TORONTO, May 31, 2022 (GLOBE NEWSWIRE) -- Discovery Silver Corp. (TSX-V: DSV, OTCQX: DSVSF) (“Discovery” or the “Company”) is pleased to provide a project update and to announce the project study team for the Pre-Feasibility Study (“PFS” or “the Study”) on its flagship Cordero project (“Cordero” or “the Project”) located in Chihuahua State, Mexico. The PFS will be led by Ausenco Engineering Canada Inc. (“Ausenco”) and is on schedule for completion in 4Q 2022.
Taj Singh, President & CEO, states: “We are very pleased with the excellent progress we have made on our PFS and to be working with the same industry-leading project team that completed our Preliminary Economic Assessment (PEA). Initial results from the PFS metallurgical testwork program highlight the exceptional metallurgical performance at Cordero with recoveries typically ranging from 90-95% for Ag, Pb and Zn from the tests completed so far. These recoveries have been achieved at a very coarse grind size and with lower reagent consumption than what was assumed in the 2021 PEA. All other aspects of the PFS are tracking well and we remain on schedule to deliver the Study in the fourth quarter of this year.”
PROJECT UPDATE
Resource update: An updated resource estimate is scheduled to be released in 4Q 2022 alongside the release of the PFS. The resource estimate will be based on a total of 283,000 m in 683 drill holes (123,000 m of historic drilling plus 160,000 m of drilling completed by the Company). This resource update will incorporate an additional 68,000 m in 203 drill holes completed since the last resource update in October 2021.
Sulphide metallurgical testwork: Comminution and flotation testwork to supplement the detailed metallurgical test program completed in 2021 is ongoing. The testwork is predominantly focused on testing rock type blends, high-grade samples (+100 g/t AgEq) to confirm a positive relationship between head grade and recovery, and optimizing reagent usage. The testwork is being conducted by Blue Coast Research Ltd. (“Blue Coast”) with oversight from Libertas Metallurgy Ltd. (“Libertas”) and Ausenco.
Results from the first batch of PFS locked cycle tests have already been received and are summarized in the tables below. Recoveries from these tests are in-line or modestly better than the recoveries assumed in the 2021 PEA and were achieved at lower reagent consumptions.
Test | Rock Type/Blend | Head Grade | Lead + Zinc Circuit | |||||
Recovery to Concentrate | ||||||||
Ag | Pb | Zn | AgEq | Ag | Pb | Zn | ||
(g/t) | (%) | (%) | (g/t) | (%) | (%) | (%) | ||
LCT-1 | Starter Pit Blend | 37 | 0.55 | 0.55 | 76 | 92 | 92 | 89 |
LCT-2 | Volcanic | 71 | 1.92 | 5.11 | 319 | 98 | 97 | 92 |
LCT-3 | NE Extension Blend | 29 | 0.52 | 0.68 | 70 | 90 | 90 | 84 |
LCT-4 | Breccia | 252 | 3.82 | 2.62 | 462 | 97 | 96 | 93 |
LCT-5 | Sedimentary | 41 | 0.82 | 1.64 | 128 | 92 | 89 | 93 |
LCT-6 | Volcanic | 46 | 0.88 | 2.14 | 151 | 94 | 93 | 96 |
LCT-7 | South Corridor Blend | 33 | 0.39 | 0.83 | 76 | 83 | 85 | 85 |
Test | Lead Circuit | Zinc Circuit | ||||||
Recovery to Conc. | Concentrate Grade | Recovery to Conc. | Concentrate Grade | |||||
Ag | Pb | Ag | Pb | Ag | Zn | Ag | Zn | |
(%) | (%) | (g/t) | (%) | (%) | (%) | (g/t) | (%) | |
LCT-1 | 85 | 92 | 3,516 | 56.5 | 7 | 89 | 287 | 53.0 |
LCT-2 | 91 | 97 | 2,518 | 71.7 | 7 | 92 | 55 | 56.7 |
LCT-3 | 80 | 90 | 3,085 | 61.1 | 10 | 84 | 249 | 50.7 |
LCT-4 | 93 | 96 | 4,634 | 72.6 | 4 | 93 | 219 | 52.2 |
LCT-5 | 79 | 89 | 2,395 | 53.5 | 13 | 93 | 182 | 52.7 |
LCT-6 | 86 | 93 | 3,270 | 68.6 | 8 | 96 | 100 | 55.5 |
LCT-7 | 65 | 85 | 2,868 | 43.8 | 18 | 85 | 446 | 52.9 |
Oxide metallurgical testwork: Additional column leach testwork to supplement the column leach tests completed in 2021 will commence later this quarter. In addition, flotation testwork of an oxide-sulphide blend (~10% oxides / ~90% sulphides) recently commenced. Preliminary results have demonstrated that economic oxide silver recoveries may be achieved for an oxide/sulphide blend without a significant detrimental impact to lead and zinc recoveries and concentrate grades.
Process Design: The process design will incorporate staged expansions. The first phase will incorporate a flotation circuit only (the PEA incorporated both a flotation and heap leach circuit). The second phase will incorporate an expansion of the flotation circuit and the potential addition of a heap leach circuit pending the results of the metallurgical testwork outlined above. The elimination of the heap leach circuit in the first phase simplifies the crushing/grinding circuit, reduces upfront capital expenditures and simplifies the permitting process. A proposed flowsheet of the updated processing circuit can be found here in Figure A.
Throughput tradeoff studies will commence shortly (see Mining section below) and will consider mill throughput rates of 20,000 – 27,500 tonnes per day (“tpd”) for the first phase and 35,000 – 45,000 tpd for the expanded phase.
Mining: Mine scheduling evaluation will commence later this quarter and will be completed by AGP Mining Consultants Inc. (“AGP Mining”). This work will assess the impact of different mining rates, mill throughput rates and cut-off grade and stockpiling strategies in order to optimize the capital efficiency and Net Present Value of the Project.
Geotechnical: Knight Piésold Consulting (“Knight Piésold”) completed a site visit to Cordero in April 2022. The site visit included a review of drill core to assess pit wall stability and the selection of three geotechnical holes to be drilled within the open pit (see Figure B). The completion of these three holes will supplement the two geotechnical holes completed in 2021 and is expected to bring the open pit geotechnical assessment up to Feasibility Study standards. Geotechnical drilling of infrastructure locations is expected to commence in the third quarter of 2022.
Hydrogeology: Mexican specialist consultant Investigacion y Desarrollo de Acuiferos y Ambiente (“IDEAS”) recently completed site assessment work and identified six hydrogeology holes within and adjacent to the pit area (see Figure B). Hydrogeological drilling will commence later this quarter with results to be incorporated in the site wide water balance for the PFS.
Tailings: The PFS, similar to the PEA, will incorporate thickened tailings for the Tailings Storage Facility (“TSF”). The tailings design for the PFS has been adjusted to achieve a significant reduction of the footprint of the TSF. Knight Piésold have also completed a TSF location assessment study in which eight potential locations have been identified (see Figure C). The final location is expected to be confirmed later this quarter and will be followed up with site investigations and geotechnical drilling.
ESG: An environmental baseline study managed by CIMA Consultores (“CIMA”) was completed in January 2022. A desktop social baseline assessment completed by Vinfidem Consultoria (“Vinfidem”) in 2021 is being supplemented by ongoing field work. Key findings from both sets of work will be included in the PFS. This work along with the Company’s ESG approach as it relates to strategy, planning and risk management will also be outlined in the 2021 ESG Report scheduled for completion in 3Q 2022.
PFS PROJECT TEAM
The PFS project team is the same team that completed the 2021 PEA. The PFS team will be led by Ausenco Engineering Canada Inc., an industry leader in cost-effective process design and construction. Ausenco is a global company providing innovative, value-add consulting studies, project delivery, asset operations and maintenance solutions in the minerals and metals industry with recent and relevant study, project construction (“EPC”) and construction management (“EPCM”) experience on projects within the Americas.
Ausenco has recent experience with process plants of similar size and/or recovery flowsheet to what is expected at Cordero including Adriatic Metals Plc’s Vares project in Bosnia & Herzegovina (PFS, FS and Detailed Engineering), Hudbay Minerals Inc.’s Constancia mine in Peru (EPCM), Marcobre S.A.’s Mina Justa mine in Peru (FS & EPCM) and Capstone Copper Corp.’s Mantoverde project in Chile (EPC).
Area of Responsibility | PFS Qualified Person | Third Party Input/Review |
Principal Author | Ausenco | - |
Resource Estimate | Red Dot 3D | RockRidge Consulting |
Metallurgy | Ausenco | Libertas / Blue Coast |
Processing | Ausenco | - |
Mining | AGP Mining | - |
Pit Geotech | Knight Piésold | - |
Tailings Management | Knight Piésold | |
Environment | Ausenco | CIMA |
Social | Ausenco | Vinfidem |
QP CONSULTANT / THIRD PARTY WEBSITES
Ausenco – www.ausenco.com
AGP Mining – www.agpmining.com
Blue Coast – www.bluecoastresearch.ca
CIMA – www.cimasc.com.mx
IDEAS – www.ideasenagua.com
Knight Piésold – www.knightpiesold.com
Libertas - LinkedIn profile
Red Dot 3D – LinkedIn profile
RockRidge Consulting – www.rockridgeconsult.com
Vinfidem – www.vinfidem.com.mx
About Discovery
Discovery’s flagship project is its 100%-owned Cordero project, one of the world’s largest silver deposits. The PEA completed in November 2021 demonstrates that Cordero has the potential to be developed into a highly capital efficient mine that offers the combination of margin, size and scalability. Cordero is located close to infrastructure in a prolific mining belt in Chihuahua State, Mexico. Continued exploration and project development at Cordero is supported by a strong balance sheet with cash of approximately C$60 million.
On Behalf of the Board of Directors,
Taj Singh, M.Eng, P.Eng, CPA
President, Chief Executive Officer and Director
For further information contact:
Forbes Gemmell, CFA
VP Corporate Development
Phone: 416-613-9410
Email: forbes.gemmell@discoverysilver.com
Website: www.discoverysilver.com
Qualified Person
Gernot Wober, P.Geo, VP Exploration, Discovery Silver Corp., 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 this news release is accurate.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
This news release is not for distribution to United States newswire services or for dissemination in the United States.
This news release does not constitute an offer to sell or a solicitation of an offer to buy nor shall there be any sale of any of the securities in any jurisdiction in which such offer, solicitation or sale would be unlawful, including any of the securities in the United States of America. The securities have not been and will not be registered under the United States Securities Act of 1933, as amended (the “1933 Act”) or any state securities laws and may not be offered or sold within the United States or to, or for account or benefit of, U.S. Persons (as defined in Regulation S under the 1933 Act) unless registered under the 1933 Act and applicable state securities laws, or an exemption from such registration requirements is available.
Cautionary Note Regarding Forward-Looking Statements
This news release may include forward-looking statements that are subject to inherent risks and uncertainties. All statements within this news release, other than statements of historical fact, are to be considered forward looking statements. Forward-looking statements including, but not limited to Discovery’s future plans and objectives regarding the Cordero Project and the prospect of further discoveries there, which constitute forward looking information that involve various risks and uncertainties. Although Discovery believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and actual results or developments may differ materially from those described in forward-looking statements. Factors that could cause actual results to differ materially from those described in forward-looking statements include fluctuations in market prices, including metal prices, continued availability of capital and financing, and general economic, market or business conditions. There can be no assurances that such statements will prove accurate and, therefore, readers are advised to rely on their own evaluation of such uncertainties. Discovery does not assume any obligation to update any forward-looking statements except as required under applicable laws.
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