Oyu Tolgoi has achieved an important underground development milestone with the commissioning of Shaft 5, which is 1,178 meters (m) deep and 6.7 m in diameter. Turquoise Hill Resources now expects a step-up in underground activities with the increased ventilation capacity from Shaft 5. The company is looking forward to the first draw bell in mid-2020 and sustainable first production in 2021.

Meanwhile, production at Oyu Tolgoi continues according to plan. “During the second quarter, Oyu Tolgoi continued processing Phase 4A ore resulting in improved gold grades, production and recovery,” said Luke Colton, interim CEO for Turquoise Hill. “This trend is expected for the remainder of the year. Mill throughput during the quarter benefited from high-intensity blasting, which was introduced in 2017. Oyu Tolgoi continues to make good underground development progress, as evidenced by the completion of Shaft 5.”

The positive impact of the high-intensity blasting program is expected to increase mill throughput for 2018 to approximately 40 million metric tons (mt). Mill throughput during the second quarter increased 6.3% over the first quarter, which was attributed to the high-intensity blasting program. Copper production in the second quarter increased 1.5% over the first quarter, but was offset slightly by lower grades from the depletion of Phase 6 ore. Gold production increased 19% over the first quarter due to stronger mill utilization rates, higher grades from Phase 4A and increased recovery. Sales in the second quarter benefited from improved logistics as inventory accumulated during the first quarter force majeure worked its way through the system.

Oyu Tolgoi is expected to produce 125,000 mt to 155,000 mt of copper and 240,000 ounces (oz) to 280,000 oz of gold in concentrates for 2018.