Phase 4A Metallurgical Testing Of Oxide Material From Rangefront Zone

VANCOUVER - Liberty Gold Corp. reported on the Phase 4A metallurgical testing of oxide material from the Rangefront Zone at its Black Pine Oxide Gold Project in southeastern Idaho. The Phase 4A column leach testing on the Rangefront Zone included 24 variability composites from large-diameter (PQ) drill core representing the range of rock types and gold (“Au”) grades encountered in oxide mineralization. Key results include: 1) 86.9% “weighted average gold extraction”1 from column leach tests. 2) Gold extractions ranging from 54.1% to 95.8%. 3) >80% of leachable gold extracted within 10 days.

This new metallurgical data was not included in the recent mineral resource update (the “Black Pine Resource”) and will be added to the next resource update expected in late 2023. New column test results suggest an increase in recoverable gold in the Rangefront Zone of approximately 4% in the upper plate sandstone unit (Ppos) and approximately 10% in the middle plate limestone unit (Pola) relative to the recovery models used in the Black Pine Resource.

The Rangefront Zone mineralization comprises approximately 27% of the Black Pine Resource. The new data is being used to develop metallurgical recovery equations to feed into an updated, deposit-wide gold recovery model for use in future resource, engineering, and economic modeling.  Aggregate metallurgical data from all phases of test-work to date indicate a gold recovery percentage in the mid-70s at the average grade used in the Black Pine Resource.

Aggregate test results across four phases of metallurgical study over four years, comprising test-work on 113 composites and six bulk samples, continue to support a technically simple, low initial capital, low operating cost, run-of-mine (ROM) heap leach processing route for Black Pine oxide mineralization.

Jon Gilligan, Chief Operating Officer, said, “Data from the extensive metallurgical test work completed at Black Pine continue to indicate rapid leaching and relatively high gold extractions from these oxide ores. With these results, the Rangefront Zone is now the highest-recovery oxide material we have found at Black Pine. Recovery continues to be relatively insensitive to particle size and there is a predictable grade-recovery relationship, both of which support run of mine heap leaching as the preferred processing route. The quality and quantity of metallurgical information today equals or exceeds pre-feasibility level requirements, significantly de-risking the project.”

Two additional phases of metallurgical test-work are currently in progress, comprising: Phase 4B: Discovery Zone, E-Pit, A-Pit, F Zone, Tallman Pit and M Zone – 25 composites; and Phase 4C: C/D Pit – 12 composites. Results from these two phases of testing will be completed in the second half of 2023.

Internal clay content and rock quality models indicate that a small portion of the Black Pine Resource may require in-pit or top-of heap blending, eliminating the need for a crush/agglomeration flowsheet component, and supporting simple ROM heap leaching at Black Pine. Metallurgical test-work completed on Black Pine to date equals or exceeds pre-feasibility requirements, with oxide ROM heap leach recoveries characterized currently by 16 different grade-recovery relationships. It is anticipated that one further phase of test-work beyond that currently in progress is required to meet feasibility standards on current resources.