The Pucamarca mineralization is considered to be high sulphidation epithermal gold hosted in brecciated volcanics with associated vuggy silica alteration or silica – alunite alteration. The hydrothermal breccias at surface are characterized by abundant iron oxide cement within zones of silica – alunite alteration.

Pucamarca MU is open pit mine of gold (main) and silver.

Crushing: During this stage of the production process the size of ore from the mine is reduced to less than 5 inches. In addition, lime is added to achieve protective alkalinity.

Metallurgical process to recover gold and silver includes following steps: ore crushing, heap leaching of cyanide solution and recovery with activated charcoal at ADR Plant. The product obtained is the electrolytic cement which will be smelted at the refinery to final obtain the Dore Bar.

Leaching: The crushed ore is moved to the leaching pad and is deposited in an area of 10,000 m2 to extract the metal from the rock using a solution of 200 ppm sodium cyanide giving an average consumption of 0.12 kg/ton of ore.

Subsequently the gold-rich solution is collected by the drain pipes placed on the geomembrane, which are protected by a 1.5 inch layer of crushed rock (“Overliner”) on the pad. This solution is sent to the PLS pool (pregnant leach solution).

ADR Plant – Active carbon absorption: The rich solution from the PLS pool is pumped to 5 beds of activated carbon, where the metal values are adsorbed. The impoverished solution is discharged into the sludge ........