TORONTO, Dec. 8, 2022
/PRNewswire/ - Denison Mines Corp. ("Denison" or
the "Company") (TSX: DML) (NYSE American: DNN) is pleased to
announce highly successful results from long-term core
leach metallurgical testing completed to further
support the Feasibility Study ("FS") underway for the Phoenix
In-Situ Recovery ("ISR") uranium mining operation proposed for the
Company's 95% owned Wheeler River project ("Wheeler River" or the
"Project"). View PDF Version
To support the establishment of ISR production
and recovery curves to be used in the FS, the Company
completed a long-term test of a representative intact core sample
("Core 4A") using specialized equipment to replicate the in-situ
leaching conditions of the Phoenix
deposit.
The results from long-term core leach testing of Core
4A are highlighted by the following:
- Overall recovery of uranium in excess of 97% – demonstrating
excellent recovery of uranium from intact high-grade core, without
the use of permeability enhancement.
- Average recovered solution uranium head grade of 18.3 grams per
litre ("g/L") – exceeding the assumed 15 g/L uranium head grade
being used in FS plant designs (see news release dated August 4, 2021).
- Continuous intact core leach testing over a period of 377 days,
with uranium recovery head grades consistently maintained above 5
g/L during the final stages of the production curve and then
declining during the ramp-down stage.
- Maximum recovered solution uranium head grade of 49.8 g/L
achieved using similar lixiviant concentrations as to those used
during the Feasibility Field Test ("FFT").
Kevin Himbeault, Denison's Vice
President of Plant Operations & Regulatory Affairs,
commented, "The
positive results of
the long-term intact core
leach test carried out on Core
4A add to the weight-of-evidence
de-risking the use of
the ISR mining
method at the
high-grade Phoenix uranium
deposit. The ability to demonstrate the recovery
of over 97% of the uranium from
a high-grade intact
core sample is quite positive and
provides notable support for the estimated recovery
value of 85% used in the 2018 Pre-Feasibility
Study ("PFS"). Additionally,
demonstrating an average uranium head grade of
18.3 g/L, over
a year of testing Core
4A, provides further tangible
support for the assumed 15 g/L
uranium head grade being used in FS plant
designs."
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.
Since 2019, Denison has completed several core leach
tests using intact core samples obtained from
Phoenix during various field test programs. The test
work has been completed at the Saskatchewan Research Council
("SRC") laboratories in Saskatoon,
and makes use of specialized equipment intended to replicate the
in-situ leaching conditions of the Phoenix deposit – including maintaining
the core in its original shape and exerting uniform pressure on
the exterior of the core (simulating in-situ
overburden pressure) to ensure lixiviant must travel through
the natural pathways existing within the core sample.
Previous core leach testing focused on the basic leaching
characteristics of intact core from different hydrogeological
units, allowing assessment of varying lixiviant
compositions, uranium grade ramp-up, lixiviant flow
characteristics through the intact core, and the neutralization
efficiency of intact core. The core leach test of Core
4A was used to study similar parameters; however, it was
leached longer term to develop an aggregate
life-of-well recovery and production profile,
including the initial ramp-up and the gradual decline of the
UBS head grade. This profile will be used to support wellfield
production modelling and optimization.
Core 4A is calculated to have a grade of
26.7% U3O8, which is comparable to
the average grade of the estimated Indicated Mineral Resources for
Phoenix of 19.14%
U3O8, and is representative of one
of the main hydrogeological units identified within the
Phoenix deposit.
The actual grade of Core 4A was calculated
post-test, as the intact core cannot be assayed without
destroying the integrity of the core. Upon termination of the core
leach test, the remaining core was crushed, ground, and
assayed to determine the final residual uranium mass
contained within the leached-out core sample. The
residual mass of uranium, along with the mass of uranium
recovered during leaching, was used to calculate both the
overall recovery as well as the original grade of the core.
About Wheeler
River
Wheeler River is the largest undeveloped uranium project 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%
U3O8), 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 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,
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 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-production capital expenditures 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
scientific and technical information, as well as after-tax results
attributable to Denison's ownership interest, 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.
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 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%). Denison's
exploration portfolio includes further interests in properties
covering ~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 sites in the Elliot Lake region and provides related
services to certain third-party projects.
Qualified Persons
The disclosure of scientific or technical information related
to the FFT, the core leach testing, 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 identified by the use of
forward-looking terminology 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: scope, objectives
and interpretations of the FS process for the proposed ISR
operation for the Phoenix deposit,
including metallurgical testing programs described herein and the
interpretation of the results therefrom; the scope and
design, and related test work, with respect to plans and process
designs for the FS; 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 cause the actual results, level of
activity, 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 the Wheeler River Project are based may not
be maintained after further work is completed. In addition,
Denison may decide or otherwise be required to
discontinue testing, evaluation and development work if
it is unable to maintain or otherwise secure the necessary
resources (such as testing facilities, capital funding, regulatory
approvals, etc.). Denison believes that the expectations
reflected in this forward-looking information are reasonable but no
assurance can be given that these expectations will prove to be
accurate and results may differ materially from 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 factors discussed in Denison's Annual
Information 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.
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-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 release 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 mineral
reserves of the Canadian Institute of Mining, Metallurgy 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
mineral resources may not form the basis of feasibility or other
economic studies. United States
investors are cautioned not to assume that all or any part
of an inferred mineral resource exists, or is economically or
legally mineable. United States investors are also cautioned
not to assume that all or any part of measured 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 CIM Standards, as required under NI
43-101. However, information regarding mineral resources or
mineral reserves in Denison's disclosure may not be comparable to
similar information made public by United
States companies.
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SOURCE Denison Mines Corp.