Summary

Mine Type	Open Pit
Status	Closing / Closed
Commodities	Uranium
Mining Method	Truck & Shovel / Loader
Production Start	...
Snapshot	Ranger mine operated as a uranium mine for 40 years before closing in 2021. Rio Tinto continues to operate under the Management Services Agreement (MSA) with Energy Resources of Australia Ltd. (ERA) to manage the Ranger Rehabilitation Project with oversight from the ERA board. In 2025, Rio Tinto progressed Pit 3 dry capping, installing geotextile and beginning the initial dry capping layers. Rio Tinto continues to face challenges in drying the tailings surface and are assessing engineering options and solutions to continue the capping works in 2026. Rio Tinto remains committed to the rehabilitation of the Ranger Project Area to a standard that will establish an environment similar to the adjacent Kakadu National Park, a World Heritage site.

Deposit type

• Sedimentary

Summary:

The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes U3O8 in highly chloritized metasediments of the lower Proterozoic Cahill Formation within about 500 m of the projected sub-Kombolgie Formation unconformity. In both orebodies, oxidized and reduced uranium minerals occur chiefly in quartzose schists that have highly variable amounts of muscovite, sericite, and chlorite.

Below the oxidized zone, uranium occurs chiefly as uraninite and pitchblende disseminated through thick sections of quartz-chlorite-muscovite schist and has no apparent association with graphite or sulfides. In fact, graphite is rare and sulfides are generally low in abundance (<0.5 percent). Higher ore grades occur in disrupted zones a few centimeters thick and in some quartz chlorite vein-like zones of uncertain origin. Uranium correlates strongly with chlorite, but not all of the many ages of chlorite have associated uranium. At least five textural varieties of chlorite are present and represent at least 3 ages. Preliminary microprobe analyses suggest that Mg-Fe-Al contents are relatively uniform. Apatite commonly occurs with chlorite. Uranium is not common in carbonate rocks and seems to occur only in disrupted zones that have chlorite alteration.

The structure of the orebodies is outwardly simple, particularly in No. 3; dips are less than 40° on most lithologic contacts. The No. 1 orebody is in a basin-like structure about 400 m wide that probably formed in part by progressive removal of carbonate rocks that are as much as 200 m thick adjacent to the No. 1 orebody and below the No. 3 orebody. Quartz-chlorite breccias have formed in the zone of carbonate thinning; uranium is spotty and low grade in these breccias. Chloritized and uraniferous broken and sheared zones, a few centimeters to a few meters thick, have an unknown attitude but must have small displacement. Blocks of altered Kombolgie sandstone are downfaulted into the No. 3 orebody and locally contain reduced uranium minerals. One or more shear zones 5-30 m thick.

Mining Methods

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Comminution

Crushers and Mills

Processing

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Commodity Production

Commodity	Units	2020	2019	2018	2017	2016	2015
Uranium	t	....	1,751	1,999	2,294	2,351	2,005

Operational metrics

Metrics	2020	2019	2018	2017	2016	2015
Tonnes milled	....	2.5 Mt	2.5 Mt	2.6 Mt	2.7 Mt	2.5 Mt

Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Mar 17, 2025

Total Workforce	Year
......	2020
......	2018
......	2017
......	2016