First Mining Gold Corp. has reported positive results from an updated independent preliminary economic assessment (PEA) of its 100% owned Springpole gold project in northwest Ontario. The PEA contemplates production of 410,000 ounces per year (oz/y) of gold and 2.4 million oz/y of silver during years two through nine of open-pit mining and milling operations and reflects updated metallurgical testwork that has demonstrated the potential for significantly improved recoveries.
Initial capital costs are estimated at $809 million, based on an owner-operated mining scenario. Mine life is estimated at 12 years, with a 2.5-year preproduction period. Life-of-mine production is estimated at 3.9 million oz of gold and 22 million oz of silver at a mill feed grade of 1 grams/metric ton (mt) gold and 5.3 g/mt silver.
The Springpole project is located approximately 110 km northeast of the town of Red Lake. The PEA update evaluates recovery of gold and silver from a 36,000 mt/d open-pit operation, with a process plant that includes crushing, grinding, flotation, fine grinding of the flotation concentrate, and agitated leaching of both the flotation concentrate and the flotation tails, followed by a carbon-in-pulp recovery process to produce doré bullion.
Mining would occur as a series of open pits, with a maximum depth of approximately 400 m. The project is planned to produce a total of 139 million mt of plant feed and 319 million mt of waste over a 12-year mine operating life. The current life-of-mine plan focuses on achieving consistent processing feed production rates, mining of higher-grade material early in the schedule, and balancing grade and strip ratios.
The deposit is located under a small portion of the northern bay of Springpole Lake. Three dewatering dikes (coffer dams), with a total length of approximately 510 m, will be required to allow this portion of the lake to be dewatered. The coffer dams will have a height of 3 m above the waterline. The area proposed to be dammed and dewatered totals 152 ha and represents approximately 6% of the surface area of the lake and approximately 3% of its volume.