Name of the Project
Wheeler River uranium project.

Location
The project is located in northern Saskatchewan, Canada.

Project Owner/s
The project is a joint venture (JV) between Denison (90%) and JCU (Canada) Exploration Company (10%).

Project Description
The project is the largest undeveloped uranium project in the eastern portion of the Athabasca basin.

A prefeasibility study (PFS) on the project has evaluated the potential economic merit of co-developing the Phoenix and Gryphon deposits.

The Phoenix high-grade deposit has been designed as an in situ recovery (ISR) mining operation, with associated processing to a finished product occurring at a plant to be built on site at Wheeler River. The Gryphon deposit has been designed as an underground mining operation using a conventional longhole mining approach, with mine production processed at the McClean Lake mill.

The Phoenix ISR and Gryphon underground operations have combined probable mineral reserves of 109.4-million pounds of uranium from 1.39-million tonnes, comprising 59.7-million pounds of uranium from 141 000 t at 19.1% uranium for Phoenix and 49.7-million pounds of uranium from 1.26-million tonnes at 1.8% uranium for Gryphon.

The project has a mine life estimated at about 14 years, with average yearly production estimated at 7.8-million pounds of uranium.

Potential Job Creation
Not stated.

All-in Sustaining Costs/All-in Costs
Not stated.

Net Present Value/Internal Rate of Return
Wheeler River has a pretax net present value (NPV), at an 8% discount rate, of $1.31-billion and an internal rate of return (IRR) of 38.7%, with a payback of about 24 months.

Phoenix has a pretax NPV, at an 8% discount rate, of $930.4-million and an IRR 43.3%.

Gryphon has a pretax NPV, at an 8% discount rate, of $560.6-million and an IRR of return of 23.2%.

Capital Expenditure
Initial capital costs are estimated at $322.5-million.

Planned Start/End Date
Preproduction activities are estimated to begin in 2021, assuming receipt of required regulatory approvals, with first production from the Phoenix deposit expected in 2024.

Initial construction at Gryphon is expected to start by 2026, with first production expected to be achieved in 2030.

Latest Developments
Denison Mines’ confidence in the application of ISR at the Wheeler River project’s Phoenix deposit is growing.

The results of testwork completed in 2019 have “meaningfully” boosted the company’s confidence using ISR mining at Phoenix, CEO David Cates has said.

“Today, the prospect of successfully bringing ISR mining to the Athabasca basin is higher than it has ever been,” he has said in a statement highlighting the company’s achievements in 2019.

During 2019, Denison completed a 23-week “first-of-its-kind” ISR field test programme designed to validate the permeability of the Phoenix orebody, which was identified as the most significant technical risk for the Phoenix ISR operation in the Wheeler River PFS. The field programme was implemented in a staged manner, progressing from the completion of preliminary hydrogeological tests in a series of small diameter test wells to the completion of the two large-diameter, commercial scale wells – the first wells in the history of the Athabasca basin intended for ISR mining.

“The results from this testwork show significant hydraulic connectivity within the test areas of the Phoenix orebody and have confirmed our ability to achieve bulk hydraulic conductivity values, in a commercial scale well, that are consistent with those used in the prefeasibility study,” Cates has noted.

Further, results from a specialised core leach test has also indicated that the uranium concentrations from the solution to be recovered have the potential to significantly exceed the concentrations assumed in the PFS.

The initial data from core leach tests includes elemental uranium concentrations, after test startup, in the range from 13.5 g/ℓ to 39.8 g/ℓ, with an average of 29.8 g/ℓ over 20 days of testing. This compares with previous metallurgical testwork completed to assess the use of the ISR mining method at Phoenix – which supported a uranium concentration of 10 g/ℓ for the ISR processing plant design used in the PFS. 

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Denison Mines, tel +1416 979 1991, fax +1416 979 5893 or email info@denisonmines.com.