Canadian Mining Journal


COPPER: Sierra updates resources, reserves for Bolivar mine

MEXICO – Toronto-based Sierra Metals has updated the resource and reserve numbers for its Bolivar copper mine in Chihuahua state. The estimate is based on drilling and production reports between January 2013 and September 2016.

The Bolivar copper mine site belonging to Sierra Metals.

The updated information includes a probable reserve of 4.3 million tonnes averaging 1.18% copper equivalent (0.31 g/t gold, 0.85% copper, and 17.5 g/t silver). The indicated resource is now 9.3 million tonnes at 1.23% copper equivalent (0.30 g/t gold, 0.90% copper and 18.1 g/t silver). The inferred category includes 9.1 million tonnes grading 1.20% copper equivalent (0.33 g/t gold, 0.86% copper and 17.9 g/t silver).

At the same time as updating the resources, Sierra was able to further refine the orebody thanks to new exploration drilling, lower commodity price assumptions, sampling, face mapping information and geologic interpretations, as well as grade estimates.

Small-scale mining was conducted near the Bolivar mine during the Spanish colonial days but no records were kept. While the Bencomo family operated Bolivar from 1998 to 2000, again no records for this period are available. Sierra is currently mining the upper El Gallo sub-deposit using room and pillar methods with ramp access. The mill, built in 2011 and since then expanded, has a capacity of 2,500 t/d.

Additional information about the Bolivar project is available at