New copper push, Rio Tinto’s Oyu Tolgoi mine technology steps into focus

Edited by ad hoc news New Releases & Launches Desk. Reviewed before publication on 06/15/2026 at 8:26 PM ET. Details in the imprint.

Rio Tinto is tightening its focus on copper with an aggressive ramp-up of underground production at the Oyu Tolgoi copper-gold mine in Mongolia, one of the largest known copper deposits in the world. The project’s latest phase centers on bringing high-tech block-cave mining fully online, a step that should significantly lift copper output over the rest of the decade while reducing unit costs at the remote site.

Oyu Tolgoi underground moves from project to production pillar

Oyu Tolgoi combines an existing open-pit operation with a massive new underground mine that Rio Tinto says will eventually supply up to 500,000 tons of copper a year at peak, making it a key long-life asset for the group and a major source of copper for global energy-transition demand. The underground portion relies on large-scale panel cave mining, with ore extracted via a network of tunnels more than 1,300 feet below the surface and conveyed to the surface for processing, allowing a much higher grade feed than the current open pit.

The ramp-up has taken years of construction and negotiations with the Mongolian government and project partners, but Rio Tinto now reports that multiple production panels are in operation and that additional drawpoints are being added as development tunnels advance, supporting a steady increase in mined tonnage from the underground levels. The company highlights the use of extensive automation, including remotely operated loaders and digital mine-planning systems, to manage ground conditions and maximize ore recovery while keeping on-site personnel exposure lower in the complex cave environment. This underground expansion is designed to extend Oyu Tolgoi’s mine life well into the 2050s and beyond, turning what was once a frontier greenfield project into one of Rio Tinto’s core copper hubs according to its latest project updates on the official Oyu Tolgoi operations page.

Alongside the technical ramp-up, investment has gone into on-site infrastructure in the Gobi Desert, ranging from power and water management to worker accommodations and logistics links to smelters and export routes. Oyu Tolgoi ore is processed into concentrate on site before being trucked out of Mongolia, and Rio Tinto has been working with authorities on improving border procedures and exploring long-term options for power security, both of which are key to keeping the underground mine’s high-throughput design running smoothly. These steps are meant to stabilize operations in a region known for harsh climatic conditions, ensuring that the expanded output can be sustained once the mine reaches planned capacity.

The Oyu Tolgoi development also fits into a broader pivot at Rio Tinto, which has been increasingly framed by analysts as a copper growth story rather than purely an iron ore major. In recent commentary, market observers have pointed out that strong copper prices in 2025 and early 2026, driven by demand from grid upgrades, electric vehicles and renewable projects, have boosted valuations for diversified miners with scalable copper assets such as Oyu Tolgoi. According to recent coverage from the Australian investment press, the market has rewarded miners that can show clear, funded pathways to higher copper production over the coming years as highlighted in a June 2026 analysis of Rio Tinto’s copper outlook.

In technical terms, Oyu Tolgoi’s underground block-cave mine involves undermining a large orebody so that it progressively caves under its own weight, with broken ore collected through hundreds of drawpoints and moved by automated loaders and conveyors. Rio Tinto emphasizes that this method, while capital intensive upfront, supports very low operating costs per ton once fully ramped and allows the company to access deeper, higher-grade ore that would be uneconomic with conventional open-pit techniques. Digital modeling tools and real-time monitoring of rock movement are used to plan cave propagation and adjust draw strategies, helping to manage dilution and keep copper grades within targeted ranges as the cave expands.

From a portfolio perspective, Oyu Tolgoi gives Rio Tinto geographic and commodity diversification on top of its core iron ore operations in Western Australia, and the mine’s projected output could make it one of the world’s most important single copper sources at full production. Independent industry analysis has noted that large, low-cost copper assets are scarce and that recent direct-reduction steel trials using Rio Tinto’s Pilbara Blend iron ore underscore how the miner is trying to position its broader portfolio for lower-carbon industrial processes, even as copper becomes an increasingly central earnings driver according to a June 2026 report on its steelmaking collaborations.

Strategically, the Oyu Tolgoi underground mine is one of Rio Tinto’s flagship growth projects and a major contributor to its stated goal of lifting mined copper volumes in the coming decade, with the potential to support long-term contracts into electrification and infrastructure markets. Shares of Rio Tinto (GB0007188757) most actively trade in London and on the Australian Securities Exchange, where recent market commentary notes that the group’s valuation has increasingly reflected its copper growth pipeline, including Oyu Tolgoi, rather than only its traditional iron ore strength.

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