Name of the Mine
Xavantina Operations (formerly NX mine). 

Location  
South-eastern Mato Grosso State, Brazil.

Mine Owner/s  
Ero Copper (97.6%).

Brief Description  
The Xavantina Operations encompass fully integrated underground mining and processing facilities.

The high-grade, shear-zone-hosted quartz vein system is accessed through a decline, and current mining operations are focused on the Santo Antônio vein.

Brief History  
The Xavantina Operations started commercial production in 2012, with the first full year of production starting in 2013.

Primary Metals/Minerals  
Gold.

Secondary Metals/Minerals  
Silver.

Geology/Mineralisation  
Gold and silver mineralisation at the Xavantina Operations can be characterised as a shear zone-hosted, sulphide-rich, laminated quartz vein. Economic mineralisation on the property, to date, has been hosted within the north-east-trending Araés shear zone, which crosscuts the deformed and metamorphosed volcano-sedimentary sequence of the Proterozoic Cuiabá Group and is generally associated with felsic dikes. 

Economic gold and silver mineralisation at the Xavantina Operations is structurally controlled within the Araés shear zone. Gold and silver are currently mined from a major sulphide-rich, laminated quartz vein dipping about 40 º north-north-west and striking to the west-south-west – the Santo Antônio vein.

The known extent of gold mineralisation at the Xavantina Operations is structurally controlled and hosted in four major sulphide-rich quartz veins/bodies, from west to east – Buracão, Santo Antônio, Brás and Matinha. The veins are hosted in strongly deformed metamorphosed sedimentary rock units and diorite that trend generally to the north-east. The veins exhibit a typical laminated pattern parallel with the vein contacts. The laminations are characterised by alternating quartz bands and foliated host rocks indicative of multiple pulses of mineralised fluids during formation.

Reserves  
As at December 31, 2023, the mine had proven and probable reserves of 1.51-million tonnes grading 7.95 g/t.

Resources  
Measured and indicated resources were estimated at 1.47-million tonnes grading 10 g/t gold. Inferred resources were estimated at 513 000 t grading 8.86 g/t gold.

Type of Mine
Underground.

Mining Method  
A combination of inclined room-and-pillar and cut-and-fill using paste fill as backfill.

Mining method selection has been based upon the desired selectivity, geometry of the orebodies (planned and previously mined) and geotechnical characteristics of the quartz vein, as well as the footwall and hanging wall.

Major Infrastructure/Equipment  
The facilities include the mine portal, processing plant, tailings storage facility, mechanical workshop, administrative offices, metallurgical laboratory, security gate and guard facilities, medical clinic and cafeteria, as well as a gravel airstrip used to fly out doré bars after production.

Ore is processed using a conventional three-stage crushing circuit, milling and a combination of gravity concentration and intensive leaching and flotation, followed by carbon-in-leach at the Xavantina mill, located adjacent to the underground mine.

Prospects 
In 2023, the Xavantina Operations successfully completed the NX60 initiative, is focused on achieving sustained gold production levels of about 60 000 oz/y, primarily through the development of a second source of mill feed, and the use of excess capacity at the Xavantina mill. 

Contact Details 
Ero Copper
Tel +1 604 449 9244
Email info@erocopper.com

Sources
Eros Copper. Website: https://erocopper.com/
Eros Copper. Ero Copper Demonstrates Significant Near-Term Growth in Updated 5-Year Outlook (April 5, 2023).
Eros Copper. Technical report on the Xavantina Operations, Mato Grosso, Brazil (May 12. 2023).
Eros Copper. Ero Copper Reports Fourth Quarter and Full Year 2023 Operating and Financial Results (March 7, 2024).