The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes l^Og 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 at Ranger involved a conventional open cut process, which begins with drilling and blasting. Pit 1 was mined out in 1994 and mining in Pit 3 ceased in November 2012. Prior to the completion of mining in the pits, mined material was categorised by a discriminator, which measured the gamma emissions of each load to calculate uranium grade for either stockpiling or immediate processing according to the grade of the ore (percent uranium oxide). Low-grade ore will be returned as backfill to the mined-out pits and covered by unmineralised rock to create the final landform.

The major ore processing stages are described below:
• Uranium ore is crushed and ground, then the fine ore is then mixed with water to
produce a slurry.
• The ore slurry is pumped to leaching vessels where, over a period of 24 hours, more
than 90 percent of the uranium in the ore is dissolved using sulfuric acid and pyrulosite
(an oxidant).
• The uranium in solution is then separated from the depleted ore in a seven stage
washing circuit.
• After separation, the acidity of the depleted ore (tailings) is partially neutralised with
lime before being pumped to the tailings dam, while the leach solution is clarified and
filtered.
• The uranium is extracted from the leach solution and concentrated, then pumped to
precipitation tanks.
• A bright yellow uranium compound (ammonium diuranate), commonly referred to as
'yellowcake' is precipitated using ammonia.
• In the final stage of the process, the yellowcake is heate ........