Newmont Mining's (NYSE: NEM) Ahafo mine in Ghana started producing gold from an open pit in 2006 and now the underground portion of the mine has launched commercial production on schedule and within budget.
Starting next year, Subika underground will add an average of between 150,000 and 200,000 ounces of gold production a year over the first five years of an initial mine life of about ten years.
The Subika underground project cost about US$186 million to develop.
Once the company completes the expansion of its Ahafo mill in the second half of 2019, the mine's average all-in sustaining costs are expected to improve by between US$250 and US$350 per oz. compared with 2016.
The underground mine uses semi-autonomous loading, proximity detection for vehicles, personnel tracking and will also benefit from the installation of ventilation-on-demand systems.
The new mining operation will provide an underground platform to explore "additional upside potential in adjacent ore bodies," Gary Goldberg, the company's CEO, says in a news release.
Ahafo has two primary ore zones: Ahafo South and Ahafo North.
The mine is 307 km northwest of the nation's capital of Accra and is situated along the Sefwi Volcanic Belt, a northeast-southwest trending volcanic belt in Ghana. Ahafo is in the Brong Ahafo region.
The gold and copper producer has built ten new mines and expansion projects on or ahead of schedule and at or below budget, over the last five years.