Ero Copper uses sustainable, best-in-class management practices at our one operating and three non-operating tailings facilities at the Caraíba Operations and three operating tailings facilities at the Xavantina Operations. Our Company’s internal technical teams, third-party engineering firms and the applicable regulatory agencies routinely inspect the tailings sites at the Caraíba Operations and Xavantina Operations.
The limited height of the tailings facilities, combined with the relatively flat regional topography, results in a low-risk classification in accordance with National Mining Agency (ANM) of Brazil regulations for the Ero Copper dams.
Caraíba Operations
The Caraíba Operations used a conventional tailings dam until 2015. The operations maintain the inactive dam in accordance with environmental regulations. It has a capacity of 45 million cubic meters spanning an area of 653 square hectares. Rehabilitation is in progress.
The Caraíba Operations currently employ two different systems for tailings disposal, including 1) back-filling of open stopes within the Pilar Underground Mine with cemented paste fill and 2) disposal of tailings into paddocks on top of waste rock stockpiles. Caraíba Operations mix approximately 10% of tailings generated in the milling operations with cement and apply them to the Pilar Underground Mine for paste-backfill, which provides ground stability by filling the vertical stopes left from where copper had been extracted.
Xavantina Operations
At the Xavantina Operations, the Company stores non-inert tails in a High Density Polyethylene (HDPE) lined excavated pit. A non-inert tailings pond is used for natural degradation of residual cyanide, complemented by a cyanide detoxification circuit. Inert tails are stored in a single-lift rockfill dam of segmented ring-dyke design, with only one cell operational at any given time until the tails are de-watered. De-watered inert tails are transported periodically from the tailings storage facility to legacy areas that were disturbed by artisanal mining activity prior to the mine’s construction. Once filled, these areas are revegetated and reclaimed as part of the Company’s ongoing environmental sustainability practices.
The Xavantina Operations initiated a new project in 2019 to extend the inert tailings storage area by 79 thousand square meters on the mine property, extending the deposition capacity to 15 years. The expansion is crucial for the longevity of the operation and allows an adequate area within the safety and environmental regulations.
Please refer to the technical reports for both the Caraíba Operations and Xavantina Operations for additional scientific and technical information regarding the Company's tailings management practices, available on the Company's website, SEDAR (www.sedar.com) and EDGAR (www.sec.gov).