Liberty Gold Corp. has completed Phase 6 metallurgical testing on the Black Pine oxide gold project in southeast Idaho, returning a weighted average gold extraction of 72.4% from coarse run-of-mine bulk column tests.

The pre-production validation program used seven bulk samples weighing 10 to 15 tonnes each, with particle sizes ranging from 2 to 8 inches. Testing was conducted in large columns measuring 4 feet in diameter by 20 feet high at the Reno laboratory of Kappes, Cassiday & Associates to simulate commercial heap leach performance.

The findings validate recovery assumptions incorporated into the Feasibility Study released on September 8, 2026, which outlined an after-tax net present value of US$2.397 billion and initial capital costs of US$411.4 million. Previous Phase 5B metallurgical testing recorded a weighted average column leach gold extraction of 81.9% at a finer average head grade of 0.65 ppm gold.

The bulk column results confirm that gold extractions at Black Pine are largely insensitive to particle size. On average, reducing rock size from 10 inches to 1 inch increased gold extraction by less than 3%, indicating that crushing costs are not justified by the modest recovery uplift.

Individual sample performance highlighted distinct operational characteristics across deposit zones. The Rangefront Ppos sample achieved 95% extraction at a 0.43 g/t gold head grade, outperforming modeled recovery by over 13%. Conversely, the I-pit Pold sample delivered 51.9% extraction, aligning with expected lower recoveries for that rock unit. Silver extractions reached up to 39%, with a weighted average recovery of 21%.

The testing also demonstrated rapid leach kinetics, with 90% of total gold extraction achieved within 36 days on average. Reagent consumption values for cyanide and lime matched feasibility study estimates, while compacted permeability testing confirmed adequate solution percolation up to 150 meters of simulated compaction.

Liberty Gold is advancing subsequent metallurgical programs to support detailed engineering design. Jon Gilligan, President and CEO, commented, “At Black Pine, we’re conducting the detailed metallurgical work that many heap leach projects overlook. This is part of our disciplined, technical approach to the study phase and it will materially de-risk delivery as we move towards a construction decision.”

Liberty Gold expects results from Phase 8B column leach testing on legacy heap pad composites in the first half of 2027, and targets the submission of the formal cyanidation permit application package for Black Pine in the first quarter of 2027.

Read the full announcement: Liberty Gold Validates Predicted Operating Gold Leach Recoveries Through Bulk Column Tests at Run-of-Mine Sizing