Wheeler River
Wheeler River
The Wheeler River Project (“the Project”) is the largest undeveloped uranium project in the eastern Athabasca Basin. The Project is a joint venture between Denison Mines Corp. (“Denison”) (90%) and Japan (Canada) Exploration Ltd. (“JCU”) (10%). JCU is 50% owned by UEC indirectly through its ownership of UEX Corporation. The Project operator is Denison Mines.
Denison intends to mine the Phoenix Deposit using In-Situ Recovery (ISR) technology. This mining method is newly applied to the Athabasca Basin but has been used since the 1960’s to access uranium in porous and unconsolidated sediments, including UEC’s projects in Wyoming and Texas and projects in Asia and Australia. It will allow The Wheeler River JV to produce yellowcake without the expense of accessing a conventional mill and reduces up front and sustaining capital necessary for a mining operation. Denison has recently made significant progress on de-risking activities while working on the feasibility study for the project. In addition, the project’s EIS submission has entered the federal technical review stage. (1)
The Gryphon Deposit is hosted in the basement rocks below the unconformity and consequently is amenable to conventional mining methods. As described in Denison’s current PFS technical study, production at Gryphon is scheduled to begin after Phoenix. Peak production from the Gryphon Deposit after ramp-up is projected at 9 million lb U3O8 / year with production scheduled over 9 years. (2)
1 Denison Mines news release dated November 29, 2022, a copy of which is available on Denison's website and under its profile on SEDAR at www.sedar.com and on EDGAR at www.sec.gov/edgar.shtml.
2 Technical report titled "Prefeasibility Study for the Wheeler River Uranium Project, Saskatchewan, Canada" with an effective date of September 24, 2018, copies of which are available on Denison's website and under its profile on SEDAR at www.sedar.com and on EDGAR at www.sec.gov/edgar.shtml.
The Wheeler River property is located near the southeastern margin of the Athabasca Basin. Local geology is comprised of late Paleoproterozoic Athabasca Group sandstones and conglomerates that have a thickness from 170 to 560 m and overlie the crystalline basement rocks. Basement rocks in the project area are part of the Wollaston Domain and are comprised of metasedimentary and granitoid gneisses. The metasedimentary rocks include graphitic and non-graphitic pelitic and semipelitic gneiss, meta‐quartzite, and rare calc‐silicate rocks. Pegmatitic segregations and intrusions are common in all units.
The Phoenix uranium deposit was discovered in 2008 and is hosted at the unconformity. The deposit is approximately 400 m below surface and has three zones (A, B, and C) that cover a strike length of 1.1 km. The deposit has a high‐grade core surrounded by a lower grade shell. The deposit is interpreted to be structurally controlled by the WS shear, a prominent fault which occurs in the lower part of the graphitic‐pelite. The high-grade uranium mineralization within the Phoenix deposit is massive to semi‐massive uraninite associated within an envelope of hematite, dravite, illite, and chlorite alteration.
The Gryphon uranium deposit was discovered in 2014 and is hosted in the basement rocks below the unconformity from 520 to 850 m below surface. The deposit dips to the southeast, has a strike length of 610 m, is 390 m along its plunge axis, and is between 2 and 70 m thick. There are multiple mineralized lenses that are controlled by faults, these faults generally conform to the basement stratigraphy. Mineralization within the Gryphon deposit is generally massive, semi‐massive, or fracture‐hosted uraninite that is associated with an alteration assemblage comprising hematite, dravite, illite, chlorite, and kaolinite.