Denison Planning to Develop 2 Mines at Wheeler River

Denison Mines has reported the results of the prefeasibility (PFS) of its flagship Wheeler River uranium project at the eastern end of the Athabaska Basin in northern Saskatchewan. The PFS supports development of two mines on the property, an in-situ recovery (ISR) mine on the Phoenix deposit and an underground mine utilizing conventional longhole stoping on the Gryphon deposit.

ISR product from the Phoenix deposit would be processed to a finished product on site. Gryphon mine ore is assumed to be processed at Denison’s 22.5% owned McClean Lake mill. Taken together, the two mines would produce an estimated 109.4 million lb of U3O8 over a 14-year mine life, with initial pre-production capital expenditures estimated at C$322.5 million.

The Wheeler River project is a joint venture between Denison (63.3% owner and operator), Cameco (26.7%), and JCU (Canada) Exploration Co. (10%). Denison is increasing its ownership in the project to up to 90% under two recently announced agreements with Cameco. The Wheeler River PFS was prepared on a 100% project basis, as each of the partners in the joint venture are subject to different tax and other obligations.

“The selection of ISR mining for the high-grade Phoenix deposit is a defining moment for our company and a potentially transformational development for the future of uranium mining in the Athabasca Basin, bringing the world’s lowest-cost uranium mining method to the jurisdiction hosting the world’s highest-grade uranium deposits,” Denison President and CEO David Cates said.

“Based on an estimated production cost of US$3.33/lb U3O8 and relatively modest initial capital costs, the Phoenix operation is expected to have superior leverage to an anticipated recovery of the spot price of uranium owing to the fact that the operation may not require a book of long-term contracts to support a development decision,” he added. “The Gryphon deposit is a perfect complement to Phoenix, as it is expected to supply additional low-cost pounds, financed through cash flow from Phoenix, at a time when the uranium market is expected to be in a significant supply deficit.”

The Wheeler River project is the largest undeveloped uranium project in the eastern portion of the Athabasca Basin. The project is situated in close proximity to important regional infrastructure, including the Provincial electrical transmission grid and an all-season Provincial highway.

The suitability of ISR mining for the Phoenix deposit has been confirmed by significant field and laboratory work, including drill hole injection, permeability, metallurgical leach, agitation, and column tests. Results demonstrate high rates of recovery in both extraction (+90%) and processing (98.5%) following a simplified flowsheet that precipitates uranium directly from the uranium- bearing solution, without the added costs associated with ion exchange or solvent extraction circuits.

The Gryphon deposit is located approximately 3 km northwest of the Phoenix deposit and occurs 520 m to 850 m below surface, dominantly within competent basement rocks. The deposit has an overall strike length of 610 m, dip length of 390 m, and variable thickness from 2 to 70 m, depending on the number of mineralized lenses present.

As featured in Womp 2018 Vol 11 -