The study outlined a project with a production target of 31.9Mt grading 0.3g/t gold and 6.09g/t silver, comprising 73% indicated resources and 27% inferred resources, to deliver estimated production of 250,000oz gold and 1.77Moz silver over a 9.7 year mine life.
This is expected to deliver post-tax NPV and IRR of $511m and 64% respectively.
Payback is estimated at 1.4 years using an assumed gold price of $6128/oz and silver price of $93/oz on capex of $119m.
Black Bear Minerals (ASX:BKB) also highlighted the low estimated all-in-sustaining cost of $2248/oz net of silver byproduct credits.
Chief executive officer Dennis Lindgren said the study demonstrated a compelling preliminary development case for a conventional, low-capital heap-leach operation.
“Importantly, these outcomes utilise only a portion of the current MRE and exclude both the substantially larger current epithermal resource and the high-grade skarn resource,” he said.
“This provides a strong foundation for the next phase of work, as we incorporate the current resource, advance technical studies and assess opportunities to further enhance the scale and value of the project.”
Independence sits near the town of Battle Mountain and is directly adjacent to Nevada Gold Mine’s Phoenix project.
It has a global resource of 2.2Moz including a high-grade skarn resource of 1Moz at 6.3g/t gold and 1.2Moz gold equivalent chert-hosted epithermal resource from surface.
Gold mineralisation within chert is amenable to heap-leach extraction, a method used widely across Nevada’s epithermal deposits.
The scoping study considers open pit mining of near-surface epithermal material, with the deeper skarn mineralisation excluded.
Development consists of contract-mined open pits using conventional drill, blast, load and haul methods, two-stage crushing, heap leaching and Merrill-Crowe recovery at 9000tpd.
Supporting infrastructure would include water supply and storage, grid power, emergency generation, process ponds, site roads, administration facilities, a laboratory, warehouse and maintenance facilities.
Preproduction mining is scheduled to start about three months before first crusher feed to establish initial working areas and support commissioning and ramp-up.
Subject to board approval, BKB plans to advance Independence through updated mine planning, infill drilling, metallurgical and geotechnical test work, environmental studies and permitting.
