The tenements are 100% owned by Langer Heinrich Uranium (Pty) Ltd which, in turn, is 75% indirectly owned by Paladin Energy Ltd. The remaining 25% is owned by CNNC Overseas Uranium Holdings Ltd. (CNNC).
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Summary:
Langer Heinrich is a calcrete-related uranium deposit associated with valley-fill sediments occurring within an extensive Tertiary palaeodrainage system. The calcretes are limestone deposits formed as chemical precipitates developed under arid to semi-arid climate conditions. At Langer Heinrich, calcretisation has affected a complex sequence of fluvially-derived conglomerates, grits, sandstone, silts and clay deposits worked in a braided stream depositional environment.
Beneath the sediments is a rugged basement topography, which occasionally rises high enough to form outliers exposed above the valley sediments. As the basement rocks alternate between erosionally resistant and softer lithologies, the valley width changes from 1 km to 2 km wide, to narrow gorges only a few hundred metres wide.
The fluvial sedimentary sequence comprising the Langer Heinrich Formation is up to 100 m thick and comprises clasts of angular to rounded basement debris in alternating bands of conglomerate, grit, sand, clay-grit and clay. The sediments have undergone variable cementation by calcium carbonate (CaCO3) known as calcrete that precipitated from groundwater moving down the valley. This CaCO3 can comprise up to 15% of the total rock mass.
Uranium mineralization has been defined along 15 km of the east-west trending palaeovalley and is nearly continuous along this section of the palaeovalley system. The mineralization is still open to the west where the cover is in excess of 40 m.
Mineralization
Mineralization at Langer Heinrich consists of sub-horizontal carnotite that has been precipitated within clastic valley-fill rock units, which vary from conglomerates through grits and sands to micaceous claystone. In a general way, mineralization becomes finer grained with depth and hence mineralization from beneath the water table is mainly micaceous claystone.
Carnotite is the only uranium mineral reported at Langer Heinrich. It occurs as finelydisseminated specks, as blebs up to 20 mm thick and coatings in open pore spaces, which are irregularly distributed within the matrix of all host lithologies within the valley. The carnotite occurs preferentially in the less-cemented portions of the host sediments.
The mineralization occurs as an undulating 1 m to 30 m thick layer, shaped like a subterranean meandering river. At intervals down the valley, thick “pond-like” pods of higher-grade uranium have formed. These are generally located immediately upstream of a narrowing of the valley. The high-grade pods have probably formed where depositional solutions have ponded in basement depressions.
Grade distribution within a layer, in cross-section, is as a series of broad concentric ellipsoidal shells, with highest grades in a central core and decreasing towards the bottom, top and banks of the channel. Within these mineralized ellipsoidal shells grade distribution in detail is very erratic or nuggetty. However, the overall continuity of the mineralization in plan view is quite strong.
Calcium carbonate is an important constituent and mineralization can be divided into low and high-carbonate categories. Calcium carbonate occurs in concentrations from 5% up to 35% and cements clastic particles together until, at high concentrations, an indurated rock has been formed. The indurated layers are not related to lithology and tend to form sub-horizontal layers of varying thickness. The hard carbonate-cemented layers contain disseminated carnotite, but generally at lower concentrations than in the more-porous, less-cemented sediments.
Below the water table, mineralization appears to be hosted in a relatively unconsolidated micaceous silt-sand-clay. Mineralogical investigation of the mineralization shows uranium present only as carnotite, the potassium uranyl-vanadate mineral [K2(VO4)2(UO2)2.3H2O]. Carnotite is interstitial to the clastic grains, generally as fine-grained flakes, though larger blebs, clumps and open-space coatings are present. Carnotite occurs preferentially in less-cemented sections of mineralization but shows no relationship to any rock type. It does not occur within the matrix of any of the clasts, whether boulder, sand, or silt size.
Commodity Production
The Langer Heinrich Mine re-commenced commercial production on 30 March 2024, and the production numbers provided are for the period from that date to 30 June 2024.
| Commodity | Units | 2025 | 2024 | 2018 | 2017 | 2016 | 2015 |
|
Uranium
|
M lbs
| .... | .... | 2.7 | 4.2 | 4.8 | 5 |
All production numbers are expressed as U3O8.