The Yauli unit region shows mineralization related to polymetallic epithermal systems, replacement bodies and polymetallic vein systems, as well as porphyry mineralization and skarns, thus indicating the great potential of the area.

The Carahuacra deposit lies on the southwest flank of the Yauli anticline, formed by Tertiary folding. Manto ore, formed before the climax of the Andean orogeny, consists mainly of ferroan sphalerite and pyrite, with negligible chalcopyrite. These were later brecciated tectonically to form two zones of 'breccia ore'. The last phase of mineralization involved formation of epithermal cross veins with sphalerite, pyrite, galena, tetrahedrite, and jamesonite, and irregular cementation of fragments in the breccia ore by sphalerite-galena and pyrite-marcasite. Supergene alteration, particularly pronounced in the breccia zone, has formed ore much enriched in silver (native silver, argentite, pyrargyrite).

(Translated from Spanish by Google Translate)
The Carahuacra underground mine is a part of Yauli operating unit.

In this area, mining is consolidated using the OCF method utilizing Hydraulic backfill.

In 2022, there was an increase in the head grades of zinc, lead and copper by 19%, 2% and 26% respectively. However, the silver head grade decreased by 22%, the scheduled law was not reached due to delays in primary and secondary developments in 2021, as a result of the impact of the third and fourth waves of covid-19 in addition to the paralysis of the Mary vein due to geomechanical reinforcement issues. The volume of production contribution was 4% lower than in 2021, due to lower contribution of Mary vein

Seismic events occurred in the Mary vein, which paralyzed its production contribution for a period of three months. In this period, the installation of cable bolting and additional support was implemented to strengthen the mining with a higher safety factor.

The exploration was aimed at evaluating polymetallic mantle systems and main veins, as well as new areas with high geological-economic potential close to current operational infrastructure, such as Paula - Principal mantles and the eastern extension of the Lourdes vein. The results record high metallic contents of Zn, Pb and Ag.

Andaychagua's processing plant include grinding circuit consist of primary ball mills #1, 2 (10.5 'x 14', 8 'x 10') and secondary grinding ball mill (7’ x 12’).

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