Northwest Copper Reports Positive Metallurgical Recoveries of 94% Copper, 71% GOLD and 92% Silver at the Lorraine Deposit
News Release
NORTHWEST COPPER REPORTS POSITIVE METALLURGICAL RECOVERIES OF 94%
COPPER, 71% GOLD AND 92% SILVER AT THE LORRAINE DEPOSIT
Vancouver, BC – June 24, 2024 – NorthWest Copper (“NorthWest” or “the Company”) (TSX -V: NWST) is pleased to
report that positive metallurgical results have been achieved from the first modern metallurgical work completed
on samples from the Lorraine copper-gold-silver deposit, located in north-central British Columbia. Highlights of the
test work include:
• High batch cleaner flotation recoveries of up to 94% , 71% and 92% for copper (Cu), gold (Au) and silver
(Ag), respectively.
• High metal recoveries at a relatively coarse primary grind size of 80% passing 150 microns.
• Production of Cu concentrates with 31 to 54% Cu that contain 7.4 to 25.4 g/t Au and 152 to 405 g/t Ag,
and also up to 1.64 g/t palladium (Pd) and anomalous platinum (Pt).
• Low concentrations of potentially deleterious trace elements in the Cu concentrate.
“These metallurgical results demonstrate that mineralization in our Lorraine deposit can potentially produce high
metal recoveries to a clean, high-grade salable copper concentrate”, stated Tyler Caswell, Vice President Exploration
for NorthWest. “The results also highlight several opportunities for optimizing future metallurgical work, improving
metal recoveries and evaluating other beneficial metal recovery-energy consumption trade-offs to positively impact
future project evaluation.”
The test work program described below was designed by Base Metallurgical Laboratories Ltd. (“Base Met”) and
BOMENCO Minerals Engineering Corp. The work was executed by Base Met in their facilities in Kamloops, BC. Both
groups are independent of NorthWest. Samples for compositing were collected by the NorthWest Copper geology
team.
Composite Samples
The metallurgical program tested five composite samples that ranged from 19.6 kg to 37.4 kg in size, and included
one from the Bishop Zone (BZC) and four from the Lower Main Zone (LMC1-4; Table 1). Two composites were created
from half-split historical drill core, which was deemed suitable for scoping test work because it was intact, had been
well stored, and had very low pyrite concentration that minimized surface oxidation of sulphide minerals . The
remaining three samples are from the Lower Main Zone and comprised assay coarse reject material from drill holes
completed by Northwest in 2022 . These crushed materials have a large surface area compared to intact core, and
to prevent surface oxidation of the sulphide minerals these three samples were placed in frozen storage immediately
after routine geochemical analyses. The samples contain disseminated copper mineralization hosted by pyroxenite
and syenite, which are the predominant material types in the Lorraine deposit. The samples were selected to be
reasonable geological and geochemical representations of the main styles of mineralization at Lorraine, as currently
understood, and therefore are interpreted to be reasonable for use in the scoping metallurgical test work reported
here. Copper concentrations in the five composites range from approximately average (0.61 % Cu) to higher grade
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(1.21% Cu) , in comparison to t he average grade of 0.55% Cu in the indicated mineral resources estimate at the
Lorraine deposit.1
Table 1. Composite characteristics and head assay grades.
Composite Material
Used Rock Type Mass
(kg)
Head Assay
Cu% Au g/t Ag g/t Pt g/t Pd g/t S%
Bishop
Zone (BZC) Half core pyroxenite 36.5 1.15 0.14 9.60 <0.01 0.03 0.51
Lower Main
Zone
(LMZ1)
Half core syenite 31.5 1.21 0.86 8.80 <0.01 0.01 0.64
Lower Main
Zone
(LMZ2)
Coarse
Rejects syenite 26.7 0.79 0.31 4.80 <0.01 0.01 1.16
Lower Main
Zone
(LMZ3)
Coarse
Rejects
syenite &
monzonite 37.4 0.77 0.36 6.00 <0.01 0.01 0.38
Lower Main
Zone
(LMZ3)
Coarse
Rejects pyroxenite 19.6 0.61 0.30 3.40 <0.01 0.03 0.46
Summary of Recovery Tests
Two sets of five-stage rougher flotation tests compared results from typical porphyry (75 µm) and coarse (150 µm)
primary K80 grind sizes (Table 2). Copper recoveries of 94-98% were achieved at the finer grind, whereas the coarse
grind recovered 90-99% Cu (Figure 1). Overall recoveries at the two grind sizes ranged from 66-90% for Au, and from
86-97% for Ag. The results support potential to beneficiate Lorraine mineralization at a relatively coarse, possibly
energy-saving grind size without a large impact on metal recovery, and this opportunity can be assessed by future
grind size versus metal recovery trade off studies . A gravity test on 150 µm grind size material recovered 4-24% of
gold to a gravity concentrate, and when the gravity tails were treated by rougher flotation there was a modest
improvement in overall gold recovery, providing an additional possible avenue to further improve performance.
Table 2. Summary of rougher flotation recoveries.
Comp
Primary
Grind Size
(µm K80)
Recovery (%)
Cu Au Ag Pt Pd
BZC 75 97.8 86.3 96.9 37.9 75.2
150 99.0 89.5 97.0 35.4 75.0
LMC1 75 94.3 80.4 92.9 20.9 37.8
150 89.7 70.5 85.6 31.8 38.3
LMC2 75 96.5 76.8 90.8 15.6 45.5
150 95.3 82.9 85.7 29.3 50.6
LMC3 75 93.9 81.5 93.2 19.7 41.9
1 See NI 43 -101 technical report titled “Lorraine Copper-Gold Project NI 43 -101 Report & Mineral Resource Estimate Omineca Mining Division, B.C”,
dated September 12, 2022 with an effective date of June 30, 2022, filed under the Company’s SEDAR + profile at www.sedarplus.com.
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150 93.6 85.7 88.3 20.5 47.1
LMC4 75 95.5 75.4 88.5 33.8 68.1
150 91.8 66.4 88.1 38.5 62.9
Figure 1. Copper recovery curves for rougher flotation tests at two primary grind sizes .
Cleaner flotation tests go an important step beyond rougher tests and more closely simulate concentrate production
potential. Cleaner tests were completed on material ground to 150 µm for initial rougher flotation, followed by a
regrind targeting a 25 µm size before progressing through three-stage open circuit cleaner flotation. The samples
performed extremely well (Table 3). The Bishop Zone composite had Cu, Au and Ag recoveries of 94%, 71% and 92%,
respectively, to a concentrate with 54% Cu , 7.4 g/t Au , and 405 g/t Ag . Samples from the Lower Main Zone had
recoveries of 83-89% Cu, 57-70% Au, and 74-83% Ag to concentrates with 31-49% Cu, 11-25 g/t Au, and 152-360 g/t
Ag. The high Cu concentrations in the concentrate (up to 54% Cu) reflect the h ypogene (unweathered) copper
sulphide mineralogy of the mineralization, which in addition to chalcopyrite (~34 wt % Cu) also includes bornite (~63
wt % Cu) and chalcocite (~80 wt % Cu). Intriguingly, two samples also returned 1.41 and 1.64 g/t P d accompanied
by significantly anomalous P t. Analyses of the five copper conc entrates pro duced by the cleaner flotation tests
demonstrate that Lorrain e can produce high quality concentrates with all trace elements below likely penalty
threshold concentrations.
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Table 3. Cleaner concentrate compositions and recoveries.
Comp
Cleaner Concentrate Performance
Assay % or g/t Recovery%
Cu Au Ag Pt Pd Cu Au Ag Pt Pd
BZC 54.4 7.35 405 0.21 1.41 94.2 71.2 91.5 28.8 76.1
LMC1 48.4 25.4 317 0.06 0.21 83.4 57.2 78.5 10.2 27.6
LMC2 31.3 11.3 152 0.04 0.22 89.1 69.3 74.3 7.8 29.9
LMC3 48.9 22.5 360 0.08 0.38 85.6 70.1 82.5 9.1 29.9
LMC4 52.3 20.0 292 0.26 1.64 87.4 64.8 79.5 19.5 53.6
Comminution Tests
Bond Ball Mill work indices were measured on each of the five composites to assess grindability. Results range from
15.0 kWh/t (average hardness) to 20.3 kWh/t (very hard) and are in line with expectations that were based on core
competency and rock mineralogy and texture.
Table 4. Glossary of Terms2
Ball Mill A mill in which tumbling steel balls grind larger particles to a smaller size.
Comminution The breaking of large particles into smaller particles. The most common comminution
processes are crushing and grinding.
Composite A larger sample created by combining several smaller samples.
Concentrate The valuable product from a flotation mineral processing plant.
Flotation
A common mineral recovery process whereby chemicals are added to water to cause
target minerals (such as Cu minerals) to attach to rising air bubbles, which are then
removed to recover the ore minerals into a concentrate.
Recovery The percentage of the valuable metal present in the feed that reports to the concentrate.
Lorraine
The Lorraine deposit is part of the Lorraine Project. The Lorraine Project covers 56,000 hectares and is located in
north-central British Columbia, 280 km northwest of Prince George, BC and approximately 40 km from NorthWest’s
Kwanika-Stardust Project. The Lorraine deposit is located near the centre of the Project tenure and is a silica -
undersaturated alkalic copper-gold porphyry deposit, which is the same classification as the Galore Creek and Mount
Polley deposits. 3 Mineralization at the Lorraine deposit is hosted mostly by Early Jurassic syenite and pyroxenite
intrusions that are part of the Duckling Creek Syenite Complex (“DCSC”). A modern, compliant mineral resource
estimate (MRE) was completed in 2022 that includes indicated resources of 12.952 Mt grad ing 0.55% Cu and 0.16
g/t Au, and inferred resources of 45.252 Mt grading 0.43% Cu and 0.10 g/t Au. 4 As described in previous disclosures,
however, gold concentration is likely understated and silver was not included in the estimation because many
historical drill holes were inconsistently analyzed for the two metals . The MRE extends to surface and includes the
2 https://www.911metallurgist.com/blog/mineral-processing-glossary
3 Lang et al. (1995) Triassic-Jurassic silica-undersaturated and silica-saturated alkalic intrusions in the Cordillera of British Columbia: Implications for arc
magmatism. Geology, v. 23, p. 451-454.
4 See NI 43 -101 technical report titled “Lorraine Copper -Gold Project NI 43 -101 Report & Mineral Resource Estimate Omineca Mining Division, B.C”,
dated September 12, 2022 with an effective date of June 30, 2022, filed under the Company’s SEDAR + profile at www.sedarplus.com.
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Lower Main, Upper Main, and Bishop Zones and intervening rock. Copper sulphides manifest various combinations
of chalcopyrite, bornite and hypogene chalcocite, and the concentration of pyrite is generally low. Gold and silver,
where analyzed, are spatially related to the copper mineralization, and elevated concentrations of platinum and
palladium have been reported in several published papers.
Quality Assurance / Quality Control (QA/QC)
Geochemical analyses reported by Base Met utilize a variety of analytical methods to optimize results for specific
elements and elemental groups . All analyses were completed by Base Met, with exception of chlorine and fluorine
analysis. Gold was analyzed by fire assay with AAS finish , whereas platinum-palladium is based on fire assay with
ICP-OES finish. Sulphur and TOC were measured by LECO. Copper was determined by single element aqua regia
digestion with AAS finish , whereas silver, arsenic and antimony use d an ICP-OES finish. Other trace elements were
measured by aqua regia digestion and ICP -OES analysis. Whole rock analy ses use ICP-OES following total digestion
by lithium metaborate fusion. Chlorine was analyzed by Short Lived INAA using method code 4F-Cl, and fluorine was
determined by Fusion Specific Ion Electrode analysis (method code 4F- F) at Activation Laboratories in Ancaster,
Ontario. All methods employed certified reference materials for analytical control.
Drilling completed at Lorraine in 2022 was supervised by on -site NorthWest personnel who collected and tracked
samples and implemented a full QA/QC program using blanks, standards and duplicates to monitor analytical
accuracy and precision. The samples were sealed on site and shipped to AGAT Laboratories (AGAT) in Calgary,
Alberta. AGAT’s quality control system complies with global certifications for Quality ISO 9001:2015. Core samples
were analyzed using a combination of AGAT’s 201 -071 process for low -level concentrations (ICP -MS/4 Acid
digestion) and higher-level concentrations were finalized with method 201- 097 (Sodium Peroxide Fusion/ICP -OES).
Gold assaying was completed with 202-055, a 30-gram fire assay with ICP finish.
Technical aspects of this news release have been reviewed, verified, and approved by Tyler Caswell, P.Geo., VP
Exploration of NorthWest, and Matt Bolu, M.Sc., P.Eng., P rincipal Metallurgical Engineer, BOMENCO Minerals
Engineering Corp , both of who m are qualified persons as defined by National Instrument 43 -101 – Standards of
Disclosure for Minerals Projects.
About NorthWest Copper:
NorthWest Copper is a copper-gold explorer with a pipeline of advanced and early-stage projects in British Columbia.
With a robust portfolio in a tier one jurisdiction, NorthWest Copper is well positioned to participate fully in a
strengthening global copper market. We are committed to responsible mineral exploration and are working
collaboratively with First Nations to ensure future exploration and development incorporates stewardship best
practices and traditional land use. Additional information can be found on the Company’s website at
www.northwestcopper.ca.
On Behalf of NorthWest Copper Corp.
“Tyler Caswell”
Vice President, Exploration
For further information, please contact:
604-683-7790
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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Cautionary Statement Regarding Forward-Looking Information
This news release contains “forward-looking information” within the meaning of applicable securities laws. All statements, other than statements
of historical fact, are forward-looking statements and are based on expectations, estimates and projections as at the date of this news release.
Any statement that involves discussion with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions, future
events or performance (often, but not always using phrases such as “plans”, “ex pects”, “is expected”, “budget”, “scheduled”, “estimates”,
“forecasts”, “intends”, “anticipates”, or “believes” or variations (including negative 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) are not statements of historical fact and may
be forward-looking statements. In this news release, forward-looking statements relate, among other things, to statements with respect to; plans
and intentions of the Company; the potential increase to metal recoveries, the expected copper concentrate quality, the potential for reduction
in ball mill grinding energy, the expected copper , gold and silver recoveries, the possibility of adding gold and silver in future Mineral Resource
Estimates and studies, proposed exploration and development of NorthWest’s exploration property interests; the Company’s ability to finance
future operations; the potential size of a mineralized zone or potential expansion of mineralization; geological interpretations; the estimation of
Mineral Resources; future operations; mine plans, and magnitude or quality of mineral deposits.
All statements, other than statements of historical fact, included herein, constitutes forward-looking information. Although NorthWest believes
that the expectations reflected in such forward-looking information and/or information are reasonable, undue reliance should not be placed on
forward-looking information since NorthWest can give no assurance that such expectations will prove to be correct. Forward-looking information
involves known and unknown risks, uncertainties and other factors that may cause ac tual results or events to differ materially from those
anticipated in such forward-looking information, including the risks, uncertainties and other factors identified in NorthWest’s periodic filings with
Canadian securities regulators. Forward-looking information are subject to business and economic risks and uncertainties and other factors that
could cause actual results of operations to differ materially from those contained in the forward-looking information. Important factors that could
cause actual results to differ materially from NorthWest’s expectations include risks associated with the business of NorthWest; risks related to
reliance on technical information provided by NorthWest; risks related to exploration and potential development of the Compan y’s mineral
properties; business and economic conditions in the mining industry generally; fluctuations in commodity prices and currency exchange rates;
uncertainties relating to interpretation of drill results and the geology, continuity and grade of mineral deposits; the need for cooperation of
government agencies and First Nation groups in the exploration and development of properties and the issuance of required per mits; the need
to obtain additional financing to develop properties and uncertainty as to the availability and terms of future financing; the possibility of delay in
exploration or development programs and uncertainty of meeting anticipated program milestones; uncertainty as to timely availability of permits
and other governmental approvals; and other risk factors as detailed from time to time and additional risks identified in NorthWest’s filings with
Canadian securities regulators on SEDAR+ in Canada (available at www.sedarplus.com).
Forward-looking information is based on estimates and opinions of management at the date the information are made. NorthWest does not
undertake any obligation to update forward -looking information except as required by applicable securities laws. Investors should not place
undue reliance on forward-looking information.