EX-99.1
2
dmc-prnov222022fftleachin.htm
PRESS RELEASE DATED NOVEMBER 22, 2022
dmc-prnov222022fftleachin
Exhibit 99.1
Denison Mines
Corp.
1100 – 40
University Ave
Toronto, ON M5J
1T1
www.denisonmines.com
PRESS
RELEASE
Denison Announces Additional Highlights from Highly
Successful
Leaching Phase of Phoenix ISR Feasibility Field Test
Toronto, ON –November 22,
2022. Denison Mines Corp. (“Denison” or the
“Company”) (TSX: DML; NYSE American: DNN) is pleased to
announce additional highlights from the completion of the highly
successful leaching phase of the ongoing Phoenix in-situ recovery
(“ISR”) Feasibility Field Test (“FFT”) at
the Company’s 95% owned Wheeler River project (“Wheeler
River” or the “Project”).
●
Recovered approximately 14,400 lbs
U3O8
over ten days of active leaching
following completion of initial acidification of the Leaching Area
(defined below).
●
Returned
maximum uranium head grade of recovered solution of 43 grams per
litre (“g/l”) when the leaching phase of the FFT was
completed, with grades still rising (indicative of the ramp-up
segment of a well production profile).
●
Achieved
suitable acidification for ISR mining within 7 days post initial
injection at 5 metre well spacing (GWR-41) and within 17 days for
10 metre well spacing (GWR-38).
●
Demonstrated
ability to achieve and maintain uranium mass flow rate consistent
with the assumptions in the Pre-Feasibility Study
(“PFS”) prepared for the Project in 2018.
●
Further
demonstrated hydraulic control of injected solution during the FFT,
reporting no responses in the monitoring wells outside of the
designed FFT test area.
●
Confirmed
breakthrough times between injection and recovery wells, consistent
with the Project’s hydrogeological model and the previously
completed tracer test.
David Cates, Denison’s President & CEO,
commented, “The
detailed results from the leaching phase of the Phoenix ISR FFT are
very encouraging. Using only one injection well and two recovery
wells for a period of active leaching of only ten days, we
recovered an estimated 14,400 lbs U3O8
–
representing approximately 1% of the mineral reserves estimated to
be within the perimeter of the FFT test area. These results provide
further tangible evidence of the viability of the ISR mining method
at the Company’s high-grade Phoenix uranium
deposit.”
Kevin Himbeault, Denison’s Vice President of
Plant Operations & Regulatory Affairs, added,
“Uranium
head grades were increasing at the time the leaching phase of the
FFT was completed – returning a maximum uranium head grade of
43 g/l. This is over 300% higher than the head grade assumed in the
2018 PFS, and further supports the Company’s decision to
increase the assumed ISR mining head grade by 50% for the
feasibility study. Overall, the leaching phase of the FFT has been
highly successful – accomplishing our objectives for uranium
head grade recovery, uranium mass flow rates, and hydraulic
conductivity within the ore zone. These results further support the
hydrogeological and metallurgical modelling expected to be
incorporated into the feasibility study.”
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.
In
2021, following the completion of various metallurgical tests,
Denison announced a decision to adapt its plans for further
metallurgical test work and project designs to reflect a 50%
increase in the assumed head grade of uranium bearing solution to
be recovered from the Phoenix well-field – from 10 g/L (as
outlined in the PFS) to 15 g/L (see news release dated August 4,
2021 for details). An increase in head grade is expected to allow
for optimization of operating parameters and processing plant
designs in the feasibility study for the Project (see news release
dated September 22, 2021).
The
increasing uranium head grade observed during the leaching phase of
the FFT, including results that exceeded 15 g/L, provide additional
support for the decision to increase the assumed head grade in the
feasibility study. In a production setting, the uranium bearing
solution recovered from ‘new’ production wells,
yielding higher than average head grades during the ramp-up segment
of a well production profile, is expected to be combined with
recovered solution from ‘existing’ production wells
producing gradually decreasing head grades over the life of well
production profile.
FFT Leaching Phase
The leaching phase of the FFT commenced in
September 2022 (see news release dated September 26, 2022),
designed to assess the effectiveness and efficiency of the leaching
process in the ore zone located approximately 400m below the
surface, is now complete. The leaching phase consisted of the
controlled injection of an acidic mining solution into a portion of
the existing Test Pattern (defined below) within the ore zone (the
“Leaching Zone”) and the recovery of the solution back
to the surface using existing test wells. Commercial-scale test
well GWR-40 was used as the injection well, while uranium bearing
solution was recovered from commercial-scale test wells GWR-41 and
GWR-38. These wells are located within Phase 1 of the planned
mining areas for Phoenix (See Figure 1 and 2 for photos from the
FFT site). Additional details about Phase 1 and the estimated
Probable mineral reserves contained therein are provided
below.
Throughout
the test program, both vertical and horizontal containment of the
mining solution was maintained, with no migration of the mining
solution observed above, below or outside of the designed FFT test
area along the leaching zone. These results were consistent with
the findings from the 2021 tracer test (see news release dated
October 28, 2021) and further confirmed that both targeted mining
head grades and flow rates are achievable while maintaining
containment of ISR mining activities to defined areas in the ore
zone.
Following
the completion of the leaching phase of the FFT in mid-October,
field activities transitioned to the neutralization phase of the
FFT. The final phase of the FFT, which involves the management of
the recovered solution, is expected to begin in the spring of
2023.
Feasibility Field Test Background
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
hydraulic 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.
As
described above, the leaching phase is now complete. The
neutralization phase was initiated in mid-October 2022, 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 is
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) mineralized precipitates and (ii) a
neutralized treated solution.
About Phoenix Phase 1
As outlined in the Company’s news release dated December 1,
2020, Denison has decided to adapt its plans for the Project to use
a phased mining approach, which is expected to allow for the
targeted extraction of the least capital-intensive reserves first,
based on the grade and distribution of ore in various areas of the
deposit. The supporting trade-off study provides for mining to
occur over 5 phases.
Phase 1 of the deposit is estimated to
contain approximately 22.2 million pounds U3O8 (37,242 tonnes at 27.1% U3O8,
above a cut-off grade of 0.8% U3O8) in Probable mineral reserves. Based on current
designs, the Company estimates approximately 6.6 million
pounds U3O8 (7,717 tonnes at 39.2% U3O8, above a cut-off grade of 0.8%
U3O8) in Probable mineral reserves are contained
within the expected operating perimeter of the commercial scale
wells in the 5-spot Test Pattern. Of these estimated Probable
mineral reserves, the Company further estimates that 1.4 million
pounds U3O8 (2,326 tonnes at 26.2% U3O8, above a cut-off grade of 0.8%
U3O8) are contained within the operating perimeter of
GWR-38, GWR-40, and GWR-41. These estimates are derived as a direct
subset of those reported in the 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 (the “PFS Report”). The key
assumptions, parameters and methods used to estimate the mineral
reserves herein remain unchanged.
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).
The 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 PFS Report, 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.
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.
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 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.
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: expectations with respect
to the FFT program, scope, timing and the anticipated results
thereof; the interpretation of the results of the FFT obtained
to-date; scope, objectives and interpretations of the feasibility
study process for the proposed ISR operation for the Phoenix
deposit, including metallurgical testing programs described herein
and the interpretation of the results therefrom; the
interpretations of the PFS as reflected in the PFS Report; 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 exploration and/or 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 exploration,
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 press release may use terms such as
“measured”, “indicated” and/or
“inferred” mineral resources and “proven”
or “probable” mineral reserves, which are terms defined
with reference to the guidelines set out in the Canadian Institute
of Mining, Metallurgy and Petroleum (“CIM”) Definition
Standards on Mineral Resources and Mineral Reserves (“CIM
Standards”). The Company’s descriptions of its projects
using CIM Standards may not be comparable to similar information
made public by U.S. companies subject to the reporting and
disclosure requirements under the United States federal securities
laws and the rules and regulations thereunder. United States investors are cautioned not to
assume that all or any part of measured or indicated mineral
resources will ever be converted into mineral reserves. United
States investors are also cautioned not to assume that all or any
part of an inferred mineral resource exists, or is economically or
legally mineable.
Figure 1: Phoenix - Phase 1 Feasibility Field Test
Area
Figure 2: Phoenix – Feasibility Field Test Wells and
Injection Module