REG - Rio Tinto - Mineral Resources and Ore Reserves updates
19/02/2026 07:00
For best results when printing this announcement, please click on link below:
https://newsfile.refinitiv.com/getnewsfile/v1/story?guid=urn:newsml:reuters.com:20260219:nRSS5784Ta&default-theme=true
RNS Number : 5784T Rio Tinto PLC 19 February 2026
Notice to
ASX/LSE
Mineral Resources and Ore Reserves updates
19 February 2026
Rio Tinto has today announced to the Australian Securities Exchange (ASX)
changes in Mineral Resources and Ore Reserves to support its 2025 annual
reporting 1 , including:
· Increased Proved and Probable Ore Reserves and decreased Mineral
Resources at the Rio Tinto Copper (RTC) Oyu Tolgoi Oyut open pit deposit in
Mongolia.
· A significant conversion of Mineral Resources to Ore Reserves at
the Rio Tinto Copper Kennecott Bingham Canyon open pit deposit in Utah, USA,
resulting in a material reduction in reported Mineral Resources.
· An increase in reported Mineral Resources and Ore Reserves at the
Rio Tinto Copper Kennecott Bingham Canyon underground deposit in Utah, USA.
· Increased Ore Reserves and improved confidence with an associated
decrease in Mineral Resources at the Rio Tinto Aluminium (RTA) Pacific
Operations Amrun deposit in Queensland, Australia.
· Increased Mineral Resources and revised classification for the
Ore Reserves at Rio Tinto Borates (RTB) Boron deposit.
Supporting information for the changes in Mineral Resources and Ore Reserves
is set out in the Table 1 Release and its appendices. This release provides a
summary of those changes. Mineral Resources and Ore Reserves are quoted in
this release on a 100 percent basis. Mineral Resources are reported in
addition to Ore Reserves. The figures used to calculate Mineral Resources and
Ore Reserves are often more precise than the rounded numbers shown in the
tables, hence small differences may result if the calculations are repeated
using the tabulated figures.
These changes will be included in Rio Tinto's 2025 Annual Report, to be
released to the market on 19 February 2026 (London time), which will set out
in full Rio Tinto's Mineral Resources and Ore Reserves position as at 31
December 2025, and Rio Tinto's interests.
Rio Tinto Copper - Oyu Tolgoi
Mineral Resources and Ore Reserves for the Oyu Tolgoi deposits 2 are
presented in Table A and Table B. Proved Ore Reserves have increased by 17
million tonnes (Mt) and Probable Ore Reserves have increased by 63 Mt, for an
overall increase in Ore Reserves of 80 Mt (8%). Within the Oyut open pit
Proven Ore Reserves have increased by 17 Mt (7%) and Probable Ore Reserves
have increased by 61 Mt (17%), for an overall increase of 79 Mt (14%).
There is no material change to Mineral Resources at the Property level. Within
the Oyut open pit Measured and Indicated Mineral Resources have increased by
65 Mt (60%), while Inferred Mineral Resources have decreased by 125 Mt (39%)
for an overall decrease of 60 Mt (14%).
The material change in both Oyut open pit Ore Reserves and Mineral Resources
is largely driven by the Oyut block model update and resulting conversion of
Inferred Mineral Resources into Indicated Mineral Resources and subsequently
Ore Reserves through increased drilling density and geological confidence,
with mining production depletions being the other minor contributing factor.
There has been no material change to other modifying factors, including mine
design, governmental, tenure, environmental, cultural heritage or community
factors and the methodology for determining Mineral Resources remains
unchanged. Note the material variance is solely at the Oyut open pit level,
and at Property level there no material change to Mineral Resources or Ore
Reserves.
Rio Tinto Copper - Kennecott Bingham Canyon open pit
Mineral Resources and Ore Reserves for the Kennecott Bingham Canyon open pit
deposit 3 are presented in Table C and Table D. Measured and Indicated
Mineral Resources tonnes have decreased by 63 Mt and Inferred Mineral
Resources have increased by 7 Mt for an overall decrease of 56 Mt (74%) as a
result of the conversion to Ore Reserves.
Rio Tinto Copper - Kennecott Bingham Canyon underground
Mineral Resources and Ore Reserves for the Kennecott Bingham Canyon
underground deposit 4 are presented in Table E and Table F. These Mineral
Resources have increased by 32 Mt (122%) and Ore Reserves have increased by
4.0 Mt (85%). These updated Mineral Resources and Ore Reserves reflect
increased confidence in the Mineral Resources due to the completion of orebody
knowledge drilling, a lower cut-off grade that considers current mining costs,
and ongoing experience mining the orebody.
Rio Tinto Aluminium Pacific Operations - Amrun
Mineral Resources and Ore Reserves for the RTA Pacific Operations, including
the Amrun deposit 5 , are presented in Table G and Table H. The updated Ore
Reserves at Amrun reflects a material increase in Ore Reserves, and a material
change in Ore Reserve classification. Proved Ore Reserves have increased by
258 Mt (55%), while Probable Ore Reserves have decreased by 161 Mt (31%), for
a net increase of 123 Mt (13%), offset by 25 Mt depletion, to a total of
1,076 Mt. The increase in Ore Reserves has resulted from a routine review
of economic assumptions over the life of the mine, and updated orebody
knowledge. The change in Ore Reserves classification reflects a higher level
of confidence in the modifying factors resulting from increased confidence in
the underlying Mineral Resources due to updated orebody knowledge. There has
been no material change to other modifying factors, including governmental,
tenure, environmental, cultural heritage or community factors. Mineral
Resources exclusive of Ore Reserves have decreased by 94 Mt (13%) at Amrun due
to the conversion of Mineral Resources to Ore Reserves, updated orebody
knowledge and increased resource confidence.
Rio Tinto Borates - Boron
Mineral Resources and Ore Reserves for the RTB Boron Operations 6 are
presented in Table I and Table J. Mineral Resources have increased by 9.3 Mt
saleable boric oxide (B(2)O(3)), reflecting an increase in the level of
studies to process mineralised stockpiles. This provides reasonable prospects
for eventual economic extraction of the additional material.
Total Ore Reserves (combined Proved and Probable) remain consistent with 2024,
with mining depletion of 0.5 Mt B(2)O(3) the only change. However, there has
been a change in the classification methodology whereby a higher level of
geotechnical study is now required for Proved Ore Reserves. Applying this
change has converted 1.7 Mt B(2)O(3) of Ore Reserves previously classified as
Proved Ore Reserves to Probable Ore Reserves. There is no change to level of
geotechnical information supporting the Ore Reserves, nor are there changes to
any other modifying factors, including governmental, tenure, environmental,
cultural heritage or community factors. The result of this change is that
Proved Ore Reserves have decreased by 2.2 Mt B(2)O(3) and Probable Ore
Reserves have increased by 1.7 Mt B(2)O(3).
1 These Mineral Resources and Ore Reserves were reported in accordance with
the Australasian Code for Reporting of Exploration Results, Mineral Resources
and Ore Reserves, 2012 (JORC Code) and the ASX Listing Rules in a release to
the ASX dated 19 February 2026 titled "Ore Reserve and Mineral Resource
updates: supporting information and Table 1 checklists" (Table 1 Release). Rio
Tinto confirms that it is not aware of any new information or data that
materially affects the information included in the Table 1 Release, that all
material assumptions and technical parameters underpinning the estimates in
the Table 1 Release continue to apply and have not materially changed, and
that the form and context in which the Competent Persons' findings are
presented have not been materially modified.
(2) The Competent Person for the information in the Table 1 Release that
relates to Oyu Tolgoi Mineral Resources is Ms Joanna Marshall MAusIMM. The
Competent Person for the information in the Table 1 Release that relates to
Oyu Tolgoi Ore Reserves is Mr Nathan Robinson MAusIMM.
3 The Competent Persons for the information in the Table 1 Release that
relates to Kennecott Bingham Canyon open pit Mineral Resources is Mr Gerry
Austin MAusIMM and Mr Pancho Rodriguez MAusIMM. The Competent Person for the
information in the Table 1 Release that relates to Kennecott Bingham Canyon
open pit Ore Reserves is Mr Eric Hoffmann MAusIMM.
(4) The Competent Person for the information in the Table 1 Release that
relates to Kennecott Bingham Canyon underground Mineral Resources is Mr Ryan
Hayes MAusIMM. The Competent Person for the information in the Table 1
Release that relates to Kennecott Bingham Canyon underground Ore Reserves is
Mr Charles McArthur MAusIMM.
(5) The Competent Person for the information in the Table 1 Release that
relates to RTA Pacific Operations Mineral Resources is Mr Angus C. McIntyre
MAusIMM. The Competent Person for the information in the Table 1 Release
that relates to RTA Pacific Operations Ore Reserves is Mr William Saba
MAusIMM.
(6) The Competent Person for the information in the Table 1 Release that
relates to RTB Boron Mineral Resources and Ore Reserves is Mr Brandon
Griffiths who is a Registered Member of the Society for Mining, Metallurgy,
and Exploration.
Table A Rio Tinto Copper Oyu Tolgoi Mineral Resources as at
31 December 2025
Likely Measured Mineral Resources Indicated Mineral Resources Total Measured and Indicated Mineral
mining
method(1) as at 31 December 2025 as at 31 December 2025 Resources as at 31 December 2025
Tonnage Grade Tonnage Grade Tonnage Grade
Copper Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo
Oyu Tolgoi (Mongolia)(2)
- Heruga ETG U/G - - - - - - - - - - - - - - -
- Heruga OT U/G - - - - - - - - - - - - - - -
- Hugo Dummett North(3) U/G 53 1.91 0.50 4.28 - 375 1.39 0.35 - - 428 1.45 0.37 3.37 -
- Hugo Dummett North Extension U/G - - - - - 83 1.63 0.55 4.21 - 83 1.62 0.55 4.21 -
- Hugo Dummett South U/G - - - - - - - - - - - - - - -
- Oyut Open Pit O/P 23 0.41 0.28 1.01 - 150 0.32 0.26 1.07 - 173 0.33 0.27 1.06 -
- Oyut Underground U/G 12 0.46 0.85 1.24 - 88 0.38 0.55 1.22 - 100 0.39 0.58 1.22 -
Total 87 1.32 0.49 3.02 - 696 1.06 0.38 2.63 - 784 1.09 0.39 2.67 -
Inferred Mineral Resources Total Mineral Resources Rio Tinto Total Mineral Resources
interest
as at 31 December 2025 as at 31 December 2025 as at 31 December 2024
Tonnage Grade Tonnage Grade Tonnage Grade
Copper Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo % Mt % Cu g/t Au g/t Ag % Mo
Oyu Tolgoi (Mongolia)(2)
- Heruga ETG 1,502 0.41 0.40 1.44 0.012 1,502 0.41 0.40 1.44 0.012 56.0 1,502 0.41 0.40 1.44 0.012
- Heruga OT 107 0.42 0.30 1.58 0.011 107 0.42 0.30 1.58 0.011 66.0 107 0.42 0.30 1.58 0.011
- Hugo Dummett North(3) 716 0.83 0.29 2.47 - 1,143 1.06 0.32 2.81 - 66.0 1,145 1.06 0.32 2.80 -
- Hugo Dummett North Extension 161 1.04 0.37 2.84 - 244 1.24 0.43 3.31 - 56.0 244 1.24 0.43 3.31 -
- Hugo Dummett South 731 0.83 0.07 1.87 - 731 0.83 0.07 1.87 - 66.0 731 0.83 0.07 1.87 -
- Oyut Open Pit 197 0.28 0.19 1.16 - 370 0.30 0.23 1.11 - 66.0 430 0.30 0.21 1.04 -
- Oyut Underground 117 0.42 0.40 1.15 - 217 0.40 0.48 1.18 - 66.0 203 0.40 0.49 1.23 -
Total 3,530 0.60 0.29 1.78 0.005 4,314 0.69 0.31 1.94 0.004 4,362 0.69 0.31 1.93 0.004
1. Likely mining method: O/P = open pit/surface.
2. Copper Mineral Resources are stated on a dry in situ weight basis.
3. The Hugo Dummett North Mineral Resources include approximately 1.3
million tonnes of stockpiled material at a grade of 0.35% copper, 0.11 g/t
gold and 0.85 g/t silver.
Table B Rio Tinto Copper Oyu Tolgoi Ore Reserves as at 31
December 2025
Type Proved Ore Reserves Probable Ore Reserves Total Ore Reserves
of
mine(1) as at 31 December 2025 as at 31 December 2025 as at 31 December 2025
Tonnage Grade Tonnage Grade Tonnage Grade
Copper(2) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo
Oyu Tolgoi (Mongolia)
- Hugo Dummett North(3) U/G - - - - - 374 1.56 0.30 3.20 - 374 1.56 0.30 3.20 -
- Hugo Dummett North Extension U/G - - - - - 36 1.68 0.59 3.96 - 36 1.68 0.59 3.96 -
- Oyut Open Pit O/P 241 0.54 0.39 - - 409 0.38 0.26 1.10 - 650 0.44 0.31 1.15 -
- Oyut stockpiles S/P - - - - - 76 0.32 0.13 0.94 - 76 0.32 0.13 0.94 -
Total 241 0.54 0.39 - - 895 0.92 0.28 2.08 - 1,136 0.84 0.30 1.90 -
Average mill recovery % Rio Tinto interest Rio Tinto share recoverable metal Total Ore Reserves
as at 31 December 2024
Tonnage Grade
Copper(2) Cu Au Ag Mo % Mt Cu Moz Au Moz Ag Mt Mo Mt % Cu g/t Au g/t Ag % Mo
Oyu Tolgoi (Mongolia)
- Hugo Dummett North(3) 92 79 81 - 66.0 3.57 1.88 20.44 - 386 1.58 0.31 3.25 -
- Hugo Dummett North Extension 93 81 84 - 56.0 0.31 0.31 2.13 - 36 1.68 0.60 3.97 -
- Oyut Open Pit 76 67 55 - 66.0 1.43 2.84 8.69 - 571 0.46 0.32 1.22 -
- Oyut stockpiles 71 54 50 - 66.0 0.11 0.12 0.77 - 63 0.31 0.13 0.98 -
Total 5.42 5.14 32.04 - 1,056 0.90 0.31 2.04 -
1. Type of Mine: O/P = open pit/surface, S/P = stockpile, U/G =
underground.
2. Copper Ore Reserves are reported as dry mill feed tonnes.
3. The Hugo Dummett North Ore Reserves include approximately 1.9
million tonnes of stockpiled material at a grade of 0.48% copper, 0.14 g/t
gold and 1.18 g/t silver.
Table C Rio Tinto Copper Kennecott Bingham Canyon open pit
Mineral Resources as at 31 December 2025
Likely Measured Mineral Resources Indicated Mineral Resources Total Measured and Indicated Mineral
mining
method((1))
as at 31 December 2025 as at 31 December 2025 Resou
rces
as at
31
Decem
ber
2025
Tonnage Grade Tonnage Grade Tonnage Grade
Copper((2)) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US)
- Bingham Open Pit ((3)) O/P - - - - - - - - - - - - - - -
Inferred Mineral Resources Total Mineral Resources Rio Tinto Total Mineral Resources
interest
as at 31 December 2025 as at 31 December 2025 as at
31
Decem
ber
2024
Tonnage Grade Tonnage Grade Tonnage Grade
Copper((2)) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo % Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US)
- Bingham Open Pit ((3)) 20 0.13 0.30 2.91 0.008 20 0.13 0.30 2.91 0.008 100.0 76 0.37 0.18 2.65 0.017
1. Likely mining method: O/P = open pit/surface.
2. Copper Mineral Resources are stated on a dry in situ weight basis.
Table D Rio Tinto Copper Kennecott Bingham Canyon open pit
Ore Reserves as at 31 December 2025
Type Proved Ore Reserves Probable Ore Reserves Total Ore Reserves
of
mine((1)) as at 31 December 2025 as at 31 December 2025 as at 31 December 2025
Tonnage Grade Tonnage Grade Tonnage Grade
Copper((2)) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US)
- Bingham Open Pit((3)) O/P 442 0.38 0.18 1.98 0.034 288 0.34 0.19 1.93 0.025 730 0.36 0.18 1.96 0.030
Average mill recovery % Rio Tinto Rio Tinto share Total Ore Reserves
interest
recoverable metal as at 31 December 2024
Tonnage Grade
Copper((2)) Cu Au Ag Mo % Mt Cu Moz Au Moz Ag Mt Mo Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US)
- Bingham Open Pit((3)) 88 68 71 65 100.0 2.35 2.90 32.68 0.14 777 0.36 0.18 1.97 3.34
1. Type of Mine: O/P = open pit/surface.
2. Copper Ore Reserves are reported as dry mill feed tonnes.
3. Bingham Canyon Open Pit Ore Reserve molybdenum grades interpolated
from exploration drilling assays have been factored based on a long
reconciliation history to blast hole and mill samples.
Table E Rio Tinto Copper Kennecott Bingham Canyon
underground Mineral Resources as at 31 December 2025
Likely Measured Mineral Resources Indicated Mineral Resources Total Measured and Indicated Mineral
mining
method((1))
as at 31 December 2025 as at 31 December 2025 Resou
rces
as at
31
Decem
ber
2025
Tonnage Grade Tonnage Grade Tonnage Grade
Copper((2)) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US) - Underground Skarns
- Lower Commercial Skarn U/G 0.9 1.49 0.62 9.70 0.027 7.2 1.51 0.62 9.53 0.021 8.1 1.51 0.62 9.55 0.022
- North Rim Skarn U/G - - - - - 25 2.06 0.96 12.89 0.008 25 2.06 0.96 12.89 0.008
Total Underground Skarns 0.9 1.49 0.62 9.70 0.027 32 1.94 0.88 12.14 0.011 33 1.93 0.88 12.08 0.011
Inferred Mineral Resources Total Mineral Resources Rio Tinto Total Mineral Resources
interest
as at 31 December 2025 as at 31 December 2025 as at
31
Decem
ber
2024
Tonnage Grade Tonnage Grade Tonnage Grade
Copper((2)) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo % Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US) - Underground Skarns
- Lower Commercial Skarn 4.5 1.33 0.99 9.15 0.020 13 1.45 0.75 9.41 0.021 100.0 7.5 1.89 0.85 11.26 0.015
- North Rim Skarn 20 2.15 0.82 13.27 0.009 45 2.10 0.90 13.05 0.008 100.0 18 2.92 1.11 15.77 0.007
Total Underground Skarns 24 2.00 0.85 12.51 0.044 58 1.96 0.87 12.26 0.011 26 2.62 1.04 14.47 0.009
1. Likely mining method: U/G = underground.
2. Copper Mineral Resources are stated on a dry in situ weight basis.
Table F Rio Tinto Copper Kennecott Bingham Canyon
underground Ore Reserves as at 31 December 2025
Type Proved Ore Reserves Probable Ore Reserves Total Ore Reserves
of
mine((1)) as at 31 December 2025 as at 31 December 2025 as at 31 December 2025
Tonnage Grade Tonnage Grade Tonnage Grade
Copper((2)) Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US) - Underground Skarns
- Lower Commercial Skarn U/G 0.8 1.68 0.59 9.83 0.042 1.2 1.46 0.47 7.23 0.040 2.0 1.54 0.52 8.25 0.040
- North Rim Skarn U/G - - - - - 6.6 2.25 1.29 15.59 0.007 6.6 2.25 1.29 15.59 0.007
Total Underground Skarns 0.8 1.68 0.59 9.83 0.042 7.8 2.13 1.16 14.28 0.012 8.6 2.08 1.11 13.86 0.014
Average mill recovery % Rio Tinto Rio Tinto share Total Ore Reserves
interest
recoverable metal as at 31 December 2024
Tonnage Grade
Copper((2)) Cu Au Ag Mo % Mt Cu Moz Au Moz Ag Mt Mo Mt % Cu g/t Au g/t Ag % Mo
Kennecott (US) - Underground Skarns
- Lower Commercial Skarn 90 71 76 71 100.0 0.03 0.02 0.40 0.000 1.7 1.89 0.71 10.01 0.044
- North Rim Skarn 93 69 64 45 100.0 0.14 0.19 2.13 0.001 3.0 2.39 1.77 16.66 0.010
Total Underground Skarns 0.17 0.21 2.54 0.001 4.7 2.21 1.39 14.30 0.022
1. Type of Mine: U/G = underground.
2. Copper Ore Reserves are reported as dry mill feed tonnes.
Table G Rio Tinto Aluminium Pacific Operations Mineral
Resources as at 31 December 2025
Likely Measured Mineral Resources Indicated Mineral Resources Total Measured and Indicated Mineral
mining
method((1))
as at 31 December 2025 as at 31 December 2025 Res
our
ces
as
at
31
Dec
emb
er
202
5
Tonnage Grade Tonnage Grade Tonnage Grade
Bauxite Mt % Al(2)O(3) % SiO(2) Mt % Al(2)O(3) % SiO(2) Mt % Al(2)O(3) % SiO(2)
Rio Tinto Aluminium (Australia)
- Amrun((2)) O/P 143 48.9 11.7 276 49.6 12.0 419 49.4 11.9
- East Weipa and Andoom((2)) O/P 32 48.0 9.0 - - - 32 48.0 9.0
- Gove((3)) O/P 9 47.6 8.8 0.1 49.0 7.6 9 47.6 8.8
- North of Weipa((3)) O/P - - - 212 51.9 11.3 212 51.9 11.3
Total (Australia) 183 48.7 11.1 488 50.6 11.7 671 50.1 11.5
Inferred Mineral Resources Total Mineral Resources Rio Tinto Total Mineral Resources
interest
as at 31 December 2025 as at 31 December 2025 as
at
31
Dec
emb
er
202
4
Tonnage Grade Tonnage Grade Tonnage Grade
Bauxite Mt % Al(2)O(3) % SiO(2) Mt % Al(2)O(3) % SiO(2) % Mt % Al(2)O(3) % SiO(2)
Rio Tinto Aluminium (Australia)
- Amrun((2)) 234 51.4 12.4 653 50.1 12.1 100.0 747 50.1 12.0
- East Weipa and Andoom((2)) - - - 32 48.0 9.0 100.0 36 48.0 8.9
- Gove((3)) - - - 9 47.6 8.8 100.0 10 47.7 9.0
- North of Weipa((3)) 1,179 51.8 11.3 1,391 51.9 11.4 100.0 1,451 51.9 11.4
Total (Australia) 1,412 51.7 11.5 2,083 51.2 11.5 2,244 51.3 11.6
1. Likely mining method: O/P = open pit/surface.
2. Bauxite Mineral Resources for Amrun and East Weipa and Andoom are
stated as dry product tonnes and total alumina and silica grades.
3. Bauxite Mineral Resources for Gove and North of Weipa are stated as dry
crude tonnes and total alumina and silica grades.
Table H Rio Tinto Aluminium Pacific Operations Ore Reserves
as at 31 December 2025
Type Proved Ore Reserves Probable Ore Reserves Total Ore Reserves
of
mine((1))
as at 31 December 2025 as at 31 December 2025 as
at
31
Dec
emb
er
202
5
Tonnage Grade Tonnage Grade Tonnage Grade
Bauxite((2)) Mt % Al(2)O(3) % SiO(2) Mt % Al(2)O(3) % SiO(2) Mt % Al(2)O(3) % SiO(2)
Rio Tinto Aluminium (Australia)((3))
- Amrun O/P 724 54.1 9.0 351 54.5 9.4 1,076 54.2 9.1
- East Weipa and Andoom O/P 44 50.3 8.4 1 49.5 9.9 45 50.3 8.4
- Gove O/P 35 50.1 6.7 5 49.9 6.9 40 50.1 6.7
Total (Australia) 803 53.7 8.8 357 54.4 9.4 1,161 53.9 9.0
Rio Tinto interest Rio Tinto share recoverable mineral Total Ore Reserves as at 31 December 2024
Tonnage Grade
Bauxite((2)) % Mt Mt % Al(2)O(3) % SiO(2)
Rio Tinto Aluminium (Australia)((3))
- Amrun 100.0 1,076 978 54.4 9.0
- East Weipa and Andoom 100.0 45 56 50.5 8.1
- Gove 100.0 40 48 50.0 6.4
Total (Australia) 100.0 1,161 1,083 54.0 8.8
1. Type of Mine: O/P = open pit/surface.
2. Bauxite Ore Reserves are stated as recoverable Ore Reserves of
marketable product after accounting for all mining and processing losses. Mill
recoveries are therefore not shown.
3. Australian bauxite Ore Reserves are stated as dry tonnes and total
alumina and silica grade.
Table I Rio Tinto Borates Boron Mineral Resources as at 31
December 2025
Likely Measured Mineral Resources Indicated Mineral Resources Total Measured and Indicated Mineral
mining
method(1)
as at 31 December 2025 as at 31 December 2025 Resources as at 31 December 2025
Tonnage Tonnage Tonnage
Borates Mt Mt Mt
Boron (US)(2) O/P 2.4 1.1 3.5
Inferred Mineral Resources Total Mineral Resources Rio Tinto Total Mineral Resources
interest
as at 31 December 2025 as at 31 December 2025 as at 31 December 2024
Tonnage Tonnage Tonnage
Borates Mt Mt % Mt
Boron (US)(2) 5.8 9.3 100.0 -
1. Likely mining method: O/P = open pit/surface.
2. Boron Mineral Resources are reported as dry mineable B(2)O(3)
tonnes incorporating a mining recovery, rather than marketable product as in
Ore Reserves.
Table J Rio Tinto Borates Boron Operations Ore Reserves as
at 31 December 2025
Type Proved Ore Reserves Probable Ore Reserves Total Ore Reserves
of
mine(1)
as at 31 December 2025 as at 31 December 2025 as at 31 December 2025
Tonnage Tonnage Tonnage
Borates Mt Mt Mt
Boron (US)(2) O/P 5.0 7.0 12.0
Rio Tinto interest Rio Tinto share marketable product Total Ore Reserves as at 31 December 2024
Tonnage
Borates % Mt Mt
Boron (US)(2) 100.0 12.0 12.6
1. Type of Mine: O/P = open pit/surface.
2. Ore Reserves of borates are expressed in terms of marketable
product (B(2)O(3)) tonnes after all mining and processing losses. Mill
recoveries are therefore not shown.
Contacts
Please direct all enquiries to media.enquiries@riotinto.com
Media Relations, Media Relations, Media Relations,
United Kingdom Australia Canada
Matthew Klar Matt Chambers Simon Letendre
M +44 7796 630 637 M +61 433 525 739 M +1 514 796 4973
David Outhwaite Alyesha Anderson Malika Cherry
M +61 434 868 118
M +44 7787 597 493
M +1 418 592 7293
Rachel Pupazzoni
Vanessa Damha
M +61 438 875 469
M +1 514 715 2152
Bruce Tobin
M +61 419 103 454
Media Relations,
US & Latin America
Jesse Riseborough
M +1 202 394 9480
Investor Relations, Investor Relations,
United Kingdom Australia
Rachel Arellano Tom Gallop
M +44 7584 609 644
M +61 439 353 948
David Ovington
Eddie Gan-Och
M +44 7920 010 978
M +61 477 599 714
Laura Brooks
M +44 7826 942 797
Weiwei Hu
M +44 7825 907 230
Rio Tinto plc Rio Tinto Limited
6 St James's Square Level 43, 120 Collins Street
London SW1Y 4AD Melbourne 3000
United Kingdom Australia
T +44 20 7781 2000 T +61 3 9283 3333
Registered in England Registered in Australia
No. 719885 ABN 96 004 458 404
This announcement is authorised for release to the market by Andy Hodges, Rio
Tinto's Group Company Secretary.
riotinto.com
(#_ftnref1)
(#_ftnref2)
(#_ftnref3)
(#_ftnref4)
(#_ftnref5)
(#_ftnref6)
This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact
rns@lseg.com (mailto:rns@lseg.com)
or visit
www.rns.com (http://www.rns.com/)
.
RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our
Privacy Policy (https://www.lseg.com/privacy-and-cookie-policy)
. END UPDUWSRRNOUUAUR
Copyright 2019 Regulatory News Service, all rights reservedRecent news on Rio Tinto
See all newsREG - Rio Tinto - Total Voting Rights
AnnouncementREG - Rio Tinto - Director/PDMR Shareholding
AnnouncementREG - Rio Tinto - Director/PDMR Shareholding
AnnouncementREG - Rio Tinto - Director/PDMR Shareholding
AnnouncementREG - Rio Tinto - Final Results
Announcement