Liberty Gold Reports Weighted Average 86.9% Gold Extraction from Metallurgical Column Leach Testing on Rangefront Zone Oxide Gold Mineralization, Black Pine Project, Idaho Rangefront Zone Comprises the Most Leach-Amenable Oxide Material at
Page 1 of 10
News Release 23-06 March 22, 2023
Liberty Gold Reports Weighted Average 86.9% Gold Extraction from
Metallurgical Column Leach Testing on Rangefront Zone Oxide Gold
Mineralization, Black Pine Project, Idaho
Rangefront Zone Comprises the Most Leach-Amenable Oxide Material at
Black Pine
VANCOUVER, B.C. – Liberty Gold Corp. (TSX: LGD; OTCQX: LGDTF) (“Liberty Gold” or the
“Company”) is pleased to report results from Phase 4A metallurgical testing of oxide material from
the Rangefront Zone at its Black Pine Oxide Gold Project (“Black Pine”) in southeastern Idaho.
HIGHLIGHTS
• 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:
o 86.9% “weighted average gold extraction”1 from column leach tests.
o Gold extractions ranging from 54.1% to 95.8%.
o >80% of leachable gold extracted within 10 days.
• These new metallurgical data were not included in the recent mineral resource update (the
“Black Pine Resource”) 2 and will be added to the next resource update expected in late
2023.
• These 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 2.
1 Weighted average gold extraction is obtained using the following equation: (composite head grade (grams/tonnes) multiplied by
extraction (%) for all head grades)/sum of all head grades. Using arithmetic averages tends to over-represent low grade composites
and under-represent high grade composites. The arithmetic extraction average of the 24 column tests is 76%.
2 See press release dated February 7, 2023 and the technical report entitled “Technical Report on the Updated Mineral Resource
Estimate at the Black Pine Gold Project, Cassia and Oneida Counties, Idaho, USA”, effective January 21, 2023, and signed March 10,
2023, co-authored by Ryan Rodney, CPG, and Gary L. Simmons, MMSA, both independent Qualified Persons under NI 43-101; and
Moira Smith, Ph.D., P.Geo. of Liberty Gold Corp, available on SEDAR.com.
Page 2 of 10
• These new data are 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 testwork 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
testwork 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 for Liberty Gold 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 metallu rgical information today equals or
exceeds pre-feasibility level requirements, significantly de-risking the project.”
BLACK PINE METALLURGICAL TEST WORK
Liberty Gold has completed multiple phases of metallurgical testing at Black Pine including:
• Bulk sample column test results
o Phase 1A3 (6 x 300 kilogram surface bulk samples):
78.9% weighted average gold extraction, ranging up to 92.8%
• Variability composite column tests (113 composites from PQ drill core)
o Phase 1B4 (29 composites):
82.9% weighted average gold extraction, ranging up to 94.5%
o Phase 25 (45 composites):
80.8% weighted average gold extraction, ranging up to 94.8%
o Phase 36 (15 low-grade composites):
65.2% weighted average gold extraction ranging up to 80.3%
o Phase 4A (24 composites):
86.9% weighted average gold extraction, ranging up to 95.8%
Results generated by the Liberty Gold metallurgical program are consistent with historical column
test results from three surface bulk samples and five drill core samples generated by Noranda in
1988 prior to mining, which returned 80.8% weighted average gold extraction.
3 Previously referred to as “Phase 1” – see press release dated June 16, 2020
4 Previously referred to as “Phase 2” – see press release dated August 18, 2020
5 Previously referred to as “Phase 3” – see press release dated October 27, 2021
6 Previously referred to as “Phase 4” – see press release dated October 27, 2021
Page 3 of 10
The deposit-wide gold extraction is represented through the aggregate test data illustrated in
Figure 1 below. This graphic illustrates the gold grade to gold extraction relationship for all column
tests conducted to date at Black Pine and clearly demonstrate s a) the improve d metallurgical
response from the Rangefront Zone materials relative to the other samples and b) the Phase 3
low-grade samples performing consistently with the grade-extraction trend for Black Pine material
overall.
For a graph of results of the Liberty gold grade-gold extraction results for all column test work to
date, see Figure 1 or click here:
https://libertygold.ca/images/news/2023/March/Figure1BlackPineGoldGradeGoldExtractionResults03222023.pdf
Figure 1: Black Pine Gold Grade-Gold Extraction Results
*Data from several columns of Transitional Material are included in the above graph.
Two additional phases of metallurgical testwork are currently in progress, comprising:
• Phase 4B: Discovery Zone, E-Pit, A-Pit, F Zone, Tallman Pit and M Zone – 25 composites.
• Phase 4C: C/D Pit – 12 composites.
Results from these two phases of testing will be completed in the second half of 2023.
Page 4 of 10
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 characterised currently by 16 different
grade-recovery relationships. It is anticipated that one further p hase of testwork beyond that
currently in progress is required to meet feasibility standards on current resources.
All metallurgical work at Black Pine has been supervised by Gary Simmons MMSA, formerly the
Director of Metallurgy and Technology for Newmont Mining Corp. Mr. Simmons has managed or
supervised many metallurgical testing programs on similar Carlin -style sedimentary rock-hosted
oxide gold deposits throughout the Great Basin.
PHASE 4A TEST RESULTS
• The 24 Rangefront Zone column leach tests produced a weighted average 86.9% gold
extraction at an average gold grade of 0.47 grams per tonne gold (“g/t Au”), with a range from
54.1% to 95.8% gold extraction (see Table 1 below).
• Gold extraction was rapid, with >80% of the leachable gold extracted within the first 10 days
of column leaching (see Figure 2 below).
• Percent gold extraction is well-correlated with head grade, with the highest-grade composites
returning the higher extraction numbers (see Figure 1 above). Of the 24 column tests:
o 17 column tests were conducted on material below 0.5 g/t Au and returned weighted
average 79.4% gold extraction.
o 7 column tests were conducted on material between 0.5 g/t Au and 1.0 g/t Au and
returned weighted average 90.9% gold extraction.
• Gold extraction is relatively insensitive to particle size. Most composite extraction results can
be projected to coarse particle sizes without significant loss of gold extraction . The relative
percent gold extraction insensitivity to increasing particle size is shown in Table 2.
For a table of results of the Black Pine Phase 4A variability composite test results, see Table 1 or
click here:
https://libertygold.ca/images/news/2023/March/Table1BlackPinePhase4AVariabilityCompositeTestResults03222023.pdf
Page 5 of 10
Table 1: Results, Black Pine Phase 4A Variability Composite Testing
For a graph of results of the Black Pine Phase 4A variability composite leach curves, see Figure 2
or click here:
https://libertygold.ca/images/news/2023/March/Figure2BlackPinePhase4AVariabilityCompositeLeachCurves03222023.pdf
Page 6 of 10
Figure 2: Cumulative Leach Curves Confirm Rapid Leach Kinetics
For a table of results of the Black Pine Phase 4A variability composite gold extraction sensitivity
to modelled crush size testing, see Table 2 or click here:
https://libertygold.ca/images/news/2023/March/Table2BlackPinePhase4AVariabilityCompositeGoldExtractionSensitivitytoCrushSiz
e03222023.pdf
Page 7 of 10
Table 2: Results, Black Pine Phase 4A Variability Composite Gold Sensitivity to
Crush Size
METALLURGICAL TEST PROGRAM
Samples for Phase 4A test work were obtained through drilling PQ core holes. Composites were
selected through consideration of rock type, alteration and gold grade to achieve a wide range of
geo-metallurgical types. Composites were assembled in Elko, Nevada by Liberty Gold staff,
utilizing one-half or three-quarter sawed core, then shipped to Kappes, Cassiday and Associates
in Reno, Nevada for metallurgical testing, comprising bottle rolls, column testing and geo -
metallurgical characterization, including gold and silver assays, cyanide solub ility, sulphur
and carbon speciation, preg-robbing analysis, ICP geochemical assays, whole rock analysis, QXRD,
load-permeability tests, modified SMC comminution testing , Bond Abrasion (Ai) testing and
environmental chemistry.
For a map showing locations of drill holes used for metallurgical testing, see Figure 3, below, or
click here:
https://libertygold.ca/images/news/2023/March/Figure3BlackPineMetMap03222023.pdf
Page 8 of 10
Figure 3: Location of Drillholes used for Black Pine Metallurgical Samples
Program details included:
• Coarse bottle roll tests (target of 80% passing 10 mesh or 1.7 millimeter (“mm”) particle size).
• Fine bottle roll tests (target of 80% passing 200 mesh or 75 micron particle size).
• The direct leach samples were rolled/agitated in bottles in a 1.0 grams per liter (“g/l”) dilute
sodium cyanide (“NaCN”) solution for 72 hours (for 200 mesh) or 144 hours (for 10 mesh).
• The 200 mesh (75 microns) CIL samples were rolled/agitated in bottles for 72 hours in a 1.0
g/l dilute NaCN solution, containing 20 g/l of activated carbon.
• Composites were leached in 10.2 mm and 15.2 mm ( four and six inch) diameter columns
between 78 to 90 days. And were leached with low strength (0.50 g/l) NaCN solution.
QUALIFIED PERSON
Peter Shabestari, P.Geo., Vice -President Exploration, Liberty Gold, is the Company's designated
Qualified Person for this news release within the meaning of National Instrument 43- 101
Standards of Disclosure for Mineral Projects ("NI 43 -101") and has reviewed and validated that
the information contained in the release is accurate.