Canadian Mining Journal


COPPER-GOLD: Turquoise Hill updates progress of underground development

Underground development project at Oyu Tolgoi and the block caving mining method. (Image: Turquoise Hill Resources)

MONGOLIA – As the pit exhausts it resources, mining is moving underground at the Oyu Tolgoi copper-gold mine in the South Gobi area. Owner Turquoise Hill Resources of Vancouver updates the progress.

Rio Tinto, holder of a 51% interest in Turquoise Hill, is the operator of the underground project. Construction is slightly behind the timeline, and the US$5.3 billion budget is under scrutiny. First ore production scheduled for Q3 2021. Shaft 5, certain underground infrastructure, and a new 5,500-person camp have already been completed.

The completion of Shaft 2 is having a negative influence on the timeline because ground conditions are challenging. The availability of this shaft will play a role in whether underground development can be sped up and whether the primary crusher No.1 and the material handling systems will be ready for ramp-up after production begins. Delays with this shaft have already pushed the first ore target back several months.

Meanwhile, Turquoise Hill is reviewing the cost and production schedule.

The mine has its own website at