Mongolia's largest copper and gold mining company Oyu Tolgoi LLC has marked a “significant milestone” for the world-class Oyu Tolgoi underground project by completing Shaft 2 in Khanbogd soum, Umnugovi Province.

Celebrating the completion of the 1,300-meter shaft, Oyu Tolgoi held a ceremony last Friday with national contractors and other key stakeholders who were crucial for the development the shaft project. Shaft 2 is one of the largest and most modern shafts in the world, with a headframe 96-meters above surface which is approximately the height of the Statue of Liberty, according to the company.

Chairman of the Board of Directors of Oyu Tolgoi LLC G.Batsukh delivered special remarks, stressing the immense support provided by the Mongolian government for this remarkable achievement, which “increases Mongolia’s global competitiveness” in terms of the mining and technology development.

The company’s CEO Armando Torres said, “Shaft 2 construction – from sinking through to equipping – has taken three years and four months in total. Close to 50 national companies and 2,500 people worked safely on Shaft 2 for approximately 2.6 million hours to complete this critical and complex piece of infrastructure that will accelerate the underground development of our Oyu Tolgoi mine”.

Noting that the mining sector will be Mongolia's primary sector for the next 20 to 30 years, Minister of Mining and Heavy Industry D.Sumiyabazar said advancement in the mining sector will benefit the whole country and enable other sectors to develop. The Oyu Tolgoi project is Mongolia's “business card”, he said.

Shaft 2 with a depth of 1,284 meters is the main production shaft and primary access point for people and materials and provides infrastructure for the materials handling system in the underground mine. Its production hoist is the largest Koepe (Friction) rope hoist system in the world with two 60 tons capacity skips capable of hoisting 28,000 tons of ore per day at a maximum speed of 59 kilometers per hour. Shaft 2 can carry 300 people per cage cycle versus a maximum of 60 people per cage cycle through Shaft 1. Shaft 2’s hoist rope-up process took 23 days by a team of approximately 500 people – one of the safest and most efficient rope-ups undertaken anywhere in the world, the company claims.

Shaft 2’s role in the underground project

Once Shaft 2 is fully commissioned and receives state licensing, it is expected to enable the following two important steps forward for the underground mine:

•    Additional crews, materials and equipment to be transported and operate underground

•    More rock to be removed from underground to enable further development and access to the ore body

The company stated, “From this point, the number of people working underground will no longer be constrained by the Service lift capacity of Shaft 1, but rather by volume of air moving through the underground via the existing ventilation (shafts 1, 2 and 5). Additional ventilation capacity is under construction with two more ventilation shafts --Shaft 3 (intake) and 4 (exhaust). Currently, 700 people are able to work underground per shift.”

Oyu Tolgoi has five shafts in total with Shaft 1 currently operational, providing access to underground project area for people and materials. Shafts 3 and 4 are still under construction with a depth of 1,148 meters and 1,149 meters respectively. According to the company, both shafts will provide additional ventilation (intake and exhaust) to support life of mine operations.

Shaft 5 is currently operational with a depth of 1,174 meters, allowing ventilation capacity two-fold enabling increase in lateral development and underground construction capability.