A pit expansion study at New Jersey Mining Co.'s Golden Chest gold mine and New Jersey Mill in northern Idaho yielded a 14-fold increase in tonnage and a 12-fold increase in minable ounces of gold.
The study concluded that the pit can be widened further to the west and deepened, with the expanded pit design containing 180,000 tonnes of ore at 4.26 g/t of gold for 24,600 ounces of gold, with an overall stripping ratio of 5.1 to 1.
The company used around 450 blast-hole assays from the current mining operation to test the viability of expanding its open pit mine and update the block model.
The study used current operating costs, metallurgical recoveries achieved at its New Jersey Mill, current concentrate contract terms and a gold price of US$1,200 per ounce.
The over 10-fold increase in the size of the open pit provides a great start to the company's mine-life expansion efforts and its objective to perpetually have three to five years of production ahead, President John Swallow said.
The study also showed potential for an additional "starter pit" near the surface expression of the Klondike-Katie Dora area, about 370 meters north of the current operations
The company is evaluating the potential for additional open pits on ore shoots to the north. Underground mining is now expected to ramp-up in July.
New Jersey Mining submitted an environmental permit for the pit expansion to the Idaho Department of Lands and anticipates approval within the next 30 to 60 days, according to a June 8 release.