Company: RTNTF
Filing Date: 2025-02-20
Form Type: 20-F
Source: 0001628280-25-006642
Chunk: 532

Company: RIO TINTO LTD
Filing Date: 2025-02-20
Form: 20-F
Chunk 532
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 included in the calculation of a copper equivalent cut-off. At Heruga, molybdenum is also included as a payable element. For more information regarding the material assumptions for the Mineral Resource estimates, see Section 11 of the Oyu Tolgoi Technical Report Summary filed as exhibit 96.3 to the 2022 Form 20-F . Mineral Reserves The table on pages 282 - 283 sets out the amount, grade, price and metallurgical recovery of Oyu Tolgoi ‘s Proven and Probable Mineral Reserves for the year ended 31 December 2024. The 5% reduction in Mineral Reserves compared to the year ended 31 December 2023 is primarily due to the 2024 mined (production) Proven and Probable ore from the Oyut open pit Mineral Reserves. The Mineral Reserves estimates for Oyu Tolgoi are based on a Life of Mine plan that has been developed according to SK-1300 and using industry accepted strategic planning approaches which defined the life of the mines at Oyu Tolgoi. Inferred Mineral Resources have been treated as waste. The final reserves plan is the outcome of the application of appropriate modifying factors in order to establish an economically viable and operational mine plan. At Oyu Tolgoi, a variable cut-off grade strategy is applied to develop the mine plan. The Mineral Reserves estimate includes both the Oyut and Hugo North deposits and more detail is provided in Table 1.2 of exhibit 96.3 of the 2022 Form 20-F . Material assumptions in the estimation of Mineral Reserves are: – The resource model reflects the continuity and complexity of the deposit with the confidence stated in the classification. – Mineral Reserves are reported as dry mill feed tonnes. – A variable net smelter return cut-off strategy that maximises throughput for the concentrator. – Commodity prices, operating and capital costs. – Geology models contain tonnage estimates on a dry in situ basis. The estimated water content (moisture) for each block model block is added. – Metallurgical and processing recovery estimates are applied to crusher feed tonnages based on ore types.

| Annual Report on Form 20-F 2024 | 352 | riotinto.com |

Additional information | US Disclosure Uncertainties that affect the reliability or confidence in the Mineral Reserves estimate include but are not limited to: – Future macro-economic environment, including metal prices and foreign exchange rate. – Changes to operating cost assumptions