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Mining News: Junior reopens historic gold mine A century after miners first discovered gold at Lucky Shot, Full Metal restores historic mine shaft and tunnels to high-grade ore Shane Lasley Mining News
Full Metal Minerals Ltd. has taken the first step in transitioning from explorer to miner at its Lucky Shot high-grade gold property in the historic Willow Mining District about 145 kilometers, or 90 miles, north of Anchorage.
The company is tunneling into the mountain to recover a 5,000 metric-ton bulk sample of the high-grade mineralization it has outlined with two years of surface drilling at the property. The exploratory mining will help define the resource and the gold recovered will help pay for the exploration.
Because mineralization at Lucky Shot is a mesothermal, high-grade, narrow-vein structure, the Vancouver B.C.-based junior said it becomes impractical to drill from the surface as the mineralization dips under the mountain.
Thus, Full Metal has turned its efforts to an underground bulk-sample program.
Crews tunnel toward high-grade area To access the mineralization discovered with surface drilling, crews rehabilitated a section of one of the historic tunnels used to extract about 252,000 ounces of gold from the Lucky Shot Mine during the first half of the 20th century.
With the tunnel restored — including repairs to the rails and ore cars left behind from past miners — the junior began driving a drift from the recently restored tunnel toward the Coleman Zone, the western limit of the Lucky Shot Shear.
Crews plan to start carting the 5,000-metric-ton bulk sample to the surface as soon as the new tunnel reaches the Coleman mineralization, about 120 meters into the mountain from the pre-existing tunnel. The company expects to reach the high-grade ore by mid-September.
Rob McLeod, Full Metal’s vice president of exploration, told Mining News that once the tunnel reaches mineralization “we are going to drift along and stope out a couple of areas, test various mining methods and test the processing circuit we have designed.”
Proximity to the historic tunnel is not the only reason Full Metal is targeting Coleman for bulk sampling. The highest grade gold intercepts of more than 30,000 meters drilled at Lucky Shot have been at Coleman. These include hole C05-09 that intercepted 3.1 meters grading 62.2 grams per metric ton gold, hole C05-12 that intercepted 4.0 meters grading 219.1 g/t gold and hole C06-16 that intersected 4.6 meters grading 51.5 g/t gold.
Gravity the choice for recovery Meanwhile, crews working on the surface are preparing a recently purchased 200-metric-ton-per-day mill to process the bulk sample. Pre-existing infrastructure, including a tailings facility and building to house the mill, is reducing the time and capital investment required to start the bulk sampling.
A Falcon gravity concentrator will be used to recover the gold out of the bulk sample. Full Metal had three samples lab-tested to determine the amount of gold recoverable with a gravity concentrator as well as the size of grind necessary to maximize recovery. The sample grades were 4.7 g/t, 4.7 g/t gold and 7.8 g/t gold. Total recoveries were 68.2 percent, 68.5 percent and 78.3 percent, respectively. These tests along with historic mine records suggest that gold recovery should improve with higher grades. One of the objectives of the 2008 bulk sample is to confirm this model.
Scott Eubanks, president of Alaska Hardrock Inc., (the company leasing Lucky Shot to Full Metal) is keeping one eye on the weather and the other on the progress of the bulk sampling program. Familiar with the weather of Alaska’s high country, Eubanks knows that remaining days in the 2008 mining season are numbered.
The length of the season will be determined to a large part by the availability of water to process the ore. Mining can continue after the mill is shut down.
Full Metal geologist Asa East told Mining News that the company plans to continue work at Lucky Shot until the end of December and return to the historic mine in March 2009.
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