositions. The pre-designed 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 PLS production.

In all cases, Metso can provide end-to-end expertise from batch tests, modelling and pilot tests to engineering, equipment deliveries and plant commissioning, and training. In addition, the company provides services, spare parts and digital solutions to optimize continuous process and plant performance.