Sierra Metals Inc. (Sierra Metals) has lowered the minerals resources estimate in its Bolivar, Mexico mine to 11.63mn mt, with the total indicated minerals resources for copper averaging 0.95pc.
The copper equivalent represents a 12pc overall tonnage decrease from Sierra Metals’ previous estimate, which also includes depletions since the original estimate was issued in 2017. The mine’s copper grade has also decreased 9pc since then.
The total inferred minerals resources at the mine, located in Chihuahua, Mexico is 16.69mn mt with copper averaging 0.93pc. The copper equivalent represents a 108pc overall tonnage increase from the previous inferred resource estimate. The copper grade also fell 3pc.
Cut off grades at the mine were left with lower value material due to a net smelter return reduction the company indicated.
Sierra Metals’ updated estimate is based on drilling that occurred between November 2017 and September 2019, which includes 13,698 meters of infill drilling and 41,553 meters of exploration drilling.