With production growing from its open-pit operations (above), Oyu Tolgoi ventures underground. (Photo: Turquoise Hill)

“Oyu Tolgoi also exceeded both copper and gold production guidance for the year,” said Jeff Tygesen, Turquoise Hill chief executive officer. “Concentrator performance during the fourth quarter was strong with the highest throughput since production began. Oyu Tolgoi is well-positioned to sustain the 2017 grade challenges.”

In the fourth quarter of 2016, concentrator throughput increased 7.4% over third-quarter 2016 resulting in an average daily rate of 106,700 metric tons (mt) for the quarter, which was a quarterly high. Copper production was broadly consistent with the third quarter while fourth-quarter gold production increased 32.4% over the third quarter due to the final processing of Phase 2 ore. Copper grades in the fourth quarter were as expected as operations focused mainly on Phase 6 of the open pit.

Oyu Tolgoi is expected to produce 130,000 to 160,000 mt of copper in concentrates and 100,000 to 140,000 oz of gold in concentrates for 2017. During the fourth quarter, the underground project workforce ramped up to more than 2,000 people and progress was made in key areas including Shaft Nos. 2 and 5 and related activities and construction of critical on-site facilities while the bulk excavation component for the convey-to-surface work stream was completed. Lateral development rates are progressing well with a further increase expected in 2017 when additional underground crushing capacity is added.

Turquoise Hill Resources is an international mining company whose primary operation is its 66% interest in the Oyu Tolgoi copper-gold-silver mine in southern Mongolia.