Mineros Secures Environmental Certification for Porvenir's Processing Plant and Tailings Storage Facility

• Nicaragua's Attorney General's Office issued the environmental certification for Porvenir's processing plant and tailings storage facility in April 2026.
• Porvenir has received six regulatory approvals covering mining, environmental, forestry, and land use categories, with the first issued in April 2024.
• Two authorisations remain outstanding: sectorial forest management approvals, with documentation submissions targeted by end of Q2 2026 and approvals expected by end of Q4 2026; and a treated wastewater discharge permit, for which no specific timeline has been provided.
• The 2026 Prefeasibility Study (PFS) returns an after-tax net present value (NPV) of $460 million, an internal rate of return (IRR) of 37.9%, and a two-year payback period on initial capital of $206.8 million.
• Life-of-mine after-tax free cash flow is estimated at $727 million; Mineros is evaluating accelerating the project timeline, with construction guidance expected in late 2026.

Mineros S.A. (TSX:MSA / OTCQX:MNSAF / BVC:MINEROS) is a Colombian-based gold mining company with producing assets in Colombia and Nicaragua and a development and exploration pipeline that includes the La Pepa Project in Chile and an exploration project near Cajamarca in the Tolima region of Colombia. With over 50 years of operating history, the company maintains a stated focus on safety, sustainability, and disciplined capital allocation.

Environmental Certification for Porvenir Processing Plant and Tailings Storage Facility

In April 2026, Nicaragua's Attorney General's Office issued the environmental certification authorising the construction and operation of Porvenir's processing plant and tailings storage facility. A processing plant is the facility where extracted ore is treated to recover metals, while a tailings storage facility (TSF) is an engineered containment structure used to store the residual material, known as tailings, left over after metals have been separated from the ore. The certification followed the regional environmental authority SERENA-CRACCN's issuance of the environmental permit for these structures in December 2025.

The TSF has been designed as a three-stage downstream rockfill dam with a storage capacity of approximately 5.85 million cubic metres. The design meets the standards of both the Canadian Dam Association (CDA) and the Global Industry Standard on Tailings Management (GISTM), an internationally adopted framework for the safe construction and management of tailings facilities. The approved design incorporates process water recycling, lined containment with drainage systems, surface water diversion channels, and treatment of excess water prior to environmental discharge.

Maria Vallejo, Vice-President of Strategic Growth and Technical Services at Mineros, commented: 

"The receipt of the environmental certification for Porvenir's processing plant and tailings storage facility, along with the already secured mining permits, represents more than regulatory compliance, it validates our technical approach to developing Nicaragua's next major mining operation. The approved infrastructure incorporates engineered controls that meet international standards for tailings management, including the GISTM classification requirements. Mineros is positioned to advance the Porvenir Project through detailed engineering and construction planning. The project's polymetallic nature, producing copper-lead and zinc concentrates along with gold and silver ore, represents a strategic diversification of our portfolio while maintaining our operational footprint within the established mining district in Nicaragua."

Porvenir Project Permitting Progress and Regulatory Status

Porvenir has received six regulatory approvals since April 2024, spanning underground mining, forest management, environmental certification, and municipal land use categories. The six approvals, in sequence, were underground mining permits from SERENA-CRACCN in April 2024, forest management authorisations for the main road and underground mine from MARENA in September 2025, environmental certification of those forest authorisations from the Attorney General's Office in April 2025, municipal approvals from the Bonanza Municipal Government for land use and project opinion between October and November 2025, an environmental permit for the processing plant and TSF from SERENA-CRACCN in December 2025, and the environmental certification of that permit from the Attorney General's Office in April 2026.

Two authorisations remain outstanding. Sectorial forest management authorisations are required for certain project areas; Mineros expects to complete submission of the relevant documentation to the competent institutions by end of Q2 2026, with approvals anticipated by end of Q4 2026. A treated wastewater discharge authorisation is also required, though the company has not stated a specific timeline for this permit. Mineros has indicated it is now focusing its regulatory efforts on preparing these submissions.

The public consultation process was concluded on 13 March 2024. The news release notes that certain areas of the project are already cleared for the commencement of construction, while other areas require the outstanding forest management and wastewater discharge authorisations before proceeding. Mineros expects to provide updated construction timeline and capital guidance in late 2026.

Project Development Timeline and Economics from the 2026 PFS

A prefeasibility study (PFS) is a technical and financial assessment used to evaluate whether a project has sufficient merit to advance toward detailed engineering and construction. Mineros published the 2026 PFS for Porvenir, formally titled "NI 43-101 Technical Report Hemco Property, Region Autonoma de la Costa Caribe Norte, Nicaragua," effective 31 March 2026. Based on consensus metal price assumptions of $3,150 per ounce for gold, $45.00 per ounce for silver, $4.72 per pound for copper, and $1.22 per pound for zinc, the project returns an after-tax NPV of $460 million at a 5% discount rate, an after-tax IRR of 37.9%, and a payback period of two years on initial capital of $206.8 million. After-tax free cash flow over the life of mine is estimated at $727 million.

Porvenir is a polymetallic underground project, meaning it is designed to produce multiple metals simultaneously: gold, silver, copper, and zinc. The project is designed to process 2,500 tonnes of ore per day and is expected to produce an average of 72,300 gold-equivalent ounces (AuEq) per year over a 9.2-year production life at steady state. Total Proven and Probable Mineral Reserves at the deposit stand at 6.48 million tonnes. The all-in sustaining cost (AISC), which represents the estimated total cost per ounce produced including operating expenses and sustaining capital, is $1,295 per AuEq ounce.

The Porvenir deposit is located within a broader polymetallic district that also includes the Guillermina, Leticia, and San Antonio deposits. These deposits share similar geological characteristics and are being considered within a district-scale development framework centred on Porvenir's processing plant as a central facility for ore from multiple sources. On a combined basis across all four deposits, the 2026 PFS reports approximately 736,000 AuEq ounces in Proven and Probable Mineral Reserves, with an additional 406,000 AuEq ounces in Measured and Indicated Mineral Resources and 313,000 AuEq ounces in Inferred Mineral Resources. The district-scale framework carries the potential to extend the project's mine life beyond the initial 9.2-year production plan.

Outlook

With the environmental certification for the processing plant and TSF now received, Porvenir has secured all primary approvals for its core processing infrastructure. The two remaining authorisations are on a stated submission schedule, with forest management approvals expected by end of Q4 2026. Mineros is currently evaluating whether to accelerate into detailed engineering, which would advance the project from the study phase toward construction. Updated guidance on construction timelines and capital requirements is expected in late 2026.

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