Concentrator, Oyu Tolgoi

Oyu Tolgoi

Oyu Tolgoi is one of the largest known copper and gold deposits in the world. It is also one of the most modern, safe and sustainable operations in the world.

Copper & Gold



Copper Production





Q3 2020 figures. 94.7% of workforce is Mongolian. Oyu Tolgoi also produced 36,743 ounces of gold and 219,000 of ounces of silver. Rio Tinto owns 50.8% of Turquoise Hill Resources, which owns 66% of Oyu Tolgoi.

South Gobi, Mongolia

Oyu Tolgoi, in the South Gobi region of Mongolia, is one of the largest known copper and gold deposits in the world. It is also one of the most modern, safe and sustainable operations in the world. When the underground is complete, it will be the world’s fourth largest copper mine.

Open pit mining began at Oyu Tolgoi in 2011 and the copper concentrator, the largest industrial complex ever built in Mongolia, began processing mined ore into copper concentrate in 2013. Current infrastructure at Oyu Tolgoi will allow the mine to operate for decades to come.

Oyu Tolgoi is jointly owned by the government of Mongolia, which has 34% ownership, and Turquoise Hill Resources, which owns 66%. Rio Tinto owns 50.8% of Turquoise Hill Resources and manages the operation on behalf of the owners.

Oyu Tolgoi at sunset

Innovation at Oyu Tolgoi

Most of the value lies deep underground and to reach the ore body we are building a world-class underground mine. It will include a state of the art control room to oversee the operation that will have approximately 200 kilometres of tunnels.

5 Shafts

Deepest Reaching 1.3KM

5.5m x 5m

Average Tunnel Height & Width

We will use leading underground mining technology known as block caving to mine the ore body. Block caving is technically complex, but it is also one of the safest and most cost-effective methods of mining ore from deep below the ground as it uses the force of gravity.

Put simply, a void is created under the ore body, which then collapses gradually under its own weight. The ore passes through ‘funnels’ in the rock, known as draw points. A series of lateral tunnels over several levels are used to extract the ore and to haul it for crushing before it is transported to the surface via shaft or conveyor belt.

We have continued to make progress on a number of key elements in the construction of the Oyu Tolgoi underground mine during 2020, despite COVID-19 controls and ongoing international travel restrictions.

Preliminary indications from the definitive estimate process are that first sustainable production is expected between October 2022 and June 2023. The estimated development capital cost remains within the range of $6.6 to $7.1 billion. This assessment includes known cost and schedule impacts from COVID-19 and assumes an easing of travel restrictions and COVID-19 related controls from the last quarter of 2020.

At Oyu Tolgoi, we are using technology to build a connected mine and keep our people safe. We are installing a wireless network to connect our people and equipment underground with the teams on the surface. All team members have a Personal Location Indicator, which allows us to track their whereabouts, providing critical information during an emergency. Similar sensors allow us to track the location and performance of all equipment and we have real time monitoring of atmospheric conditions. The team in Mongolia are supported by the Rio Tinto Underground Mining Centre, which connects our caving experts in the Brisbane hub with our operations team at Oyu Tolgoi. These groups work together to improve safety and productivity performance by using the vast amount of data being collected.

See how we use block caving to transport the ore body at Oyu Tolgoi


Global demand for copper is set to grow, driven by urbanisation, industrialisation and increasing requirements for renewable energy: copper plays a key role in electrification and power production. For example, a wind turbine capable of generating a megawatt of power – enough to supply several hundred homes – needs more than three tonnes of copper. 

Given its significance to the global copper industry and the likely multi-generational nature of the business, Oyu Tolgoi is being developed with a distinctly long-term view. Guided by Oyu Tolgoi's vision, 'From natural wealth to enduring value, knowledge and skill', the partners and stakeholders involved in the project are focused on delivering a safe and globally competitive copper business that contributes to and facilitates the prosperity of Mongolia. 

At full production, the underground mine will produce 95 thousand tonnes of ore each day. This will triple Oyu Tolgoi’s annual production of copper concentrate; making us the world’s fourth largest copper mine.

Latest Oyu Tolgoi Releases

16 December 2020

Rio Tinto confirms development capital and timeline for Oyu Tolgoi underground

LONDON--(BUSINESS WIRE)-- Rio Tinto today unveiled a pathway for the ongoing development of the underground project at Oyu Tolgoi in Mongolia, one of the largest known copper and gold deposits in the world. The definitive estimate details how Oyu Tolgoi underground will achieve sustainable production for Panel 0 by October 2022 for development capital of $6.75 billion. Rio Tinto and its partn

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15 September 2020

Rio Tinto provides update of its beneficial ownership of common shares of Entrée Resources Ltd.

LONDON--(BUSINESS WIRE)-- Rio Tinto announced today an update in respect of its beneficial ownership of common shares of Entrée Resources Ltd. (“Entrée”) held by its wholly owned subsidiary Rio Tinto International Holdings Limited (“RTIH”). As a result of its greater than 50% shareholding in Turquoise Hill Resources Ltd. (“TRQ”), Rio Tinto is deemed to beneficially own the common shares of En

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10 September 2020

Rio Tinto and Turquoise Hill Resources agree funding plan for Oyu Tolgoi

LONDON--(BUSINESS WIRE)-- Rio Tinto and Turquoise Hill Resources (TRQ) have entered into a memorandum of understanding (MOU), which provides a clear pathway to progress the financing for completion of the Oyu Tolgoi Underground Project in Mongolia and address TRQ’s funding position. The MOU reflects the parties’ agreement that, subject to timing, availability and terms and conditions being ac

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Contact Oyu Tolgoi

Concentrator, Oyu Tolgoi, Mongolia
Concentrator, Oyu Tolgoi, Mongolia

Oyu Tolgoi

Monnis Tower
Chinggis Avenue 15
Sukhbaatar District
Ulaanbaatar 14240

E: OT Enquiries
T: +976 11 331880