Gold and silver

Underground operation

Castilla, Arequipa

3,800 masl

Started in 1967

Orcopampa (100% BVN) is an underground gold and silver operation located in the District of Orcopampa, Province of Castilla, Region of Arequipa. It commenced operations in 1967. 

Geology: Orcopampa is an epithermal/mesothermal gold and silver deposit, hosted in volcanic rocks from the Tertiary, consisting of flows and domes with a dacitic and andesitic makeup. Mineralization is found in tellurides, native gold, electrum, and sulfosalts, among others, in veins of quartz and anhydrite. Chipmo Mine is the current operating area with vein systems running NE-SW: Nazareno, Prometida, Pucará, etc. The Calera and Chipmo veins, from which more than 90% of Orcopampa´s production come from, were discovered by our geologists.

Mining: There are two areas currently under exploitation: Nazareno and Prometida, whose mineral production is extracted via shafts of the same name. The exploitation method used is mechanized overhand cut and fill, with low-profile equipment. At the exploitation levels, ore is transported by locomotives and mining cars to the shafts, in order to then be extracted to the surface, from where the ore is transported to the concentrating plant, located 7 km away, using trucks with a 20 m3 capacity. Access to mining areas is mainly gained via three ramps. The barren material is recirculated as backfill to the pits, and the excess material is transported to the barren material deposit. For the ventilation of the works, there are three main fans with a capacity of 350,000 cfm each, and secondary fans for the explorations and developments. There are water pumping stations for drainage, with a total capacity of 420 l/s.

Metallurgy: The final products of the Orcopampa processing plant are doré bars and bulk concentrate. Operations include crushing, milling/sorting, gravimetry, cyanidation, thickening, CIP, flotation, cyanidation with gravimetric concentrates, desorption/electrowinning, Merrill-Crowe (zinc precipitation), smelting, carbon acid washing, carbon regeneration, cyanide destruction, and tailings disposal.

Current Treatment Capacity: 1,500 MTD

Note: As of december 31st of the year indicated.