Rio Tinto (NYSE: RIO) files 6-K on lithium, copper and iron ore projects

Rhea-AI Filing Summary

Rio Tinto filed a Form 6-K summarising a series of December 2025 announcements by Rio Tinto plc and Rio Tinto Limited. The report bundles stock exchange notices and media releases on capital structure, management shareholdings, project development and community agreements.

Key items include an updated total voting rights and issued capital statement, several disclosures on shareholdings of persons discharging managerial responsibility and key management personnel, and notifications of unquoted equity securities and director interest changes. Operationally, the exhibits cover initial reporting of lithium Mineral Resources and Ore Reserves, a lithium-focused investor "Deep Dive" and site visit to Argentina, first copper produced using Rio Tinto’s Nuton technology, and a media release on battery-electric haul trucks in the Pilbara with BHP. The filing also highlights Indigenous agreement updates and a $191 million feasibility study for the Rhodes Ridge Joint Venture on an iron ore mine of up to 50Mtpa in the Pilbara.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13A-16 OR 15D-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of December 2025

Commission file number: 001-10533			Commission file number: 001-34121
Rio Tinto plc			Rio Tinto Limited
			ABN 96 004 458 404
(Translation of registrant’s name into English)			(Translation of registrant’s name into English)
6 St. James’s Square			Level 43, 120 Collins Street
London, SW1Y 4AD, United Kingdom			Melbourne, Victoria 3000, Australia
(Address of principal executive offices)			(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☒ Form 40-F ☐

EXHIBITS

99.1Stock Exchange announcement dated 1 December 2025 entitled ‘Total Voting Rights and Issued Capital’.

99.2Stock Exchange announcement dated 1 December 2025 entitled ‘Shareholdings of persons discharging managerial responsibility (PDMR) / Key Management Personnel (KMP)’.

99.3Media release dated 2 December 2025 entitled ‘Karlka Nyiyaparli Aboriginal Corporation and Rio Tinto sign updated Native Title Agreement’.

99.4Stock Exchange announcement dated 4 December 2025 entitled ‘Initial reporting of lithium Mineral Resources and Ore Reserves’.

99.5Stock Exchange announcement dated 4 December 2025 entitled ‘Initial reporting of lithium Mineral Resources and Ore Reserves: supporting information and Table 1 checklists.’

99.6Media release dated 4 December 2025 entitled ‘Rio Tinto’s Nuton technology produces first copper’.

99.7Stock Exchange announcement dated 4 December 2025 entitled ‘Shareholdings of persons discharging managerial responsibility (PDMR) / Key Management Personnel (KMP)’.

99.8Stock Exchange announcement dated 4 December 2025 entitled ‘Shareholdings of persons discharging managerial responsibility (PDMR) / Key Management Personnel (KMP)’.

99.9Media release dated 5 December 2025 entitled ‘BHP and Rio Tinto welcome first Caterpillar battery-electric haul trucks to the Pilbara’.

99.10Stock Exchange announcement dated 8 December 2025 entitled ‘Appendix 3G – Notification of issue, conversion or payment up of unquoted equity securities’.

99.11Stock Exchange announcement dated 8 December 2025 entitled ‘Appendix 3Y – Change of Director’s Interest Notice’.

99.12Stock Exchange announcement dated 8 December 2025 entitled ‘Lithium Deep Dive and investor site visit to Argentina’.

99.13Stock Exchange announcement dated 8 December 2025 entitled ‘Lithium Deep Dive – Argentina (presentation)’.

99.14Media release dated 8 December 2025 entitled ‘Rio Tinto’s first Pilbara-made rail car built by Gemco in Karratha’.

99.15Media release dated 12 December 2025 entitled ‘Yinhawangka Aboriginal Corporation and Rio Tinto sign Interim Modernised Agreement’.

99.16Media release dated 16 December 2025 entitled ‘Rhodes Ridge Joint Venture partners begin $191 million feasibility study on up to 50Mtpa Pilbara iron ore mine’.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned, thereunto duly authorised.

Rio Tinto plc						Rio Tinto Limited
(Registrant)						(Registrant)
By			/s/ Andrew Hodges			By			/s/ Tim Paine
Name			Andrew Hodges			Name			Tim Paine
Title			Company Secretary			Title			Company Secretary
Date			5 January 2026			Date			5 January 2026

FAQ

What does Rio Tinto (RIO) report in this December 2025 Form 6-K?

The Form 6-K consolidates multiple December 2025 stock exchange announcements and media releases from Rio Tinto plc and Rio Tinto Limited, including capital, management shareholding, project, technology and community agreement updates.

What major project study is mentioned for Rio Tinto (RIO)?

One exhibit is a media release stating that Rhodes Ridge Joint Venture partners have begun a $191 million feasibility study on an iron ore mine of up to 50Mtpa in the Pilbara.

How does the 6-K address Rio Tinto’s lithium activities?

The exhibits include stock exchange announcements on initial reporting of lithium Mineral Resources and Ore Reserves and materials titled "Lithium Deep Dive" and an investor site visit to Argentina, plus a related presentation.

What technology and equipment developments are highlighted for Rio Tinto (RIO)?

Media releases note that Rio Tinto’s Nuton technology produced first copper, that BHP and Rio Tinto welcomed the first Caterpillar battery-electric haul trucks to the Pilbara, and that Rio Tinto’s first Pilbara-made rail car was built by Gemco in Karratha.

Are there Indigenous or native title agreements mentioned in this Rio Tinto filing?

Yes. Exhibits include media releases on updated or interim agreements with the Karlka Nyiyaparli Aboriginal Corporation and the Yinhawangka Aboriginal Corporation.

Does the December 2025 6-K include information on Rio Tinto’s share capital and management holdings?

Yes. The exhibits list a Total Voting Rights and Issued Capital announcement, multiple disclosures on PDMR/KMP shareholdings, an Appendix 3G on unquoted equity securities, and an Appendix 3Y for a change in a director’s interest.