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MINING NEWS: Fort Knox evacuated Fire crews close Steese Highway, evacuation order forces mine and mill staff to shut down; work now back to normal production Patricia Liles Mining News Editor
In the final hot and dry days of June, the Boundary wild lands fire was burning its way across rolling hills in Alaska’s Interior three to five miles from the Fort Knox gold mine, although workers couldn’t see its proximity due to smoke shrouding the area.
Weather conditions changed on July 4, with shifting winds and cooling temperatures causing the fire to shift directions. That gave Fort Knox’s general manager John Wild a view of how close the fire came to the mine and mill site, about 25 miles northeast of Fairbanks.
“It cleared up on Sunday (July 4) and we could see evidence of the fire to the north,” he said in a telephone interview July 6. “You can see it when you first exit the mill.”
Federal fire managers monitoring the Boundary fire required evacuation of the area off the Steese Highway on the afternoon of June 30, giving Alaska’s largest gold mine only a few hours to shut down operations before departing the property at 6 p.m.
“It was very smoky out here, but we did not expect to be evacuated, to shut down,” Wild said. “We were not prepared.”
Nevertheless, the day crew of roughly 200 workers at Fort Knox quickly prepared the mine and mill for an emergency shut down and evacuated the area within a few hours. “I was very pleased with the work,” Wild said. “The shutdown was very orderly, very organized and it happened very quickly.” Earthmoving equipment parked in pit Although a successful operation, the shutdown was no easy feat. All of the “rolling stock” of large earthmoving equipment was moved and parked at the bottom of the pit, potentially protecting the equipment from fire and keeping it consolidated in case fire crews needed to use the mine site, Wild said.
Tracked equipment such as loaders and bulldozers which was not already working in the pit was parked on the waste dumps.
Mill operators began procedures to shut down the mechanical and chemical processes that extract the microscopic gold from its host rock, a process completed by 8 p.m., Wild said. “We coordinated with GVEA for our electric usage, so we would not take a load off the system quickly.”
Mill operations shut down in phases, although crews did not take the final emergency step of emptying large thickener and leach holding tanks, Wild said.
A road block and closure of the Steese Highway prevented the mine’s night crew from coming to work that evening, although managers attempted to contact employees earlier in the day after receiving the evacuation notice.
Wild and a small group of employees remained on-site during that night to monitor the situation. The next day, July 1, Wild sought permission from fire managers to allow a small crew to return to Fort Knox to resume partial mill operations. Two dozer operators also returned, in order to feed the mill from a stockpile of material.
“They were very cooperative in helping to bring our people through the line on the Steese Highway,” Wild said.
Full work crews began returning to work later in the week and by July 3, the mine and mill had returned to its normal production levels, Wild said. Typical mine production rates vary between 94,000 and 130,000 tonnes per day, with an average of 37,650 tonnes per day of ore that is processed through the mill.
Despite clearing conditions in the area, the Steese Highway remained closed July 6, although Fort Knox workers are allowed access to the mine with proper employment identification.
Wild is pleased with the employees’ response to the emergency situation, despite a lack of practice or drilling for such a situation. About a month ago, the company started work on a crisis communication and development plan, he said, and the fire evacuation put to test those procedures.
“Employees clearly demonstrated their ability to act quickly and thoughtfully,” he said.
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