Oyu Tolgoi underground production to start in 2022

Development cost for the underground operation has been set at $6.75-billion, the company said.

“We now have a pathway to bring the underground project into production, which will unlock the most valuable part of Oyu Tolgoi. We will continue to work together with the government of Mongolia and Turquoise Hill Resources to progress the project, including finalising all necessary approvals and agreeing a solution on power and funding,” said Rio’s copper and diamond CEO Arnaud Soirat.

Oyu Tolgoi is expected to produce 480 000 t/y of copper on average from 2028 to 2036 from the openpit and underground, compared with 146 300 t/y in 2019 from the openpit.

The underground ore reserve has an average copper grade of 1.52%, which is more than three times higher than the openpit ore reserve, and contains 0.31 g/t of gold. The size and quality of this Tier 1 asset provides additional expansion options, which could see production sustained for many decades.

At peak production, Oyu Tolgoi is expected to operate in the first quartile of the copper cash cost curve and by 2030 is expected to be the fourth largest copper mine in the world.

Rio and its partners will continue to finalise three other milestones; the outstanding government approvals, funding and a power solution, in order to ensure that the project can commence caving operations in 2021.