The study details an eight-year mine life with 146,000ozpa production in the first three years at an all-in sustaining cost of US$579 per ounce, putting Cerro Blanco in the lowest quartile of the global cost curve.
With an initial capital investment of $196 million the project yields an after-tax internal rate of return of 34% and after-tax net present value of $241 million based on a $1,250/oz gold price and $18/oz silver price.
"We acquired the project barely 18 months ago so we have done a lot of work in a very short time," president and CEO Darren Klinck told Mining Journal.
"The feasibility demonstrates a leading gold development project that already has its exploitation license, and it will generate more cash flow in its first year of production than our current market cap."
The project has proven and probable mineral reserves of 940,000oz of gold and 3.6Moz of silver (3.4Mt grading 8.5g/t gold and 32.2g/t silver).
The study excludes an additional 357,000oz of inferred resources (1.4Mt grading 8.1g/t gold and 23.6g/t silver).
Bluestone will advance to project financing over the next six months while continuing to optimise the project.
The company said optimisation possibilities included mine life extension through upgrading some of the 360,000oz of inferred resources to measured and indicated through infill drilling, potential resource growth from step-out drilling along existing veins, the identification of new high-grade veins during infill drilling, finding alternatives to paste fill and use of ore sorting technology.
The study is based on a 1,250 tonnes per day plant with three-stage crushing and two-stage ball mill grinding.
The flowsheet includes pre-oxidation, a 48-hour leach circuit, followed by a six-hour carbon-in-pulp adsorption circuit with expected recoveries of 96% gold and 85% silver.
