Source:
January 4, 2022 - enCore Energy Corp. and Azarga Uranium Corp. are pleased to announce the closing of the previously announced plan of arrangement whereby enCore has acquired all of the outstanding shares of Azarga Uranium.
Summary:
Uranium deposits in the Dewey-Burdock Project are sandstone, roll front type. This type of deposit is usually “C” shaped in cross-section, with the down gradient center of the “C” having the greatest thickness and highest tenor. The “tails” of the “C” are usually much thinner and essentially trail the “roll front” being within the top and bottom of the sandstone unit that is slightly less permeable.
These “roll fronts” are typically a few tens of feet wide and often can be thousands of feet long. Uranium minerals are deposited at the interface of oxidizing solutions and reducing solutions. As the uranium minerals precipitate, they coat sand grains and partially fill the interstices between grains. As long as oxidizing groundwater movement is constant, minerals will be solubilized at the interior portion of the “C” shape and precipitated in the exterior portion of the “C” shape, increasing the tenor of the orebody by multiple migration and accretion. Thickness of the orebody is generally a factor of the thickness of the sandstone host unit. Mineralization may be 5 to 12 ft thick within the roll front while being 1 to 2 ft thick in the trailing tail portions. Deposit configuration determines the location of well field drillholes and is a major economic factor in ISR mining.
Ore mineralogy consists of uraninite, pitchblende and coffinite with associated vanadium in some deposits. Typical alteration in the roll-front sandstone deposit includes oxidation of iron minerals up- dip from the front and reduction of iron minerals down-dip along advancing redox interface boundaries.
Historical drillhole data (electric and lithology logs), along with Azarga’s confirmatory drilling results confirm that the mineralization at Dewey-Burdock is a roll front type uranium deposit. This is determined by the position of the uranium mineralization within sandstone units in the subsurface, the configuration of the mineralization and the spatial relationship between the mineralization and the oxidation/reduction boundary within the host sandstone units.
Summary:
Azarga plans to recover uranium at the Project Area using the In-Situ Recovery (ISR) method. The ISR method has been successfully used for over five decades elsewhere in the United States as well as in other countries such as Kazakhstan and Australia. ISR mining was developed independently in the 1970s in the former USSR and the United States for extracting uranium from sandstone type uranium deposits that were not suitable for open cut or underground mining. Many sandstone deposits are amenable to uranium extraction by ISR mining, which is now a well-established mining method that accounted for approximately 50 percent of the world’s uranium production in 2019 (ref., WNA 2019). The bottle roll tests demonstrate the potential feasibility of both mobilizing and recovering uranium with an oxygenated carbonate lixiviant.
Mining dilution (rock that is removed along with the ore during the mining process) is not a factor with the ISR method as only minerals that can be mobilized with the lixiviant are recovered. There are some metals, such as vanadium, that can be mobilized with the lixiviant and can potentially dilute the final product if not separated before packaging. If vanadium occurs in high enough concentration, it can be economically separated and sold as a separate product.
Many impactstypically associated with conventional uranium mining and milling processes can be avoided by employing uranium ISR mining techniques. The ISR benefits are substantial in that no tailings are generated,surface disturbance is minimal in the well fields, and restoration, reseeding, and reclamation can begin during operations. As a particular mining area is depleted, groundwater restoration will begin immediately after, significantly reducing both the time period of post-production restoration, and the cumulative area not restored at any point in time. At the end of the project life, affected lands and groundwater will be restored as dictated by permit and regulatory requirements.
Well fields are the groups of wells, installed and completed in the mineralized zones that are sized to effectively target delineated resources and reach the desired production goals. One or more header houses controls the operation of each well field. The mineralized zones are located within the geologic sandstone units where the leaching solutions are injected and recovered via injection and recovery wells in an ISR well field.
The Project Area is divided into two Resource Areas – Dewey and Burdock. Each of these Resource Areas is further subdivided into well fields. Each well field is serviced by several header houses depending on its size. Across the entire Project Area, Azarga estimates the average flow of individual production wells will be approximately 20 gpm, with each header house planned to produce approximately 500 gpm.
The Burdock resource area is estimated to include 19 well fields on approximately 4.2 million square feet (93 acres). There will be the equivalent of approximately 560 conventional five-spot square patterns, 120 ft x 120 ft in dimension. Actual pattern geometry may easily vary depending upon actual field conditions. Azarga expects to delineate on average, a 120 ft x 120 ft grid.
The Dewey resource area is estimated to consist of 32 well fields extending over approximately 3.2 million square feet (73 acres). Pending future changes that will reflect a clearer understanding of site specificssuch as permeability variations and well performance, there will be the equivalent of approximately 890 conventional five-spotsquare patterns, 120 ft x 120 ft in dimension. Actual pattern geometry may easily vary depending upon actual field conditions. Azarga expects to delineate on average, a 120ft x 120 ft grid.
Perimeter monitor wells will be located approximately 400 ft beyond the well field perimeter with a maximum spacing of 400 ft between wells. In addition, internal monitor wells will be located within the wellfield, at a rate of approximately one per four acres to monitor overlying or underlying hydro-stratigraphic units where required by permit.
Each injection well and production well will be connected to the respective injection or production manifold in a header house. The manifolds will route the leaching solutions to pipelines, which carry the solutions to and from the ion exchange columns located in the CPP or Satellite facility. Flow meters, control valves, and pressure gauges in the individual well lines will monitor and control the individual well flow rates. Well field piping will typically be high-density polyethylene pipe, as is appropriate to properly and safely convey the mining solutions.
In order to effectively recover the uranium, and also to complete the groundwater restoration, the wells will be completed so they can be used as either injection or recovery wells, allowing flow direction to be reversed at any time during the production or restoration phases of the Project. A slightly greater volume of water (approximately 1%) will be recovered from the mineralized resource zone hydro-stratigraphic unit than the volume injected (bleed) in order to create an inward flow gradient towards the recovery wells to minimize the potential for excursions of lixiviant from the wellfields.
Processing
- Elution
- In-Situ Recovery (ISR)
- Ion Exchange (IX)
Flow Sheet:
Summary:
The Burdock CPP Facility will be constructed to initially accept a flow rate of up to 1,000 gallons per minute (gpm) lixiviant. Capacity will be gradually expanded to accept a flow rate of 4,000 gpm of lixiviant. Resin will be transferred from IX vessels to resin trailers to be transported and processed at an off-site processing facility for the first few years. Once the flow rate capacity reaches 4,000 gpm, the Burdock CPP Facility will be expanded to include processing capabilities for up to 1.0-mlbs-pa of U3O8. Once the Burdock Resource Area has been economically depleted, the IX vessels will be removed from the CPP Facility and transported to Dewey, where a satellite facility will be constructed to mine the Dewey Resource Area. The proposed phases are as follows:
- Phase I – Construction of two header houses and the Burdock CPP Facility with one IX train (estimated 1,000 gpm average flow rate, 1,100 gpm maximum flow capacity) and capability to transfer resin to a transpo ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
U3O8
|
Recovery Rate, %
| 80 |
U3O8
|
Head Grade, ppm
| 60 |
Projected Production:
Commodity | Units | LOM |
U3O8
|
lbs
| 14,268,000 |
All production numbers are expressed as yellow cake.
Operational Metrics:
Metrics | |
Annual production capacity
| 1 M lbs of U3O8 * |
* According to 2019 study.
Reserves at December 3, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Measured
|
5,419,779 tons
|
U3O8
|
0.132 %
|
14,285,988 lbs
|
Indicated
|
1,968,443 tons
|
U3O8
|
0.072 %
|
2,836,159 lbs
|
Measured & Indicated
|
7,388,222 tons
|
U3O8
|
0.116 %
|
17,122,147 lbs
|
Inferred
|
645,546 tons
|
U3O8
|
0.055 %
|
712,624 lbs
|
Corporate Filings & Presentations:
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News:
News | Date |
Encore Energy Receives Uranium Production License for Dewey Burdock, South Dakota
|
February 14, 2022
|
Encore Energy Announces Completion of Azarga Uranium Acquisition: Creation of Top Tier United States ISR Uranium Company
|
January 4, 2022
|
enCore Energy and Azarga Uranium Receive Final Court Order Approving Plan of Arrangement and Commence Closing Process
|
December 23, 2021
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enCore Energy Secures Second Uranium Purchase Agreement; enCore Energy and Azarga Uranium Provide Plan of Arrangement Update
|
December 13, 2021
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Azarga Uranium Shareholders Approve Plan of Arrangement with enCore Energy
|
November 16, 2021
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enCore Energy and Azarga Uranium Provide Update on Proposed Transaction and Shareholder Vote
|
October 21, 2021
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Encore Energy And Azarga Uranium to Combine to Create Leading American Uranium ISR Company
|
September 7, 2021
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Azarga Receives Final EPA Permits for Flagship Dewey Burdock Project; Another Substantial Milestone Achieved
|
November 25, 2020
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Azarga Uranium Files Robust PEA for Dewey Burdock Project
|
January 20, 2020
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Azarga Reports Robust PEA Results for Dewey Burdock Project
|
December 4, 2019
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Azarga Uranium's NRC License Upheld for Dewey Burdock Project
|
February 5, 2019
|
Azarga Uranium Provides Update on Permitting Process
|
July 24, 2018
|
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