Barrick will remove and concentrate iron pyrite from the tailings to then be used in the gold production flow at Nevada Gold Mines (NGM).

"The concentrated sulfur is not only valuable, but its removal will also eliminate a source of potential groundwater contamination," the company said. "After reprocessing, the remaining benign material will be backfilled into the Mineral Hill pit."

Chief executive Mark Bristow said the project, which combined rehabilitation with value creation, would serve as a model for Barrick's future mine closures.

Barrick, which is also the majority owner and operator of NGM, said the closure project will create at least 75 jobs for the region.

"It's very much in line with Barrick's commitment to sustainability as well as our philosophy of sharing the economic benefits generated by our mines with stakeholders," Bristow said.

Golden Sunlight produced more than 3 million ounces of gold over four decades. It was mined out and subsequently idled in 2019.