Sayona Mining Ltd. said Dec. 11 that an optimized pre-feasibility study for the Authier lithium project in Quebec estimated a pretax net present value, discounted at 8%, of C$221 million, an internal rate of return of 56% and a 2.5-year payback.
The optimized study incorporated an expanded ore reserve of 120,098 tonnes of lithium oxide contained in 11.7 million tonnes grading 1.03% Li2O and an upgraded mineral resource of 186,953 tonnes lithium oxide contained in 18.4 million tonnes grading 1.02% lithium oxide in the combined measured, indicated and inferred categories.
A previous prefeasibility study, completed in February this year, returned a pretax net present value, based on an 8% discount rate, of C$140 million, an internal rate of return of 39% and a 2.2-year payback period.
Annual average production in the updated study was cut to 96,000 tonnes from 99,000 tonnes at a higher-grade 6% lithium oxide, with average annual revenue at C$73 million.
Initial CapEx for the construction of an open-cut mining operation and processing facility producing spodumene concentrate is C$64 million, including C$5.5 million for contingency, with sustaining CapEx of C$45.8 million over the 17-year mine life.
Life of mine cash operating costs were estimated at C$370 per tonne on a mine-gate basis, or C$430 per tonne FOB for the port of Montreal.
Authier is scheduled for phase-three drilling to collect a pilot plant metallurgical sample and reserve definition. Construction is now targeted during the second half of 2018 and commissioning at the end of 2019, with a definitive feasibility study being finalized.
