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The Rössing Mine is part
of the Rio Tinto Group, which currently holds (68.6%) of the Rössing
equity. Other shareholders include South African Industrial Development
Corporation (10%), the Namibian Government (3.5%) among others.
A mining license has recently been granted to Paladin Resources Ltd to start developing the Langer Heinrich uranium deposit. The Langer Heinrich Mine will be the second uranium mine in Namibia. The deposit is situated approximately 80 km east of the major harbour at Walvis Bay. Langer Heinrich Mine is expected to have a production of 1,180 tonne U3O8 per annum, and a minimum mine life of 11 years. Several
uranium deposits are known in Namibia, which are grouped into three
types: |
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| Rössing-type The Rössing Mine is located close to the town of Arandis, 65 kilometres inland from Swakopmund, in the Namib Desert. Rössing is the world’s largest open-pit uranium mine, which started operations in 1976. The ore body is an enormous low-grade (300 ppm U3O8) alaskite-hosted deposit. Uranium occurs mostly as uraninite (55%) and beta-uranophane (40%) in the form of interstitial grains and crystal inclusions in minerals; betafite makes up for the remaining 5%. There is potential for similar alaskite-hosted uranium deposits in central western Namibia, for example Valencia (25.2 million tonnes of ore at an average grade of 300 ppm U3O8) and Goanikontes (potential resource of several million tonnes of low grade ore). Furthermore, several pegmatite hosted uranium occurrences were recognized in southern Namibia. |
 Rössing Open Pit Mine |
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The
uranium mineralization takes the form of carnotite (K2(UO2)
2 (VO4) 2-1-3H2O), a secondary uranium mineral.
Carnotite occurs in small patches and lenses around grains and pebbles,
or finely disseminated. Several discontinuous, tabular mineralized
bodies of economic interest occur over an area measuring 15 km by
0.5 km. Mineralization occur in a zone above and below the water
table. Thickness of the mineralized zones varies from less than
1 m to 15 m, but may locally exceed 30 m. The total historical resource
for Langer Heinrich is 22 .2 Mt at 0.1% U3O8.
This figure however was improved through the recent exploration
conducted by Paladin Resources (Pty) Ltd. |
 carnotite a yellow secondary uranium mineral |
The
arid coastal belt of western Namibia has numerous calcrete-hosted
uranium deposits, which could be further investigated and developed.
Examples of some known occurrences include: Klein Spitzkoppe uranium
(5 Mt ore grading 287 ppm U3O8), Klein Trekkopje
(49 Mt ore grading 140 ppm U3O8), Mile 72
(330 000 t of ore grading 230 ppm U3O8). |
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Unconformity-type
The base of the Nama Group is a target for unconformity-type uranium in southern Namibia. Other known unconformity-type deposits include Engo Valley in north western Namibia. Unconformity-type uranium deposits are formed where groundwater in permeable sandstone or conglomerate encounters the interface between oxidizing and reducing conditions. Uranium in solution is precipitated at the interface, often forming a crescent-shaped roll-front ore body. The crescent tips often string out and create tabular blanket deposits, which may contain black and yellow uranium oxides. Oxidized zones are often distinctive features of uranium deposits. |
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