Tolgoi

Tolgoi, officially Oyu Tolgoi, is a copper–gold mining complex in the South Gobi Desert of Mongolia, in Ömnögovi Province near the Khanbogd district. The Mongolian word tolgoi means hill, and Oyu Tolgoi is commonly translated as Turquoise Hill.

Discovery and development: The Oyu Tolgoi ore deposit was identified in 2001 by Ivanhoe Mines. Development was undertaken by a joint venture that later involved Turquoise Hill Resources and Rio Tinto. Construction of the open pit began in the late 2000s, and commercial production from the initial pit started in 2013, with underground development commencing in 2016 to access deeper, higher-grade ore.

Operations and geology: Oyu Tolgoi sits on a large porphyry copper-gold system. The operation includes an open pit component that produces copper concentrate and gold-bearing byproducts, with a planned underground operation to extend mine life and improve throughput as expansion proceeds.

Ownership and governance: The project is managed by Oyu Tolgoi LLC, a joint venture whose ownership has included the Government of Mongolia and a Rio Tinto-led consortium via Turquoise Hill Resources. Negotiations over ownership shares, funding for underground development, and revenue arrangements have featured prominently in Mongolian political and economic discussions.

Significance: Oyu Tolgoi is one of the world’s largest known copper-gold reserves and has been a major driver of investment in Mongolia. It plays a central role in export earnings, infrastructure development, and the mining sector, while facing ongoing debates over ownership, taxation, and environmental management.