The company's goal is to become a 100,000-plus ounce per year gold producer and the PEA outlined an annual average production of 95,000oz, with a peak of about 117,000oz, at a headgrade of 0.48g/t.
It put the preproduction capex at US$113.2 million, after-tax NPV (5%) at $129.5 million and an internal rate of return of 29.4%, with a 2.3-year payback.
The all-in sustaining costs were slated at $793/oz recovered for the 7.5-year minelife.
The PEA was based on the maiden resource unveiled in February and restated using a lower 0.2g/t cut-off, for an indicated 925,000oz at 0.5g/t and an inferred 296,000oz at 0.47g/t.
"The lower cut-off improves the economics of the project, delivers a lower strip ratio, produces more ounces and extends the mine life," president and CEO Cal Everett said.
"The PEA does not include any potential benefits from by-product silver production, or from processing residual gold remaining in the historical heap leach pads, which are currently being drill-tested."
The company was working to further de-risk the project through more drilling, pursuing a silver resource, metallurgical test work, social license considerations and mine plan optimisation.
Liberty had $7.2 million in working capital at the end of March.
RCF Opportunities Fund took an 8.4% stake in the company as part of a C$10.5 million (US$8 million) private placement in January.
Liberty shares closed unchanged yesterday at C44.5c, a midpoint in the 52-week range of 36.5-53c.