The company said the Tanami expansion project, which involved building a second decline and increasing plant capacity, had reached commercial production on time and within budget.

The expansion is expected to increase Tanami’s annual gold production by 80,000 ounces per year to 425,000-475,000oz of gold per annum, lower all-in sustaining costs to $700-750 per ounce, and extend mine life by three years.

Tanami was Australia’s fourth-largest producer last year with output of 459,000oz at AISC of $739/oz.

“Tanami’s team has more than doubled gold production while cutting costs by about two-thirds and significantly improving resource confidence since 2012,” Newmont president and CEO Gary Goldberg said.

“The expansion project continues this trajectory, offering robust returns of 35% at a $1200 gold price.”

The current gold price is more than $1320/oz.

The Tanami mill was expanded from 2.3 to 2.6 million tonnes per annum following the completion of the second decline a year ago.

“The team also delivered this project safely and on schedule despite a one-month delay caused by record rainfall in the first quarter,” Goldberg added.

Studies to develop a second expansion are underway, thanks to exploration success at the operation.

Earlier this year, Goldberg said the company was looking at a variety of options, including additional declines, a production shaft, or a change in how the deposit was mined.