Sep. 7--Project will allow earlier start to lower-cost gold processing

Up to 100 people are currently working in shifts around the clock on the new heap leach processing facility being built at the Fort Knox gold mine, an effort to complete construction this fall in order to begin recovering gold next spring from the lower-cost extraction method.

"We're pushing hard as we can push. We started laying liner this week," said Delbert Parr, Fort Knox environmental manager. "We're hoping to get the pond in with both liners run. We really don't want to get caught in the middle-we think we've got a good shot at getting it completed."

The current stage of the construction project involves first laying out a secondary liner over the graded, prepared stack area at the bottom of the heap leach, then covering that with crushed rock and topping that with the primary liner. It will take six to eight weeks, depending on weather.

The construction project began last fall and ramped up in earnest earlier this year. Efforts have been plagued by an unusually wet summer in Interior Alaska, according to the second quarter report of the mine's Toronto-based owner, Kinross Gold Corp.

"Construction of the heap leach project pad is advancing, with construction approximately 57 percent complete. Delays have been encountered in the placement of the lead pad liner due to unseasonably wet weather conditions," Kinross said in its report, released Aug. 12. "Scheduled start-up of leaching operations is in the third quarter of 2009."

Local managers are working to improve that schedule. If crews can finish placing the two layers of containment liners this fall, mine crews will begin to haul ore into the valley heap leach facility.

"As soon as the weather allows in spring, after breakup, we'll apply solution," Parr said. "That brings us into production into spring. If we have to wait until spring to get the heap storage pond constructed, we're looking at fall before we start applying solution and get any production."

Current plans call for placing up to 160 million tons of low-grade gold-bearing rock on the heap leach pad being constructed in the Walter Creek valley drainage, located above the mine's existing tailings impoundment.

A water and cyanide solution will drip through the pad, filtering through the stack. Gold attracts to the cyanide and the mineralized solution is captured at the bottom of the pile. The gold-bearing solution will be pumped via enclosed pipeline to a carbon-in-column (CIC) plant also being built at Fort Knox, where gold is extracted from the cyanide solution.