Name of the Mine
MCSA Mining Complex.

Location  
North-eastern Bahia state, in Brazil, about 385 km north-north-west of Salvador.

Mine Owner/s 
Ero Copper.

Brief Description  
MCSA comprises fully integrated mining operations and processing facilities, including the Pilar and Vermelhos underground mines and the Surubim openpit mine. Ore is processed using conventional crushing and flotation at the Caraíba mill, adjacent to the Pilar underground mine.

Brief History  
MCSA has an extensive operating history in the Bahia region. Openpit and processing operations started in 1979, while underground mining operations started in 1986.

Primary Metals/Minerals  
Copper.

Secondary Metals/Minerals  
None stated.

Geology/Mineralisation  
The Curaçá Valley’s mafic-ultramafic complex is located within the Curaçá high-grade metamorphic gneissic terrain – part of the Salvador-Curaçá orogen, a northern extension of the Atlantic coast granulite belt, in the São Francisco craton.

The mining and development projects within the MCSA Mining Complex are situated within a Trans-Amazonian age belt, bordered by volcano-sedimentary rocks of the Jacobina Group in the west and by the Itiúba intrusive syenite rocks in the east.

Known copper deposits are hosted within the Rio Curaçá and Tanque Novo sequences, differentiated by metamorphic facies. The two sequences are located across the base of the MCSA Mining Complex and include the mafic-ultramafic rocks, as well as granite, granodiorite and syenite. Pyroxenite has been described within the mafic-ultramafic lenses at the Caraíba, R22W, Angicos, Suçuarana, Surubim OP and Vermelhos UG mines.

The copper-rich deposits are hosted by irregular-shaped intrusive bodies of pyroxenite (hypersthenite) and minor gabbro-norite that have been intruded into granulite facies gneiss and migmatite at the northern margin of the São Francisco craton. The intrusions have been interpreted as either deformed sill-like bodies or irregular-shaped intrusions into an anastomosing ductile shear zone.

Mineralised textures include interstitial, net-textured, stringer and sulphide-rich matrix breccias. There is additional evidence throughout the Curaçá Valley of sulphide zonation, characterised as pyrrhotite +/- pentlandite zoning to pyrrhotite +/- pentlandite plus chalcopyrite, and finally to chalcopyrite plus bornite. High-grade mineralisation is often closely associated with phlogopite enrichment. Additional work is under way to evaluate recent observed occurrences of nickel and platinum-group elements throughout the Curaçá Valley.

Reserves  
Total proven and probable underground reserves as at September 30, 2021, were estimated at 29.97-million tonnes grading 1.44% copper.

Total proven and probable openpit reserves as at September, 30, 2021, were estimated at 29.31-million tonnes grading 0.60% copper.

Resources  
Total measured and indicated underground resources as at September 31, 2021, were estimated at 69.36-million tonnes grading 1.46% copper. Inferred resources were estimated at 40.3-million tonnes grading 1.14% copper.

Total measured and indicated openpit resources as at September 30, 2021, were estimated at 35.34-million tonnes grading 0.59%. Inferred resources were estimated at three-million tonnes grading 0.50%.

Mining Method  
Openpit and underground.

Major Infrastructure/Equipment  
The current mining operations include the Pilar and Vermelhos underground mines.

Primary components of installed infrastructure comprising the MCSA mining complex, outside of the individual mining operations, include: the 3.2-million-tonne-a-year Caraíba mill processing plant; access to water through an MCSA-owned, -operated and -maintained 86-km-long permanent steel pipeline from the São Francisco river; a water treatment plant; a metallurgical laboratory; a main substation and transformers;  power lines supplied by State-owned power company Companhia; ancillary surface buildings, including maintenance, security and administration; and inactive solvent extraction and electrowinning operations.

Prospects  
Ero is conducting aggressive exploration across the Curaçá Valley.

Contact Details
Ero Copper
Tel +1 604 449 9244
Email info@erocopper.com
Website https://www.erocopper.com/

Sources
Ero Copper. January 2022 Corporate Presentation.
Ero Copper. 2020 Updated Mineral Resources and Mineral Reserves Statements of Mineração Caraíba’s Vale do Curaçá Mineral Assets, Curaçá Valley (January 14, 2021).
Ero Copper. Website: https://www.erocopper.com/operations/mcsa-mining-complex/overview/ (accessed February 9, 2022).