Announcement PDF ASX Announcement 20 May 2026 ASX: OD6 1 HISTORIC UNION CARBIDE TESTWORK INDICATES POTENTIAL TO PRODUCE ACIDSPAR AT QUINN FLUORSPAR PROJECT Historical testworks achieved acid-grade concentrate of 97.83% CaF₂ via flotation, de-risking the processing pathway at Quinn HIGHLIGHTS  Historic metallurgical testwork completed by Union Carbide Corporation (and not OD6) confirms strong upgrade potential for fluorspar mineralisation at both Mammoth and Horseshoe  Testwork was performed on a low-grade 28.29% CaF₂ sample from Mammoth and a high-grade 58.57% CaF₂ sample from Horseshoe  Conventional Grinding and Flotation was identified as the primary and most effective method, capable of producing high-grade concentrate from the feed material  Historical Union Carbide and Galigher Company testwork indicated concentrate grades of 95.0% CaF₂ at 82.7% recovery and 97.83% CaF₂ at 70% recovery from Mammoth mineralisation.  The historical results suggest Quinn mineralisation may be capable of producing Acidspar using conventional grinding and flotation methods, subject to confirmation through modern metallurgical testwork. The testwork completed was preliminary and unoptimised allowing for further enhancement of product quality and recoveries.  Recent OD6 field programs have collected extensive metallurgical samples across multiple prospects at Quinn ready for modern day metallurgical testing  Samples to be sent for optical ore sorting testwork with TOMRA (Germany)  Additional new metallurgical flotation testwork planned to commence this quarter  OD6 to apply for bulk sample permits across multiple areas to support advanced metallurgical testwork  The data establishes a significant metallurgical foundation, potentially reducing the scope and cost of future metallurgical programs required to support development studies at Quinn Managing Director Brett Hazelden, commented: “The historical Union Carbide metallurgical testwork provides encouraging evidence that fluorspar mineralisation at Quinn may be amenable to conventional processing techniques. Importantly, the historic results suggest the potential to upgrade both low-grade and high-grade mineralisation to produce commercial fluorspar concentrates, including acid-grade product, subject to confirmation through modern metallurgical testwork. With extensive representative samples now collected from across the project, OD6 is preparing to commence modern metallurgical programs, including optical ore sorting with TOMRA and flotation optimisation with specialist laboratories. These programs are designed to validate the historical results and support the development of Quinn as a potential domestic US source of high-grade fluorspar.” 2 UNION CARBIDE HISTORIC METALLURGICAL TESTWORK OD6 Metals Limited (“OD6” or “the Company”) is pleased to report the identification and review of historic metallurgical testwork completed by Union Carbide Corporation (“UCC”) on fluorspar mineralisation from the Mammoth and Horseshoe deposits, part of the Quinn Fluorspar Project in Nevada, USA. The metallurgical programs, completed in 1957, provide valuable early-stage validation of the beneficiation characteristics of the Quinn mineralisation. Data Acquisition As recently announced, the Company has acquired a rare dataset of Company records from Union Carbide Corporation (refer announcement dated 7 May 2026). The dataset was acquired for a nominal value representing exceptional value against an estimated replacement cost in excess of A$1.0 million at current market rates. The acquired Union Carbide data includes high-quality scans of cross-sections, maps, and geological records from historical exploration programs, providing OD6 with a significant informational advantage. Metallurgical testwork was included in the dataset inclusive of grinding and flotation further enabling prior works to be utilised for the upcoming preliminary metallurgical testwork to assess processing characteristics and support future development studies. The acquisition represents a major de-risking milestone for the Quinn Fluorspar Project and positions OD6 to execute a highly targeted, capital-efficient exploration program at one of North America's most prospective fluorspar assets. Cautionary Statement The historical metallurgical testwork results referred to in this announcement were documented by Union Carbide Corporation and The Galigher Company in 1957 prior to the introduction of Appendix 5A of the ASX Listing Rules and JORC Code (2012 Edition) (JORC Code 2012). Due to limitations with these historical reports, the Company notes that the metallurgical test results in this announcement are not JORC Code 2012 compliant and are instead provided on a provisional basis under the format of ASX Mining FAQ 36. The Competent Person undertook a review of the historical reports to ensure reliability and compliance with Mining FAQ 36, including identifying areas of limitation and areas that will require field validation by the Company as part of its ongoing exploration activities and metallurgical testing at the Quinn Fluorspar Project. Such review indicated that the reported head grades are consistent with grades observed in recent field sampling conducted by the Company, and that the flotation reagents and processing techniques described remain broadly consistent with conventional fluorspar processing methods used today. In addition, no material inconsistencies were identified and the results were deemed satisfactory for reporting purposes in accordance with Mining FAQ 36. For the purposes of ASX Mining FAQ 36, the Company confirms that:  The exploration results in this announcement have not been reported in accordance with the JORC Code 2012;  a Competent Person has not done sufficient work to disclose the Exploration Results in accordance with the JORC Code 2012; 3  it is possible that following further evaluation and/or exploration work that the confidence in the exploration results reported in this announcement may be reduced when reported under the JORC Code 2012;  that nothing has come to the attention of Company that causes it to question the accuracy or reliability of the historical exploration results referred to in this announcement; but  the Company has not independently validated the historical exploration results contained in this announcement and therefore is not to be regarded as reporting, adopting or endorsing those results. The Company has addressed the additional information required pursuant to ASX Mining FAQ 36 in the table at Appendix 1 of this announcement. About Union Carbide Union Carbide Corporation is a historically significant US industrial company, founded in 1917, with a legacy of technical excellence in chemicals, critical minerals and resource development across the US. Its historical exploration programs were conducted to high technical standards, with datasets often regarded as robust and suitable for modern geological reinterpretation. Union Carbide was acquired by The Dow Chemical Company in a transaction valued at $11.6 billion. Acidspar and Metspar Fluorspar (also known as fluorite) is a simple mineral with the formula CaF2, which contains 48.9% fluorine by weight. Fluorspar is the main mineralogical source of fluorine. High-grade fluorspar mineralisation is typically upgraded through simple processing to produce concentrates known as Acidspar, and Metspar. MetSpar is a mineral product containing >60% fluorspar (CaF2) and is sold to the steel industries as a fluxing agent. As a fluxing agent, the MetSpar improves slag fluidity, remove impurities, lower the melting temperature, protect refractory materials and to enhance high-end stainless steel products. MetSpar needs to be >60% CaF2, and less than 5,000ppm lead (Pb) and 3,000ppm sulphur (S). AcidSpar is an upgraded mineral product containing >97% fluorspar (CaF2) and is sold to the chemical industry for hydrofluoric acid production, and ultimately is used in the nuclear fuels industry, battery technologies, solar panels, defence technologies and AI chip manufacturing. AcidSpar requirements are indicated to be <1.5% silica (SiO2), 10-12ppm arsenic, <1,000ppm sulphur (S) and 100-550ppm phosphorous (P). Penalties or refusal are potentially applied for high lead (Pb) and other base-metals (Cu, Zn, Mo), and pollutants such cadmium, chromium or any radioactive elements such as uranium or thorium. The historic testwork demonstrates that Quinn mineralisation has the potential to produce both Metspar and premium Acidspar products, depending on processing configuration and optimisation. 4 Mammoth Testwork (1957) A preliminary metallurgical program undertaken by The Galigher Company for UCC to evaluate a sample of low- grade fluorspar ore for the potential amenability to produce Acidspar via separation and flotation techniques Key details from the records (refer Appendix 2) inclusive of findings by The Galigher Company, September 13, 1957, include:  Head grade sample of approximately 28.3% CaF₂  Screen analysis – It was stated that “the results did not indicate any effective concentration by such techniques” OD6 review: the screen analysis showed that whilst there was some difference in size and grade, a final processing facility would need to treat the full material and not a select screened portion.  Heavy media separation (HMS) – a single HMS media was selected at 2.674 specific gravity on ore as received with minus 10 mesh (2mm) removed and screened at 3 mesh (6.68mm) and 6 mesh (3.327mm). No discernible gravity separation point was noted however, It was commented that “additional test work on heavier media would be necessary in order to fully evaluate” OD6 review: there was insufficient HMS media specific gravities selected to provide useful insight into gravity separation potential. There was however some notable separation of CaF2 from the waste material. Different selected screen sizing and specific gravities may yield optimised results.  Flotation – only preliminary tests were conducted on six samples. - Test 6 conditions: 50% solids, pH not stated, 3.0 soda ash, 5.0 silicate, 0.3 oleic acid 0.5 quebracho; followed by cleaner float 2.0 silicate, 0.1 quebracho; followed by boiling with 0.1 oleic acid, clean three times using 0.5 silicate OD6 note: the flotation tests should be considered sighter test only to prove that an Acidspar product can be achieved, with further optimisation testwork required. o “the flotation tests indicate that high recoveries of fluorspar can readily be achieved from a 65 mesh (208 micron) grind in a product assaying over 95% CaF2 at 82.7% Recovery” o “boiling of the concentrate allowed for the production of an Acidspar grade of 97.83% at 70 % Recovery” o “Future Testwork – there remains several points to be investigated in order to determine the optimum conditions and recoveries for this ore” OD6 review: The results suggest that Mammoth mineralisation is amenable to beneficiation and floatation, with potential to produce commercial-grade fluorspar concentrates. Notably, the ability to upgrade low-grade material to high-grade concentrate supports the broader scale potential of the system. A modern day test program would consider mineralogy to identify a rougher float grind size followed by a regrind and multistage cleaner float. This would optimise concentrate grade, recovery and further optimise reagent selection and consumption. 5 Horseshoe Testwork (1957) Preliminary metallurgical amenability testing was completed by the Union Carbide Nuclear Company, and undertaken on Horseshoe mineralisation included screening, heavy media separation and flotation circuits. Key details from the records (refer Appendix 3) inclusive of findings by L.E.Saussa UCC October 29, 1957, include:  Head grade sample of approximately 58.6% CaF₂  Specific gravity of the minerals 3.01 - 3.25 CaF2  Screen analysis – It was stated that “it is apparent that there is no tendency for the minerals to distribute themselves into any specific size fractions” OD6 review: the screen analysis showed that whilst there was some difference in size and grade, a final processing facility would need to treat the full material and not a select screened portion.  Heavy media separation (HMS) – various HMS media gravities were tested from 2.48 to 2.85 specific gravity on ore as received with minus 10 mesh (2mm) removed. No discernible gravity separation point was noted however, It was commented that “HMS is not usually the most economical concentrating method” OD6 review: utilising HMS on ore as received with minus 10 mesh (2mm) removed has little utility given the coarse nature of the material which should really be crushed prior to conducting the testing.  Flotation – only preliminary tests were conducted on eight samples. - 4 tests at 20OC, 70% solids, pH 9.1 to 9.4, 0.5 to 1.0 soda ash, 0 to 1.5 silicate, 0.2 oleic at 8 to 10 minute grind time. - 4 tests at 60OC, 70% solids, pH 9.1 to 9.4, 0.5 soda ash, 0 to 1.0 silicate, 0.05 to 0.1 oleic at 8 to 10 minute grind time. OD6 note: the flotation tests should be considered as a rougher or sighter test only as no typical cleaner float seen in current process circuit design, which generally improves recovery and concentrate grade: o tests produced concentrates of up to ~89% CaF₂ and up to ~90% recovery, indicating strong amenability to conventional processing o “Exploratory tests at room temperature with conventional reagents for fluorite concentration indicates a typical fluorite flotation could be expected” o “Increasing the pulp temperature (60O C) improved results with less reagent consumption”, suggesting optimisation upside o “Tails analysis showed no tendance for the minerals to distribute in any specific size fraction” o “An increase in grinding time does seem to improve recovery” OD6 review: The results suggest that Horseshoe mineralisation is amenable to beneficiation and floatation, with potential to produce commercial-grade fluorspar concentrates. A modern day test program would consider mineralogy to identify a rougher float grind size followed by a regrind and multistage cleaner float. This would optimise concentrate grade, recovery and further optimise reagent selection and consumption. It is noted that a second program was due to commence at the Galigher Company, an Ore Testing and equipment supplier in Salt Lake City, in July 1958 with new samples provided but the program was put on hold and never recommenced. 6 Figure 1: Quinn Fluorspar Project with, deposit locations, background geology and alteration map (refer release dated 25 March 2026 for further information) 7 NEXT PHASE METALLURGICAL PROGRAM OD6 is advancing a staged metallurgical testwork program to validate and optimise processing flowsheets. The historic data establishes a significant metallurgical foundation, potentially reducing the scope and cost of future metallurgical programs required to support development studies at Quinn Recent OD6 field programs have collected extensive metallurgical samples across multiple prospects at Quinn ready for modern day metallurgical testing. OD6 intends to use existing cash reserves and/or funds raised from future capital raisings to undertake this work.  Samples to be sent for optical ore sorting testwork with TOMRA (Germany) o Upgrade feed grade prior to processing o Reduce processing costs and plant size o Assess reject/waste separation efficiency o OD6 expects the TOMRA testwork to commence this quarter, with results to be available in quarter 3  Additional metallurgical flotation testwork o Flotation optimisation o Dense media separation o Grind size and reagent testing o Product specification validation (Acidspar vs Metspar) o OD6 expects the flotation testwork to commence this quarter, with results anticipated to be available in in the second half of the year  OD6 to apply for bulk sample permits across multiple areas to support advanced metallurgical testwork o Provide representative material for pilot-scale testing o Support flowsheet development o Generate potential offtake samples for customers Due Diligence and Next Steps As part of its due diligence program in connection with the Quinn Fluorspar Project (see announcement dated 4 March 2026, “OD6 TO ACQUIRE ULTRA HIGH GRADE USA FLUORSPAR PROJECTS”), OD6 intends to collect new samples from the surface showings to test the veracity of historic reports, including:  Digitise scanned paper logs and cross-sections into a geological model  Receipt and interpretation of assay results  Expand systematic channel and rock chip sampling  Validate and replicate historic high-grade results  Undertake detailed geological and structural mapping  Complete soil geochemistry programs  Identify and prioritise drill targets  Initiate permitting for maiden drilling  Progress metallurgical testwork planning 8 Forward Looking Statements Certain information in this document refers to the intentions of OD6 Metals, however these are not intended to be forecasts, forward looking statements, or statements about the future matters for the purposes of the Corporations Act or any other applicable law. Statements regarding plans with respect to OD6 Metals projects are forward looking statements and can generally be identified by the use of words such as ‘project’, ‘foresee’, ‘plan’, ‘expect’, ‘aim’, ‘intend’, ‘anticipate’, ‘believe’, ‘estimate’, ‘may’, ‘should’, ‘will’ or similar expressions. There can be no assurance that the OD6 Metals plans for its projects will proceed as expected and there can be no assurance of future events which are subject to risk, uncertainties and other actions that may cause OD6 Metals actual results, performance, or achievements to differ from those referred to in this document. While the information contained in this document has been prepared in good faith, there can be given no assurance or guarantee that the occurrence of these events referred to in the document will occur as contemplated. Accordingly, to the maximum extent permitted by law, OD6 Metals and any of its affiliates and their directors, officers, employees, agents and advisors disclaim any liability whether direct or indirect, express or limited, contractual, tortuous, statutory or otherwise, in respect of, the accuracy, reliability or completeness of the information in this document, or likelihood of fulfilment of any forward-looking statement or any event or results expressed or implied in any forward-looking statement; and do not make any representation or warranty, express or implied, as to the accuracy, reliability or completeness of the information in this document, or likelihood of fulfilment of any forward-looking statement or any event or results expressed or implied in any forward-looking statement; and disclaim all responsibility and liability for these forward-looking statements (including, without limitation, liability for negligence). Competent Persons Statement The information in this ASX Release that relates to historical and foreign metallurgical testwork is an accurate representation of the available data and studies for the Quinn Project reviewed by Mr Brett Hazelden (Managing Director and CEO) of OD6 Metals Limited. Mr Hazelden is a Member of the AusIMM and has sufficient experience relevant to hydrometallurgical processes and mineral processing to qualify as a Competent Person as defined by the JORC Code. Mr Hazelden owns shares in the Company and participates in the Company’s employee securities incentive plan. Mr Hazelden consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears. No new information Except where explicitly stated, this announcement contains references to prior exploration results, all of which have been cross-referenced to previous market announcements made by the Company. The Company confirms that it is not aware of any new information or data that materially affects the information included in the relevant market announcements. The information in this report relating to the Mineral Resource estimate for the Splinter Rock Project is extracted from the Company’s ASX announcements dated 18 July 2024. OD6 confirms that it is not aware of any new information or data that materially affects the information included in the original announcement and that all material assumptions and technical parameters underpinning the Mineral Resource estimate continue to apply. This announcement has been authorised for release by the Board of OD6 Metals Limited 9 About OD6 Metals OD6 Metals is an Australian public company pursuing exploration and development opportunities within the critical minerals sector, namely rare earths, copper and fluorspar. Rare Earth Elements OD6 Metals has successfully identified clay hosted rare earths at its 100% owned Splinter Rock Project which is located in the Esperance-Goldfields region of Western Australia. The Company released a Mineral Resource Estimate (MRE) for Splinter Rock in May 2024, confirming that the project hosts one of the largest and highest-grade clay-hosted rare earths deposits in Australia with an Indicated Resource of 119Mt @ 1,632ppm TREO and an Inferred Resource of 563Mt @ 1,275ppm TREO with an overall ratio of ~23% high-value Magnetic Rare Earths (MagREE). An innovative Process Flow sheet has been selected utilising Heap Leaching, Nano-filtration and Ion Exchange Technologies that have achieved ~75% Nd & Pr overall recovery, produced a high-quality Mixed Rare Earth Carbonate or Hydroxide (MREC/H) of ~56-59% TREO, with low levels of impurities (Al, Fe, P, Si) and extremely low uranium and thorium content. Fluorspar (Fluorite) The Company secured an option to acquire the Quinn Fluorspar Project in Nevada, USA. Nevada is regarded as one of the world’s premier mining jurisdictions and is currently ranked second in the 2025 Fraser Institute’s Mining Attractiveness Index. Historically a number of the Quinn Fluorspar deposits were mined in the 1950’s for Fluorspar. In 1969. The United States Geological Survey (USGS) conducted a survey and confirmed fluorspar grading up to 72% CaF2 in bulk samples. The USA currently imports 100% of all Fluorspar consumed domestically with 68% of all global supply sourced from China (USGS 2024). Fluorspar is listed as a Critical Mineral by the USGS and is essential in the production of hydrofluoric acid, AI semi-conductor chip etching, advanced battery technologies and nuclear fuel processing with other applications in defence and aerospace technologies. Copper The Company is advancing the Gulf Creek Copper-Zinc VMS Project located near the town of Barraba in NSW. Gulf Creek was mined at around the turn of the 20th century and was once regarded as the highest-grade copper mine (2% to 6.5% Cu) in NSW until its closure due to weak copper prices in 1912. Very little exploration has occurred at the project in over 100 years, with OD6 aiming to apply modern day exploration technologies. The 2025 maiden drilling program successfully defined high grade copper below the historical mine plus confirmed the strong relationship between magnetism and massive sulphide mineralisation. Geophysical modelling has identified multiple, high priority and targets providing over >3km of strike in the immediate mine-stratigraphy, and over >10km across the tenement. Corporate Directory Managing Director Non-Executive Chairman Non-Executive Director Financial Controller/ Joint Company Secretary Joint Company Secretary Technical Advisor to the Board Contact OD6 Metals Ltd ACN 654 839 602 www.od6metals.com.au Mail to: info@od6metals.com.au Phone: +61 8 6189 8515 Level 1, 1 Alvan Street, Subiaco, WA 6008 Mr Brett Hazelden Mr Piers Lewis Dr Mitch Loan Mr Troy Cavanagh Mr Joel Ives Dr Darren Holden Investor Relations Lucas Robinson Corporate Storytime lucas@corporatestorytime.com Phone: +61 408 228 889 10 JORC 2012 – Table 1: Quinn Fluorspar Project Section 1 Sampling Techniques and Data (Criteria listed in the preceding section also apply to this section) Criteria JORC Code explanation Commentary Sampling techniques  Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling.  Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used.  Aspects of the determination of mineralisation that are Material to the Public Report.  In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information  Historic samples collected – with unknown sampling techniques . Drilling techniques  Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).  Historic samples collected – with unknown drilling techniques Drill sample recovery  Method of recording and assessing core and chip sample recoveries and results assessed.  Measures taken to maximise sample recovery and ensure representative nature of the samples.  Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.  Historic samples collected – with unknown sampling recovery Logging  Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies.  Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography.  The total length and percentage of the relevant intersections logged.  Historic samples collected – with unknown logging . Sub-sampling techniques and sample preparation  If core, whether cut or sawn and whether quarter, half or all core taken.  If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry.  For all sample types, the nature, quality and appropriateness of the sample preparation technique.  Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples.  Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling.  Whether sample sizes are appropriate to the grain size of the material being sampled.  Historic samples collected – as stated in Appendix 2 and 3 Quality of assay data and laboratory tests  The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.  For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.  Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks)  Assays are reported as assayed by Union Carbide Corporation or The Galigher Company. Union Carbide was a large chemical company and had its own laboratories for test work. It is not known which technique was used, though the Bidtel (Bidtel 1912) method was commonly used at this time. Refer Appendix 2 and 3 . 11 Criteria JORC Code explanation Commentary and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. Verification of sampling and assaying  The verification of significant intersections by either independent or alternative company personnel.  The use of twinned holes.  Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols.  Discuss any adjustment to assay data.  Historic drill results for geology and assaying are consistent with the order of magnitude for grades and fluorspar observed and sampled at surface by the Company. And as such, is believed to be a reasonable representation, requiring further test work to confirm. Location of data points  Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.  Specification of the grid system used.  Quality and adequacy of topographic control.  Historic samples collected – were collected from the Mammoth and Horseshow Mineralisation areas as noted in Figure 1. Exact locations within each mineralisation area is not recorded. Data spacing and distribution  Data spacing for reporting of Exploration Results.  Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied.  Whether sample compositing has been applied.  Historic samples collected – with unknown data spacing and distribution. Orientation of data in relation to geological structure  Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.  If the relationship between the drilling orientation