Tumas Project

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Mine TypeOpen Pit
  • Uranium
  • Vanadium
Mining Method
  • Truck & Shovel / Loader
Mine Life... Lock
SnapshotThe Tumas Project includes the Tumas 1, Tumas 2, Tumas 3, Tumas 1 East and Tubas Red Sand/Calcrete orebodies.

Shortly following the release of the Tumas DFS Re-Costing Study, the Namibian Ministry of Mines and Energy issued the mining licence for the Tumas Project. The licence is valid for 20 years from date of issue (September 2023) and allows Deep Yellow to progress the Project towards production, establishing Tumas as the 4th uranium mine in Namibia.

The environmental approvals for the Project, water pipeline and powerline were granted in late September/early October 2023, with the Environmental Clearance Certificates (ECC) for Tumas and the water pipeline received on 28 September 2023. The approval of the power line was received on 29 September 2023 and the ECC was issued 6 October 2023.


Reptile Uranium Namibia (Pty) Ltd. (operator) 100 % Direct
Deep Yellow Ltd. 100 % Indirect
Deep Yellow Ltd., an Australian uranium exploration and development company, owns the Tumas Project through its indirect Namibian subsidiary Reptile Uranium Namibia (Pty) Ltd.



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Deposit type

  • Calcrete hosted


The Tumas Project is comprised of a series of palaeochannel/calcrete-type uranium deposits: the Tumas 1, Tumas 2, Tumas 3, Tumas 1 East and Tubas Red Sand/Calcrete.

Surficial uranium deposits occur on the coastal plain of the Namib Desert, mainly between the Great Escarpment in the east and the coast in the west.

Uranium mineralisation occurs as carnotite (secondary uranium-vanadium mineral), hosted by Tertiary and Quaternary fluvial sediments occupying narrow and steepsided palaeochannels. Host rocks vary from hard, carbonatecemented sandstones and conglomerates (calcrete) to poorly consolidated and friable sands.

All uranium mineralisation within the Tumas deposits is secondary in nature (carnotite) and is hosted by calcretised channel fill sediments of late Tertiary to Quaternary age.

The palaeochannel sediments are mainly composed of poorly sorted polymictic gravels and conglomerates which locally turn to be clayey and/or silty with minor sands and silts. Fine-grained calcite-cemented sandstone occurs locally at the bottom and bottom edges of the palaeochannel. The detrital components consist mainly of sub-angular quartz and feldspar granules with abundant debris of surrounding basement rocks, e.g., mica schists, meta-quartzites, and granites. Calcrete bodies are interbedded with porous gravel units throughout the sedimentary column.

Two main types of calcretes are observed. One is pale to dark brown and hard, the other is white-whitish and commonly chalky. Other minor types are darker, like a dark reddish brown to pale red, very hard, fine-grained calcrete.

The mineralisation considered in this study is divided from East to West into the Tumas 1 East, Tumas 1, Tumas 2 and Tumas 3 orebodies.

The Tumas 1 East deposit is located in the most easterly part of the Tumas palaeochannel. It varies in width from a narrow 100 m to 400 m and increases in depth from east to west from 10 m to 20 m. It includes tributary channels to the north and south of the main channel. Mineralisation is occurring from surface to the channel base.

The Tumas palaeochannel Zone 1 is relatively shallow and narrow, up to a maximum of 15 m to 20 m depth and up to 200 m wide. The zone sits directly west of the Tumas 1 East zone. It continues westwards, cuts through the north-east striking Tinkas Formation and bends to the north into the Tumas 2 zone. Two mineralised fining up sequences are observed whereby higher-grade mineralisation occurs at the transition zone between the lower cross-stratified coarser and locally calcretised deposits and an overlying planar horizontal laminated silty sandy grit.

Further downstream, at the southern end of Tumas 2, the Tumas palaeochannel turns to a north-northwesterly direction and its depth gradually increases to slightly over 40 m towards the northern end of Tumas 2. The north-northwesterly trending Tumas 2 palaeochannel is 200 to 500 m wide. The +100 ppm eU3O8 mineralisation is generally patchier than at Tumas 1 and 3.

At Tumas 2, the 15 m thick upper sequence is moderate reddish to light brown in colour and consists of crudely stratified, less calcareous and more oxidised deposits. The base of the sequence comprises calcite-cemented and matrix-supported sandy conglomerates and grits with abundant angular to subangular clasts of the surrounding bedrock (i.e., mica-schist, quartzite) and lenses of silty to sandy grit. The top of the sequence consists predominantly of planar horizontal laminated silty to clayey sand which locally can be gritty. Higher grade uranium mineralisation occurs at the contact zone of the upper and lower sequence.

At Tumas 3 the palaeochannel turns into a west-north-westerly direction. Here sediments include 40 to 60 m of palaeochannel fill deposited over the so-called Namib Unconformity Surface. This palaeosurface is characterised by partially steep incised palaeochannels, deeply carved into the folded and metamorphosed Damara sequence. The palaeochannel can reach up to 1.5 km wide. Mineralised tributaries enter the main palaeochannel from the east and south.

The Tumas 3 orebody is characterised by at least two sedimentary cycles overlying each other. The fining-upward sequences are composed of coarse conglomerates at the bottom, especially at the bedrock contacts followed by gravels and sand and clays with calcrete layers developed towards their tops.

Four mineralisation types have been defined within the Tumas-Tubas palaeochannel based on the type of host rock: calcrete, gypcrete, red sand and basement. Of these, the calcrete-type mineralisation contains most of the uranium. The calcrete ranges from sand to granule size, with about 30 % consisting of pebbles with a maximum dimension of 6.4 cm. The only uranium-bearing mineral of economic importance is carnotite (K2(UO2)2V2O8•3(H2O)), which contains vanadium with a U/V ratio of 4.5. Detailed mineralogical and geochemical analysis shows that vanadium is also contained in iron oxide and titanium minerals. The calcrete-type mineralisation contains on average 3-4 wt% clay with the clays species being illite and palygorskite (magnesium-bearing). Investigations of leach samples show that a small portion of uranium behaves refractorily as it occurs as submicron-sized carnotite inclusions in calcite.

Gypcrete is defined as palaeochannel sediment with greater than 0.35 wt% total in sulphur (equivalent to 1.58 wt% bassanite, a calcium sulphate mineral). Gypcrete forms a thin, discontinuous layer, a few metres below the surface and generally defines the upper limit of uranium mineralisation. It is only mineralised with uranium in a few locations and is likely to make up only a very small portion of the total resource.



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Mining Methods


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Crushers and Mills


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CommodityProductUnitsAvg. AnnualLOM
Vanadium Vanadyl sulfate M lbs 1.2

Operational metrics

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* According to 2023 study.

Production Costs

Credits (by-product) U3O8 USD  ....  Subscribe
All-in sustaining costs (AISC) U3O8 USD  ....  Subscribe
C1 cash costs U3O8 USD  ....  Subscribe
C2 total cash costs U3O8 USD  ....  Subscribe
C3 fully allocated costs U3O8 USD  ....  Subscribe
Assumed price U3O8 USD  ....  Subscribe
Assumed price Vanadium USD  ....  Subscribe
* According to 2023 study / presentation.
** Net of By-Product.

Operating Costs

Total operating costs ($/t milled) USD 15.2  

Project Costs

MetricsUnitsLOM Total
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After-tax NPV @ 8% $M USD  ......  Subscribe
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Heavy Mobile Equipment


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Mine Management

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