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.

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.

The newly found Ticlio Cu-Au porphyry prospect is a single granodiorite intrusion showing a pronounced zonation pattern with respect to mineralization and alteration. Its central part is characterized by the occurrence of high density quartz-magnetite±K-feldspar stockwork. The zone rimming the core shows strong K-feldspar alteration with low-density magnetite and quartzmagnetite veining. This zone hosts small amounts of chalcopyrite and bornite as disseminations and in veinlets.

In 2014, 2,866 meters were drilled in nine diamond-drill perforations from inside the mine aimed at intercepting the Mary Vein, to delineate new inferred resources with 70 x 70 meter grids at 200 meters below 1,070 level (3,960 masl). The boreholes also intercepted the Ramal Mary and Tensionales veins with positive results in terms of polymetallic mineralization, mainly zinc. The ore potential in Manto Principal has been confirmed with favorable results. Principal has been confirmed with favorable results.

The Yauli unit is located in the Junín Region, 40 kilometers from the city of La Oroya and 170 kilometers from Lima, and it is accessible by road and rail.

The unit consists of four underground mines and one open pit, from which the ore is treated in three concentrator plants, which have a joint installed capacity 11,400 tonnes per day.

There are currently four underground mines in operation: San Cristóbal, Carahuacra, Andaychagua and Ticlio. The Carahuacra Norte Pit was halted in 2018.

During 2019, Yauli Mining Unit managed to consolidate the ore production from its four mines. Work has been done to improve the operational conditions by significantly reducing its risks, optimizing the long-term mining plans (LOM), oriented to generate higher value for the mines.

In 2019, the ventilation models were updated and calibrated using VentSim software across all Ming Units. Also, progress has been made with the execution of the programs for raise boring ventilation and related services, as well as with the installation of main and secondary ventilators, in order to improve coverage and needs of fresh air in the operations.

Andaychagua underground mine
In 2015, Andaychagua mine continued the preparatory work for long-hole drilling in the high zone (Recuay), which resulted in a 400 tpd production increase, for a total of 3,400 tpd of mine capacity.

In 2018, production was primarily from the Andaychagua vein at depths, production began through the sublevel stopping method in the Adriana vein, with mostly Zn, and the Prosperidad 1 and Prosperidad Techo veins, consolidating the aforementioned mining method.

Pump system project works culminated at level 1200, with a 180 l/s capacity that guarantees the depth of the Andaychagua vein and the other veins mentioned.

During 2019, production was primarily focused at Andaychagua vein and Prosperidad 1 and Prosperidad T Ore bodies, this last is considered a main Zn source.

Exploration in 2019 had good results with the discovery and exploration of two new high-grade zinc structures known as Salvadora and Salvadora N, and there were also good results in the exploration of the low zone of Prosperidad Techo with high values of Zinc.

San Cristóbal underground mine
In 2018, the operating strategy for production continued, increasing the volume of the sublevel stopping mining method and reducing cut and fill.

In 2019, the implementation of the sublevel stopping mining method was consolidated throughout all veins.

Exploration was directed towards the Split 658 and RP722 Veins, with favorable results in Zn and Ag, mainly in the upper and lateral area of the mine.

The infrastructure of the first stage of the 10,000 volts electrical system for the deepening circuits was completed, guaranteeing 2 MW of installed capacity.

Ticlio underground mine
In 2014 the Ticlio Mine achieved production of 1,200 tpd, thanks to an increase in preparation of the Ramal Techo vein, where 50% of the production was obtained through long-hole drilling. In addition, improvements were made to pumping systems in the lower levels of the mine and six raise borer chimneys were built for the ventilation and services systems. Ore extraction was resumed at the Ariana body using the ascending cut-and-fill method, which allowed for better control of the stability of limestone rock.

During 2019, production was mainly from the Ramal Techo Vein, specially from Stopes located at Deep areas of the mine, 61% of production came from using the sublevel stopping method in structures such as Ramal Techo East and West, Julissa, Kelly and Reemplazamiento Veins.

This impact was the result of not having the mine prepared for 2019, mainly in the west area of Ramal Techo (highgrade zinc), and there were also failures of the pumping system during the process, which restricted the progress of the deepening ramp. Another important contributing factor was low availability of mine equipment fleet, as well as the long adaptation and learning curve that resulted from the change in Contractor Company.

The communication project for underground and surface operations (Tetra radios) was also completed, meaning that the mine is 100% integrated in radio communication.

Carahuacra underground mine
During 2019, production was mainly focused on Mary and ML Veins, representing 79% of total production. In the West area, mining started in Huaripamapa Ore Body at SL_1070, the Main Manto at SL_1020 and Galáctico Ore Body at SL_780, contributing with a total of 15% of the production and with a higher contribution of Zn and Ag. Also, in this area, mining is consolidated using the OCF method utilizing Hydraulic backfill.

Works for the pumping system project at Level 1220 were completed, with a 130 l/s capacity that will provide better reliability to the system.

Currently there are four underground mines operating: San Cristóbal, Carahuacra, Andaychagua and Ticlio, whose extracted ore is treated in three concentrator plants: Victoria, Mahr Tunel and Andaychagua, with a total installed capacity of 11,400 tpd.

Victoria concentrator plant
The operation of the Victoria concentrator plant is automated, including Courier online analysis systems and a control system that regulates the ratio of water to ore during the milling process. It is worth highlighting that the Victoria concentrator plant can separate low-grade lead and copper concentrates by flotation.

During 2019, the capacity of the Victoria concentrator plant to process 5,200 tpd was maintained. As a result, production from the Victoria plant represented 42% of treated tonnage for the Yauli UEA.

Selective zinc flotation was implemented, eliminating 100% of the use of lime in the flotation process, thereby lowering the flotation costs, lowering the ratio ........