There are two types of deposits in the San Cristobal district, veins and mantoso Veins are roughly perpendicular to the axis of the Chumpe Anticline and mantos are emplaced along the Mitu volcanic rocks-Paria limestone contact.

The San Cristobal Vein system is made up of two main mineral-bearing structures, the San Cristobal Main Vein and the Siberia 1 Vein, The Oyama-Triunfo Vein, which is located on the northeast limb of the anticline, appears to be an extension of the San Cristobal Main Vein, Both veins are separated on the surface by Chumpe lake and no underground workings exist below the area that permit a clear correlation.

The San Cristobal Main Vein extends all the way along the San Cristobal fault, considering the Oyama-Triunfo Vein as its extension. The Siberia 1 Vein is located in the axial zone of the anticline# At present the San Cristobal mine is working in the San Cristobal Main Vein. This vein is well known underground and carries zinc, lead, copper, and silver minerals and locally tungsten minerals. The Siberia 1 Vein is little known in underground workings and carries mainly tungsten mineralization.

(Translated from Spanish by Google Translate)
San Cristobal is an underground mine, a part of Yauli unit.

There was a 1% increase in the Zn head grade. However, the law was reduced head of the other metals: 7% in Pb, 9% in Cu, 8% in Ag, due to the delays in the primary developments of 2020 as a consequence of covid-19, which caused the pits scheduled for 2021 had a lag in their exploitation, mainly in the Split 658 vein, the main contributor in volume and grade.

Ore production was 48% higher than in 2020, the results of production of fines in zinc, lead and silver were above in relation to 2020 in 53%, 38% and 36%, respectively.

Sub-level stoping is utilized as a primary mining method.

Exploration was directed towards the lateral areas of the Ramal Piso 722 veins, vein 658 and Split 658 vein at levels 820, 1320 and 1420, with favorable results.

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’).

(Translated from Spanish by Google Translate)
Currently, four underground mines operate: San Cristóbal, Carahuacra, Andaychagua and Ticlio, whose extracted ore is treated in two concentrator plants, Victoria and Andaychagua, with an installed capacity of 8,650 tpd. The Mahr Tunnel Plant with a capacity of 2,750 tpd is in care & maintenance.

Victory plant
The Victoria concentrator plant has an available processing capacity of 5,300 tpd. During 2021, the flow sheet in zinc flotation was modified to implement the RCS-100 and RCS-30 cells in the Rouger, Scavenger and Cleaner circuits, with the aim of improving the recovery and increasing the quality of the concentrate of zinc.

The following recoveries were achieved: zinc 94.5%, lead 83.3% and silver 87.0%; in the 2021, which represent an increase in zinc by 3%, silver by 2% and a decrease in lead by 0.4% compared to 2020.

Likewise, the silica content in zinc concentrates was reduced, which allowed ........