The mineral deposits of the Colquijirca district belong to a member of the family of porphyry copper (Cu) related deposits known as Cordilleran deposits. These types of deposits, which are generally formed in the upper parts of a porphyry Cu, are fundamentally characterized by prominent zoning with internal parts that are dominated by Cu and external zones where Zn, Pb and Ag are the main economically-interesting elements. In the case of the Colquijirca district, and specifically the area between the Marcapunta Norte and Colquijirca sectors, such zoning generally consists of three zones, which mineralogically consist mainly of enargite in the internal parts; chalcopyrite in the intermediate parts; and sphalerite and galena in the external parts (El Brocal, 2021).

Due to the advance of stoping over the years, the Colquijirca deposit is currently exposed, which facilitates the geological identification of the Tertiary basin. Asymmetric anticlines and synclines composed of carbonate and detrital rocks, attributed to the Eocene-Oligocene Calera Formation, can be found and considered as the host of mineralization. The deposit also presents volcano-clastic intercalations (ash tuffs), which is evidence of volcanic activity that was contemporaneous to sedimentation. In addition, with the review of 5 drillholes, the Shuco conglomerate sequence of the upper Eocene has been identified in depth, which underlies Lower Calera and overlies in depositional contact with the Mitú sa ........

The mining method in Tajo Norte is an open pit. It is a conventional truck and shovel operation, through a contractor. The height of a workbench is 6 meters and the equipment used includes DM45 and DML drilling rigs. Loading is by hydraulic excavators EC950E (5.6 m3) and 374D (4.6 m3) and hauling is by G500 B8X4 trucks (24.5 m3). For 2023, we are planning to increase the underground mine production (up to 10,000 tons per day) and to reduce the open pit production due to a permit delay. To maximize mine production, Tajo Norte mine employs a fleet management system that supports the transmission and receipt of data across the mobile fleet and supports the collection of data which is input directly by equipment operators. We are testing this system in the underground mine to optimize the fleet utilization. Open pit operations: 1.Tajo Norte 2.Tajo Sur The following design parameters have been considered for the open pit operation: - Bench height: 6 m. - Berm width: variable between 5 and 8 m. - Ramp width: considering equipment width, safety distances, and safety berm, the open pit have ramp widths of 12 m with a 10% slope. - Optimum turning radius according to the equipment fleet is 6.4 m. - Minimum loading width considering the excavator and the minimum spaces to carry out operational activities is 20 m. However, one excavator is expected to work with two trucks. As such, the estimated width can be up to 60 m. Open pit mining production: 9,500 tpd (2022 – 2032).

- subscription is required.

- subscription is required.

- subscription is required.