Denison Receives Approval to Construct and Operate Phoenix Feasibility Field Test Facility from Saskatchewan Minister of Environment
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
PRESS RELEASE
Denison Receives Approval to Construct and Operate
Phoenix Feasibility Field Test Facility from Saskatchewan Minister of Environment
Toronto, ON – July 12, 2022. Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML; NYSE
American: DNN) is pleased to announce that it has received approval from the Province of Saskatchewan to
prepare, construct, and operate the facilities required to carry out the In-Situ Recovery (“ISR”) Feasibility
Field Test (“FFT”) planned for the Phoenix deposit at the Company’s 95% owned Wheeler River project.
The approval was granted by the Saskatchewan Minist er of Environment (the “Minister”) and authorizes
Denison to operate “pollutant control facilities” – which is typical for mining operations and allows for the
management of material recovered from mineral extraction through to waste water treatment, discharge, and
storage (as applicable). The approval followed the comp letion of a process involving the review of and
consultation on the Company’s permit application and supporting materials related to the FFT.
Kevin Himbeault, Denison’s Vice President of Plant Operations & Regulatory Affairs, commented “We are
pleased to have received approval from the Province of Saskatchewan to prepare and operate the
Phoenix FFT. This is a significant advancement for the FFT, which is a key step in the process of de-
risking the proposed Phoenix ISR uranium mining operation and is expected to provide important
details to support the ongoing Feasibility Study. Overall, Denison was pleased with the permit
submission, review, and community consultation pro cess – as it reflected a shared objective of all
interested parties to ensure the safe and envir onmentally responsible ope ration of the facilities
required to complete the FFT.”
David Cates, Denison’s President & CEO, added “The permitting of the FFT is an excellent
demonstration of our team’s technical and regulatory capabilities. The FFT represents a first-of-its-
kind test of a uranium mining method that is new to Canada. Successfully navigating the regulatory
environment in Saskatchewan to develop conditions for the oversight of a novel advanced field test
is a notable accomplishment for both the Denison team and the regulatory team from the Ministry of
the Environment.”
With receipt of the Approval to Operate Pollutant Control Facilities from the Minister, preparation and
construction of the FFT facilities, described below, are now fully authorized and are expected to commence
shortly.
The Canadian Nuclear Safety Commission has determined that a Nuclear Substance License is also required
for Denison to possess and store a nuclear substance (mineralized solution containing uranium) resulting
from the operation of the FFT. The process to obtain this license is well advanced, and the licence is expected
to be received before the site preparation and commissioning activities are completed.
This press release constitutes a “designated news release” for the purposes of the Company’s prospectus
supplement dated September 28, 2021, to its short form base shelf prospectus dated September 16, 2021.
Feasibility Field Test
The FFT is designed to use the existing commercial-scale ISR test pattern (“Test Pattern”), installed at
Phoenix in 2021 (see news releases dated July 29, 2021 and October 28, 2021), to facilitate a combined
assessment of the Phoenix deposit’s hydr aulic flow properties with the l eaching characteristics that have
been assessed through the metallurgical core-leach testing program. Overall, the FFT is intended to provide
further verification of the permeability, leachability, and containment parameters needed for the successful
application of the ISR mining method at Phoenix and is expected to validate and inform various feasibility
study design elements – including the production and remediation profiles expected for the project.
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The operation of the FFT is planned to occur in thre e phases: (1) the leaching phase, (2) the neutralization
phase, and (3) the recovered solution management phase.
The majority of the test activities (leaching and neut ralization phase) will occur within an estimated 60-day
operating time frame, with the construction and placement of temporary facilities commencing approximately
two months prior to the commissioning of the test facilities and initiation of the leaching phase.
The leaching phase is designed to assess the effect iveness and efficiency of the leaching process in the
mineralized zone, at a depth of approx imately 400m below the surface. The leaching phase includes the
controlled injection of an acidic solution into a portion of the existing Test Pattern within the mineralized zone
(the “Leaching Zone”) and the recovery of the solution back to the surface using existing test wells. The
recovered solution from the leaching phase is expect ed to contain dissolved mi nerals, including uranium,
copper, iron, molybdenum, and zinc. Once on surface, the recovered solution (up to a maximum of 500 cubic
metres) will be stored temporarily in tanks in accordance with approved environmental protection containment
measures.
The neutralization phase includes the recovery of the remainder of the leached mineralized solution from the
Leaching Zone and is intended to verify the efficiency and effectiveness of the process for returning the
Leaching Zone to near baseline conditions. During this phase, a mild alkaline (basic) solution will be injected
into the Leaching Zone to neutralize the area and reverse the residual effects of the acidic solution injected
during the leaching phase. The recovered solution from the neutralization phase (up to a further maximum
of 500 cubic metres) will also be stored temporarily on surface in tanks in ac cordance with approved
containment measures.
The recovered solution management phase involves separating the solution recovered from both the leaching
phase and the neutralization phase into (i) mineralized precipitates and (ii) a neutralized treated solution. The
mineralized precipitate will be temporarily stored on surface in steel tanks and the neutralized treated solution
will be re-injected into a designated subsurface area.
FFT Facilities
Temporary surface facilities required to complete t he FFT are planned to be installed at the Phoenix site
during the third quarter of 2022. The procurement of necessary materials, equipment, and supplies, as well
as detailed engineering of the facilities are already well advanced.
The FFT site is planned to include the following facilities and infrastructure:
• Tanker pad – for storage of tanker trucks used for delivery of reagents to site.
• Injection solution preparation module – a modular unit where grou ndwater will be mixed with
reagents to prepare the injection solution.
• Test pattern coverall building – a tension-fabric building to be built over the test area.
• Recovered solution surge tank – the surge tank will receive recovered solution from the test wells.
• Solution storage tanks – six (6) tanks are expected to be installed to provide a total of 1,000 cubic
metres of solution storage. These tanks are designed to receive solution pumped from the recovered
solution surge tank for temporary storage before separating the recovered solution into mineralized
precipitates and a neutralized treated solution during the recovered solution management phase of
the FFT.
• Piping – double-walled transfer piping will run from the recovered solu tion surge tank (next to the
test wells) to the solution storage tanks.
• Recovered solution management modules – two modular units will be mobilized to site that
contain equipment for managing the recovered solutions.
• Mineralized precipitate storage tanks – during the recovered solution management phase, the
mineralized precipitate will be transferred into fully enclosed and lockable storage tanks. The
mineralized precipitate storage tanks will be placed in a secure fenced area for temporary storage.
• Laboratory – a mobile laboratory will be located on site and equipped for bench -scale testing of
samples.
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• Construction / Operations Centre – a mobile office will serve as a construction office and
operations centre as well as the main gate entry point for the site.
• Wash car and change room – a mobile facility will allow staff to change and wash before and after
each shift at the Phoenix site.
• Perimeter fence – the entire area (~8,820 square meters) will be fenced and gated to control access
and minimize interactions with wildlife.
All civil earthworks required for the FFT site are ex pected to occur on previously disturbed areas and no
additional land clearing is planned.
Figure 1 provides a plan view of the expected FFT site layout. Figures 2 and 3 provide isometric schematics
of the site facilities.
Approval to Operate Pollutant Control Facilities
Under the terms of the Approval to Operate Pollutant Control Facilities obtained from the Minister, Denison
is authorized to construct and operate various regulated elements associated with the FFT, including pollutant
control facilities, mineralized precipitate facilitie s, radon air pollution abatement equipment, and hazardous
substances and waste dangerous goods storage facilities.
The approval includes specific operating conditions related to (a) mineralized precipitate, recovered solution
and drill cuttings, handling, and transportation, (b) hazardous substances material storage, handling, and
transportation, (c) air management, (d) wate r/wastewater management, and (e) waste handling,
transportation, and disposal. Additionally, the approval includes provisions related to inspections, monitoring,
reporting, and decommissioning and reclamation.
About Wheeler River
Wheeler River is the largest undeveloped uranium projec t in the infrastructure rich eastern portion of the
Athabasca Basin region, in northern Saskatchewan – including combined Indicated Mineral Resources of
132.1 million pounds U 3O8 (1,809,000 tonnes at an average grade of 3.3% U 3O8), plus combined Inferred
Mineral Resources of 3.0 million pounds U3O8 (82,000 tonnes at an average grade of 1.7% U3O8). The project
is host to the high-grade Phoenix and Gryphon uranium deposits, discovered by Denison in 2008 and 2014,
respectively, and is a joint venture between Deni son (operator) and JCU (Canada) Exploration Company
Limited ("JCU"). Denison has an effective 95% owners hip interest in Wheeler River (90% directly, and 5%
indirectly through a 50% ownership in JCU).
A PFS was completed for Wheeler River in 2018, considering the potential economic merit of developing the
Phoenix deposit as an ISR operation and the Gryphon deposit as a conventional underground mining
operation. Taken together, the project is estimat ed to have mine production of 109.4 million pounds U 3O8
over a 14-year mine life, with a base case pre-tax NPV of $1.31 billion (8% discount rate), Internal Rate of
Return (“IRR”) of 38.7%, and initial pre-production capital expenditures of $322.5 million. The Phoenix ISR
operation is estimated to have a stand-alone base ca se pre-tax NPV of $930.4 million (8% discount rate),
IRR of 43.3%, initial pre-production capital expend itures of $322.5 million, and industry-leading average
operating costs of US$3.33/lb U3O8. The PFS is prepared on a project (100% ownership) and pre-tax basis,
as each of the partners to the Wheeler River Joint Venture are subject to different tax and other obligations.
Further details regarding the PFS, including additional sci entific and technical information, as well as after-
tax results attributable to Denison's ownership intere st, are described in greater detail in the NI 43-101
Technical Report titled “Pre-feasibility Study for the Wheeler River Uranium Project, Saskatchewan, Canada”
dated October 30, 2018, with an effective date of September 24, 2018. A copy of this report 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.
Denison suspended certain activities at Wheeler River during 2020, including the EA process, which is on
the critical path to achieving the project development schedule outlined in the PFS. While the EA process
has resumed, the Company is not currently able to estimate the impact to the project development schedule
outlined in the PFS, and users are cautioned against relying on the estimates provided therein regarding the
start of pre-production activities in 2021 and first production in 2024.
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About Denison
Denison is a uranium exploration and development company with interests focused in the Athabasca Basin
region of northern Saskatchewan, Canada. In addition to its effective 95% interest in the Wheeler River
project, Denison's interests in the Athabasca Basin include a 22.5% ownership interest in the McClean Lake
joint venture, which includes several uranium deposits and the McClean Lake uranium mill that is contracted
to process the ore from the Cigar Lake mine under a toll milling agreemen t, plus a 25.17% interest in the
Midwest Main and Midwest A deposits, and a 66.90% interest in the Tthe Heldeth Túé (“THT”, formerly J
Zone) and Huskie deposits on the Waterbury Lake property. The Midwest Main, Midwest A, THT and Huskie
deposits are each located within 20 kilometres of the McClean Lake mill.
Through its 50% ownership of JCU, Denison holds additi onal interests in various uranium project joint
ventures in Canada, including the Millennium project (JCU 30.099%), the Kiggavik project (JCU 33.8123%)
and Christie Lake (JCU 34.4508%). Denis on's exploration portfolio includes further interests in properties
covering ~280,000 hectares in the Athabasca Basin region.
Denison is also engaged in post-closure mine care and maintenance services through its Closed Mines group
(formerly Denison Environmental Services), which manages Denison's reclaimed mine sites in the Elliot Lake
region and provides related services to certain third-party projects.
For more information, please contact
David Cates (416) 979-1991 ext 362
President and Chief Executive Officer
Mac McDonald (416) 979-1991 ext 242
Executive Vice President and Chief Financial Officer
Follow Denison on Twitter @DenisonMinesCo
Qualified Persons
The disclosure of scientific or technical information related to the FFT or Wheeler River project contained in
this release has been reviewed and approved, as applic able, by Mr. David Bronkhorst, P.Eng, Denison’s
Vice President, Operations or Mr. Andrew Yackulic, P. Geo., Denison's Director, Exploration, who are
Qualified Persons in accordance with the requirements of NI 43-101.
Cautionary Statement Regarding Forward-Looking Statements
Certain information contained in this news release constitutes ‘forward-looking information’, within the meaning of the applicable United
States and Canadian legislation, concerning the business, operations and financial performance and condition of Denison. Generally,
these forward-looking statements can be identif ied by the use of forward-looking termi nology such as ‘potential’, ‘plans’, ‘expects’,
‘budget’, ‘scheduled’, ‘estimates’, ‘forecasts’, ‘intends’, ‘anticipates’, or ‘believes’, or the negatives and/or variations of such words and
phrases, or state that certain actions, events or results ‘may’, ‘could’, ‘would’, ‘might’ or ‘will’ ‘be taken’, ‘occur’ or ‘be achieved’.
In particular, this news release contains forward-looking information pertaining to the following: expectati ons with respect to the FFT
program, scope, timing and the anticipated results thereof; the expectation that Denison will receive all required permitting for the FFT,
including CNSC approvals; and expectations regarding its joint venture ownership interests and the continuity of its agreements with its
partners and third parties.
Forward looking statements are based on the opinions and estimates of management as of the date such statements are made, and
they are subject to known and unknown risks, uncertainties and other factors that may c ause the actual results, level of activi ty,
performance or achievements of Denison to be materially different from those expressed or implied by such forward-looking statements.
For example, the modelling and assumptions upon which the work plans for ex ploration and/or the Wheeler River Project are based
may not be maintained after further work is completed. In addi tion, Denison may decide or other wise be required to discontinue
exploration, testing, evaluation and development work if it is unable to maintain or otherwise secure the necessary resources ( such as
testing facilities, capital fundi ng, regulatory approvals, etc.). Denison believe s that the expectations reflected in this for ward-looking
information are reasonable but no assurance can be given that these expectations will pr ove to be accurate and results may diff er
materially from those anticipated in this forward-looking information. For a discu ssion in respect of risks and other factors t hat could
influence forward-looking events, please refer to the factors discussed in Denis on’s Annual Information Form dated March 25, 2022 or
subsequent quarterly financial reports under t he heading ‘Risk Factors’. These factors are not, and should not be construed as being
exhaustive.
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Accordingly, readers should not place undue reliance on forward-looking statements. The forward-looking information contained in this
news release is expressly qualified by this cautionary statement. Any forward-looki ng information and the assumptions made with
respect thereto speaks only as of the date of this news release. Denison does not undertake any obligation to publicly update or revise
any forward-looking information after the date of this news releas e to conform such information to actual results or to changes in
Denison's expectations except as otherwise required by applicable legislation.
Figure 1: Plan map showing location of FFT facilities
Figure 2: Isometric view of the planned FFT site and associated facilities
Figure 3: Isometric view of the coverall building on the FFT site, including test wells,
injection solution preparation module, and recovered solution surge tank