Company: RTNTF
Filing Date: 2025-02-20
Form Type: 20-F
Source: 0001628280-25-006642
Chunk: 515

Company: RIO TINTO LTD
Filing Date: 2025-02-20
Form: 20-F
Chunk 515
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 • Detritals are reported in relation to their Bedded origins; ≥ 58% Fe for Marra Mamba detritals, ≥ 60% Fe for Brockman detritals; or Boolgeeda detritals are reported as High Grade ≥ 60% Fe and as Blending Aluminous ≥ 55% Fe < 60% and ≥ 3% Al 2 O 3 < 6.5%. • CIDs are reported primarily based on strand (geological subdivision), but with some exceptions where a cut-off grade is applied based on metallurgical processing recovery assumptions. In addition, Mineral Resources are reported for major strands only. – Metallurgical Factors or Assumptions – It is assumed that crushing, screening and beneficiation processes used by Rio Tinto will be applicable for the processing of reported Mineral Resources. Predicted yield and upgrade are deposit specific and are based on metallurgical test work conducted on representative samples collected from those deposits or adjacent analogous deposits. – Environmental Factors or Assumptions – Extensive environmental surveys and studies will be completed during the project study phases to determine if the project requires formal State and Commonwealth environmental assessment and approval. Mapping of oxidised shales, black carbonaceous shales, lignite, and the location of the water table, is used to predict and manage potential environmental impacts. – Heritage Factors or Assumptions – Extensive cultural heritage studies, surveys and engagement with traditional owners will be completed during project study phases to determine if projects require additional assessment, monitoring, or exclusion areas to be maintained during mining, to manage potential impacts to sites and cultural values. For more information regarding the material assumptions for the Mineral Resources estimates, see Section 11 of the Pilbara Operations Technical Report Summary filed as exhibit 96.1 to the Form 20-F for the year ended 31 December 2021 (“2021 Form 20-F ”). Mineral Reserves The table on pages 280 - 281 of this Form 20- F sets out the amount, grade, prices and metallurgical recovery of the Pilbara Property’s Proven and Probable Mineral Reserves for the year ended 31 December 2024 (Australian Iron Ore operations). Compared to the year ended 31 December 2023, the Mineral Reserves decreased by 1%. Changes were due to mining depletion, which was offset by the addition of new deposits and changes to cut-off grade. Other minor changes are attributed to updated

| Annual Report on Form 20-F 2024 | 344 |