Denison announces new results for Wheeler River studies

26 June 2023

The company has released the full results of a feasibility study on in-situ leach (ISL) mining of the high-grade Phoenix uranium deposit and a cost update to its pre-feasibility study for conventional underground mining of the Gryphon uranium deposit. The deposits are part of the Wheeler River project in the Athabasca Basin of northern Saskatchewan, Canada.

Further studies have been carried out at Wheeler River (Image: Denison)

Phoenix is planned to be the first ISL uranium mining operation in the Athabasca. The feasibility study, carried out by Wood Canada Limited, WSP USA Environment and Infrastructure Inc, SRK Consulting (Canada) Inc and Newmans Geotechnique Inc "confirms robust economics and the technical viability of an ISR uranium mining operation with low initial capital costs and a high rate of return", the company said. (ISR stands for in-situ recovery, a term often used instead of ISL in North America).

The study reflects several design changes and the results of a "rigorous technical de-risking programme" carried out since the publication of a pre-feasibility study for Phoenix in 2018, the company said. It "reflects independent third-party validation of the selection of the ISR mining method for Phoenix, and builds on the findings from a comprehensive and rigorous multi-year technical de-risking process highlighted by the highly successful completion of the leaching and neutralisation phases of the Phoenix Feasibility Field Test in late 2022".

The company has reported an updated mineral resource estimate of 70.5 million pounds U3O8 (27,118 tU) for Phoenix, with 30.9 million pounds in the measured resources category and 39.7 million pounds of indicated resources.

The update to the pre-feasibility study for the basement-hosted Gryphon deposit focused on a review and update of capital and operating costs, Denison said. Mining and processing plans remain largely unchanged from the earlier study, apart from "minor scheduling and construction sequencing optimisations". The updated study shows the project as being "amongst the lowest-cost uranium mines in the world", providing an additional source of low-cost potential production, it added.

Denison President and CEO David Cates said the studies "confirm the robust economics of the two projects situated within the Company's flagship Wheeler River property, producing base-case after-tax net present values of CAD1.6 billion and CAD0.9 billion (USD1.2 billion and USD0.8 billion), respectively."

Despite the "considerable capital cost pressures experienced by the global mining industry" over the past two years, the economics of an ISL operation at Phoenix remain "exceptionally robust", Cates added, and the company has already shifted its focus to advancing front-end engineering and design efforts, with a target of transitioning into detailed design before the end of the year.

Wheeler River is a joint venture between Denison (90%) and JCU (Canada) Exploration Company Ltd (10%), with Denison as operator. Denison also owns 50% of JCU.

Researched and written by World Nuclear News