Highland Copper Completes Phase 1 Engineering and Announces Positive Results from Trade-Off Studies at Its Copperwood Project
October 15, 2025
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HIGHLAND COPPER COMPLETES PHASE 1 ENGINEERING AND ANNOUNCES POSITIVE RESULTS
FROM TRADE-OFF STUDIES AT ITS COPPERWOOD PROJECT
VANCOUVER, BRITISH COLUMBIA – October 15, 2025 – Highland Copper Company Inc. (TSXV: HI; OTCQB:
HDRSF) (“Highland” or the “Company”) has successfully completed Phase 1 detailed engineering (“Phase
1”) for its 100% -owned Copperwood Project in Michigan, USA. Phase 1 represented a comprehensive re-
evaluation of the project, and in key areas, confirmation of overall project design. The work has delivered
meaningful improvements to both the process plant and mine, strengthening the overall project, improving
its environmental footprint and advancing Copperwood toward Phase 2 detailed engineering (“Phase 2”).
Phase 2 will advance engineering to approximately 35 -40%, supporting a potential construction decision
and technical due diligence for project financing in 2026. Phase 2 will also update capital and operating
costs to reflect inflation and other changes since the Feasibility Study.
Phase 1 was overseen by Highland Copper ’s internal engineering team under the leadership of Project
Director, Dr. Wynand van Dyk. Dr. van Dyk has a PhD in Extractive Metallurgical Engineering and a 30 -year
career in metallurgical design, construction and operations. His addition in late 2024 significantly
strengthened the Company’s technical capacity to advance Copperwood toward a construction decision.
Engineering for the process plant and mine was carried out by DRA Americas Inc ( “DRA”). Overall water
balance engineering was completed by Foth Infrastructure & Environment, LLC ( “Foth”) and Tailings
Disposal Facility (“TDF”) engineering was completed by Tetra Tech.
Process Plant Redesign Highlights
As announced on September 4, 2025, based on the positive results from the 2025 metallurgical test work
program, the process plant has been broadly redesigned.
• Higher Recoveries and Lower Costs: The redesigned circuit is expected to achieve 87.6% copper
recovery at a concentrate grade of 25% copper, while also reducing operating costs through lower
power and reagent consumption. Particularly, an optimized reagent scheme reduce s processing
costs by approximately $1.00 per tonne milled. This represents a clear improvement over the 2023
Feasibility Study from a recovery and cost perspective.
• More Efficient Comminution : The adoption of an MF2 circuit with a coarser primary grind, a de-
sliming stage ahead of the secondary milling and optimized regrind using ISAMill technology,
reduces power demand and operating costs while minimizing fine particle losses.
• Smaller, Smarter Flotation Plant : The integration of Jameson cell ultrafine flotation technology
substantially reduced the overall flotation plant footprint and complexity, lowering capital costs and
improving ESG performance.
• Operational Improvements : A larger ore storage silo, enhanced pump redundancy and the
adoption of a Programmable Logic Controller/Supervisory Control and D ata Acquisition
(“PLC/SCADA”) control system will improve reliability and align with local expertise.
Collectively, these refinements increase copper recoveries, reduce costs , and de -risk execution while
strengthening Copperwood’s environmental and operational profile.
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Mine Engineering Highlights
Phase 1 mine engineering re-evaluated the mining method, mining equipment and underground ore handling
with the goal of reducing technical risk and improving economics.
• Mining Method: While the 2023 Feasibility Study proposes room-and-pillar (R&P) mining, Phase 1
evaluated drift-and-fill (D&F) in high -grade zones of the ore body . It was identified that D&F could
potentially increase mine recoveries from 69% to approximately 94%, extend mine life, and reduce
the tailings footprint by using paste backfill. A hybrid approach of D&F in the west and R&P in the
east may present an opportunity to improve the economic return s of the project , subject to
successful paste test work early in Phase 2 engineering. If paste backfill is determined to be
technically viable, Highland will consider other relative merits , including environmental and
permitting implications, before considering changing from the R&P mining method for certain areas
of the deposit. We are encouraged by the optionality D&F provides and will provide updates on this
engineering during Phase 2.
• Mining Equipment: During the Phase 1 review, DRA review ed the productivity assumptions
regarding roadheader (continuous miner) utilization, particularly their maneuverability and cycle
times. As part of an overall mine plan review early in Phase 2 , we will continue to assess the
technical and financial merits of roadheaders versus conventional drill-and-blast using jumbos.
• Underground Ore Handling : Trade-off studies confirmed conveyors as the preferred option over
truck haulage, offering the lowest operating cost, minimal ventilation needs, and long -term
scalability. The design also maintains flexibility to adopt battery electric vehicle technology in the
future.
Tailings & Water Management Engineering Highlights
An integrated approach between DRA, Foth and Tetra Tech delivered a more efficient, lower risk plan for
tailings deposition and water management.
• Thickened Tailings: The addition of a tailings thickener increases solids content to approximately
50% by mass , cutting tailings handling costs , reducing the scale of the tailings disposal facility
(“TDF”) footprint, and providing for the immediate recycle of more than 80% of process water needs
directly back to the plant. Additionally, the TDF will no longer be used for contact water storage ,
further reducing dam failure risk. Instead, contact water will be managed in a permanent rainwater
retention dam, improving safety and aligning with global standards.
• Underground Tailings Disposal: Studies indicate that approximately 7.9 Mm³ of thickened tailings
could potentially be stored underground , reducing the required surface TDF footprint by
approximately 40%. This option will be further assessed in Phase 2 engineering, including
environmental and permitting implications.
• Water Resilience: Updated water balance modeling confirmed robust water management across a
range of climate scenarios, strengthening ESG performance.
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Considerations in Phase 2 Engineering
Labor Costs: As the Copperwood Project advances toward Phase 2 engineering, an updated labor cost
survey will be required to accurately reflect the costs and benefits necessary to attract and retain skilled
technical personnel and experienced underground equipment operators in Michigan’s Upper Peninsula.
Several outcomes of the Phase 1 trade -off studies , including mining method selection, equipment
deployment, and ore handling strategies , are sensitive to labor costs. These costs will directly impact the
overall unit mi ning cost and, by extension, the project’s operating cost structure. A refreshed labor cost
baseline will ensure that Copperwood’s mine plan is both competitive and realistic, aligning workforce
expectations with project requirements while supporting the l ong-term sustainability of operations in the
region.
Integrated Mine Plan Review: The Company will update the Copperwood mine plan to incorporate a revised
cut-off grade, integrating the results of the updated labor survey, potential modifications to the mining
method and equipment strategy, and broader market inputs such as copper price movements and relevant
cost indices. During Phase 2, an in-depth review of the ground support design and associated back height
will be undertaken. Given the unique geotechnical conditions, the excavation method, back height , and
ground support are highly interdependent and must be evaluated as an integrated system. This integrated
systems approach will guide final decisions on mining method selection (including the potential adoption
of D&F), ground support design, and the potential implementation of underground tailings disposal . The
resulting mine plan will align updated technical solutions and economic assumptions , ensuring both
operational efficiency and long-term project viability.
Project Considerations: To the extent any technical optimizations require permit amendments, the project
schedule will be adjusted to appropriately reflect timing considerations . Permit amendments may be
needed to reflect the optimized process plant design flow sheet, the addition of a tailings thickener,
selection of power source to site, and potential mining method and tailings disposal changes. If permits are
amended, we will also take the opportunity to resolve any minor discrepancies to project design . We are
encouraged that permit amendments under consideration generally improve the environmental footprint of
the project , as well as its technical and financial strength . The reduced scale of the process plant,
incorporation of a tailings thickener, consideration of D&F mining method , as well as paste backfill of
tailings, all demonstrate improved environmental, health and safety characteristics. We are also
encouraged by our recent success in amending permits in a timely basis. If we elect to amend permits, the
targeted construction decision of Q2 2026 will likely defer to the second half of 2026.
Qualified Person Statement
The technical information in this news release has been reviewed and approved by Dr. Wynand van Dyk, a
qualified person as defined by National Instrument 43-101, Standards of Disclosure for Mineral Projects. Dr
van Dyk is employed by Copperwood Resources Inc, a wholly owned subsidiary of Highland Copper, in the
role as Project Director.
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About Highland Copper Company
Highland Copper Company Inc. is a Canadian company focused on exploring and developing copper
projects in the Upper Peninsula of Michigan, U.S.A. The Company owns the Copperwood deposit through
long-term mineral leases and 34% of the White Pine North proje ct through a joint venture with Kinterra
Copper USA LLC. The Company also owns surface rights securing access to the Copperwood deposit and
providing space for infrastructure at Copperwood as required. The Company has 736,363,619 common
shares issued and outstanding. Its common shares are listed on the TSX Venture Exchange under the symbol
"HI" and trade on the OTCQB Venture Market under symbol "HDRSF".
More information about the Company is available on the Company’s website at www.highlandcopper.com
and on SEDAR+ at www.sedarplus.com.
Cautionary Note Regarding Forward-Looking Information
This news release contains “forward -looking statements” and “forward -looking information” (collectively
“forward-looking statements”) within the meaning of applicable Canadian securities legislation. These
statements include, without limitation, statements with respect to: (a) Phase 1 engineering work , and the
anticipated benefits thereof ; including with respect to: (i ) the process plant redesign; (ii) changes to mine
engineering and potential changes to the mining method for Copperwood; (iii) improvements to tailings and
water management; (b) the potential to advance to Phase 2 engineering work at Copperwood and the timing
thereof; (c) potential updates to the Copperwood mine plan; (d) the impact on the project schedule if
permitting amendments are required; and (e) the potential timing of a construction decision and project
financing with respect to Copperwood . The for ward-looking statements are subject to a number of
assumptions, including those set out in the technical reports entitled “Feasibility Study Update Copperwood
Project Michigan, USA” and the Company’s annual information form for the year ended June 30, 2024 (the
“AIF”). These underlying assumptions may prove to be incorrect. Important factors that could materially
impact the Company's expectations include: changes in project parameters as plans continue to be refined;
availability of services, materials and skilled labour to complete work programs, testing and drilling; effects
of regulation by governmental agencies; the fact that permit extensions, renewals and amendments are
subject to regulatory approvals, which may be conditioned, delayed or denied; there is no assurance that
the grant funding we have applied for will be available, and any such approval may be subject to conditions;
advancement to a construction decision at Copperwood is subject to additional studies, for which the
Company will require additional funds, which may not be available on a timely basis and accordingly could
delay a construction decision; the Company will be required to repay the loan facility from Kinterra in July,
2026, or will have its interest at White Pine diluted; unexpected cost increases, which could include
significant increases in estimated capital and operating costs and the effects of inflation; fluctuations in
metal prices and currency exchange rates; general market and industry conditions, the results of bas eline
studies and test work may result in unforeseen issues which could delay or hamper advancement of the
projects, the results of drill programs may not result in identification or confirmation of resources, and the
other risks set out in the Company’s public di sclosure documents, including the AIF, filed on SEDARPlus.
Although the Company believes that the assumptions and factors used in preparing the forward -looking
statements in this news release are reasonable, undue reliance should not be placed on forward looking
statements. All forward-looking statements in this press release are based on information available to the
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Company as of the date hereof, and the Company undertakes no obligation to update forward -looking
statements except as required by law.
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.
For further information or media requests, please contact:
Barry O’Shea, CEO
Email: [email protected]
Website: www.highlandcopper.com