Fireweed Announces Positive Metallurgy from Boundary Zone, Macmillan Pass
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NEWS RELEASE
November 1st 2022 TSXV: FWZ
OTCQB: FWEDF
FSE:20F
Fireweed Announces Positive Metallurgy from Boundary Zone, Macmillan Pass
Vancouver, British Columbia: FIREWEED METALS CORP. (“Fireweed” or the “Company”)
(TSXV: FWZ; OTCQB: FWEDF, formerly known as Fireweed Zinc Ltd.) is pleased to
announce the results of the first metallurgical and ore-sorting test work from Boundary
Zone, an emerging zinc discovery at Macmillan Pass, Yukon, Canada.
Highlights
• Open circuit cleaner flotation tests show up to 97% zinc recovery.
• Zinc concentrates show high grades ranging from 53% to 63% zinc.
• A coarse grind size yields excellent recovery, with up to 99% in rougher tests.
• Three critical minerals are present in concentrates: zinc, germanium, and gallium.
• Selective use of ore sorting only on low-grade material shows promising results for
potentially increasing feed grades, decreasing processing costs, and reducing
tailings volumes whilst preserving the value in the abundant high-grade zones at
Boundary.
CEO Statement
Brandon Macdonald, CEO, stated “The first metallurgical results from Boundary Main are
back and show excellent results. The coarse nature of the sphalerite means that a relatively
coarse grind size is all that is needed to produce a high-grade zinc concentrate with high
recoveries. We have shown that Boundary Zone, like Tom and Jason, can produce high-
quality zinc concentrates that we anticipate would be attractive to global markets. High
concentrations of germanium and moderate concentrations of gallium in the zinc
concentrates highlight the potential for recovery of these critical metals as by-products
during the zinc smelting process. Even though we see by far the most potential economic
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value in the zinc, the addition of germanium and gallium to the mix brings the total of
different critical metals present at Boundary Zone to three. This elevates the potential of the
Macmillan Pass project to be one of Canada’s leading critical minerals projects.”
Plain Language Summary
Preliminary test work has been carried out on samples from Fireweed’s new zinc discovery
at Boundary Zone at the Macmillan Pass project, Yukon. These tests provide an initial
impression of how the zinc- and lead-bearing rocks may respond to crushing, grinding, and
processing to produce zinc and lead concentrates.
The test results are very promising: the rocks have a moderate to moderately high
hardness; a reasonably coarse grind size is sufficient to liberate zinc and lead minerals; and
high-grade zinc concentrates can be produced from most of the material tested from
Boundary Zone with only small amounts of zinc loss during processing.
Lead is only a minor component of the mineralization at Boundary Zone and only samples
with appreciable amounts of lead were metallurgically tested with a dedicated lead circuit.
Lead test work results were variable and generally poorer than for zinc. With the relatively
low lead content of Boundary Zone shown to date, this likely limits the overall economic
importance of lead.
Likewise, there is limited silver in much of Boundary Zone Main, and the samples showed
low silver grades. This metallurgical testing showed variable results for the limited silver in
the material tested, however silver has never been of material economic importance in this
zone.
Ore sorting is a process where mined material is scanned for various properties, including
density and metal concentration, and then sorted to remove waste before milling. The test
work results showed that the low-grade material that surrounds the higher grade zones at
Boundary Main has properties which make it suitable for ore sorting, and there exists an
exciting possibility of deploying this technology to reduce costs and improve economics at
the project. Higher grade zones would likely not be sorted to prevent any losses of the
higher-value material during the sorting process.
The test work is preliminary in nature, and further testing is required to more accurately
predict the behaviour of Boundary Zone material during processing. However, the results
suggest metallurgical performance for zinc could be excellent and should not be an
impediment in demonstrating reasonable prospects for eventual economic extraction.
Description of Metallurgical Test Work
Approximately 2.6 tonnes of drill core from Boundary Zone were analyzed by Base
Metallurgical Laboratories of Kamloops, BC for ore characterization, preliminary flotation
optimization, variability testing, and ore sorting test work. Two parallel streams of test work
were conducted: one conventional flotation stream, and a stream with an ore sorting pre-
concentration step.
Representative drill core from Boundary Zone was quartered, with one set of quarter-core
samples used for the conventional flotation test work stream without sorting, and the other
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parallel set of quarter-core samples used for ore sorting tests prior to flotation test work. A
total of nine composites were made to represent the range of lithologies and mineralization
styles found at Boundary Zone; two were waste rock domains and not subjected to
metallurgical testing.
Flotation test work involved the production of a zinc concentrate in an open circuit batch
test. Two of the seven mineralized composites had significant lead head grades and
included a lead circuit to produce a lead concentrate prior to zinc flotation. Rougher tests
were performed, followed by open circuit cleaner flotation tests.
Preliminary ore sorting test work was carried out to demonstrate the potential to use
sensor-based particle sorting as a pre-concentration step to increase feed grades for the
lower grade material at Boundary Zone. A sequential combination of X-Ray Transmission
(XRT) and X-Ray Fluorescence (XRF) sensors was tested.
Composite Selection and Boundary Zone Geology
The nine composites described in Table 1 below were created from NB19-001 and NB19-
002, two holes drilled at Boundary during the 2019 field season (Map 1), representing the
mineralization styles and waste rock present at Boundary Main. The five composites
selected for cleaner flotation tests are shown on Cross Section A-A’ with preliminary
geometallurgical domains that have been interpreted based on rocks of similar lithology
and mineralogy.
Table 1: Description of sample composites, head grades, and flotation tests conducted.
Composite Description Zinc (%) Lead (%) Silver (g/t) Testing
Volcanic 1 Typical material
present from surface
to vertical depths of
200-250 m,
comprising bulk of
zinc mineralization
interpreted present
at Boundary Main
4.20 0.10 4.9 Zn circuit
Clastic 2 1.39 0.03 1.8 Zn circuit
High Grade
3
16.70 0.37 30.0 Zn circuit
Clastic 5 Pyrite-rich material
sampled in footwall
of a significant fault
at Boundary Main;
small domain above
Volcanic 1
1.56 0.64 10.2 Zn circuit,
Pb circuit
Clastic 6 Low grade 0.62 0.14 4.2 Zn rougher
circuit
Volcanic 7 Small domains that
occur at depth at
Boundary Main
3.60 1.87 30.1 Zn circuit,
Pb circuit
Mudstone 8 1.64 0.24 6.4 Zn circuit
Waste 4 Waste. Not used
Waste 9 Waste. Not used
Further test work is required to fully evaluate the variability across Boundary Zone and
assess whether the metallurgical behaviour throughout each domain is consistent.
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The massive sulphide mineralization at Boundary West was discovered after samples were
selected for this first round of metallurgy testing and is not represented by composites
disclosed in this news release (for details of Boundary West mineralization see Fireweed
news releases dated February 3rd 2021, and September 16th 2021). Flotation test work is
currently underway on a composite of that new domain. The laminated stratiform
mineralization at Boundary West (see Fireweed news release September 16th 2021) and at
Boundary Main (see Fireweed news release September 13th 2022) was also discovered after
initial metallurgy sample selection so is not represented in this news release, but is
anticipated to have a similar metallurgical response to the texturally and mineralogically
comparable styles of mineralization previously tested at the Tom and Jason deposits (see
Fireweed news release dated May 15th 2018) and will be the subject of future metallurgical
testwork.
Rougher Flotation Tests
All rougher tests were conducted using a primary grind size of 75 µm K80 except for
composite High Grade 3, which used a coarser grind of 95 µm K80. Recovery of zinc was
very good, with recoveries of 94-99% for the Volcanic 1, Clastic 2, High Grade 3 and Clastic 5
composites that represent the bulk of the near-surface mineralized material at Boundary
Main (Cross Section A-A’). These composites yielded zinc rougher concentrates that ranged
from 14.5% Zn to 44.6% Zn, reflecting a wide range of head grades of 1.39% Zn to 16.7% Zn.
Slightly lower recoveries of 78-88% were produced from the Clastic 6, Volcanic 7 and
Mudstone 8 composites (Table 2).
The material tested from Boundary Main was generally lead-poor, unlike the stratiform,
laminated mineralization that occurs at Tom, Jason and other parts of Boundary Zone. Only
two composites were tested with a lead circuit prior to the zinc circuit. Clastic 5 had poor
performance with 10.9% rougher recovery at 1.7% Pb due to low head grades (0.64% Pb) and
high pyrite content. Volcanic 7 had better results with rougher recovery of 77.5% at 7.75% Pb
due in part to higher head grade (1.87% Pb).
Open Circuit Cleaner Flotation Testing
Regrinding of rougher concentrates was carried out to a sizing of K80 13 to 36 µm for the zinc
circuit and 12-21 µm for the lead circuit, where tested. Open circuit zinc cleaner tests were
conducted on six samples that yielded zinc recovery between 68 and 97 percent at
concentrate grades between 53 and 63 percent zinc (Table 3). Similar to rougher tests, the
near-surface geometallurgical domains Volcanic 1, Clastic 2, High Grade 3, and Clastic 5 that
represent the bulk of the mineralization at Boundary Main produced better results, with zinc
recovery of 83.3 to 97.1 percent, showing higher recovery at higher feed grades.
Zinc cleaner concentrate grades are above grades typically required for marketable zinc
concentrates. Silver is present in the zinc concentrate at levels below the typical threshold
to be payable. The concentrate is anticipated to be saleable, although it will attract a
modest penalty due to the moderate mercury concentrations (Table 4). Mercury penalties
could potentially be reduced by blending with lower mercury content concentrate, such as
the 155 ppm mercury in zinc concentrate produced from the global composite tested from
the Tom and Jason deposits (see Fireweed news release dated May 15th, 2018). Mercury
concentrations are lower in the near surface Volcanic 1, Clastic 2 and High Grade 3 domains
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than the smaller geometallurgical domains present at greater depths. Iron is present in
desirably low concentrations (2.35-6.39%). The critical metals germanium and gallium are
present in concentrations that are potentially recoverable by zinc smelters with appropriate
recovery circuits.
Two composites had head grades high enough to warrant consideration of a lead circuit
and test work yielded mixed results, with silver generally reporting to the lead concentrate.
Only a limited amount of optimization was carried out to attempt to improve recovery as
lead and silver comprise only a small portion of the mineralization discovered to date at
Boundary Main and much of the mineralization is zinc-only. Fireweed anticipates that
running a zinc-only flotation circuit for low lead-silver material in any future potential
Boundary Zone development plans has the potential to reduce processing costs compared
to running both lead and zinc circuits. If Boundary Zone were to be co-developed with the
Tom and Jason deposits, Fireweed anticipates that a lead circuit would be implemented
before the zinc circuit to recover lead and silver from zones at Tom, Jason and Boundary
where high lead and silver grades occur.
Ore Sorting Results
Ore sorting test work was performed by Steinert (Germany), and resultant assays and
analyses were performed by Base Metallurgical Laboratories (Kamloops, BC). XRT sorts
material by density whereas XRF sorts by geochemistry; XRF was included due to the
presence of dense siderite (iron carbonate) which cannot be distinguished from dense
sulphide minerals in XRT testing alone. A combination of XRT and XRF yielded the best zinc
recovery (87-99%) but at a high mass pull (42-90%). Sorting by XRF only showed promising
results, particularly for lower grade material where lower recovery may be deemed more
acceptable, with zinc recovery of 75-88 percent at mass pulls of 36 to 52 percent (Table 5).
The high-grade composite was not included in ore-sorting tests, as such material is prone
to risk of excessive metal loss from sorting, assuming the material is selectively mined. Ore
sorting has the potential to add value to the project by potentially reducing processing
costs, increasing feed grades by pre-concentration, and reducing tailings volumes.
Although Fireweed sees the potential for a successful project without the need for ore
sorting, Fireweed anticipates that the pre-concentration of only the low-grade material by
ore sorting has the greatest potential to add additional value to the project. Ore sorting on
the lower grade composites achieved the highest mass rejection, resulting in the greatest
upgrade ratio of the feed material. This upgrading shows the potential for the extraction of
the critical mineral zinc from stockpiles of material that may normally be considered as
waste, mined coincidentally whilst extracting higher-grade material, potentially increasing
value and lowering environmental impacts. Fireweed cautions that the ore sorting test
results are preliminary in nature, and may or may not be included in future processing plans
at Boundary Zone.
Comminution
Comminution test work determined the grinding energy required to liberate zinc and lead
minerals prior to flotation, and abrasion testing to determine mill and grinding media wear
characteristics:
• Bond ball mill work index (BWi) tests at a sieve size of 106 µm showed the material to be
moderate to moderately hard with BWi values ranging from 13.2 to 18.3 kWh/t.
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• SAG mill comminution testing derived A*b values between 39 to 52, which classifies the
composites as average with respect to hardness.
Mineralogy
A QEMSCAN Bulk Mineral Analysis (BMA) and quantitative X-Ray Diffraction (XRD) were
conducted to determine the mineralogical composition of the seven composites.
Mineralogical composition was used to estimate the concentrations of reagents to optimize
flotation. Up to 26.8% sphalerite and up to 2.5% galena was present in the composites,
confirming the un-oxidized, sulphide nature of the mineralization.
Notes on sampling, assaying, and data aggregation: The diamond drill core logging and
sampling program was carried out under a rigorous quality assurance / quality control
program using industry best practices. Drill intersections in this release are all HQ3 (split
tube) size core (61.1mm / 2.4-inch diameter) with recoveries typically above 85%. After
drilling, core was logged for geology, structure, and geotechnical characteristics, then
marked for sampling and photographed on site. The cores for analyses were marked for
sampling based on geological intervals with individual samples 1.5 m or less in length. Drill
core was cut lengthwise in half with a core saw and each half cut again to produce four
parallel quarter-core samples; one quarter was sent for assay (previously reported in
Fireweed news releases dated October 16th 2019 and November 5th 2019), one quarter
stored on site for reference, one quarter used for ore sorting tests, and one quarter used for
flotation test work with no ore-sorting. In September 2019, samples were transported to
Base Metallurgical Laboratories, Kamloops, BC, by truck and stored there until test work
was initiated in Q2 2021. Samples were transported between Base Metallurgical
Laboratories and Steinert, Germany, by air and ground courier. Metallurgical test work,
assays, mineralogy, comminution tests, and final reporting were completed by September
2022.
Metallurgical test work, and associated assays, including Zn, Pb, and Ag assays of heads,
tails, and cleaner concentrates were performed by Base Metallurgical Laboratories Ltd.,
Kamloops, British Columbia (Independent laboratory). Rougher flotation batch tests used a
representative 2 kg split, except for composite High Grade 3 that used a 1 kg split. Rougher
concentrates were used as inputs for the cleaner tests following re-grinding. Cleaner test
sample sizes varied depending on the mass pull to the rougher concentrates (Table 2).
Extended multi-element assays of zinc concentrates were performed by ActLabs of
Ancaster, Ontario (Independent laboratory) by sodium peroxide fusion ICP-OES and ICP-MS,
Hg-cold vapour atomic absorption and aqua regia ICP-MS. Assay data verification was
achieved by the analysis of laboratory standards, duplicates, and blanks. Head assays were
taken in duplicate and average values are reported here. Flotation test assay data were
verified through the comparison of recalculated and measured heads. Sample size for Bond
mill work index tests was 750 ml. SAG mill comminution tests used 100 pieces of cut drill-
core.
Qualified Person Statement
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Technical information in this news release has been approved by Jack Milton, P.Geo., Ph.D.,
Chief Geologist and a ‘Qualified Person’ as defined under Canadian National Instrument 43-
101.
About Fireweed Metals Corp. (TSXV: FWZ; OTCQB: FWEDF; FSE:20F): Fireweed Metals is a
public mineral exploration company on the leading edge of Critical Minerals project development.
The Company has three projects located in northern Canada:
• Macmillan Pass Zinc-Lead-Silver Project: Fireweed owns 100% of the district -scale 940
km2 Macmillan Pass project in Yukon, Canada, which is host to the Tom and Jason zinc-
lead-silver deposits with current Mineral Resources and a PEA economic study (see
Fireweed news releases dated 10 th January 2018, and 23 rd May 2018, respectively, and
reports filed on www.sedar.com for details) as well as the Boundary Zone, Boundary Zone
West, Tom North Zone and End Zone which have significant zinc -lead-silver
mineralization drilled but not yet classified as mineral resources. The project also includes
large blocks of adjacent claims with known showings and significant upside exploration
potential. A large , four-rig 2022 drill program is now complete and assay results are
pending.
• Mactung Tungsten Project: The Company has a binding Letter of Intent to acquire 100%
interest in the 37.6 km2 Mactung Tungsten Project located adjacent to the Macmillan Pass
Project. Mactung contains historic resources that make it one of the largest and highest -
grade undeveloped tungsten resources in the world. Located in Canada, it is one of the
rare large tungsten resources outside of China. Due diligence and validation work on
historic data as well as relogging and sampling of historic drill core is underway and will
support a new mineral resource estimate.
• Gayna River Zinc- Gallium-Germanium Project: Fireweed has 100% of the 128.75 km 2
Gayna River project located 180 kilometres north of the Macmillan Pass project. It is host
to extensive critical minerals mineralization including zinc, gallium and germanium as well
as lead and silver, outlined by 28,000 metres of historic drilling and significant upside
potential. The 2022 field program of airborne LiDAR topographic surveying, and ground
geophysics was recently completed and data is being interpreted toward defining 2023
drill targets.
In Canada, Fireweed (TSXV: FWZ) trades on the TSX Venture Exchange. In the USA, Fireweed
(OTCQB: FWEDF) trades on the OTCQB Venture Market for early stage and developing U.S. and
international companies and is DTC eligible for enhanced electronic clearing and settlement. The
Company is current in its reporting and undergoes an annual verification and management
certification process. Investors can find Real -Time quotes and market information for the
Company on www.otcmarkets.com. In Europe, Fireweed (FSE: 20F) trades on the Frankfurt Stock
Exchange.
Additional information about Fireweed and its projects can be found on the Company’s website
at
www.FireweedMetals.com and at www.sedar.com .
ON BEHALF OF FIREWEED METALS CORP.
“Brandon Macdonald”
CEO & Director
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Neither the 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.
Cautionary Statements
Forward Looking Statements
This news release may contain “forward -looking” statements and information relating to the
Company and its projects that are based on the beliefs of Company management, as well as
assumptions made by and information currently available to Company management. Such
statements reflect the current risks, uncertainties and assumptions related to certain factors
including but not limited to, without limitations, exploration and development risks, expenditure and
financing requirements, general economic conditions, changes in financial markets, the ability to
properly and efficiently staff the Company’s operations, the sufficiency of working capital and funding
for continued operations, title matters, First Nations relations, operating hazards, political and
economic factors, competitive factors, metal prices, relationships with vendors and strategic
partners, governmental regulations and oversight, permitting, seasonality and weather, technological
change, industry practices, and one -time events. Should any one or more risks or uncertainties
materialize or change, or should any underlying assumptions prove incorrect, actual resu lts and
forward-looking statements may vary materially from those described herein. The Company does not
undertake to update forward‐looking statements or forward‐looking information, except as required
by law.
Contact:
Brandon Macdonald
Phone: (604) 646-8361