North of 60 Mining News - The mining newspaper for Alaska and Canada's North

Kinross Gold Corp. May 7 reported that the Fort Knox Mine in Interior Alaska produced 37,613 ounces of gold during the first three months of 2019, less than half the 79,928 oz of gold produced during the same period last year.

The lower production resulted in a significant rise in costs at this open-pit operation about 25 miles north of Fairbanks. The cost for each ounce of gold sold during the first quarter was US$1,023, compared to US$530/oz during the first three months of 2018.

Kinross anticipated lower production at Fort Knox during the first quarter due to a strategy to preserve tailings storage capacity for the highest grade ore.

A minor pit wall slide that occurred last spring, however, restricted access to some of the higher-grade ore destined for the mill. This problem was compounded by higher than average rainfall in the second half of 2018, which affected geotechnical stability.

As a result, the company has reduced mill throughput until the higher grade ore can be reached.

During the first quarter of 2019 the mill at Fort Knox processed 1.56 million metric tons of ore averaging 0.72 grams per metric ton gold, this is nearly half the 3.11 million metric tons averaging 0.7 g/t gold processed during the first three months of last year.

This lower mill production, coupled with the normal seasonal fluctuation in heap leach recoveries, resulted in the lowest quarterly gold output on record at Fort Knox.

In addition to ore fed into the mill, 4.3 million metric tons of ore averaging 0.22 g/t gold was stacked on the Walter Creek heap leach pad at Fort Knox during the first quarter, compared to 5.84 million metric tons averaging 0.2 g/t gold during the same period last year.

Kinross said the Gilmore project at Fort Knox remains on schedule and on budget, with initial ore from the expansion project expected early next year.

J. Paul Rollinson

A feasibility published for the Gilmore expansion last year envisions nearly all of the gold mined from Gilmore will be recovered via heap leaching, a process that involves stacking the ore on a lined pad and using a mildly acidic leaching agent trickled over the ore to dissolve the gold into a solution that is pumped through a facility that recovers the gold.

To accommodate the ore mined from Gilmore, Kinross has begun construction on the Barnes Creek Heap Leach Pad.

"The Fort Knox Gilmore project is on schedule and heap leach construction activities are ramping up," said Kinross Gold President and CEO J. Paul Rollinson.

Procurement and contracting for 2019 heap construction activities are proceeding well, with the majority of contracts issued and awarded, and contractors mobilizing to site.

Stripping at Gilmore is expected to get underway during the third quarter.

–SHANE LASLEY