Hercules Metals Achieves Strong Phase I Metallurgical Results with Recoveries of 90% Copper and Over 80% Silver
Toronto, December 3, 2024 - Hercules Metals Corp. (TSXV: BIG) (OTCQB: BADEF) (FSE: C0X) ("Hercules Metals" or the "Company") is pleased to announce results from its first phase of initial metallurgical testing at the Hercules Project in western Idaho ("Hercules" or the "Property"). Metallurgical testing was conducted on four composite samples, each weighing over 50 kilograms, including samples of oxide and sulfide silver from the near surface epithermal system, as well as copper mineralization from the underlying porphyry system. Conventional flotation of porphyry copper mineralization achieved a strong recovery of ± 87% in initial open cycle tests, with ongoing locked cycle testing now projected to recover ± 90%. A straightforward two-step leaching process on the near-surface silver delivered impressive recoveries of 86% for oxide mineralization and 82% for sulfide mineralization.
Highlights
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Initial copper recoveries of ± 87% were achieved in the first pass open cycle tests, with ongoing locked cycle testing now projected to recover ± 90%.
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Minimal deleterious elements in concentrate.
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Overall silver recoveries of 86% (oxide) and 82% (sulfide) for the near surface silver mineralization, utilizing a sulfurous acid leach followed by conventional cyanidation. Approximately 60% of silver is free milling.
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Phase I metallurgical scoping tests were completed at Forte Dynamics ("Forte"), by Deepak Malhotra, PhD, with experience in many large silver deposits, and recipient of the AIME James Douglas Award, the Gaudin Award and Arthur C. Daman Lifetime Achievement Award by the Society of Mining and Metallurgy and Exploration Engineers.
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Next steps include Cu-Mo separation analysis, optimization of the two-step leaching process for silver, and optimization of locked cycle flotation of copper.
Chris Paul, CEO and Director of the Company, noted: "These initial recovery values exceeded our expectations and highlight that a commercial-grade clean concentrate can be produced, without deleterious elements like arsenic or antimony. Moving forward, we anticipate that future optimization studies will work to further enhance these strong initial numbers from our phase I study.
Perhaps most encouraging are the exceptionally strong silver recoveries achieved on the near-surface epithermal mineralization. By developing a simple two-step leaching process, Deepak and his team at Forte have improved on historical recoveries by over 20%. This alone may have a profound impact on the future development of the Property, as the ability to implement low-cost leaching of the near surface silver mineralization not only enhances its viability, but also strongly positions us to unlock the underlying porphyry system."
Silver Recoveries
Forte initially completed a review of historical met work completed in the 1980's prior to proposing a new process which had potential to improve on the historical recoveries. Composite samples were prepared on both the silver oxide and sulfide mineralization from 2023 drill core assay rejects.
Initial bottle roll tests demonstrated that approximately ± 60% of the silver in both composites was directly cyanide soluble, reflective of the free-milling silver component. To improve on this, a two-step recovery process was implemented. The first step involved a sulfurous acid leach, which liberated silver bound to manganese minerals, enhancing its availability for subsequent recovery. The second step, a cyanide leach of the acid-treated material, delivered recoveries of ± 86% for the oxide composite and ± 82% for the sulfide composite, representing a remarkable 22-26% improvement from the initial single-step cyanidation tests. Results are shown in Table 1 below.
Table 1: Cyanide Leach Test Results After Sulfurous Acid Leading
Sample | Extraction % Ag | Residue g/t Ag | Head g/t Ag | Reagent Consumption kg/t | |
NaCN | Lime | ||||
Oxide | 86.2 | 28.0 | 202.5 | 1.738 | 6.5 |
Sulfide | 82.1 | 17.0 | 94.8 | 1.124 | 2.0 |
Copper-Molybdenum Recoveries
Rougher flotation tests were performed at varying grind sizes. The test results indicated that both copper and molybdenite recoveries were independent of the grind sizes tested. The results also indicated that 12 minutes of flotation time recovered ± 95% of copper and ± 84% of molybdenite in the rougher concentrate at a fairly coarse grind of P80 of 100 mesh (Table 2).
Table 2: Cu-Mo Rougher Flotation Results at Varying Grind Sizes
Primary Grind Size (mesh) | Flotation Time, min | Recovery % | Concentrate Grade % | |||
Wt | Cu | Mo | Cu | Mo | ||
100 | 12 | 9.97 | 95.8 | 84.0 | 8.8 | 0.07 |
150 | 12 | 10.01 | 95.4 | 83.7 | 8.4 | 0.10 |
200 | 12 | 9.86 | 95.0 | 83.2 | 8.6 | 0.10 |
A large scale (10 kg) flotation test was then carried out to produce a rougher concentrate on which cleaner flotation could be carried out. The large-scale rougher concentrate recovered ± 8% of the weight, ± 96% of the Cu, and ± 64% of the Mo, assaying ± 10% Cu and 0.1% Mo.
Table 3: Large Scale (10 kg) Rougher Flotation Test Results at P80 of 100 Mesh
Product | Recovery % | Concentrate Grade % | |||
Wt | Cu | Mo | Cu | Mo | |
Rougher Concentrate | 8.2 | 95.8 | 64.1 | 10.3 | 0.0998 |
Rougher Tailing | 91.8 | 4.2 | 35.9 | 0.04 | 0.005 |
Open cycle cleaner flotation tests were run in two stages on the rougher concentrate. Copper recoveries were 93.6% after the first stage and 90.5% after the second stage. Locked cycle tests are underway with projected cleaner recoveries of ± 95%. A concentrate grade of ± 22% Cu was achieved without regrind of the rougher concentrate and Forte is projecting ± 24% Cu in the locked cycle tests, demonstrating that a marketable grade copper concentrate can be produced with a simple conventional flowsheet.
Table 4: Open Circuit Cleaner Flotation Test Results without Regrind
Product | Flotation Time, min | Recovery % | Concentrate Grade % | |||
Wt | Cu | Mo | Cu | Mo | ||
Cleaner 2 Con 1 | 1 | 27.6 | 69.4 | 62.6 | 22.52 | 0.21 |
Cleaner 2 Con 2 | 1 | 7.4 | 16.0 | 15.9 | 21.36 | 0.18 |
Cleaner 2 Con 3 | 1 | 2.8 | 5.1 | 5.5 | 19.28 | 0.15 |
Cleaner 2 Tail | - | 8.8 | 3.1 | 5.5 | 6.24 | 0.03 |
Cal Cleaner 1 Con | 4 | 46.4 | 93.6 | 89.6 | ||
Cleaner 1 Tail | - | 53.6 | 6.4 | 10.4 | 1.94 | 0.01 |
Cal. Rougher Con. | - | 100 | 100 | 100 | 9.92 | 0.08 |
Outlook
With the early arrival of seasonal winter conditions, Hercules has initiated a shutdown of the Phase III program to ensure the safe demobilization of personnel and equipment. The Phase IV drill program is anticipated to commence as soon as weather conditions permit, with preparations already underway.
Drill results from the remaining Phase III holes are still pending, and these, along with other exploration updates, are expected to be released through to early 2025.
The Phase III program has successfully expanded the enrichment zone to 1.6 km by 1.1 km, demonstrating significant continuity which remains open in all directions. The Company has also identified a number of other new targets which will be further discussed in a coming news release. Notably, the recent identification of a new zone of shallow porphyry mineralization to the southeast, a zone of increasing grade to the north, and the discovery of a new hydrothermal breccia, all demonstrate the strong potential for near-term discovery of additional porphyry centers.
Qualified Person
The scientific and technical information in this news release, including the sampling, analytical and test data underlying the information has been reviewed and approved for disclosure by Deepak Malhotra SME-RM, Director of Metallurgy, of Forte Dynamics. Mr. Maholtra is a "Qualified Person" independent of the Company within the meaning of National Instrument 43-101 - Standards of Disclosure for Mineral Projects.
About Hercules Metals Corp.
Hercules Metals Corp. (TSXV: BIG) (OTCQB: BADEF) (FSE: C0X) is an exploration Company focused on developing Idaho's newest copper and silver district.
The 100% owned Hercules Project located northwest of Cambridge, hosts the newly discovered Leviathan porphyry copper system, one of the most important discoveries in the region to date. The Company is well positioned for growth through continued drilling, supported by extensive historical and current exploration and a strategic investment by Barrick Gold.
With the potential for significant scale, the Company's management and board of directors aims to build on its proven track record which includes the discovery and development of numerous precious metals projects worldwide.
For further information please contact:
Nisha Hasan
Investor Relations
Telephone +1 (604) 425-1408
Email: nisha@herculesmetals.com
Chris Paul
CEO & Director
Telephone +1 (604) 670-5527
Email: chris@herculesmetals.com
This news release does not constitute an offer to sell or a solicitation of an offer to buy any of the securities in the United States. Any securities referred to herein have not and will not be registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act") or any state securities laws and may not be offered or sold within the United States or to U.S. Persons unless registered under the U.S. Securities Act and applicable state securities laws of an exemption from such registration is available.
Disclaimer for Forward-Looking Information
This news release contains certain information that may be deemed "forward-looking information" with respect to the Company within the meaning of applicable securities laws. Such forward-looking information involves known and unknown risks, uncertainties and other factors that may cause the Company's actual results, performance or achievements, or developments in the industry to differ materially from the anticipated results, performance or achievements expressed or implied by such forward-looking information. Forward-looking information includes statements that are not historical facts and are generally, but not always, identified by the words "expects," "plans," "anticipates," "believes," "intends," "estimates," "projects," "potential" and similar expressions, or that events or conditions "will," "would," "may," "could" or "should" occur. Forward-looking information contained in this press release may include, without limitation, the expected execution of future exploration programs on the Property; assay results of future drill holes; results of operations, and the expected financial performance of the Company.
Although the Company believes the forward-looking information contained in this news release is reasonable based on information available on the date hereof, by its nature, forward-looking information involves assumptions and known and unknown risks, uncertainties and other factors which may cause our actual results, level of activity, performance or achievements, or other future events, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information.
Examples of such assumptions, risks and uncertainties include, without limitation, assumptions, risks and uncertainties associated with general economic conditions; the Covid-19 pandemic; adverse industry events; the receipt of required regulatory approvals and the timing of such approvals; that the Company maintains good relationships with the communities in which it operates or proposes to operate, future legislative and regulatory developments in the mining sector; the Company's ability to access sufficient capital from internal and external sources, and/or inability to access sufficient capital on favorable terms; mining industry and markets in Canada and generally; the ability of the Company to implement its business strategies; competition; the risk that any of the assumptions prove not to be valid or reliable, which could result in delays, or cessation in planned work, risks associated with the interpretation of data, the geology, grade and continuity of mineral deposits, the possibility that results will not be consistent with the Company's expectations, as well as other assumptions risks and uncertainties applicable to mineral exploration and development activities and to the Company, including as set forth in the Company's public disclosure documents filed on the SEDAR+ website at www.sedarplus.ca.
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