REPROCESSING & RETREATMENT
The Metalkol tailings reprocessing facility in DRC
Tailings turnaround
The reprocessing of tailings is very much in focus today, ticking a lot of boxes from sustainability to circularity as well as the drive to source more critical minerals, reports Paul Moore
Reprocessing of tailings is becoming an ever more important part of the mining industry, driven by the challenges in developing primary ore deposits, advances in mineral processing technologies like flotation to make reprocessing more efficient, and the advantages reprocessing brings in terms of remediation and circularity.
Metalkol, a facility wholly owned by Eurasian Resources Group( ERG), officially commenced The Copper Mark assurance process in 2024 – which was significant as it is the the first tailings reprocessing site to do so. Metalkol is located near Kolwezi in DRC and is a comprehensive hydro-metallurgical facility which has become one of the world’ s largest producers of cobalt and a large producer of copper. Unlike conventional mining operations which extract primary ore, at Metalkol, the historic copper-cobalt tailings from third-party mining activities are reclaimed and reprocessed.
Undertaking the assurance process reflects Metalkol’ s commitment to upholding responsible and sustainable practices, in line with the principles and goals stated in the OECD Due Diligence Guidance for Responsible Supply Chains of Minerals. This is according to a letter of commitment signed by Metalkol and The Copper Mark on September 12, 2024.
The Copper Mark is a leading assurance framework launched in 2020 to address growing international demand for the responsible sourcing and production of minerals, promoting best practice across the copper, nickel, molybdenum and zinc value chains. The assurance process is a voluntary, transparent and independent award based on third-party assessments by approved assessors that will verify that Metalkol meets the requirements for responsible production practices, the companies say.
Michèle Brülhart, Executive Director of the Copper Mark, said:“ We welcome Metalkol as the first tailings reprocessing site to commit to the Copper Mark assurance process. Reprocessing of mine waste is an important part of ensuring responsible production both in terms of minimising the site’ s long-term impact, and maximising its efficiency.”
Nicolas Treand, CEO of ERG Africa, said:“ The acceptance of our application into The Copper Mark assurance process is a significant milestone for both ERG in Africa and the whole group. Undergoing this assurance process reflects our commitment to adhere to the highest sustainability standards and contribute to the responsible development of the mining sector in the Democratic Republic of the Congo, which is
essential for the future of the country and its people.”
Achieving The Copper Mark award will align with ERG Africa’ s sustainable production commitments, outlined in its Clean Cobalt & Copper Framework. The framework also commits Metalkol to the Responsible Mineral Initiative’ s Responsible Minerals Assurance Process for which it is already annually certified.
Mount Isa and Flin Flon tailings being lined up for reprocessing
Other major mining companies are taking significant steps towards tailings reprocessing. In Australia, Glencore remains in discussions with the Crisafulli Government on the future of its Mount Isa copper smelter and Townsville copper refinery operations in Queensland. Glencore plc CEO Gary Nagle met recently with the Queensland Premier, Treasurer and Minister for Resources to discuss a range of issues including the copper smelter operations. Glencore says it has committed to working with third parties to explore options for reprocessing of Mount Isa Mines tailings and is progressing studies for the Black Star Open Cut( BSOC). Mount Isa Mines owns and operates a tailings storage facility 3.9 km south-west of Mount Isa, Queensland. It contains some remnant metals, including zinc-lead-silver and copper, but mostly sand, silt and clay particles. The tailings storage facility covers an area of 1,500 hectares. It is surrounded by steep hills, which help naturally contain the tailings. The facility comprises five large retaining embankments. The closure of the Mount Isa Copper Operations( MICO) mining operations themselves is underway and expected to be completed in July 2025.
The development of tailings reprocessing at Mount Isa would follow one of the world’ s most successful operations of this
Hudbay is advancing studies to evaluate the opportunity to reprocess Flin Flon tailings in Manitoba
32 International Mining | JUNE 2025