Mr. Stuart McDonald reports

TASEKO ANNOUNCES IMPROVED ECONOMICS FOR ITS FLORENCE COPPER PROJECT

Taseko Mines Ltd. has released the results of recent technical work and updated economics for its 100-per-cent-owned Florence copper project, located in Arizona, United States. The company has filed a new technical report entitled "NI 43-101 Technical Report -- Florence Copper Project, Pinal County, Arizona," dated March 30, 2023, on SEDAR. The technical report was prepared in accordance with National Instrument 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 derisked the project significantly. The PTF operated 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 well field performance. This detailed modelling data, along with updated costing, has been used to update assumptions for the ramp-up and operation of the commercial well field and processing facility.

Project highlights:

• Net present value of $930-million (U.S.) (after tax, at an 8-per-cent discount rate);
• Internal rate of return of 47 per cent (after tax);
• Payback period of 2.6 years;
• Operating costs (C1) of $1.11 (U.S.) per pound of copper;
• Annual production capacity of 85 million pounds of LME Grade A cathode copper;
• 22-year mine life;
• Total life-of-mine production of 1.5 billion pounds of copper;
• Total estimated initial capital cost of $232-million (U.S.) remaining;
• Long-term copper price of $3.75 per pound (U.S.).

Stuart McDonald, president and chief executive officer 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 [in situ copper recovery] 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 well field 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 U.S. 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.

In situ copper recovery (ISCR)

The extraction method proposed for the Florence copper project is ISCR. ISCR extracts copper by injecting a weak sulphuric 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.

Production test facility

Florence copper operated a demonstration-scale ISCR facility referred to as the PTF, where leaching under commercial operating conditions was completed between December, 2018, and June, 2020. The PTF facilities included an ISCR well field, an SX/EW processing plant, an acidic reverse osmosis water treatment plant, a water impoundment, runoff pond and associated infrastructure. The PTF well field was composed 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 well field 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 the 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

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 per cent over all. This result confirms the projected long-term sweep efficiency of 90 per cent used in the model.

Overall recovery plan

The total copper recovery to cathode is projected to be 65.8 per cent at an estimated acid consumption of 6.0 pounds per pound copper. PLS grade feeding the SX/EW plant will average 1.7 grams per litre of copper over the life of the project.

SX/EW plant operations

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 per cent and produced a total of 1.1 million pounds of high-grade copper cathode product from the ISCR leach solutions.

Qualified persons and National Instrument 43-101 disclosure

The report has been prepared for Taseko, a producing issuer, under the supervision of Richard Tremblay, PEng, MBA, Richard Weymark, PEng, MBA, and Robert Rotzinger, PEng. Mr. Tremblay is employed by the company as senior 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).

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, and 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.

Note to U.S. investors

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 U.S. 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. 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 U.S. Securities and Exchange Commission 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 (Canadian Institute of Mining, Metallurgy and Petroleum) 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 with similar information made public by U.S. companies subject to the reporting and disclosure requirements under the U.S. 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, and the company's Form 40-F, a copy of which will be filed on EDGAR.

Note: All currency amounts are stated in U.S. dollars. Measurement units used in this release are in imperial (United States).

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, will be also filed on EDGAR and will be made available on the Taseko website.

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