VANCOUVER, BC, March 30, 2023 /CNW/ - Taseko Mines Limited (TSX: TKO) (NYSE American: TGB) (LSE: TKO) ("Taseko" or the "Company") is pleased to announce the results of recent technical work and updated economics for its 100%-owned Florence Copper Project, located in Arizona, U.S.A (the 'Florence Copper Project" or "Florence Copper"). The Company has filed a new technical report entitled "NI 43-101 Technical Report – Florence Copper Project, Pinal County, Arizona" dated March 30, 2023 (the "Technical Report") on SEDAR. The technical report was prepared in accordance with NI 43-101 and incorporates updated capital and operating costs for the commercial production facility and refinements made to the operating models, based on the Production Test Facility ("PTF") results.
The technical work completed by Taseko in recent years has been extensive and has de-risked the project significantly. The PTF operated successfully over an 18-month period and provided a valuable opportunity to test operational controls and strategies which will be applied in future commercial operations. In addition, a more sophisticated leaching model has been developed and calibrated to the PTF wellfield performance. This detailed modeling data, along with updated costing, has been used to update assumptions for the ramp up and operation of the commercial wellfield and processing facility.
Project Highlights:
Stuart McDonald, President & CEO of Taseko, stated, "Despite global cost inflation in recent years, the Florence Copper Project continues to demonstrate robust economics and remains one of the lowest capital intensity copper development projects in the world. The operational experience and technical information that we gained through the PTF testwork has been invaluable and we're well positioned to build and operate the commercial-scale ISCR facility. The new Technical Report includes updated capital cost estimates based on detailed engineering and recent contractor and vendor quotations. The main cost increases relate to construction labour and wellfield drilling costs which impact both initial and sustaining capital costs."
"The inflationary environment we have been in has also driven copper prices higher. With a lack of new mines being developed today and copper's critical role in the global energy transition, the long-term price outlook remains very attractive for copper producers. The low-carbon, low impact production method at Florence Copper is expected to make it a preferred supplier of green, low carbon copper in the US domestic market. With procurement of long-lead items well advanced, we are ready to commence construction of the commercial facility following the issuance of the final UIC permit in the coming months," Mr. McDonald concluded.
The extraction method proposed for the Florence Copper Project is ISCR. ISCR extracts copper by injecting a weak sulfuric acid solution, referred to as raffinate, through targeted portions of the mineral deposit using an array of injection wells. The raffinate passes through natural fractures and voids in the deposit and dissolves the copper mineralization. The copper laden solution, known as pregnant leach solution ("PLS"), is collected in recovery wells where it is pumped to the surface for processing. Copper is extracted from the PLS using solvent extraction and electrowinning ("SX/EW") techniques producing a saleable copper cathode product.
Florence Copper operated a demonstration scale ISCR facility referred to as the PTF, where leaching under commercial operating conditions was completed between December 2018 to June 2020. The PTF facilities included an ISCR wellfield, an SX/EW processing plant, an acidic reverse-osmosis water treatment plant, a water impoundment, run-off pond, and associated infrastructure. The PTF wellfield was comprised of four injection wells, nine recovery wells, seven observation wells, and four multilevel sampling wells.
The purpose of the PTF was to demonstrate hydraulic control and confirm the oxide ore zone behaves hydrologically as an equivalent porous media thereby ensuring protection of underground sources of drinking water. Secondly, the PTF provided an opportunity to test operational controls and strategies to inform future commercial scale operations.
The PTF well field is located on the northern portion of the deposit specifically selected in a challenging hydrogeological position to demonstrate hydraulic control. The well field is situated at the edge of a graben with major faults running though the surrounding area. The location was also selected to represent the ore to be leached at the start of commercial production.
The well field was designed using the same well spacing and construction methods as those planned for the commercial-scale ISCR facility. Hydraulic performance data generated during PTF testing and operations have provided important information supporting the design and operations planning for the commercial-scale well field.
Leaching of the PTF wellfield began in December 2018 and continued under commercial operating conditions until June 2020, after which fresh acid addition was stopped and the leaching phase was ramped down and concluded with the shutdown of the process plant by end of October 2020. The PTF well field was then subsequently transitioned into a rinsing phase which is currently still in progress.
The PTF was successful in demonstrating that copper could be produced feasibly and also that hydraulic control of process solutions in the ISCR well field could be established and maintained to ensure protection of underground sources of drinking water. It has also further confirmed that the oxide ore zone behaves hydraulically as an equivalent porous media.
PTF operations provided valuable data to test operational controls and strategies to inform future commercial scale operations. Employment of strategies such as reverse flow, use of inflatable packers to target areas of the formation, and varying acid application rates through increased raffinate injection flows and or acid strengths all proved to be beneficial tools to effectively manage the leaching operation.
Sweep efficiency is defined as the fraction of the pore space contacted or 'swept' by the injected solution as it flows from injection to recovery well. Sweep efficiency increases over time as leaching progresses and more ore is contacted by process solutions. The ultimate sweep efficiency achieved over the duration of leaching indicates the proportion of the ore from which copper will be recovered.
The geophysical monitoring for the central recovery well found that all of the monitored ore zone was contacted by leach solutions in the first five weeks of leaching and achieved 90% overall. This result confirms the projected long-term sweep efficiency of 90% used in the model.
The total copper recovery to cathode is projected to be 65.8% at an estimated acid consumption of 6.0 lbs/lb copper. PLS grade feeding the SX/EW plant will average 1.7 g/L of copper over the life of the project.
The SX/EW process plant operations commenced in mid-March 2019, following a four-month initial leaching period, and was shut down in October 2020, four months after fresh acid addition to raffinate was stopped resulting in a subsequent depletion of PLS copper grades feeding the plant. For the entire PTF operational run, the plant operated at a high average availability of 99.9% and produced a total of 1.1 million pounds of high-grade copper cathode product from the ISCR leach solutions.
Proven and Probable Reserve Estimate
(Effective December 31, 2022)
Category | Tons | Total Cu | Recoverable |
Proven | 258 | 0.35 | 1.8 |
Probable | 63 | 0.40 | 0.5 |
Total | 320 | 0.36 | 2.3 |
1. | Mineral Reserves follow CIM Definition Standards for Mineral Resources and Mineral Reserves (2014). |
2. | Mineral Reserves are contained within Florence Copper's Mineral Resources. |
3. | Mineral Reserves are assumed to be extracted using ISCR extraction methods using the following assumptions: $3.05 Cu price, $31,600/acre for core hole abandonment, $240,400/acre for cultural mitigations in identified Cultural Sites, $149,600 + $263/foot well drilling costs, $160/ton acid cost, $45.30/ton acid applied for well field operating costs, 1.2% surface losses, $0.10/lb Cu for electrowinning cost, $0.12/lb Cu G&A cost, $0.69/ton reclamation cost, $0.02/lb Cu shipping cost, 7% NSR royalties on ALSD land, 3% NSR royalties on freehold land, and 2.5% royalties on net profit. |
4. | Mineral Reserves are reported without a cut-off grade and on a fully diluted basis to reflect the nature of the ISCR extraction method proposed. |
5. | Tonnage factors of 13.5 ft3/ton and 13.13 ft3/ton have been applied corresponding to 8% porosity in the upper oxide zone and 5% porosity in the lower oxide and transition zones. |
6. | Numbers may not add due to rounding. |
Florence Project Oxide Mineral Resources
(Effective December 31, 2022)
Category | Tons | Total Copper | Total Copper (B |
Measured | 292 | 0.34 | 2.0 |
Indicated | 71 | 0.39 | 0.6 |
M+I | 363 | 0.35 | 2.5 |
Inferred | 42 | 0.32 | 0.3 |
1. | Mineral Resources follow CIM Definition Standards for Mineral Resources and Mineral Reserves (2014). |
2. | Mineral Resources are reported inclusive of Mineral Reserves. |
3. | Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. |
4. | Mineral Resources are confined to the Oxide and Transition zones inside a "reasonable prospects of eventual economic extraction" boundary assuming ISCR extraction methods using the following assumptions: $3.50 Cu price, $31,600/acre for core hole abandonment, $240,400/acre for cultural mitigations in identified Cultural Sites, $149,600 + $263/foot well drilling costs, $160/ton acid cost, $45.30/ton acid applied for well field operating costs, 1.2% surface losses, $0.10/lb Cu for electrowinning cost, $0.12/lb Cu G&A cost, $0.69/ton reclamation cost, $0.02/lb Cu shipping cost, 7% NSR royalties on ALSD land, 3% NSR royalties on freehold land, and 2.5% royalties on net profit. |
5. | Mineral Resources are reported without a cut-off grade to reflect the nature of the ISCR extraction method proposed. |
6. | Tonnage factors of 13.5 ft3/ton and 13.13 ft3/ton have been applied corresponding to 8% porosity in the upper oxide zone and 5% porosity in the lower oxide and transition zones. |
7. | Numbers may not add due to rounding. |
The report has been prepared for Taseko Mines Limited, a producing issuer, under the supervision of Richard Tremblay, P.Eng., MBA, Richard Weymark, P.Eng., MBA, and Robert Rotzinger, P.Eng. Mr. Tremblay is employed by the Company as Sr. Vice President Operations, Mr. Weymark is Vice President Engineering and Robert Rotzinger is Vice President Capital Projects. All three are "Qualified Persons" as defined in National Instrument 43–101 Standards of Disclosure for Mineral Projects ("NI 43–101").
Mr. Tremblay, Mr. Weymark and Mr. Rotzinger have reviewed and approved the technical content of this news release.
Additional information regarding data verification, exploration information, known legal, political, environmental or other risks can be found in the Technical Report dated March 30, 2023, titled 'NI 43-101 Technical Report – Florence Copper Project, Pinal County, Arizona' which is available on SEDAR.
This news release has been prepared in accordance with the requirements of the securities laws in effect in Canada, which differ from the requirements of United States securities laws. Canadian reporting requirements for disclosure regarding mineral properties are governed by National Instrument 43-101 - Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators ("NI 43-101"). Taseko's estimates of "proven mineral reserves", "probable mineral reserves", "measured mineral resources", "indicated mineral resources" and "inferred mineral resources" have been prepared in accordance with these NI 43-101 requirements.
Effective February 2019, the United States Securities and Exchange Commission ('SEC') adopted amendments to its disclosure rules to modernize the mineral property disclosure requirements for issuers like Taseko whose securities are registered with the SEC under the Exchange Act and as a result, the SEC now recognizes estimates of "measured mineral resources", "indicated mineral resources" and "inferred mineral resources". In addition, the SEC has amended its definitions of "proven mineral reserves" and "probable mineral reserves" to be "substantially similar" to the corresponding definitions under the CIM Standards, as required under NI 43-101. For this reason, information contained in this news release regarding the Company's Florence Copper Project may not be comparable to similar information made public by United States companies subject to the reporting and disclosure requirements under the United States securities laws and the rules and regulations thereunder.
For further information on the differences between the disclosure requirements for mineral properties in the United States and NI 43-101, please refer to the company's Annual Information Form, a copy of which has been filed under Taseko's profile on SEDAR at sedar.com and the company's Form 40-F, a copy of which will be filed on EDGAR at edgar.com.
Note: All currency amounts are stated in US dollars. Measurement units used in this release are in imperial (US).
The Technical Report includes inferred mineral resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no assurance that the Technical Report will be realized. Investors are encouraged to read the full text of the Technical Report which has been filed on SEDAR and will be also filed on EDGAR (www.sec.gov) and made available on the Taseko website.
Stuart McDonald
President and CEO
No regulatory authority has approved or disapproved of the information contained in this news release. |
This document contains "forward-looking statements" that were based on Taseko's expectations, estimates and projections as of the dates as of which those statements were made. Generally, these forward-looking statements can be identified by the use of forward-looking terminology such as "outlook", "anticipate", "project", "target", "believe", "estimate", "expect", "intend", "should" and similar expressions.
Forward-looking statements are subject to known and unknown risks, uncertainties and other factors that may cause the Company's actual results, level of activity, performance or achievements to be materially different from those expressed or implied by such forward-looking statements. These included but are not limited to:
Such forward looking statements or information related to the Technical Report include but are not limited to statements or information with respect to the internal rate of return, the annual production, the net present value; the life of mine, the estimated capital costs, estimated operating costs, projected metallurgical recoveries, plans for further development, securing the required permits, the market price of copper and other base metals or other statements that are not statements of fact.
For further information on Taseko, investors should review the Company's annual Form 40-F filing with the United States Securities and Exchange Commission www.sec.gov and home jurisdiction filings that are available at www.sedar.com, including the "Risk Factors" included in our Annual Information Form.
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SOURCE Taseko Mines Limited
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