PERTH (miningweekly.com) – Underground production has started at the Oyu Tolgoi copper mine in the Gobi Desert.

“We are starting underground production 1.3 km beneath the remote Gobi desert from an orebody that will be critical for global copper production and Mongolia’s ongoing economic development,” said diversified miner Rio Tinto CEO Jakob Stausholm.

“The copper produced in this truly world-class, high technology mine will help deliver the electrification needed for a net zero future and grow Rio Tinto’s copper business.”

Developing the underground mine is an investment of over $7-billion, unlocking the most valuable part of the copper resource. Oyu Tolgoi is expected to produce around 500 000 t/y of copper from 2028 to 2036 from the openpit and underground, enough to produce around six-million electric vehicles annually, and an average of around 290 000 t over the reserve life of around 30 years.

Since the agreement between the government of Mongolia and Rio in January 2022 to reset the relationship and move the Oyu Tolgoi underground project forward, 30 drawbells have been blasted and copper is now being produced from the underground mine. Oyu Tolgoi is expected to become the fourth-largest copper mine in the world by 2030, operating in the first quartile of the copper equivalent cost curve.

Ore is currently being processed from Panel Zero in Hugo North Lift 1 and production will ramp up over the coming years.

The Oyu Tolgoi openpit and concentrator have been successfully operating for over a decade, and the total workforce of Oyu Tolgoi is currently around 20 000 people, of which 97% are Mongolian.

Prime Minister of Mongolia Luvsannamsrain Oyun-Erdene has welcomed the start of underground production.

“I am proud to celebrate this major milestone with our partner Rio Tinto as we look towards Mongolia becoming one of the world’s key copper producers. The start of underground production at Oyu Tolgoi demonstrates our ability to work together with investors in a sustainable manner and become a trusted partner.

“The next phase of the partnership will enable the continued successful delivery of Mongolia’s ‘New Recovery Policy’ and Vision 2050 economic diversification strategy. Mongolia stands ready to work actively and mutually beneficially with global investors and partners.”