Kinross Fort Knox celebrated another milestone last month: The gold mine poured its 8-millionth ounce of gold, nearly doubling initial forecasts that estimated that Fort Knox would produce 4.2 million ounces.
Representatives of Kinross corporate leadership and federal mining agencies were present for a ceremony on Oct. 9, when Nathaniel Shepard poured the 8-millionth ounce.
The mine staff continues looking forward, adjusting for changes in the market and working to stay ahead and operational. Anna Atchison, Kinross Fort Knox external affairs manager, attributed the mine’s continued success in part to the young engineers employed there, who she said come from a “background of innovation.”
Fort Knox, located about 25 miles from Fairbanks, poured its first bar of gold in 1996. “We’re of that age, as a mine, where we’ve been going a lot longer than we ever thought in terms of new discovery, and you know, a low-grade mine like ours, it is all about business optimization. It is all about continuous improvement. That’s the only reason we’re still here,” Atchison said.
Gold mining is often less “rich” than depicted in cartoons. In industrial mining, gold is often extracted from ore in microscopic amounts.
The amount of gold in a ton of rock is called its “grade.” At Fort Knox, the average grade in 2019 was .0097 ounces per ton — which is why the mine is considered “low-grade.” Even at $1,450 per ounce, it takes a lot of ore to make a profit. Despite that high bar, Fort Knox is not only the oldest but also the highest-producing gold mine in Alaska, according to Atchison.
Further, the grizzled, pick-bearing prospector pulling fist-sized, shining nuggets from a wooden-beamed tunnel is far removed from the reality of modern mining. At sites like Fort Knox, mining looks a lot more like trust: engineers and geologists give the word and highly trained operators move millions of tons of earth out of the pit and spray it with chemicals to extract gold they cannot see.
To achieve its high production, Fort Knox, like many other surface gold mines, generates giant piles of ore — 2.2 million square feet worth on one heap leach pad alone — and sprays it with a cyanide solution. The solution binds with the gold in the rock and trickles out onto an impermeable liner. Then, the solution, now “pregnant,” is collected and the gold is separated and poured into bars.
It was initially thought that heap-leaching couldn’t be done in Alaska, but Fort Knox made it work by using natural insulation and continuously working in the area. Atchison explained that the method is also less power-intensive, an important factor for Golden Valley Electric Association’s largest consumer.
Then, by tweaking the method slightly, Fort Knox was able to increase gold production on the heap leach pad at Barnes Creek at the Gilmore expansion this summer. As operators piled ore at the site, they created visible levels of earth, like steps. By bulldozing the pile and creating a flatter, smoother surface on which to spray the cyanide solution, the site was able to extract more ounces from the pile than previously.
In this way, low-grade mines like Fort Knox remain in production and able to maintain the large workforces required to stay profitable. Fort Knox has more than 600 employees and operates 24 hours a day, year-round.
The mine’s production is projected to end in 2027. While exploration efforts could extend that timeline, the company is already starting work on its legacy planning and what it will leave behind in this community where it has been in operation for 23 years. Under consideration are reclamation efforts as well as community programs like the Mental Health Gala and partnerships with the Fairbanks Community Food Bank.
Fort Knox is considered a generational mine — a mine where a person might work, raise a family and their children will work there, too. Atchison listed this as a point of pride.
“It might sound a little cheesy sometimes, but we all live here — all of us, all over-600 of us — live here. We have for years. A lot of us are lifelong Alaskans, like myself. The fact that we can continue to work and do what we love and contribute to our community. That for us is what that 8 million ounces means,” she said.
Contact staff writer Cheryl Upshaw at 459-7572 or find her on Twitter at twitter.com/FDNMcity.