TORONTO, Feb. 19, 2020 /CNW/ - Denison Mines
Corp. ("Denison" or the "Company") (DML: TSX, DNN: NYSE
American) is pleased to report that initial data from core leach
tests includes elemental uranium ("uranium") concentrations, after
the initial test startup, in the range of 13.5 grams per litre
("g/L") to 39.8 g/L. This compares favourably to the previous
metallurgical test work completed to assess the use of the In-Situ
Recovery ("ISR") mining method at the high-grade Phoenix uranium deposit ("Phoenix") – which
supported a uranium concentration of 10 g/L for the ISR processing
plant design used in the Pre-Feasibility Study ("PFS") completed
for the Company's 90% owned Wheeler River Uranium Project ("Wheeler
River" or the "Project"), located in northern Saskatchewan, Canada. View PDF version.
David Bronkhorst, Denison's Vice
President Operations, commented, "The initial data from the core
leach test shows that uranium can be recovered from intact core
samples at a concentration that is significantly higher than the
levels used in the PFS. The implications of a higher uranium
concentration coming from the ISR wellfield are potentially
significant – allowing the metallurgical team to explore various
combinations of lixiviant parameters to optimize operating costs,
and processing plant configurations to potentially reduce capital
costs while maintaining the same level of annual uranium
production."
Background
The test work incorporated into the PFS (see press release dated
September 24, 2018) included column
leach and agitated leach tests, which led to the design of the
Phoenix processing plant in the
PFS based on a minimum of 10 g/L uranium content in the uranium
bearing solution expected to be recovered from the ISR wellfield.
The current metallurgical test program ("2020 Metallurgical
Program") has been designed to build upon the laboratory test data
collected as part of the PFS (see news release dated December 18, 2019).
The first stage of the 2020 Metallurgical Program involves
completing specialized tests using intact mineralized core samples,
representative of the in-situ conditions at Phoenix. The
testing apparatus used for these tests allows for intact core
samples to be mounted within a flexible sleeve with a confining
pressure applied to the exterior of the sleeve. Lixiviant (in
the case of Phoenix, an
acid-bearing mining solution) can then be injected into to the
intact core at one end of the sample without having a way to
by-pass the intact core. As a result, the lixiviant travels through
the core to the other end of the sample, where a uranium bearing
solution is recovered. Denison considers this type of specialized
test of intact competent core samples to be the most representative
available laboratory test of the natural leach conditions of the
host rock.
Current Core Leach Test
Over 50 days of testing has been completed, to date, on a
mineralized core sample recovered from drill hole GWR-016.
The core sample was recovered from between 405 and 407 metres below
surface within the extent of the high-grade core of Phoenix Zone
A. Various parameters for lixiviant composition (including
both acid and oxidant concentration) have been tested to date. In
all cases, the lixiviant is injected into the core continuously and
only interrupted periodically if a change in the lixiviant
composition is required. After the initial test startup,
uranium bearing solution recovered from the core sample has
returned uranium content in the range of 13.5 g/L to 39.8
g/L. The average uranium concentration returned over the
last 20 days of testing is 29.8 g/L – which represents a uranium
content that is approximately 200% higher than (or three times) the
minimum level used for the ISR process plant design in the
PFS.
The test with this core sample will continue as the Company
refines the optimal lixiviant parameters for the mineralized core
within Phoenix Zone A and ultimately the optimal uranium-bearing
solution parameters for the solution that will be fed into the
proposed process plant flowsheet. The initial results
reported from the testing completed, to date, reflect the uranium
concentrations recovered from a single core sample.
Additional core samples are planned for core leach testing (as
described below). The initial results reported above may not
be representative of results from further testing of the current
core sample, or future testing of additional core
samples.
Overview of the 2020 Metallurgical Test Program
In December 2019, the Company
initiated the 2020 Metallurgical Program, which is expected to
provide important information for the purpose of completing the
Environmental Assessment ("EA") and a future Feasibility Study for
the Phoenix ISR operation (see Denison's news release dated
December 18, 2019). The 2020
Metallurgical Program has been designed to use the mineralized
drill core recovered through the installation of various test wells
during the 2019 ISR field test program (see Denison's news release
dated December 18, 2019) and to build
upon the previous laboratory test data, which was collected as part
of the PFS process to assess the recovery of uranium. The
2020 Metallurgical Program has been planned in stages, allowing for
the initial results from each stage of testing to inform the design
and criteria of the further stages of testing.
The first stage of the 2020 Metallurgical Program is expected to
continue throughout the first half of 2020 using core samples
representative of the various ore types and grade ranges (~1%
U3O8 to up to 60% U3O8)
contained within Phoenix. The goal of the first stage of the
program is to determine the optimal lixiviant parameters for
various grade ranges within Phoenix, which will involve the testing of
several representative core samples. The uranium recovery
results from the first 50 days of testing of the first core sample
will allow refinement of the test program for the next core samples
planned for future intact core leach tests, and for the final
planning and design of the second stage of the 2020 Metallurgical
Program – which involves the completion of various column leach
tests.
The column leach tests planned in the second stage of the
program involve the crushing and packing of mineralized core
samples into test columns, which are then expected to utilize the
same lixiviant composition as the core leach tests to provide
additional data on the recovery of uranium, and any other metals,
from the various ore types and grade ranges associated with the
Phoenix deposit. The purpose
of the column leach tests is to correlate data from the specialized
core leach tests to the traditional ISR laboratory testing methods
used during the PFS. Additionally, the column leach tests are
able to generate uranium bearing solutions in larger quantities for
further laboratory testing of the process plant flowsheet – which
is planned as the third stage of the 2020 Metallurgical Program,
and is expected to involve bench-scale testing of the unit
operations of the proposed process plant flowsheet with
uranium-bearing solutions produced during the leach tests.
The third stage of the program is in the planning stage and will be
refined pending the results of the leach tests.
The laboratory work for the first stage and second stage of the
2020 Metallurgical Program is being carried out at the Saskatchewan
Research Council ("SRC") Mineral Processing and Geoanalytical
Laboratories, in Saskatoon, under
the supervision of Mr. Chuck Edwards
(P.Eng., FCIM).
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 (90% and operator) and JCU
(Canada) Exploration Company
Limited (10%).
A PFS was completed for Wheeler River in late 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.
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 the Wheeler River project, Denison's
Athabasca Basin exploration
portfolio consists of numerous projects covering approximately
280,000 hectares. Denison's interests in the Athabasca Basin also include a 22.5% ownership
interest in the McClean Lake joint venture ("MLJV"), which includes
several uranium deposits and the McClean Lake uranium mill, which
is currently processing ore from the Cigar Lake mine under a toll
milling agreement, plus a 25.17% interest in the Midwest and
Midwest A deposits, and a 66.57% interest in the J Zone and Huskie
deposits on the Waterbury Lake property. Each of Midwest, Midwest
A, J Zone and Huskie are located within 20 kilometres of the
McClean Lake mill.
Denison is also engaged in mine decommissioning and
environmental services through its Denison Environmental Services
division and is the manager of Uranium Participation Corp., a
publicly traded company which invests in uranium oxide and uranium
hexafluoride.
Qualified Persons
Description of the metallurgical test program and data
contained in this release was reviewed by Mr. Chuck Edwards, P. Eng., FCIM, Principal at Chuck
Edwards Extractive Metallurgy Consulting, an independent Qualified
Person in accordance with the requirements of NI 43-101.
The other technical information contained in this release has
been reviewed and approved by Mr. Dale
Verran, MSc, P.Geo, Pr.Sci.Nat., Denison's Vice President,
Exploration, a Qualified Person 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 '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', 'be achieved' or 'has the potential
to'.
In particular, this news release contains forward-looking
information pertaining to the following: the 2020 Metallurgical
Program, including its intended scope and timing, objectives and
evaluation interpretations; the current and continued use and
availability of third party technologies for testing; the results
of the PFS and expectations with respect thereto; development and
expansion plans and objectives, including plans for a feasibility
study; and expectations regarding its joint venture ownership
interests and the continuity of its agreements with its
partners.
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 initial results of the 2020 Metallurgical Program
discussed herein may not be maintained after further testing or be
representative of actual conditions within the Phoenix deposit. In addition, Denison
may decide or otherwise be required to discontinue the 2020
Metallurgical Program or other testing, evaluation and development
work at Wheeler River 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 12, 2019 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 Measured, Indicated and Inferred Mineral Resources and
Probable Mineral Reserves: This news release may
use the terms 'measured', 'indicated' and 'inferred' mineral
resources. United States investors
are advised that while 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, the United States Securities and Exchange Commission
("SEC") does not recognize them. '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
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. The estimates of
mineral reserves in this news release have been prepared in
accordance with NI 43-101. The definition of probable mineral
reserves used in NI 43-101 differs from the definition used by the
SEC in the SEC's Industry Guide 7. Under the requirements of
the SEC, mineralization may not be classified as a "reserve" unless
the determination has been made, pursuant to a "final" feasibility
study that the mineralization could be economically and legally
produced or extracted at the time the reserve determination is
made. Denison has not prepared a feasibility study for the purposes
of NI 43-101 or the requirements of the SEC. Accordingly,
Denison's probable mineral reserves disclosure may not be
comparable to information from U.S. companies subject to the
reporting and disclosure requirements of the SEC.
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SOURCE Denison Mines Corp.