The Cuajone porphyry copper deposit is located on the western slopes of Cordillera Occidental, in the southern-most Andes Mountains of Peru. The deposit is part of a mineral district that contains two additional known deposits, Toquepala and Quellaveco. The copper mineralization at Cuajone is typical of porphyry copper deposits.

The Cuajone deposit is located approximately 28 kilometers from the Toquepala deposit and is part of the Toquepala Group dated 60 to 100 million years (Upper Cretaceous to Lower Tertiary). The Cuajone lithology includes volcanic rocks from Cretaceous to Quaternary. There are 43 rock types including, pre-mineral rocks, basaltic andesite, porphyritic rhyolite, Toquepala dolerite and intrusive rocks, including diorite, porphyritic latite, breccias and dikes. In addition, the following post-mineral rocks are present: the Huaylillas formation which appears in the south southeast side of the deposit and has been formed by conglomerates, tuffs, traquites and agglomerates. These formations date 17 to 23 million years and are found in the Toquepala Group as discordance. The Chuntacala formation which dates 9 to 14 million years and is formed by conglomerates, flows, tuffs and agglomerates placed gradually in some cases and in discordance in others. Also Quaternary deposits are found in the rivers, creeks and hills. The mineralogy is simple with regular grade distribution and shaped like an inverted cone. Ore minerals include chalcopyrite (CuFeS ), chalcosine (Cu S) and molybdenite (MoS ) with occasional galena, tetraedrite and enargite as non-economic material.

The Cuajone operations consist of an open-pit copper mine and a concentrator located in southern Peru, 30 kilometers from the city of Moquegua and 840 kilometers from Lima, at an altitude of 3,430 meters above sea level.

The Cuajone operations utilize a conventional open-pit mining method to collect copper ore for further processing at the concentrator.

Our Cuajone operations use state-of-the-art computer monitoring systems at the concentrator, the crushing plant and the flotation circuit in order to coordinate inflows and optimize operations. Material with a copper grade over 0.35% is loaded onto rail cars and sent to the milling circuit, where giant rotating crushers reduce the size of the rocks to approximately one-half of an inch. The ore is then sent to the ball mills, which grind it to the consistency of fine powder. The finely ground powder is agitated in a water and reagents solution and is then transported to flotation cells. Air is pumped into the cells to produce foam for floating the copper and molybdenum minerals, but separating waste material called tailings. This copper molybdenum bulk concentrate is then treated by inverse flotation where molybdenum is floated and copper is depressed. The copper concentrate is shipped by rail to the smelter at Ilo and the molybdenum concentrate is packaged for shipment to customers. Sulfides under 0.35% copper are considered waste.