SNC-Lavalin completed the study, with capital costs for the hydromet plant estimated at US$131.1 million, with an acid leach, electro-winning and melting flowsheet to produce 61,606 tonnes per annum of lead metal ingots.
The DFS proposes a 15-year mine life – 3.3 times the existing life – with ore reserves up by more than twofold to 1.19 million tonnes of contained lead.
Life-of-mine C1 cash costs are estimated at 57c per pound of lead.
The project has a net present value of $191-303 million, an internal rate of return of 23.5-31.3% and a payback period of 3-4 years at lead prices of $2250-2575/t, or $1.02-1.17/lb.
Lead is currently trading at $2438.25/t.