Tambomayo is an epithermal/mesothermal polymetallic deposit in veins of gold and silver, with base metals in veins of quartz, emplaced in andesitic volcanic rocks from the Tertiary. Gold is found in native state and electrum, while silver is found in sulfides and sulfosalts accompanied by galena and sphalerite. It has two main systems of veins: Mirtha, running NW-SE, and Paola, running N-NE. There are also nearby exploration areas.

The underground works on the main Mirtha vein and diamond drilling carried out to date show an economic mineralization that deepens up to approximately 850 meters and it expands over 1,200 horizontal meters, increasing the size of the economic mineralization area to explore. The mineral is extracted via ramps and the 4840 cross-cut using 30-ton trucks. Mining at Tambomayo is conducted underground and utilizes the mechanized bench-and-fill and cut-and-fill methods. For the ventilation of works, there are two main 300,000 cfm fans and secondary fans for explorations and developments. For mine drainage, there is a water pumping station with a capacity of 60 l/s, which evacuates water to the 4740 level for treatment.

The metallurgical process at Tambomayo consists of primary crushing, fine milling, and cyanidation in tanks to obtain rich solutions in gold and silver to be processed using the Merrill-Crowe plant. The precipitate is dried and smelted, obtaining doré bars (gold and silver). The cyanidation tailings enter the flotation process, from where lead-silver and zinc-silver concentrates are obtained.

Treatment Capacity: 2,000 MTD.