Overview
Stage | Permitting |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Heap leach
- Resin adsorption
- Resin in leach (RIL)
- Ion Exchange (IX)
|
Mine Life | 11 years (as of Jan 1, 2017) |
Source:
p. 13, 14
On June 10, 2016, the Company completed the acquisition of African assets held by Rockgate Capital Corp. (“Rockgate”), formerly a wholly owned subsidiary of Denison Mines Corp. (“Denison”), pursuant to the Definitive Share Purchase Agreement announced on March 30, 2016. As a result of the Rockgate acquisition, the Company acquired a 100% interest in Mutanga property in Zambia.
Summary:
The primary mineralization is considered to be of the sandstone hosted fluvial channel type commonly found in the Colorado Plateau.
Sandstone deposits are contained within medium to coarse-grained sandstones deposited in a continental fluvial or marginal marine sedimentary environment. Impermeable shale or mudstone units are interbedded in the sedimentary sequence and often occur immediately above and below the mineralized horizon (Geology of Uranium Deposits n.d.). Uranium is mobile under oxidizing conditions and precipitates under reducing conditions, and thus the presence of a reducing environment is essential for the formation of uranium mineral deposits in sandstones.
The Karoo basins of southern Africa comprise what may be the world’s largest sandstonehosted uranium province. Compared to the well-known uranium-bearing sandstone basins of the western US, the area of the Karoo basins is about 30% greater, but their known uranium content as of 2003 was only about 7% of that in the US basins. Whereas both areas contain broadly similar, little deformed, predominantly non marine strata, mainly of Mesozoic age, the order of magnitude lower apparent uranium content of the Karoo basins indicates that they are relatively underexplored (Yeo, G. 2010).
Mineralization appears to be later than at least some of the normal faults which cut the Escarpment Grit Formation. This is evident from the good correlation of the radiometric logging data between adjacent holes within the Mutanga mineral deposit separated by interpreted faulting (Lusambo, V. 2011).
The source of the uranium is believed to be the surrounding Proterozoic gneisses and plutonic basement rocks. Having been weathered from these rocks, the uranium was dissolved, transported in solution and precipitated under reducing conditions in siltstones and sandstones. Post lithification fluctuations in the groundwater table caused dissolution, mobilization and redeposition of uranium in reducing, often clay-rich zones and along fractures.
Mineralization is not strictly associated with a particular unit in the stratigraphic section. It was observed to occur in both the fine grained and coarser material and mudstones especially where fractures and mud balls occur. Some mineralization occurred in association with manganese oxide or disseminated with pyrite. Mineralization in some bore holes was seen to occur where there was grey alteration, limonite and feldspar alteration and in dark grey mudstones (Sakuwaha 2011). The strata dip in the southeasterly direction and mineralization seems to occur along dip.
Uranium mineralisation on the property occurs in a number of different associations:
-Disseminated Uranium Mineralization,
-Uranium Mineralization Associated With Mudstones & Siltstones,
-Fracture Hosted Uranium Mineralization,
-Uranium Mineralization Associated With Pyrite.
Summary:
The deposits are amenable to conventional, shallow, open-cast mining methods, utilizing excavators and trucks with relatively low stripping ratios. The uranium oxide and waste are in cemented sandstone that will require blasting. Pit optimizations were run for considered deposits to determine pit limits and pushback development. Production schedules have been prepared for all deposits, assuming the same cut-off grade for each and a plant feed rate of 4.0 Mt per annum.
The total pit inventory for mineralized material is 40.8 Mt at 333 ppm U3O8. The overall strip ratio for the project is 3.4, but varies from 1.4 to 6.0, depending on the deposit.
Processing
- Heap leach
- Resin adsorption
- Resin in leach (RIL)
- Ion Exchange (IX)
Flow Sheet:
Summary:
Two process options have been investigated: alkaline leach and acid leach. Acid heap leaching was selected on the basis that it gives slightly better overall recovery for all six deposits, while being more rapid and having lower operating and capital costs.
Three separate uranium oxide preparation and leach areas will be developed adjacent to the deposits. The main facilities for recovery of uranium oxide will be located close to the Mutanga and Dibwe East pits. Separate satellite process facilities will be developed for the Dibwe and the Njame and Gwambe deposits.
At each of the sorption plants, uranium will be stripped from the leach solution and loaded onto a resin. This process is reliable and has been proven at other locations. The barren leach solution will be returned to the barren pond to be used for leach solution make-up. Resin from all sorption plants will be directed to a central stripping plant located at Mutanga-Dibwe East, where uranium oxide will b ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Uranium (U3O8)
|
Recovery Rate, %
| ......  |
Uranium (U3O8)
|
Head Grade, g/t
| 333 |
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Projected Production:
Commodity | Units | Avg. Annual | LOM |
Uranium (U3O8)
|
M lbs
| 2.4 | 26 |
All production numbers are expressed as yellow cake.
Operational Metrics:
Metrics | |
Stripping / waste ratio
| ......  |
Annual mining capacity
| ......  |
Waste tonnes, LOM
| ......  |
Ore tonnes mined, LOM
| ......  |
Total tonnes mined, LOM
| ......  |
Tonnes milled, LOM
| ......  |
* According to 2017 study.
Reserves at November 21, 2017:
Category | Tonnage | Commodity | Grade | Contained Commodity |
Measured
|
5.9 Mt
|
Uranium (U3O8)
|
366 g/t
|
4.8 M lbs
|
Indicated
|
15.7 Mt
|
Uranium (U3O8)
|
299 g/t
|
10.4 M lbs
|
Measured & Indicated
|
21.6 Mt
|
Uranium (U3O8)
|
317.5 g/t
|
15.1 M lbs
|
Inferred
|
21.6 Mt
|
Uranium (U3O8)
|
273 g/t
|
44.9 M lbs
|
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Corporate Filings & Presentations:
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