Name: Tantahuatay mine.
Location: The mine is located in the districts of Hualgayoc and Chugur, in Cajamarca, Peru.
Holding and Controlling Company: Compañía Minera Coimolache in which Buenaventura holds a 40% equity interest, Southern Peru Copper Corp 44% and Espro 16%.
Brief Description: Coimolache is an openpit operation, comprising the Tantahuatay 2 and Ciénaga Norte pits.
Brief History: Buenaventura discovered the mine and to date, the mine has produced more than 800 000 oz of gold.
Environmental impact studies for the project were approved by Peruvian authorities in 2009.
Coimolache also received the construction licence for its industrial and mining complex.
In 2011 the mine got its first doré bar.
Products: Gold and silver.
Geology/Mineralisation: Coimolache is a high-sulphidation epithermal deposit with outcropping gold and silver mineralisation in oxides, related to silicified breccia associated with a pervasive siliceous alteration.
Below the oxides level, there is mineralisation comprising predominantly of arsenical copper and, to a lesser extent, covellite and supergene chalcocite.
This epithermal event overprints a skarn with retrograde alteration identified at depth, with clean copper mineralisation.
Reserves: Total proven and probable reserves as at December 31, 2016, were estimated at 81.27-million dry metric tonnes grading 8.07 g/t silver and 0.39 g/t gold.
Resources: Total measured and indicated mineral resources in oxides as at December 31, 2016 were estimated at 49.63-million dry metric tonnes.
Inferred mineral resources in oxides were estimated at 2.23-million dry metric tonnes grading 0.24 oz/t silver and 0.26 g/t gold.
Total indicated mineral resources in sulphides as at December 31, 2016, were estimated at 488.49-million dry metric tonnes grading 0.23 g/t gold and 6.35 g/t silver.
Inferred mineral resources in sulphides were estimated at 455-million dry metric tonnes grading 0.15 g/t gold, 0.132 oz/t silver and 0.68% copper.
Mining Method: Openpit.
Major Infrastructure and Equipment: The metallurgical process at Coimolache includes leaching the run-of-mine ore, obtained from blasting in the openpit, on the leaching heap using cyanide solution. Two processes are conducted at the plant - Merrill-Crowe (zinc precipitation) and adsorption, desorption, and regeneration using activated carbon.
The material is loaded using 3 m3 excavators and transported using 20 m3 trucks.
Prospects: As part of the infrastructure necessary for operation at Ciénaga Norte pit, the process pond, setting pond, monitoring pond and acid water pond were built in 2016, including environmental controls and reclaimed slopes.
Contact: Buenaventura investor relations Rodrigo Echecopar
Contact Details:
Buenaventura
Tel +1 511 419 2500 ext 2591
Email rodrigo.echecopar@buenaventura.pe
Website http://www.buenaventura.com