CHATHAM CONFIRMS PROPOSED SALE OF AVENIR MAKATEA PTY

NEWS RELEASE 25-026 December 22, 2025 CHATHAM CONFIRMS PROPOSED SALE OF AVENIR MAKATEA PTY WELLINGTON New Zealand - Chatham Rock Phosphate Limited (TSXV: “NZP”, NZX: “CRP” and “3GRE” (Frankfurt) or the “Company”) ”) is pleased to announce that, further to its news release dated November 12, 2025, it has signed an agreement with Melbourne-based Australian company Austure Industries Pty Ltd (Austure) for the sale of Chatham’s wholly-owned Australian subsidiary Avenir Makatea Pty Ltd for consideration of AU$1.4 million. The consideration is to be comprised of AU$ 900,000 in cash over a 24-month period, and the Company receiving a 20% shareholding in Austure Phosphate AU Pty Ltd, a newly-formed subsidiary of Austure, to establish a DCP/MCP manufacturing plant in Cloncurry. Colin Randall, Chatham Executive Director has been appointed a Director of Austure Phosphate AU Pty Ltd. This agreement provides the Korella North mine with a local market for its mined rock phosphate which will be supplied to the revolutionary DCP/MCP manufacturing plant. Austure Industries Pty Ltd has developed a technology that enables a manufacturing plant to produce both Dicalcium Phosphate (DCP) and Monocalcium phosphate (MCP). This unique DCP/MCP technology was developed in Melbourne by Monash alumni chemists, of which one is a principal of Austure Industries Pty Ltd. Both DCP and MCP are utilised in lick blocks that provide cattle with supplemental phosphorus, essential for healthy cattle in the phosphorus-deficient north Queensland, Northern Territory and northern part of Western Australia. Currently Australia imports all the estimated 100,000 tonnes per annum (tpa) of DCP/MCP/MDCP utilised as supplements and in feed rations for cattle, pigs and broiler chickens. MCP has been very difficult to purchase out of China in recent months, with the CIF price passing $1400 per metric tonne. The establishment of a DCP/MCP plant in Cloncurry will provide Australian Sovereign Capability for an essential ingredient in the welfare and productivity required in Australian animal husbandry. The technology utilises a novel green process where electricity is used to generate phosphoric acid from rock phosphate. The phosphoric acid is then used to manufacture downstream products such as fertiliser and feed phosphate. The electricity can be generated from renewable resources in a private off-grid plant. The technology utilises tailings-grade rock phosphate in in P2O5 concentration as low as 16%. The tailings of rock phosphate, dry-sorted from the Korella North Mine fits with the supply criteria for the proposed plant, whilst the beneficiated (higher) grade rock phosphate is kept for export. Instead of a toxic phospho-gypsum biproduct, a high silica content biproduct is produced which can be used as a sand replacement in roads and civil works. Background CRP’s wholly owned Australian subsidiary, Avenir Makatea Pty Ltd., through its subsidiary Korella MCP Pty Ltd, has been investigating since 2021 the establishment of a 30,000 tonnes per annum (tpa) DCP/MCP plant in Cloncurry to utilise phosphate from its Korella deposits. Cloncurry based Chatham Executive Director Colin Randall led these feasibility studies. In these plant feasibility studies, Chatham always faced two significant issues. First, the matter of scale. At 30,000 tpa the proposed plant was too small for economical production. Most plants had to be 100,000 tpa and based near a seaport. Second was the dependence on the availability of sulphuric acid to be utilised in the manufacturing process. With the supply of sulphuric acid in the Northwest Mineral Province a major unknown, this posed an unacceptable risk to a Cloncurry located conventional DCP/MCP manufacturing plant. As a local supply of sulphuric acid is not a prerequisite for this new DCP/MCP manufacturing technology, it is now feasible for the plant to be in Cloncurry, with closer proximity to the DCP/MCP market. This is expected to undercut the imported DCP/MCP product due to the saving in transport costs. This new manufacturing system can be established in modules of 5,000 tpa of DCP equivalent calcium phosphate which allows rapid commencement of the plant with a low CAPEX hurdle yet permits gradual expansion at our own determined pace. The new jointly owned company Austure Phosphate AU Pty Ltd (APAU) has been licensed to utilise the technology (currently being patented). At the same time APAU will establish its competitive position in the lick block market by offering imported high quality DCP/MCP/MDCP sourced from affiliated plants of the Melbourne-based technology partner. For more information contact Chris Castle on 021 558 185 or chris@widespread.co.nz or check out www.rockphosphate.co.nz. Neither the Exchange, its Regulation Service Provider (as that term is defined under the policies of the Exchange), or NZX Limited has in any way passed upon the merits of the Transaction and associated transactions, and has neither approved nor disapproved of the contents of this press release.