|
MINING NEWS: Nixon Fork mill goes into commission Historic Alaska gold mine should be producing again soon after over three years of preparations by Mystery Creek Resources Sarah Hurst For Mining News
Everyone likes to announce something big at the Alaska Miners Association annual convention, and Mystery Creek Resources was able to do just that Nov. 10 with the news that the mill at Nixon Fork gold mine is being commissioned. The company, a subsidiary of Ontario-based St. Andrew Goldfields, has been working at Nixon Fork since 2003, delineating the resource and constructing facilities to put the historic underground mine back into operation.
“It’s kind of exciting to finally see all our efforts come to fruition,” William Burnett, the mine manager, told the convention. Burnett first worked at Nixon Fork as a mine geologist in 1995-99, when it was operated by Consolidated Nevada Goldfields, which produced 137,000 ounces of gold before shutting down due to depressed gold prices. The mine had seen several other operators in prior decades, and old equipment is still lying around the site.
The mine contains approximately 180,000 tons of proven and probable reserves, which amount to about 130,000 ounces of gold, according to Burnett. The mill had to be expanded from the 135 tons per day capacity that it had in the 1990s to 240 tons per day, which is what Mystery Creek requires. It will also have a CIL (carbon-in-leach) circuit installed this winter, to add to the flotation and gravity circuits that are already in place. In the CIL process, cyanide and carbon are used to separate the gold from the rest of the ore.
Work required at mill “In the mill we quickly discovered we had some problems, some problems with code, some safety problems, so essentially we ripped out all the wiring and reinstalled cable fittings,” Burnett said. Motor controllers and operator control stations were upgraded, and some of the motors had to be replaced. “It actually ended up being a very large job,” Burnett added.
Mystery Creek’s team also removed the old gravity circuit and installed a Falcon concentrator, a screen and a new cleaner table, as well as upgrading the crushing and grinding circuit. The cone crusher had previously been set up in the wrong place, Burnett explained, so it had to be repositioned. New conveyor belts and a new baghouse were installed. “We converted a rod mill that was being used as a ball mill in the prior operation — we converted it back to a rod mill. We had to do some bearing work to the thing and install some metal liners,” Burnett said. An overhead bridge crane was brought in to assist with moving equipment around the mill.
The company has purchased a 350 ton-per-day Larox filter press for the tailings that will be installed this winter. A fuel distribution and storage capacity with a capacity of 60,000 gallons has been constructed at the mine. Underground development at Nixon Fork began in August, using large equipment such as an MTI Vein-Runner Jumbo and a J & J Machine Works Long Tom drill carrier. Mystery Creek spent over $9 million at Nixon Fork in 2006.
Cut-and-fill technique to be used Cut-and-fill mining techniques will be employed at Nixon Fork, with development waste being used for backfill, but not tailings. Mystery Creek hopes to achieve 120 meters of development per month, ultimately mining 240 tons per day at an operating cost of $350 an ounce, for a projected mine life of four years. The company has reached out to McGrath and other villages in the region for employees and is currently at a rate of about 50-percent local hire.
“We expect everybody we hire, the skilled people, to pass along their knowledge and do on-the-job training,” Burnett said. The mine should provide 97 full-time jobs when it is in full production, he added. To date, Alaska Mechanical, Precision Power, Statewide Petroleum Service and Chiulista Camp Services are among the contractors that have helped bring Nixon Fork closer to production. As proof that Nixon Fork will justify all the hard work, Burnett showed the convention a photograph of the first gold bar poured at the mine by his company. As the camera zoomed out, it became clear that the “gold bar” was balanced on the tip of a finger. Mystery Creek is sure there will be larger bars to come.
|
