Company: RTNTF
Filing Date: 2025-02-20
Form Type: 20-F
Source: 0001628280-25-006642
Chunk: 337

Company: RIO TINTO LTD
Filing Date: 2025-02-20
Form: 20-F
Chunk 337
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 of production method, depreciation is normally calculated based on production in the period as a percentage of total expected

production in current and future periods based on Ore Reserves and, for some mines, other Mineral Resources. Other Mineral Resources may be

included in the calculations of total expected production in limited circumstances where there are very large areas of contiguous mineralisation, for

which the economic viability is not sensitive to likely variations in grade, as may be the case for certain iron ore, bauxite and industrial mineral

deposits, and where there is a high degree of confidence that the other Mineral Resources can be extracted economically. This would be the case

when the other Mineral Resources do not yet have the status of Ore Reserves merely because the necessary detailed evaluation work has not yet

been performed and the responsible technical personnel agree that inclusion of a proportion of Measured and Indicated Resources in the calculation

of total expected production is appropriate based on historical reserve conversion rates.

The required level of confidence is unlikely to exist for minerals that are typically found in low-grade ore (as compared with the above), such as

copper or gold. In these cases, specific areas of mineralisation have to be evaluated in detail before their economic status can be predicted with

confidence.

Sometimes the calculation of depreciation for infrastructure assets, primarily rail and port, considers Measured and Indicated Resources. This is

because the asset can benefit current and future mines. The measured and indicated resource may relate to mines which are currently in production

or to mines where there is a high degree of confidence that they will be brought into production in the future. The quantum of Mineral Resources is

determined taking into account future capital costs as required by the JORC Code. The depreciation calculation, however, applies to current mines

only and does not take into account future development costs for mines which are not yet in production. Measured and Indicated Resources are

currently incorporated into depreciation calculations in the Group’s Australian iron ore business.

| Annual Report on Form 20-F 2024 | 186 | riotinto.com |

Financial statements | Notes to the consolidated financial statements

13 Property, plant and equipment continued

| Key judgement - estimation of asset livesThe useful lives of the major assets of a CGU are often dependent on the life of the orebody to which they relate. Where this is the case, thelives of mining properties, and their associated refineries, concentrators and other long-lived processing equipment are generally limited tothe expected life of the orebody.