Announcement PDF ASX Release 5 June 2025 RareX Engages Ausenco to Advance Infrastructure and Project Studies for Mrima Hill Engage with this announcement at the RareX investor hub. Highlights • Leading EPCM company, Ausenco, appointed to lead feasibility studies, process design, construction readiness, and engineering for the proposed Mrima Hill Critical Minerals Project in Kenya. RareX will ensure they are supported by local, Kenyan-based engineering and construction firms. • Mrima Hill is the subject of a proposal submitted by the RareX–Iluka Consortium, along with supporting partners, including Ausenco, as announced to the ASX on 22 April 2025. The consortium and proposal partners were recently convened by the Kenyan high Commissioner, HE Dr Kogo in Perth. • Ausenco join WSP and others as part of the consortium proposals proponents, advancing their commitments and contributions to the initiative. • Mrima Hill is a globally strategic rare earth and niobium project (also prospective for manganese and phosphate), for which RareX has assembled a team of Australian and U.S. expert institutions and financiers, and proposed a procurement, development, and operational plan to the Kenyan government. • Ausenco have significant experience in Kenya as the leading engineering, procurement and construction management company for the Kwale Mineral Sands Project. This project is in the same county as Mrima Hill, giving Ausenco exceptional local knowledge and recent learnings. RareX Limited (ASX: REE) (RareX or the Company) is pleased to announce it has formally engaged Australianbased, majority US owned, global engineering firm Ausenco to lead the early-stage infrastructure and desktop development studies for the proposed Mrima Hill Critical Minerals Project in Kenya. Ausenco is a recognised leader in consulting, engineering, procurement, and construction management (EPCM) and is majority owned by Resource Capital Funds, a U.S.-based investment group headquartered in Denver, Colorado. Ausenco brings deep experience delivering complex, high-impact projects across Africa and globally, including Kenya. Building Early Project Definition with Regional Expertise Ausenco will undertake early-stage work to support the responsible and well-informed development of Mrima Hill. This will include: 1. Desktop engineering studies to assess infrastructure corridors, processing options, and site layout using available data; 2. Review of regional context, leveraging Ausenco’s prior work in Kwale County to inform early project framing; 3. Identification of community-facing infrastructure needs—such as roads, power, and water—to support sustainable development; 4. Integration of engineering insight into early stakeholder engagement, social impact thinking, and prefeasibility planning; and For more information, please contact: Investors: James Durrant, Managing Director Engage and Contribute: Investor Hub RareX Limited ASX:REE ABN: 65 105 578 756 RareX HQ Level 1, 338 Barker Road Subiaco WA 6008 Australia P +61 (0) 8 6383 6593 W ree.investorhub.com/welcome P +61 (0) 8 6383 6593 E info@rarex.com.au ree.investorhub.com/welcome rarex.com.au RareX Limited (ASX:REE) @rarex_asx 5. Assessment of energy requirements for early and long-term development, including evaluation of grid capacity and identification of alternative energy options such as local geothermal sources. RareX Managing Director, James Durrant, said: “This is about laying down the foundation for a world-class project—one that is grounded in practicality, regional understanding, and long-term community value. Ausenco has already worked in this part of Kenya and brings a unique ability to translate available knowledge into actionable engineering and infrastructure design. Their early engagement allows us to move quickly and responsibly, building out a robust understanding of what Mrima Hill can look like before we access the ground. Physical works will only proceed once the appropriate licences are granted by the Government of Kenya and local communities have been engaged and brought along on the journey—ensuring both legal and social licence to operate are fully respected. “With the support of Ausenco and our broader team, RareX is demonstrating its ability to develop this project in the best possible way—structured, experienced, and respectful of the setting we’re working in.” Strategic Implications This appointment strengthens RareX’s preparedness as the lead developer of Mrima Hill. Key implications include: • Early de-risking of project infrastructure and layout, enabling faster project advancement post-licensing; • Use of existing data to build commercial and technical frameworks without delay; • Strong alignment with Kenya’s infrastructure development priorities, especially in Kwale County; and • U.S. strategic exposure through Ausenco’s ownership by Resource Capital Funds (RCF), a respected American critical minerals investor. RareX’s Mrima Hill proposal, submitted via Kenya’s Specially Permitted Procurement Method (SPPM), outlines a phased, sovereign-partnered development of one of the world’s most significant rare earths, niobium, phosphate and manganese deposits. This work with Ausenco ensures the Company remains on the front foot as ESG, social, and technical workstreams continue to progress in parallel. This announcement has been authorised for release by the Board of RareX Limited. RareX is a critical minerals company specialising in rare earths and niobium in hard rock carbonatites. The exploration focus of the business is on the new Khaleesi Project in the East Yilgarn which is a district-scale, elevated-niobium, alkaline intrusive complex, the Mt Mansbridge xenotime heavy rare earths project near Browns Range and the Cummins Range near-mine anomalies. The Company’s engineering and commercial focus is on the mid-study-level, Cummins Range Project (+$330M NPV8 post-tax*) - a carbonatite hosted rare earths, gallium, scandium and phosphate project, containing a critical metal suite including magnet grade rare earths and battery grade phosphates and technically Australia’s largest undeveloped rare earths project. RareX have been curating a portfolio of carbonatite related projects including the newly acquired bulls-eye Piper Project along trend from both Nolans Bore and the Luni niobium deposit. RareX will continue to develop and optimise its portfolio. RareX maintains material investments in Kincora Copper (ASX:KCC), Cosmos Exploration (ASX:C1X) and Canada Rare Earth Corporation (LL.V). For further information on the Company and its projects visit www.rarex.com.au * The forecast financial information was released on 22 August 2023. The Company confirms that the material assumptions underpinning the production target and forecast financial information continue to apply and have not materially changed