Marimaca Provides Positive Progress Update on the MOD and Sulphuric Acid Strategy
Marimaca Provides Positive Progress Update on the MOD and Sulphuric Acid Strategy
Vancouver, British Columbia, May 19th, 2026 – Marimaca Copper Corp. (“Marimaca Copper” or the “Company”)
(TSX:MARI, ASX:MC2) is pleased to provide an update on permitting and development activities at the Marimaca Oxide
Deposit (the “MOD” or the “Project”). The Company continues to advance the project toward a Final Investment Decision
(“FID”) with critical path items remaining on schedule in 2026.
Key Updates
Sectorial Permitting
― Following receipt of the MOD Environmental Approval (the “RCA”) in November 2025, Marimaca completed
the scheduled submission of the P roject’s critical Sectorial Permits to the Servicio Nacional de Geología y
Minería (“SERNAGEOMIN”) in April 2026.
― The submitted permits include the Closure Plan, Open Pit Mining Method and several additional approvals
required for the construction of core project infrastructure, including the crushing plant, leaching pads, and
waste and ripios storage facilities.
― Submissions were completed on schedule in April, with approvals expected in Q4 2026. Receipt of these
approvals represents a major development milestone for the MOD and would permit the full commencement
of all pre-FID construction activities.
― The Company will continue advancing and submitting the remaining Sectorial Permits required to support the
timely development and execution of the MOD.
Electrical Connection
― On May 13 th, 2026, Marimaca was granted its electrical connection authorization by the National Electric
Coordinator (“CEN”), to the 110kv El Lince Line, located approximately 13 km from the MOD Project Area.
― The connection authorization is now under a 15 -day challenge window, after which the connection
authorization will be confirmed.
Engineering Tender Packages and Early Site Works
― The tender process for the project’s lead Integration Engineer has been formally launched, with invitations
issued to a shortlisted group of globally recognized EPCM firms. The selected party will work alongside the
Marimaca Owner’s Team as part of the integrated project delivery team to support the execution of the MOD.
― Subsequent detailed engineering tender packages are expected to be released to the shortlisted bidders in
the coming weeks.
― Preparations for early site works are progressing well, with crews expected to mobilize in June to commence
upgrades to the site access road, followed by improvements to the primary intersection with the regional B -
12 highway.
― These early infrastructure activities are intended to support efficient site access and enable a rapid ramp -up
of full construction activities following receipt of the remaining key permits and approvals.
Sulphuric Acid
― Marimaca has signed a non -binding Memorandum of Understanding (“MOU”) with a large-scale sulphuric
acid plant operator and supplier in the Mejillones industrial area to explore a framework for a joint-venture
to supply the MOD with future sulphuric acid requirements.
― The MOU contemplates the optimal utilization of Marimaca’s previously acquired sulphuric acid plant (see
announcement dated August 21, 2025), the Dos Amigos Acid Plant (“PADA Plant”) , including the evaluation
of the refurbishment, relocation, integration and operation of the PADA Plant in Mejillones.
― The potential incorporation of self -supplied sulphuric acid through the PADA Plant represents a significant
strategic advantage for Marimaca, providing a hedge against volatility in the third -party acid market. By
reducing exposure to spot pricing and supply disruptions, the Company expects to lower its acid cost, improve
cost predictability and support stronger operating margins over the life of the project, while retaining
flexibility to supplement supply from external sources where appropriate and economically favourable to the
Project.
― Self-produced acid in Mejillones would allow the Company to receive acid on a “just-in-time” basis, and would
significantly reduce the transport and storage complexity of the MOD’s acid supply:
There is a substantial logistical and storage advantage associated with shipping and storing
elemental sulfur compared to high purity sulfuric acid; and
The company is evaluating long term elemental sulfur supply channels to further reduce volatility
and control the long-term supply chain for an important input cost for the Project.
― The evaluation phase contemplated under the MOU includes a structured work program over an initial period
of up to six months, during which multiple development alternatives will be assessed. Subject to the results
of the evaluation and the execution of de finitive agreements, the parties may subsequently consider the
formation of a joint venture to develop, finance, construct and operate the PADA Plant.
Surface Rights
― Marimaca has secured provisional easements covering all surface rights required for the development of the
MOD and its associated infrastructure, as contemplated in the 2025 Definitive Feasibility Study (“DFS”).
― The provisional easements provide the Company with land access certainty across key project infrastructure
areas and further support the continued advancement of development activities and project execution
planning.
― Final grant of the easements is expected in Q3 2026, following completion of final rate negotiations with the
Chilean Government.
Project Financing
― Marimaca’s independent debt advisor, Endeavour Financial, a leading p roject finance advisor, has formally
commenced its debt financing process and is currently engaged with a broad range of high -quality potential
financing partners to support the development and construction of the MOD.
― The Company will provide further updates to the market in due course, with an intention to announce the
final funding strategy for the MOD by Q4 2026.
Hayden Locke, President & CEO, commented:
“We have continued to systematically de -risk the MOD across the key workstreams required to support a construction
decision. Our permit ting, surface rights and engineering progress, and ongoing engagement with project financing
stakeholders all represent important milestones as we move steadily toward construction-ready status and a future FID.”
“In parallel, our evaluation of a potential integrated sulphuric acid solution in the Mejillones Industrial Area has the
potential to deliver meaningful strategic and operating benefits to the project, including lower costs, enhanced supply
security, improved logistics and greater protection against acid market volatility. Together, these initiatives continue to
strengthen the overall execution readiness and long-term competitiveness of the MOD.”
“We continue to progress on our three value creation strategies. Advancing the MOD towards FID and along the path to
copper production, defining our cathode production growth strategy, through the integrated Pampa Medina Oxide
Project, and new discovery with the ongoing drilling campaign at Pampa Medina and the broader Sierra de Medina project
area.”
Contact Information
For further information please visit www.marimaca.com or contact:
Tavistock
+44 (0) 207 920 3150
Emily Moss
About Marimaca Copper:
Marimaca is a TSX (“MARI”) and ASX (“MC2”) -listed copper company focused on the development of high -quality
copper assets in northern Chile. The Company’s flagship asset is the Marimaca Oxide Deposit Project (“MOD”),
located in Chile’s prolific Antofagasta region. It is one of the few globally significant greenfield copper discoveries
made in the last decade and represents a low -risk development opportunity, given the proximity to the city of
Antofagasta and port of Mejillones, with substantial exploration upside. The Company also controls additional
exploration properties at Pampa Medina and Madrugador within the Sierra de Medina region, located 30 kilometers
from the MOD, where recent drilling has identified both oxide extensions and high-grade sulphide mineralization at
depth.
Forward Looking Statements
This news release includes certain “forward -looking statements” under (without limitation) applicable Canadian
securities legislation, including, without limitation, the development of activities at the PADA Plant and the MOD.
There can be no assurance that such statements will prove to be accurate, and actual results and future events could
differ materially from those anticipated in such statements. Forward-looking statements reflect the beliefs, opinions
and projections on the date the statements are made and are based upon a number of assumptions and estimates
that, while considered reasonable by Marimaca Copper, are inherently subject to significant business, economic,
competitive, political and social uncertainties and contingencies. Many factors, both known and unknown, could
cause actual results, performance or achievements to be materially different from the results, performance or
achievements that are or may be expressed or implied by such forward-looking statements and the parties have
made assumptions and estimates based on or related to many of these factors. Such factors include, without
limitation: risks that the development activities at the MOD will not progress as anticipated, or at all, risks related to
the PADA Plant development and associated capital costs, risks related to the execution of a formal JV with Noracid
(of which there can be no assurance), risks related to share price and market conditions, the inherent risks involved
in the mining, exploration and development of mineral properties, the uncertainties involved in interpreting drilling
results and other geological data, fluctuating metal prices, sulfuric acid prices, elemental sulfur prices, the possibility
of project delays or cost overruns or unanticipated excessive operating costs and expenses, uncertainties related to
the necessity of financing, uncertainties relating to regulatory procedure and timing for permitting submissions and
reviews, the availability of and costs of financing needed in the future as well as those factors disclosed in the annual
information form of the Company dated March 31, 2026 and other filings made by the Company with the Canadian
securities regulatory authorities (which may be viewed at www.sedar.com). Readers should not place undue reliance
on forward-looking statements. Marimaca Copper undertakes no obligation to update publicly or otherwis e revise
any forward -looking statements contained herein whether as a result of new information or future events or
otherwise, except as may be required by law.
None of the TSX, ASX or the Canadian Investment Regulatory Organization accepts responsibility for the adequacy or
accuracy of this release.
This announcement was authorised for release to the ASX by the Board of Directors of the Company.