Tailings Management Facilities

Overview

Serabi operates its tailings management facilities at the Palito Complex in Pará State, Brazil. The Palito processing plant treats ore mined from both the Palito Complex and the Coringa Gold Project, with all process tailings generated from these operations managed at the Palito site.

Ore mined at Coringa is transported by road to the Palito Complex for processing. As a result, Coringa does not currently operate either conventional wet tailings storage facilities or temporary dewatering cells, as all ore is processed at the Palito Complex. This operating strategy reduces the overall environmental footprint of the Coringa operation while making use of the existing processing and tailings management infrastructure at Palito.

Tailings management at the Palito Complex is undertaken in accordance with applicable Brazilian legislation and incorporates internationally recognised engineering and governance practices throughout the design, operation and monitoring of the facilities.

The Company follows the principles of the Global Industry Standard on Tailings Management (GISTM) and complies with the requirements of the Brazilian National Dam Safety Policy (PNSB) and the regulations established by the Brazilian National Mining Agency (ANM).

The Palito operation is located within a remote region of the Amazon where population density surrounding the tailings facilities is relatively low. While this contributes to reduced potential exposure of downstream communities, the facilities are designed, operated and monitored in accordance with the same engineering and regulatory standards applied to all tailings storage facilities.

Governance and Regulatory Compliance

The Palito tailings facilities are managed through a structured governance framework involving site personnel, the Engineer of Record (EoR), independent geotechnical specialists and the Brazilian regulatory authorities.

Serabi currently retains HAGEO Engenharia as its independent geotechnical consultant to undertake the inspections and technical reviews required under Brazilian legislation, while the Company’s Engineer of Record is responsible for the day-to-day operation, surveillance and performance of the facilities.

In accordance with Brazilian regulatory requirements, Serabi undertakes continuous operational inspections by site personnel and the Engineer of Record, Regular Safety Inspections (ISR), independent annual Dam Safety Reviews by an accredited engineering consultancy, submission of the Declaração de Condição de Estabilidade (DCE) to the ANM within the prescribed reporting periods, maintenance and periodic review of the Dam Safety Plan (PSB) and Emergency Action Plan (PAEBM), regular emergency response exercises and ongoing inspections and oversight by the relevant Brazilian regulatory authorities.

This governance framework ensures that the facilities continue to operate in compliance with current Brazilian legislation and recognised international good practice.

Palito Hybrid Tailings Management System

The Palito Complex employs a Hybrid Tailings Management System that combines temporary dewatering cells with permanent dry stack storage.

Tailings generated by the processing plant are discharged into one of two engineered dewatering cells (Dam 16 or Dam 17). Dam 16 has a storage capacity of approximately 114,588 m³, while Dam 17 has a storage capacity of approximately 145,000 m³. Within the active cell, excess water is recovered and returned to the process water system while the deposited tailings undergo natural drainage and consolidation.

Once the active cell reaches its operational capacity, tailings deposition is transferred to the alternate cell. This alternating operating cycle allows the previously used cell to continue drying while maintaining uninterrupted plant operation.

After achieving the required moisture content, the dewatered tailings are excavated from the cell, transported to a dedicated engineered dry stack storage facility and placed in controlled compacted lifts for permanent storage.

This operating philosophy maximises water recovery, reduces the long-term inventory of saturated tailings and combines the operational flexibility of alternating dewatering cells with the long-term stability of dry stack storage. The system also provides increased process water recovery and reuse, improved geotechnical stability, reduced environmental footprint and progressive rehabilitation of the dry stack storage facility.

Coringa Gold Project

The Coringa Gold Project currently does not include a processing plant or tailings storage facilities. All ore mined at Coringa is transported approximately 200 km by road to the Palito Complex for processing, where the resulting tailings are managed within the Palito Hybrid Tailings Management System. Consequently, no tailings are deposited or stored at the Coringa site under the current operating configuration.

The environmental licences issued for Coringa allow for the future construction of a dedicated processing plant should this become part of the Company’s long-term development strategy. Should such a facility be developed, the current project concept incorporates filtered tailings technology and engineered dry stack storage, with only a small contingency water retention facility required for exceptional operational or climatic conditions.