Denison Completes Commissioning of Lixiviant Injection Modules for Phoenix ISR Feasibility Field Test
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
PRESS RELEASE
Denison Completes Commissioning of Lixiviant Injection Modules
for Phoenix ISR Feasibility Field Test
Toronto, ON – September 26, 2022. Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML;
NYSE American: DNN) is pleased to announce the completion of commissi oning of the lixiviant injection
system for the Phoenix in-situ recovery (“ISR”) Feasibility Field Test (“FFT”) at the Company’s 95% owned
Wheeler River project (“Wheeler River” or the “Project ”). The lixiviant injection system is the critical
operating component necessary to support the leaching phase of the FFT.
Kevin Himbeault, Denison’s Vice President of Plant Operations & Regulatory Affairs, commented, “With
the completion of construction and wet commissioning of the injection modules, we have now
successfully commenced our initial injection of lixiviant into the test area, which represents the
beginning of the leaching phase of the FFT.”
David Cates, Denison’s President and CEO, added, “We are proud of this notable milestone,
particularly given the extensive coordination an d efforts of Denison’s Saskatoon-based technical
team and our various construction partners that have delivered on the safe and timely construction
and commissioning of this first-of-its-kind test facility.”
Limited construction activities continue on-site to support future phases of the FFT (discussed below).
Construction efforts for the FFT are being completed in collaboration with Tron Construction & Mining, a
well-established operator in northern Saskatchewan that is part of the Des Nedhe Group and owned 100%
by English River First Nation. Civil earthworks for the FFT are substantially completed, and continue to be
supported by Snake Lake Contracting, another northern Saskatchewan-ba sed and Indigenous-owned
business.
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.
Background on the FFT
The FFT is designed to use the existing commercial-scal e ISR test pattern ("Test Pattern"), installed at
Phoenix in 2021 (see news releases dated July 29, 2 021, and October 28, 2021), to facilitate a combined
assessment of the Phoenix deposit's hy draulic flow properties with the leaching characteristics that have
been assessed through the metallurgical core-leach testing program.
The FFT is fully permitted, having been authorized by both the Saskatchewan Minister of Environment (see
news release dated July 12, 2022) and the Canadian Nuclear Safety Commission (see news release dated
August 8, 2022).
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 expected production and
remediation profiles.
The operation of the FFT is planned to occur in three phases: (1) the leaching phase, (2) the neutralization
phase, and (3) the recovered solution management phase.
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The leaching phase is designed to assess the effectiv eness and efficiency of t he leaching process in the
mineralized zone, which is approximately 400m below the surface. The leaching phase includes the
controlled injection of an acidic solution into a port ion of the existing Test Pattern within the mineralized
zone (the "Leaching Zone") and the recovery of the so lution back to the surface using existing test wells.
The recovered solution from the leaching phase is expected to contain dissolved minerals, including
uranium, copper, iron, molybdenum, and zinc.
The neutralization phase involves the recovery of t he 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 environmentally acceptable 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 management phase involves separating the solution recovered from both the
leaching phase and the neutralization phase into (i) mi neralized precipitates and (ii) a neutralized treated
solution.
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 U3O8 (1,809,000 tonnes at an average grade of 3.3% U 3O8), plus combined Inferred
Mineral Resources of 3.0 million pounds U 3O8 (82,000 tonnes at an average grade of 1.7% U 3O8). The
Project is host to the high-grade Phoenix and Gryp hon uranium deposits, discovered by Denison in 2008
and 2014, respectively, and is a joint venture betwe en Denison (operator) and JCU (Canada) Exploration
Company Limited ("JCU"). Denison has an effective 95% ownership interest in Wheeler River (90% directly,
and 5% indirectly through a 50% ownership in JCU).
A PFS was completed for Wheeler River in 2018, cons idering the potential economic merit of developing
the Phoenix deposit as an ISR operat ion and the Gryphon deposit as a conventional underground mining
operation. Taken together, the Project is estimated to have mine production of 109.4 million pounds U3O8
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 case pre-tax NPV of $930.4 million (8% discount rate),
IRR of 43.3%, initial pre-producti on capital expenditures of $322.5 m illion, 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 scientific 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 prof ile 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 re lying on the estimates provided therein regarding
the start of pre-production activities in 2021 and first production in 2024.
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
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Lake joint venture, which includes several uraniu m deposits and the McClean Lake uranium mill that is
contracted to process the ore fr om the Cigar Lake mine under a to ll milling agreement, plus a 25.17%
interest in the Midwest Main and Midwest A deposits, and a 67.01% 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 additional interests in various uranium project joint
ventures in Canada, including the Millennium project (JCU 30.099%), the Kiggavik project (JCU 33.8118%)
and Christie Lake (JCU 34.4508%). Denis on's exploration portfolio includes further interests in properties
covering approximately 300,000 hectares in the Athabasca Basin region.
Denison is also engaged in post-closure mine care and maintenance services through its Closed Mines
group, which manages Denison’s reclaimed mine si tes 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 informatio n related to the FFT or Wheeler River project contained
in this release has been reviewed and approved, as applicable, 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: status of commissioning and readiness
of the FFT; scope, objectives and interpretations of the FS process for the proposed ISR operation for the Phoenix deposit, including
the FFT and other testing programs and the interpretation of the results therefrom; the scope and design, and related test work , with
respect to plans and process desi gns for the FS; and expectations regarding its jo int venture ownership interests and the conti nuity
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 expre ssed or implied by such forward-looking
statements. For example, the modelling and assumptions upon which the work plans for the Wheeler River Project are based may
not be maintained after further work is completed. In additi on, Denison may decide or otherwi se be required to discontinue tes ting,
evaluation and development work if it is unable to maintain or ot herwise secure the necessary re sources (such as testing facili ties,
capital funding, regulatory approvals, etc.). Denison believes that the expectations re flected in this forward-looking informa tion are
reasonable, but no assurance can be given that these expectations will prove to be accu rate and results may differ materially f rom
those anticipated in this forward-looking information. For a discussion in respect of risks and other factors that could influence forward-
looking events, please refer to the factor s discussed in Denison’s Annual Informati on Form dated March 25, 2022 or subsequent
quarterly financial reports under the 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 re liance on forward-looking statements. The forward-looking information contained i n
this news release is expressly qualified by this cautionary statement. Any forward-looking 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 rel ease to conform such information to actual results or to changes in
Denison's expectations except as otherwise required by applicable legislation.
Cautionary Note to United States Investors Concerning Estimates of Mineral Resources and Mineral Reserves : This news
release may use the terms 'measured', 'indicated' and 'inferred' mineral resources. United States investors are advised that such terms
have been prepared in accordance with the definition standards on mi neral reserves of the Canadian Institute of Mining, Metallu rgy
and Petroleum referred to in Canadian National Instrument 43- 101 Mineral Disclosure Standards (‘NI 43-101’) and are recognized
and required by Canadian regulations. 'Inferred mineral resources' have a great amount of uncertainty as to their existence, and as to
their economic and legal feasibility. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to
a higher category. Under Canadian rules, estimates of inferred miner al resources may not form the basis of feasibility or other
economic studies. United States investors ar e cautioned not to assume that all or any part of an inferred mineral resource exis ts, or
is economically or legally mineable. Unit ed States investors are also cautioned not to assume that all or any part of measure d or
indicated mineral resources will ever be converted into mineral reserves.
Effective February 2019, the United States Securities and Exchange Commission (‘SEC’) adopted amendments to its disclosure rules
to modernize the mineral property disclosure requirements for issuers whose securities are registered with the SEC under the
Exchange Act and as a result, the SEC now recognizes estimates of “measured mineral resources”, “indicated mineral resources”
and “inferred mineral resources”. In addition, the SEC has amended its definitions of “proven mineral reserves” and “probable mineral
reserves” to be “substantially similar” to the corresponding definitions under the CI M Standards, as required under NI 43-101.
However, information regarding mineral resources or mineral rese rves in Denison’s disclosure may not be comparable to similar
information made public by United States companies.