Rio Tinto has completed its acquisition of Turquoise Hill Resources Ltd for a consideration of approximately $3.1 billion, simplifying the ownership of the world-class Oyu Tolgoi mine in Mongolia, significantly strengthening Rio Tinto’s copper portfolio, and demonstrating its long-term commitment to the project and Mongolia.
Rio Tinto now holds a 66% direct interest in the Oyu Tolgoi project with the remaining 34% owned by the Government of Mongolia through Erdenes Oyu Tolgoi. The transaction closed following approval from the Yukon court in Canada and the majority of TRQ minority shareholders supporting the deal.
Turquoise Hill has become a wholly owned subsidiary of Rio Tinto and Turquoise Hill shares will cease trading.
Oyu Tolgoi is one of the largest known copper and gold deposits in the world. 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.
In January 2022, the Oyu Tolgoi Board approved the beginning of underground operations. This step unlocks the most valuable part of the mine, with sustainable underground production expected in the first half of 2023. When the underground mine is fully operational, Oyu Tolgoi will be the fourth-largest copper mine in the world.
At peak production, Oyu Tolgoi is expected to produce 500,000 tonnes per annum of copper—equivalent to what’s needed to build: 16,400 electric vehicles per day.
To reach the underground ore body, Rio Tinto is using block caving, a process that creates a void under the ore body, which then collapses gradually under its own weight. (Earlier post.) 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.
