Thesis Gold Receives Positive Metallurgical Tests Results for Lawyers-Ranch Project: Achieves Average Precious Metal Recovery of 95% for Gold and 92% for Silver
Thesis Gold Receives Positive Metallurgical
Tests Results for Lawyers-Ranch Project:
Achieves Average Precious Metal Recovery of
95% for Gold and 92% for Silver
Vancouver, British Columbia--(Newsfile Corp. - June 5, 2024) - Thesis Gold Inc.
(TSXV: TAU) (WKN:
A3EP87) (OTCQX: THSGF) ("
Thesis
" or the "
Company
") is pleased to announce the successful
completion of preliminary metallurgical testing at the Company's 100% owned Lawyers-Ranch Project.
This testing aims to assess the economics of an expanded project that integrates high-grade feed from
Ranch and higher-grade underground material to a processing site at Lawyers. The program was
designed based on the updated Mineral Resource Estimate from May 1, 2024 (
link to news release
).
The Project is road-accessible and forms a contiguous, 495 km
2
land package in the prolific
Toodoggone Mining District in northern British Columbia.
The testing, completed by SGS Canada, focused on evaluation of the project's metallurgical response to
a variety of flowsheets investigating gravity, flotation, and cyanidation methods. The comprehensive
laboratory study concluded with the full treatment circuit evaluation including locked cycle flotation by
testing of three separate master composites.
These composites were from blended feed samples of
known resources from both the Lawyers and Ranch properties that had variations in gold, silver, and
sulphur head grade.
The laboratory full circuit evaluation demonstrated a recovery range of 93% to 96%
for gold and 86% to 96% for silver.
This included producing a primary precious metal flotation
concentrate with gold grades exceeding 160 g/t, indicating a marketable precious metal concentrate
with favorable payables.
The metallurgical results will be used as part of an updated preliminary
economic assessment of the project, scheduled for Q3-2024.
Metallurgical Testing Highlights
:
Process Flowsheet Development
: with gravity pretreatment, flotation, and leaching of
secondary concentrate and float tails.
The overall recovery range was 93% to 96% for gold and
86% to 96% for silver, demonstrating excellent extraction potential.
Gravity Pretreatment:
Recovery ranged from 20 to 38% for gold, and 2 to 10% of silver at grades
exceeding 360 g/t Au and 1190 g/t Ag, which is suitable for onsite doré production.
Primary Flotation Concentrate:
Recovery ranging from 40% to 65% of gold producing a
concentrate grade exceeding 160 g/t Au and 55% to 78% recovery for silver with a concentrate
grade of over 5,000 g/t Ag.
Leaching:
of a secondary float concentrate and the float tailing, scavenged an additional 8-20%
of gold and 12-24% of silver.
Dr. Ewan Webster, President and CEO, commented "The excellent metallurgical results from the
combined Lawyers-Ranch project highlight not only the high recoveries of 95% for gold and 92% for
silver but also the marketable concentrate grades. These findings, based on blended composites from
potential mining areas, provide a strong foundation for the upcoming preliminary economic assessment.
Given the strength of these results, our continued efforts will be directed towards optimizing capital costs,
operating costs, and maximizing payables, rather than addressing fundamental process challenges."
Flowsheet Development
The metallurgical testing initially involved variations to gravity separation, flotation, and cyanidation
procedures for process optimization. The study concluded with a locked cycle flotation test on each of
three master composites, with separate cyanidation of the scavenger concentrate. This was then
combined with the leaching of the float tailing. The data compared well to open cycle float tests.
Each of the three master composites were to represent various mineral zones from both properties.
This
includes potential underground and open pit material from Lawyers and newly identified mineral zones at
Ranch (see Table 1). Each zone composite was typically formed from 2 to 7 drill hole intervals averaging
approximately 10 metres, with varying precious metal and sulphur (S) grades. These master composites
therefore provide good confidence in the flowsheet response to the varying mineralogy of the project.
Table 1:
Master Composite Blend
To view an enhanced version of this graphic, please visit:
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The flotation flowsheet for the locked cycle tests following gravity pretreatment are illustrated in Figure 1.
Figure 1:
Flotation Flowsheet
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Following laboratory test work optimization, the metallurgical response was confirmed by using locked
cycle testing (see Figure 1 above) on three master composites representing blends from both Ranch
and Lawyers.
The test conditions consisted of grinding to an 80% particle passing size (P80) of 125
microns and subjecting the ground product to gravity treatment by centrifugal concentration.
The
centrifugal concentrate was cleaned by panning.
Gravity tailing was sent to a differential flotation circuit
with the primary (rougher) concentrate cleaned with a selective collector in three stages, while
depressing pyrite with elevated slurry pH using lime.
This generated a cleaned primary flotation
concentrate accounting for approximately 2 wt.% of the feed mass having a high precious metal grades
suitable for sale (see Table 2 below).
A lower grade secondary scavenger flotation concentrate
representing less than 3 wt.% of the mill throughput was pulled using a strong collector (potassium amyl
xanthate).
This material was then sent for aggressive leaching for 36 hours using high cyanide
concentration.
This residue was then combined with the flotation tailing for a final stage leach
maintaining 1 g/L NaCN for 24 hours.
Overall, the combined testing showed that gravity pretreatment yielded a gold recoveries ranging from
17% to 38%. The silver recoveries were typically lower, ranging from 2% to 10%. When considering the
combined processes of gravity and primary (rougher) flotation, the gold recoveries were notably high,
with 86% for Composite M1(HG), 87% for Composite M2 (MG), and 77% for Composite M3 (LG). The
combined silver recoveries were also substantial, achieving 81%, 85%, and 65% for the respective
composites. The gravity and flotation concentrates demonstrated high grades and efficient recovery
rates, for some zones. Stability in the locked cycle tests was generally good, with consistent mass, gold,
and silver recoveries observed in the final three cycles. However, adjustments may be necessary in
future test work, particularly to manage the re-floating of pyrite in high pyrite composites.
Cyanidation of the secondary flotation product further enhanced recovery. The circuit for leaching of the
concentrate is small due to low mass pull, allowing for aggressive procedures in the first stage. The
second stage leach is performed by recombing with float tailing, providing the overall leach response.
For Composite M2 (MG), the mid grade blend cyanidation recovered an additional 9% of gold and 12%
of silver. For Composite M1 (HG), the higher-grade blend recovered 8% of gold and 14% of silver, while
for Composite M3 (LG), the lowest grade blend, an additional 19% of gold and 21% of silver were
recovered from the overall leach circuit.
The combined metallurgical performance achieved excellent total recoveries of gold and silver.
Composite M2 (MG) showed a total gold recovery of 96.3% and silver recovery of 96.4%. Composite
M1 (HG) achieved 93.9% gold recovery and 94.4% silver recovery, while Composite M3 (LG)
demonstrated 96.5% gold recovery and 86.3% silver recovery. These results underscore the
effectiveness of the combined gravity, flotation, and cyanidation processes in maximizing precious metal
recoveries. Summary of the results are available in Table 2.
Table 2:
Master Composite Zone Blends and Head Assay
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The preliminary findings indicate no issues with the flowsheet in terms of mass balance or recovery,
affirming the project's robustness as it progresses.
Quality Assurance and Control
Original mineral samples that were selected for metallurgical evaluation were analyzed at ALS Global
Laboratories (Geochemistry Division) in Vancouver, Canada (an ISO/IEC 17025:2017 accredited
facility). The geological sampling program was undertaken by Company personnel under the direction of
Rob L'Heureux, P.Geol. Metallurgical testing was primarily performed by SGS Canada Inc. at their
laboratory located in Burnaby BC.
SGS is globally recognized in the mining industry and accredited with
International Standards Organization (ISO) 9001 for quality assurance, and ISO/IEC 17025 for general
requirements of laboratory competence in testing and calibration. A secure chain of custody is
maintained in transporting and storing of all samples.
The technical content of this news release has been reviewed and approved by Frank Wright, P.Eng.,
independent metallurgical consultant and qualified person as defined by National Instrument 43-101.
On behalf of the Board of Directors
Thesis Gold Inc.
"Ewan Webster"
Ewan Webster Ph.D., P.Geo.
President, CEO, and Director
About Thesis Gold Inc.
Thesis Gold is unlocking the combined potential of the Lawyers-Ranch Gold-Silver Project in the
Toodoggone mining district of north central British Columbia, Canada. A 2022 Preliminary Economic
Assessment for the Lawyers project alone projected an open-pit mining operation yielding an average of
163,000 gold equivalent ounces annually over a 12-year span
1
. By integrating the Ranch Project, the
Company aims to enhance the economics and bolster the overall project's potential. Central to this
ambition was the expansive 2023 drill program, which continues to define a high-grade out-of-pit Mineral
Resource at Lawyers and augment the near-surface high-grade deposits at Ranch. The project now
boasts a combined Measured & Indicated Mineral Resource of 4.0 Moz and an Inferred Mineral
Resource of 727 koz, at respective grades of 1.51 and 1.82 g/t AuEq. The Company roadmap includes,
new metallurgical work (now delivered), a robust 2024 exploration and drill program and a combined
updated Preliminary Economic Assessment slated for Q3 2024. Through these strategic moves, Thesis
Gold intends to elevate the Ranch-Lawyers Project to the forefront of global precious metals ventures.
1
Preliminary Economic Assessment: Lawyers Gold & Silver Project (2022). JDS Energy & Mining.
For further information or investor relations inquiries, please contact:
Dave Burwell
Vice President Corporate Development
Email:
Tel: 403-410-7907
Toll Free: 1-888-221-0915
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is
defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy
or accuracy of this press release.
Cautionary Statement Regarding Forward-Looking Information
This press release contains "forward-looking information" within the meaning of applicable Canadian
securities legislation. Forward-looking information includes, without limitation, statements regarding
the use of proceeds from the Company's recently completed financings and the future plans or
prospects of the Company. Generally, forward-looking information can be identified by the use of
forward-looking terminology such as "plans", "expects" or "does not expect", "is expected", "budget",
"scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or
variations of such words and phrases or state that certain actions, events or results "may", "could",
"would", "might" or "will be taken", "occur" or "be achieved". Forward-looking statements are
necessarily based upon a number of assumptions that, while considered reasonable by management,
are inherently subject to business, market, and economic risks, uncertainties, and contingencies that
may cause actual results, performance, or achievements to be materially different from those
expressed or implied by forward-looking statements. Although the Company has attempted to identify
important factors that could cause actual results to differ materially from those contained in forward-
looking information, there may be other factors that cause results not to be as anticipated, estimated,
or intended. There can be no assurance that such information will prove to be accurate, as actual
results and future events could differ materially from those anticipated in such statements.
Accordingly, readers should not place undue reliance on forward-looking information. Other factors
which could materially affect such forward-looking information are described in the risk factors in the
Company's most recent annual management's discussion and analysis, which is available on the
Company's profile on SEDAR at
www.sedarplus.com
. The Company does not undertake to update
any forward-looking information, except in accordance with applicable securities laws.
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