Metals and Mining firm Rio Tinto has completed the Shaft 2 to accelerate the underground development works at the Oyu Tolgoi mine in Mongolia.

Shaft 2 is a 10m diameter shaft sunk to nearly 1.3km under the surface, which has now advanced into the final stages of commissioning, said the company.

Rio Tinto growth & innovation group executive Stephen McIntosh said: “This is an important milestone because Shaft 2 significantly improves overall productivity of the underground development and allows us to move more material, equipment and people between the surface and underground.

“We have made very good progress in the past few months and completing Shaft 2 provides additional momentum as we move towards a definitive estimate for the development of this world-class ore-body in the second half of 2020.”

Rio Tinto, Government of Mongolia, jointly operate Oyu Tolgoi

According to Rio Tinto, Shaft 2 plays a crucial role in enabling a step change for delivering the underground mine. It has been designed to carry 300 people per cage cycle, while Shaft 1 could carry only a maximum of 60 people per cage cycle.

Also, Shaft 2 allows the 48 tonne capacity cage to be used for support logistics, transporting supplies and components for the development of the mine.

Oyu Tolgoi is a combined open pit and underground mining project located in Khanbogd sum (district), approximately 235kms east of the Ömnögovi Province capital Dalanzadgad, within the south Gobi Desert in Mongolia.

Discovered in 2001, the mine has been developed as a joint venture between Turquoise Hill Resources, a subsidiary of Rio Tinto, with 66% stake and the Government of Mongolia with a 34% stake.

Rio Tinto, which owns 51% shares of the Turquoise Hill Resources, is currently operating the project, which was estimated to cost between $6.5bn and $7.5bn and have a mine life of more than 50 years.

The total proven and probable mineral reserves at Oyo Tolgoi are estimated to be 1,450 million tonnes (Mt) of ore, graded at 0.86% copper, 0.3 grams per tonne (g/t) of gold, and 1.97g/t of silver.