- 388 g/t gold over 2.2 metres in WST-21-0823;
- 135 g/t gold over 6.3 metres and 24.3 g/t gold over 5.2 metres in WST-21-0828;
- 187 g/t gold over 2.5 metres in WST-21- 0763A;
- 113 g/t gold over 3.7 metres in OSK-W-21-2479-W5;
- 130 g/t gold over 2.9 metres and 38.8 g/t gold over 3.2 metres in OSK-W-21-2287-W3;
- 61.5 g/t gold over 3 metres in OSK-W-21-2544; and
- 41.5 g/t gold over 4.4 metres in OSK-W-21-2520.
The Windfall resource estimate was updated in February. Using a 3.5-g/t gold cut-off, the deposit has 6 million measured and indicated tonnes grading 9.6 g/t gold (1.9 million oz. contained gold) and 5.9 g/t silver (1.1 million oz. contained silver), There area also 16.4 million inferred tonnes grading 8 g/t gold (for 4.2 million oz.) and 2.7 g/t silver (for 1.4 million oz.).
Osisko is planning an underground mine with a pair of access ramps and a mill on site. The preliminary economic assessment was updated when the new resource numbers were tabulated. It says the project would have a net present value (after taxes and mining duties) of C$1.5 billion and an internal rate of return of 39.4%.
After pre-production capital expenses, the mine will have an 18-year life during which time approximately 4.2 million oz. of gold will be recovered. Mine start-up is expected in 2024 and full production in 2025. All-in sustaining costs net of by-product credits over the life of mine are estimated at $610.10 per ounce.
(This article first appeared in the Canadian Mining Journal)
