The Twin Creeks Underground project, which is expected to add higher-grade, lower-cost gold production to the company’s Twin Creeks operation, was wrapped up on schedule.

Newmont Mining revealed that the mine expansion project cost was $42m, which was slightly under the estimated cost of $45-55m.

According to the miner, the Twin Creeks Underground mine will produce 30,000-40,000oz of gold annually at all-in sustaining costs of $650-$750 per ounce for its first five years of production.

Newmont expects the new ore to enable processing of stockpiled ore that was classified as waste in the past while extending processing life to 2030.

Newmont president and CEO Gary Goldberg said: “The expansion extends profitable production and improves recoveries at Twin Creeks, and serves as a platform to further explore the deposit, which remains open along strike and at depth.

“This project marks the sixth that Newmont has completed on or ahead of schedule and at or below budget over the last five years, and generates an internal rate of return of about 20 percent.”

Newmont revealed that operations at the Twin Underground mine are automated by employing remotely-operated loaders for improved safety and efficiency.

The miner said that the gold ore from Twin Creeks Underground ore will also be blended with ore produced from Turquoise Ridge, where the company has a stake of 25% and is partnered by a subsidiary of Barrick Gold.

Earlier this year, Newmont and Barrick Gold agreed to move ahead with the Turquoise Ridge Mine Optimization project, which will see sinking a production shaft to access the richest part of the gold deposit.

Turquoise Ridge along with the Twin Creeks mine and the Twin Creeks Underground project make up the Twin Creeks property, which is located 56km northeast of Winnemucca.