BYN.V · 2024-02-06 12:00:00

Banyan Gold Announces Positive Metallurgical Test Results, AurMac Project,

Metallurgy & Processing

Mayo, Yukon

February 6, 2024 TSX-V: BYN | OTCQB: BYAGF

VANCOUVER, BC, February 6, 2024 - Banyan Gold Corp. (the “Company” or “Banyan”) (TSX-

V: BYN) (OTCQB: BYAGF) is pleased to announce positive results from the Phase 1 metallurgical

test program conducted on the Company’s AurMac Project in the Yukon Territory. Phase 1

metallurgical testing focused on the AurMac Project’s Powerline Deposit (“ Powerline”) as

Powerline hosts the majority of the Project’s 6.2 million ounce (“Moz”) gold inferred Mineral

Resource Estimate (“ MRE”). Results from th e metallurgical test program demonstrate robust

recoveries throughout Powerline, identifying multiple conventional mineral processing flow sheets

which the Company continues to advance and optimize through ongoing metallurgical test work.

Highlights:

• Gold recoveries averaged 91% from 75 micron (“m”) (200 Mesh) bottle roll cyanidation

tests.

• Gold recoveries estimated to be 91% for the Carbon in Leach ( “CIL”)/Carbon in Pulp

(“CIP”) process.

• Gold recoveries for the combined gravity and flotation process are estimated at 84%.

• Heap leach gold recovery is estimated to range from 64-72% based on coarse size

(9.5 mm) bottle roll testing, conventional column leach tests and Vat leach diffusion

extraction testing.

• Flotation recovery into a rougher concentrate recovered on average 89% of the gold with

a low mass pull of 3.7%, indicative that a small percentage of material would require further

processing.

• Low cyanide consumption at an average of 0.52 kg/mt for primary grind of P 80 passing

75 m.

• Gravity recovery has shown it may be an effective part of the flow sheet.

• Low sulphide concentration and excess buffering capacity indicates Powerline is non-acid

generating.

“Metallurgical test work highlights robust gold recoveries with multiple conventional mineral

processing flow sheets and further optimization has a high likelihood to result in increased overall

gold recoveries,” Tara Christie, President & CEO, stated. “These results represent a significant

step forward at AurMac and continued work will focus on crush and grind sizes, in addition to

power and reagent consumption. Work will be focused to support a future economic study using

one or more of the identified processes.”

Potential Mineral Processing Flow Sheets

Three gold recovery process flow sheets have been identified through the Phase 1 test program.

This includes CIL or CIP gold extraction processes (91% gold recovery). The CIL/CIP flow sheet

is the most commonly used milling gold recovery method worldwide. Canadian examples include

Agnico Eagle’s Detour Lake and Malartic Mines in Ontario and Quebec, respectively. The second

process is conventional mill flotation (84% gold recovery) which is used at Kinross Gold’s

Paracatu Mine in Brazil and Centamin’s Sukari Mine in Egypt. Test work supportive of gravity

recoverable gold was also carried out that indicates a gravity recovery circuit could be included in

either the CI L/CIP or mill flotation flow sheets to enhance gold recoveries and reduce reagen t

consumption. The third flow sheet is heap leach processing (64-72% gold recovery), a commonly

used method for high volume, low-grade gold deposits; examples include Victoria Gold’s nearby

Eagle Mine in the Yukon and Kinross Gold’s Fort Knox Mine in Alaska. Mines such as Fort Knox

utilize both heap leaching and conventional mill processing.

Methodology

The Phase 1 metallurg ical test program focused on the Powerline Deposit as it represents the

majority (~62%) of the AurMac Project’s current 6.2 Moz gold inferred MRE. Banyan submitted

34 individual intervals (~991 kg) of representative drill core from Powerline to Forte Analytical in

Fort Collins, Colorado. The individual intervals selected were based on gold grade, depth from

surface, spatial distribution, and lithology. Three master composite samples were prepared from

the individual sample intervals as shown in Figure 1 and the composites were based on the three

dominant l ithologies identified within Powerline which include , Comp 1 - calcareous schist

(“CSCH”), Comp 2 - muscovite quartz schist (“MQST”) and Comp 3 - sericite schist (“SSCH”).

The Phase 1 test program for Powerline included acid-base accounting, mineralogy, comminution,

bottle roll cyanidation (9.5 mm and 75 m), flotation, gravity recovery, column leach tests, Vat

leach diffusion extraction tests, and a gravity-flotation-intensive cyanidation process simulation.

The program was overseen by Deepak Malhotra (SME-RM of Forte Analytical) who is a Qualified

Person as defined by National Instrument 43 -101, Standards of Disclosure for Mineral

Projects (“NI 43-101”).

Figure 1. Metallurgical Sample Locations from the Powerline Deposit

Sample Assays and 75m Bottle Roll Testing

Head samples were assayed by both fire assay and metallic screen fire assay ( “MSFA”) (Table

1) with fire assays averaging 0.76 g/t gold for the test intervals and an overall average of 0.66 g/t

gold for metallic screen fire assays. Calculated head assays based on the bottle roll tests is shown

in Table 1. The variability in the head assays, calc ulated head grade assays and MSFAs

demonstrate the known nuggetty coarse gold exhibited in Powerline. The total sul phur in the

samples ranged from 0.39% to 1.15% with an average of 0.70%, and total carbon ranged from

0.28% to 2.07% predominantly as inorganic carbon (91%). For MSFA analysis, samples were split

via metallic screen into +140 mesh and -140 mesh fractions to split the coarse gold from the fine

gold.

Table 1. Powerline Deposit Sample Assays and 75 m Bottle Roll Results

Sample ID

Gold

Fire

Assay

Calc. Head

Assay MSFA Carbon Sulphur Extraction,

% gold Lithology

[g/t

gold] [g/t gold] [g/t gold] Total % Total % 75m

(200 Mesh)

Master Composite 1 0.415 - - 0.76% 0.68% 87.5 CSCH

Master Composite 2 0.485 - - 0.67% 0.86% 91.6 MQST

Master Composite 3 0.824 - - 0.75% 0.80% 92.6 SSCH

AX-21-79 47.29-57.9 1.871 1.07 0.68 0.73% 0.65% 78.5 MQST

AX-21-140 43.5-49.5 1.201 0.90 2.81 0.64% 0.57% 90.7 CSCH

AX-21-91 131.1-135.1 0.613 0.56 0.71 1.10% 0.45% 96.4 CSCH

AX-22-208 82.7-112.8 0.633 0.94 1.2 0.28% 0.39% 89.8 MQST

AX-22-214 10.7-35.4 0.269 0.72 0.28 0.66% 0.72% 95.1 MQST

AX-22-223 25.9-32.8 1.99 0.25 0.30 0.76% 0.46% 80.1 CSCH

AX-22-225 61.5-77.7 0.587 0.37 1.49 0.62% 0.73% 56.7 CSCH

AX-22-225 85.4-111.3 0.222 0.33 0.21 0.94% 0.81% 80.4 CSCH

AX-22-227 185.9-192 0.259 0.31 0.33 0.92% 0.73% 80.2 CSCH

AX-22-230 70.1-79.3 0.317 0.73 0.62 0.49% 0.71% 91.8 MQST

AX-22-230 99.1-109.3 0.48 0.05 0.34 0.38% 0.39% 61.1 MQST

AX-22-230 135.6-166.1 0.775 0.82 0.85 2.07% 1.15% 80.3 MQST

AX-22-230 166.1-188.5 0.159 0.17 0.16 0.73% 0.44% 79.1 MQST

AX-22-231 59.1-63.7 0.464 0.39 0.45 0.84% 0.98% 86.6 CSCH

AX-22-246 58.5-82.3 0.378 0.19 0.69 0.82% 0.79% 83.0 CSCH

AX-22-246 116.7-134.6 2.674 0.42 0.63 1.77% 0.79% 89.7 MQST

AX-22-254 76.2-79.3 0.267 0.44 0.27 1.81% 0.87% 68.7 SSCH

AX-22-272 160.8-163.9 1.496 1.04 1.07 0.50% 0.52% 93.0 MQST

AX-22-273A 50.1-56.1 0.501 0.43 0.61 0.41% 0.46% 89.4 CSCH

AX-22-274 171.8-182.8 0.812 0.77 0.40 0.87% 0.78% 89.7 GNST

AX-22-291 45.7-50.6 0.816 0.70 0.70 0.87% 0.77% 87.6 MQST

AX-22-302 51.8-59.4 1.284 0.51 0.57 0.36% 0.65% 87.7 QTZT

AX-22-302 71.6-77.2 0.302 0.46 0.49 0.33% 0.63% 76.1 QTZT

AX-22-339 175.9-179.8 0.472 0.44 0.40 1.09% 0.57% 83.5 CSCH

AX-22-347 170-175 0.173 0.25 0.21 0.49% 0.62% 92.1 CSCH

The three representative master composites returned an average of 90.6% gold recovery using

75 m bottle roll testing. Overall gold extraction percentages ranged from 56.7% to 96.4%. These

75 m bottle roll tests show that gold recovery does not significantly change across variations in

grade, depth from surface, sulphide content and lithology and that no organic carbon or other

materials present preclude or reduce leach extraction rates (commonly referred to as non preg-

robbing). The 75 m bottle roll test s had an average of 65% gold recovery within the first two

hours and over 80% average gold recovery in the first 8 hours showing rapid gold recovery

kinetics. Average cyanide consumption for the 75 m bottle rolls was low at 0.52 kg/t.

Industry standard comminution testing was completed on the composite samples to determine

crusher work index (CWi), Bond’s ball mill work index (BWi) and abrasion work index (Ai)

parameters. The average CWi for the composites was 15.2 kWh/ t and the BWi was 14.6 kWh/t,

indicating Powerline is classified as medium to hard.

Gravity Recovery

Coarse gold is evident across Powerline and, therefore, gravity recovery was assessed as part of

the Phase 1 program. Initial g ravity recovery testing was completed on the three master

composite samples and subsequently assayed as either rougher concentrate or cleaner

concentrate. The Knelson concentrate produced the rougher concentrate, which was then further

cleaned using a Gemeni table to produce the cleaner concentrate. Two grind sizes, 150 m (100

mesh) and 212 m (65 mesh), were tested throughout the gravity campaign, and the average

gold recovery from rougher gravity concentrate was 53%.

Flotation

Flotation testing was conducted on all three composites across three different grind sizes: 150 m

(100 mesh), 75 m (200 mesh), and 44 m (325 mesh). The tailings from the gravity recovery

tests completed on the three composites were also assessed for flotation response at the 100

mesh particle size. All composites demonstrated high gold recovery in rougher concentrate with

an average gold recovery of 89% from the composite samples (Table 2). Of significance is the

overall low mass pull of ~3.7% on average. The high rougher flotation concentrate recovery along

with the low mass pull suggests a small intensive cyanidation circuit leaching a flotation rougher

concentrate as a process flow sheet option to be further investigated.

Table 2. Flotation Results for Powerline Deposit Composites

Sample P80 Grind

Size

Concentrate

wt%

Gold

Recovery

Conc.

Grade

Calc.

Head Tail Grade

[m] [wt.%] [% gold] [g/t gold] [g/t gold] [g/t gold]

Comp 1 150 3.3 89.1 31.67 1.16 0.13

Comp 1 75 2.7 75.1 12.84 0.47 0.12

Comp 1 44 6.1 86.5 7.86 0.56 0.08

Comp 1 Grav Tail 150 2.6 73.1 19.31 0.69 0.19

Comp 2 150 3.0 92.8 29.74 0.95 0.07

Sample P80 Grind

Size

Concentrate

wt%

Gold

Recovery

Conc.

Grade

Calc.

Head Tail Grade

[m] [wt.%] [% gold] [g/t gold] [g/t gold] [g/t gold]

Comp 2 75 2.6 94.6 60.01 1.63 0.09

Comp 2 44 3.5 92.0 25.12 0.96 0.08

Comp 2 Grav Tail 150 2.6 91.0 37.23 1.08 0.10

Comp 3 150 4.8 86.7 19.62 1.08 0.15

Comp 3 75 2.8 89.3 35.33 1.09 0.12

Comp 3 44 4.3 92.7 28.15 1.32 0.10

Comp 3 Grav Tail 150 3.0 86.0 25.97 0.90 0.13

Gravity – Flotation - Intensive Cyanidation

Based on the individual flotation and gravity results, a non-optimized process simulation test was

completed on remaining Composite 2 material and incorporated grinding, gravity recovery,

rougher flotation, and intensive cyanidation of the concentrate products (gravity+float

concentrate). Gravity and flotation recovery of Composite 2 resulted in 95% recovery and

intensive cyanidation of the flotation and gravity concentrate returned 88% for a total recovery of

84.2%.

Heap Leaching Test Work

The response of Powerline to heap leach was assessed through a combination of coarse 9.5 mm

bottle roll tests, s tandard column ( 10 cm) leach tests and Vat leach diffusion extraction tests.

Coarse bottle roll tests at a crush size of P 80 passing 9.5 mm were completed over a 264 -hour

test duration using standard bottle roll testing parameters. The average gold recovery for the

composite weighted intervals was consistent and ranged from 33.7% – 35.6%. Conventional

10 cm diameter column leach tests at a crush size of P 80 passing 9.5 mm were completed in

duplicate on the three master composites. The overall gold recovery of all the column leach tests

was 52.3% and ranged from 34.5% - 62.6% over a 76 to 78-day leach duration. The decrease in

gold recovery with the coarse 9.5 mm crush size compared to the 75 m particle size shows that

gold recovery is likely size dependent. Bottle roll and column leach test results are shown in Table

Table 3. 9.5 mm Bottle Roll and Column Leach Test Results for Powerline Deposit

Bottle Rolls

Composite Average

10 cm Column Leach

Sample ID

Calc. Head

Grade

g/t gold

Gold

%Recovery

Leach

Duration

(hrs)

Calc. Head

Grade

g/t gold

Gold

%Recovery

Leach

Duration

(days)

Composite 1 0.46 34.9 264 0.498 57.9 76

Composite 1 Dup Na na na 0.684 57.1 78

Composite 2 0.68 35.6 264 0.726 47.0 78

Composite 2 Dup Na na na 0.911 34.5 78

Composite 3 0.57 33.7 264 0.812 55.1 78

Composite 3 Dup Na na na 0.571 62.6 78

Vat Leach Diffusion Extraction Testing

Vat leach diffusion testing was conducted on both Composite 1 and Composite 2 material at size

fractions of 12.7 mm, 9.5 mm and 6.4 mm. The Vat leach diffusion test is used in the early stages

of metallurgical testing to optimize the crush size for a heap leach process flow sheet. Discrete

particle sizes are loaded into a 15 -30 kg charged Vat with cyanide solution, then a cycle of

flooding/draining cyanide solution on a 24-hour basis in the early stages of testing, then to a

weekly basis and continues until extraction is diminished, normally completed over 100-200 days

depending on the particle size. Utilizing the Vat data of discrete particles measuring diffusion rates

of the material, diffusion modeling was performed to represent a P 80 9.5 mm particle size

distribution, with recovery curves generated for estimating heap leach recoveries over an

extended leach period (Figure 2). Long-term gold recovery is estimated at 64% for Composite 1

and 72% for Composite 2. The higher recovery from the Vats compared to the 10 cm column (P80

9.5 mm crush) tests also demonstrates a potential influence by coarse gold.

Figure 2. Modelled Vat Leach Gold Recovery Curves for Powerline Deposit Composites

Environmental

Mineralogy and acid-base accounting were performed on the three master composite samples

and the results indicate that Powerline is not acid generating and has excess buffering capacity

(Table 4). The samples were mainly composed of quartz (>70%) and minor quantities of

plagioclase, orthoclase, muscovite, biotite, clinochlore, epidote and calcite with pyrite being the

primary sulphide mineral present. The non-acid generating nature and excess buffering capacity

of Powerline is an important consideration in future permitting and waste management designs.

0 50 100 150 200 250 300 350 400 450 500

% Gold Extracted

Days Under Leach

Comp 1 Comp 2

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