Final permits in place for Phoenix ISL field test

10 August 2022

Denison Mines Corp is now fully permitted to recover a uranium-bearing solution from the Phoenix ore body at the Wheeler River project in northern Saskatchewan. The feasibility field test (FFT) will be a first-of-its-kind test and will help de-risk the planned in-situ leach (ISL) uranium mining operation.

The surface liner in place at the FFT's containment pad, currently under construction (Image: Denison)

The final permit needed for the FFT, a Nuclear Substance Licence from the Canadian Nuclear Safety Commission, has now been received. This allows Denison to possess the uranium collected from the operation of the FFT, store it on site, and to handle and transfer recovered material for laboratory analyses.

With the receipt of the final permit, Denison's focus is now on the "timely completion of the construction and operation of the FFT", the company's Denison President and CEO David Cates said. 

ISL - also known as solution mining, or in situ recovery (ISR) - recovers minerals from ore in the ground by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. The method causes little surface disturbance and generates no tailings or waste rock, but the orebody needs to be permeable to the liquids used, and located so that they do not contaminate groundwater away from the orebody. More than half of the world's uranium production is now produced by solution methods, but the technique has not so far been used in Canada.

The FFT will use an existing commercial-scale ISL test pattern at Phoenix for combined assessment of the deposit's hydraulic flow properties with the leaching characteristics that have been assessed through the metallurgical core-leach testing program.

Since receiving Saskatchewan Minister of Environment approval in July, work has begun on earthworks and associated preparation of the site for the FFT facilities. Construction of the recovered solution management modules is under way. Operation of the FFT is planned to occur in three phases: leaching; neutralisation; and recovered solution management. The leaching and neutralisation phases are expected to take place over an estimated 60-day operating time frame.

The company recently said it had substantially completed metallurgical test work to define the mechanical components for the Phoenix processing plant, with tests on core samples representative of the planned ISL wellfield demonstrating the ability to produce a saleable uranium product.

Wheeler River, a joint venture between Denison (90% and operator) and JCU (Canada) Exploration Company Limited (10%), is host to the high-grade Phoenix and Gryphon uranium deposits. While ISL operations are envisaged for Phoenix, the Gryphon deposit is envisaged as an underground mining operation, with processing carried out at the existing McClean Lake mill which is 22.5%-owned by Denison.

Researched and written by World Nuclear News