NON-TOXIC, CYANIDE-FREE TECHNOLOGY POTENTIALLY
DOUBLES SILVER RECOVERIES AND SIGNIFICANTLY CUTS LEACHING
TIMES
VANCOUVER, BC, Feb. 26,
2025 /CNW/ -- Silver One Resources Inc. (TSXV: SVE);
(OTCQX: SLVRF); (FSE: BRK1) – ("Silver One" or the "Company")
announces results of additional (phase 2) metallurgical testing
using a novel, cyanide-free leaching process from the Company's
100% owned, past-producing Candelaria
Silver Mine in Nevada
(Figure 1). Results confirm that the new technology can potentially
double silver recoveries of leach pad material and cut leaching
times. The tests were conducted on representative samples from the
two heap-leach pads (LP1 and LP2), as well as from the in-ground
mineralization marginal to the two main open-pits in the project.
The developer of the process, Extrakt Processing Solutions ("EPS"
or "Extrakt"), has a strategic global alliance with Bechtel Energy
Technologies & Solutions, Inc. ("Bechtel") to commercialize
Extrakt's TNS™ technology
(https://www.bechtel.com/newsroom/press-releases/extrakt-and-bechtel-partner-to-commercialize-groundbreaking-solid-liquid-separation-technology/).
This cyanide-free process is also being tested by other major
and junior resource companies in the US and Canada (see CJK Milling news release of
December 9, 2024, International
Mining News, December 12, 2024 and
Fulcrum Metals news release of December 18,
2024).
Although no commercial metal-leach operations using these
proprietary leach solutions exist at this time, the test results
from Candelaria mineralization are very promising, and indicate
significant potential for reducing costs and improving metal
recoveries in the near future. An upcoming Preliminary
Economic Assessment ("PEA") level study on the entire project
(Leach pad 1 "LP1", Leach pad 2 "LP2" and fresh in-situ
mineralization) will examine the potential benefits of using these
solutions in comparison to more traditional cyanide leaching
techniques. The PEA may be followed by a Pre-Feasibility Study on
the Leach Pads by themselves, and eventually on combining the leach
pads with the fresh in-situ mineralization.
Highlights
- The test results show that EPS' technology works well both in
agitated and column leaching processes. The technology is
especially effective in extracting silver from low-grade, processed
material from Candelaria's heap-leach pads LP1 and LP2, with
significantly reduced leach times compared with cyanide leaching
(see Company's news release of April 2,
2024).
- Column non-cyanide leaching has the potential to recover 63%
and up to 69% of the silver from LP1 and LP2 respectively,
compared with column cyanide leaching recoveries of 29% and 40%
from LP1 and LP2, respectively (See Table 1, and Company's news
release of May 21, 2019).
- Agitated non-cyanide leaching silver recoveries of LP1 reached
59.1% improving the 49.1% reported in the Company's news
release of April 2, 2024. These
recoveries exceed the silver recoveries achieved by agitated
cyanide leaching in earlier tests done by EPS, and in reported
historic cyanide-leach recoveries (See Company's news releases of
April 19, 2018, May 21, 2019, July 20,
2023, and April 2, 2024).
- EPS' agitated and column non-cyanide leach tests results on
fresh (not previously leached) material, suggest the innovative
technology may match or slightly exceed the silver recoveries
achieved by cyanide leaching. (See Table 1 and Company's news
releases of July 20, 2023,
June 14, 2023, and December 13, 2022).
Gregory Crowe, President and CEO
commented: "The results from the new testing confirm that EPS'
non-cyanide leach technology is effective at recovering silver, and
can potentially be a substitute to cyanide leaching. We are
particularly pleased with the results of the column tests which
simulate heap leaching extraction methods versus the more expensive
agitated leaching techniques. The column tests show that over 60%
of the silver in Candelaria's old heap-leach pads may be recovered
by using this innovative technology applied to heap leaching
methods, compared with previous studies that show only 29% to 40%
silver recoveries using cyanide leaching (Cyanide leach recoveries
were documented in Kappes Cassiday & Associates "KCA"
Candelaria Project HPGR Test Work, June
2019 unpublished report). These improved silver recoveries
may positively impact the overall economics of the project as
significant resources are contained in the leach pads (over 30
million ounces of silver in the indicated mineral resource category
and over 15 million ounces of silver in the inferred mineral
resource category, see Company's news releases of August 16, 2022 and August
18, 2020). EPS's leaching agents not only improve silver
extraction but are also more environmentally friendly and save
water by assisting in the dewatering of waste products. The
extraction process is simpler and potentially less costly.
Furthermore, we are optimistic about this innovative technology as
it is backed up by EPS' years of research and development and by
EPS' partnership with Bechtel."

Table 1. Silver recovery comparison of results between
Extrakt non-cyanide tests and Kappes Cassiday & Associates
("KCA") - McClelland lab tests (See Company's news releases of
April 2, 2024, July 20, 2023, June 14,
2023, December 13, 2022 and
May 21, 2019). Head grades for tests
are reported and discussed in Testing and Leach Results section
below.
Candelaria
- Metallurgical Testing Silver One
Samples
|
Silver
Recovery Comparison Extract - KCA -
McClelland
|
( Extracted %
Silver)
|
Sample type
&
size fraction
|
Extrakt Phase 2
Agitated Non-
Cyanide
Leach Tests
|
Extrakt
Phase 1
Agitated Non-
Cyanide
Leach Tests
|
Extrakt
Column Non-
Cyanide
Tests
|
KCA
Agitated
Cyanide
Leach
(BRT) Tests
|
KCA
Column
Cyanide
Tests
|
McClelland
Agitated
Cyanide
Leach
(BRT) Tests
|
Oxide
1.1-1.7mm
|
68.2
1
|
|
NA
|
|
52-70
4
|
|
Oxide 500 µm
|
68
|
|
|
|
|
|
Oxide 250 µm
|
71
|
|
|
|
|
|
Oxide 106 µm
|
|
|
|
60-76
3
|
|
|
|
|
|
|
|
|
|
Sulfide
1.1-1.7mm
|
59.4
1
|
|
66
|
|
60-60
4
|
|
Sulfide 500
µm
|
26
|
|
|
|
|
|
Sulfide 250
µm
|
38
|
|
|
|
|
|
Sulfide 106
µm
|
|
|
|
44-51
3
|
|
|
|
|
|
|
|
|
|
Mixed
1.1-1.7mm
|
80.4
1
|
|
NA
|
|
71-71
4
|
|
Mixed 500 µm
|
78
|
|
|
|
|
|
Mixed 250 µm
|
81
|
|
|
|
|
|
Mixed 106 µm
|
|
|
|
70-77
3
|
|
|
|
|
|
|
|
|
|
LP1
1.1-1.7mm
|
59.1
1
|
49.1
|
63
|
|
29
5
|
20.9
|
LP1 500 µm
|
51
|
59.9
|
|
|
|
|
LP1 250 µm
|
56
|
62.2
|
|
|
|
|
LP1 212 µm
|
|
|
|
|
|
32.5
|
LP1 150 µm
|
|
64.4
|
|
41-45
2
|
|
|
LP1 75 µm
|
|
71.2
|
|
|
|
42.9
|
|
|
|
|
|
|
|
LP2
1.1-1.7mm
|
51.1
1
|
|
69.4
|
|
40
5
|
27.9
|
LP2 500 µm
|
48
|
|
|
|
|
|
LP2 250 µm
|
55
|
|
|
|
|
|
LP2 212 µm
|
|
|
|
|
|
41.9
|
LP2 150 µm
|
|
|
|
54-60
2
|
|
|
LP2 75 µm
|
|
|
|
|
|
52.3
|
1
Optimized recovery after 4 tests
|
|
|
|
|
|
2 The
numbers indicate silver extraction at a low CN concentration (1%
CN) and at higher CN concentration (2% CN)
|
3 The
numbers indicate silver extraction of two different samples tested
(KCA tested 2 samples of each oxide, sulfide and mixed
material)
|
4 KCA
columns HPGR crush 1.7mm - CN Leach 158 days
|
5 KCA
columns HPGR crush 1.7mm - CN Leach 120 days
|
BRT - Bottle Roll
Test
|
Testing and Leach Results
Leach Pad Samples
Bulk samples representative of leach pad 1 (LP1) and leach pad 2
(LP2) weighing 228 kg and 263 kg respectively, composited from
sonic drill holes drilled and analyzed by Silver One in 2017 and
2018, were entirely crushed to ≤2 mm (<2000 microns) with a
Vertical Shaft Impact crusher at CEMCO's facilities in Belen, NM, and shipped to the EPS laboratory
in Kentucky for metallurgical
testing. The material consisted of leached oxide and partially
refractory material with silver head grade of 51.3 g/t and 50.1 g/t
for LP1 and LP2 respectively.
Representative portions of the bulk samples were weighed and
sieved to separate two fractions. Material smaller than 2 mm was
used for testing. The tests were conducted on 1 to 2 kg splits of
the sieved (<2 mm) material. Splits tested were prepared
according to acceptable industry standard practices (homogenized,
coned and quartered several times). The minus 2 mm size was
selected because of economic reasons, as it is a size fraction that
can be achieved with one single stage of HPGR crushing. This is
less expensive than milling to a much finer size and yields better
silver recoveries than those obtained by historical leaching of the
coarser (1 inch = 25.4 mm) material existing in Candelaria's leach
pads (see the Company's news release of April 19, 2018 and National Instrument 43-101
("NI 43-101") technical report filed on SEDAR+ by the Company in
2020 titled "Technical Report on the Heap Leach Pads within the
Candelaria Property").
The current optimized agitated-leach silver recoveries using
EPS' proprietary solutions average 59.1% for LP1, and 51.1%
for LP2 on samples as received at the lab (<2 mm = 2000
microns), which significantly exceed the 20.9% and 27.9% silver
recoveries achieved with cyanide leaching from bottle roll tests
using material of similar size of LP1 and LP2 respectively (See
Table 1 and the Company's news release dated May 21, 2019). Phase 1 leaching results of
samples tested at different particle sizes, show that the silver
recoveries increase with decreasing particle size which warrants
additional testing to optimize silver recoveries at finer grind
sizes and trade-off analysis to evaluate the economic benefits of
finer grinding. EPS' leach times during phase 2 testing were
between 6 and 7 hours further reducing the leach times of 48 hours
or more used for cyanide leaching.
EPS' column leach tests were done on minus 2 mm material for
both LP1 and LP2. The reported silver recoveries were 63% and 69%
for LP1 and LP2 respectively, which bode well for the prospects of
heap-leaching. These results above highlight the potential to use
EPS' technology in heap-leach scenarios (at crush sizes of 2 mm),
which may positively impact the economics of the project.
In-Ground Fresh Material Samples
Three drill-core samples from holes 132, 135 and 136 (see Figure
2 for location) crushed to 1.7 mm with HPGR by KCA, weighing 9.52
kg, 9.6 kg, and 37.1 kg respectively, were shipped to EPS
laboratory in Kentucky for
metallurgical testing. The samples consisted of oxide (drill hole
135), sulfide (drill hole 132) and mixed (drill hole 136)
mineralization with silver head-grades of 147 g/t, 419 g/t, and 115
g/t, respectively. These materials are representative of the
in-ground fresh mineralization extending below the Mount Diablo pit
(see Figure 1).
The samples were prepared in a similar manner as the LP samples
above. A split of the <2 mm fraction was tested as is, and 1 to
2 kg splits were further ground to 500 µm and 250 µm for agitated
leach testing. Column testing was performed on the sulfide sample
only due to insufficient oxide and mixed material.
Ther optimized silver recoveries of agitated leaching tests
using EPS' proprietary solutions are 68.2%, 59.4% and 80.4% for the
oxide, sulfide and mixed material as received at the lab (<2 mm
= 2000 microns) respectively. These recoveries are higher than the
silver recoveries reported by KCA with cyanide leaching from bottle
roll tests done at smaller particle size material (See Table 1 and
the Company's news release dated May 21,
2019). However, the column cyanide-leach silver average
recoveries obtained by KCA of 61%, 60% and 71% in the same oxide,
sulfide and mixed material crushed with HPGR to 1.7 mm (See Table 1
and the Company's news release dated June
14, 2023) suggest that cyanide leaching of fresh material
may reach similar range of recoveries so far achieved by EPS'
proprietary solutions.
Next Steps
The metallurgical test results reported here will be included
and evaluated in a Preliminary Economic Assessment ("PEA") level
study of the Candelaria project scheduled for 2025. The PEA will
cover the entire project (heap leach pads, stockpiles and in-ground
fresh mineralization). A Pre-Feasibility Study on the heap leach
pads is also being contemplated.
Analytical and QA/QC
Samples were assayed by American Assay Laboratories ("AAL") in
Sparks, NV, USA., (IAS accredited
Laboratory, ISO/IEC 17025:2005). AAL inserts blanks, standards and
includes duplicate analyses to ensure proper sample preparation and
equipment calibration. AAL analyzed heads, tails and pregnant
solution samples for silver by ICP-Ultra Trace (ICP-AES+ICP-MS
analyses). Solids were digested in acid (hydrofluoric, hydrochloric
and nitric acid) using teflon beakers. AAL is independent of both
Silver One and Extrakt.
Qualified Person
The technical content of this news release has been reviewed and
approved by Robert M. Cann, P. Geo,
a Qualified Person as defined by National Instrument 43-101 and an
independent consultant to the Company.
About Silver One
Silver One is focused on the exploration and development of
quality silver projects. The Company owns a 100%-interest in its
flagship project, the past-producing Candelaria Mine located in
Nevada. Potential reprocessing of
silver from the historic leach pads at Candelaria provides an
opportunity for possible near-term production. Additional
opportunities lie in unmined historic resources as well as in
previously identified high-grade silver intercepts down-dip, which
can potentially increase the substantive silver mineralization
along-strike from the two past-producing open pits.
The Company owns 636 lode claims and five patented claims on its
Cherokee project located in Lincoln
County, Nevada, host to multiple silver-copper-gold vein
systems, traced to date for over 11 km along-strike.
Silver One also owns a 100% interest in the Silver Phoenix
Project. The Silver Phoenix Project is a very high-grade native
silver prospect, recently permitted for drilling, which lies within
the "Arizona Silver Belt," immediately adjacent to the prolific
copper producing area of Globe, Arizona.
About Extrakt
Extrakt Process Solutions is a technology company that is
focused on separation technologies for recovering precious metals,
hydrocarbon separation as well as dewatering of mine waste and
other related processes. The company has a global patent portfolio
and continues to develop new processes and technologies.
See www.extraktps.com
About Bechtel
Bechtel is a trusted engineering, construction and project
management partner to industry and government. Differentiated by
the quality of our people and our relentless drive to deliver the
most successful outcomes, we align our capabilities to our
customers' objectives to create a lasting positive impact. Since
1898, we have helped customers complete more than 25,000 projects
in 160 countries on all seven continents that have created jobs,
grown economies, improved the resiliency of the world's
infrastructure, increased access to energy, resources, and vital
services, and made the world a safer, cleaner
place. Bechtel serves the Infrastructure; Nuclear,
Security & Environmental; Energy; Mining & Metals; and
Manufacturing & Technology markets. Our services span from
initial planning and investment, through start-up and operations.
See www.bechtel.com
Extrakt Partnership with Bechtel
Extrakt Process Solutions, LLC (Extrakt)
and Bechtel Energy Technologies & Solutions, Inc.
(BETS) have formed a strategic global technology alliance, to
commercialize Extrakt's novel, leaching technology and solid-liquid
separation technology, known as TNS™. TNS addresses the difficult
challenges of mine tailings, dewatering, and product recovery in a
sustainable, effective manner (see
https://www.bechtel.com/newsroom/press-releases/extrakt-and-bechtel-partner-to-commercialize-groundbreaking-solid-liquid-separation-technology/).
For more information, please contact:
Silver One Resources Inc.
Gary Lindsey - VP, Investor
Relations
Phone: 604-974‐5274
Mobile : (720) 273-6224
Email : gary@strata-star.com
Forward-Looking Statements
Information set forth in this news release contains
forward-looking statements that are based on assumptions as of the
date of this news release. These statements reflect management's
current estimates, beliefs, intentions and expectations. They are
not guarantees of future performance. Silver One cautions that all
forward-looking statements are inherently uncertain, and that
actual performance may be affected by a number of material factors,
many of which are beyond Silver One's control. Such factors
include, among other things: risks and uncertainties relating to
Silver One's limited operating history, ability to obtain
sufficient financing to carry out its exploration and development
objectives on the Candelaria Project, obtaining the necessary
permits to carry out its activities and the need to comply with
environmental and governmental regulations. Accordingly, actual and
future events, conditions and results may differ materially from
the estimates, beliefs, intentions and expectations expressed or
implied in the forward-looking information. Except as required
under applicable securities legislation, Silver One undertakes no
obligation to publicly update or revise forward-looking
information.
NEITHER TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICES
PROVIDER (AS THAT TERM IS DEFINED IN THE POLICIES OF THE TSX
VENTURE EXCHANGE) ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR
ACCURACY OF THIS RELEASE.
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