Denison Announces Independent “Proof of Concept” Achieved for Application of ISR Mining Method at Phoenix and Details of 2020 ISR Field Program

TORONTO, June 4, 2020 /PRNewswire/ – Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML) (NYSE American: DNN) is pleased to announce that the hydrogeologic model developed by Petrotek Corporation (“Petrotek”), for the high-grade Phoenix uranium deposit (“Phoenix), produced demonstration of “proof of concept” for the application of the In-Situ Recovery (“ISR”) mining method at Phoenix, with respect to potential operational extraction and injection rates. The hydrogeologic model was developed based on the data collected from the ISR field test completed in 2019 (“2019 Field Test”) (see press release dated December 18, 2019). Based on the positive results from the hydrogeologic model, Denison is also pleased to announce the details of its plans for the continuation of ISR field testing in 2020, within Phoenix, at the Company’s 90% owned Wheeler River Uranium Project (“Wheeler River”), located in northern Saskatchewan, Canada. View PDF version.