Antamina is considered one of the ten largest mines in the world in terms of production volumes and has been one of the largest mining investments in Peruvian mining historyat US$3.6 billion, this includes the amount invested in its expansion of operations. At Antamina, we base our performance on three fundamental pillars: safety, productivity and cost. Thus, our company’s most treasured value resides in our team, i.e. the people who make up the Antamina family. It is essential to emphasize the importance of the safety of our people and our work. Moreover, it is a source of pride for us that 100% of the workers in the area of our mining operations are Peruvian.
The mine is located in the Antamina Ravine in the District of San Marcos, Ancash Region and has a useful life estimated to extend until the year 2029. Total reserves are 745 million metric tons.
The mineral deposit in Antamina is a skarn type of deposit containing copper-zinc, silver, molybdenum and bismuth and it is currently considered the largest of its kind in the world. It is worth mentioning that our mining method is the open pit mining method, with one of its main features characterized by its 15 meter high mining extraction banks.
Antamina’s concentrator plant is a prime component of the productive process, this is where the different types of minerals are received for processing. The main function of this plant is to receive fragmented ore to put through the milling process and on to the flotation area, where, assisted by a physical – chemical process, the recovery of valuable metals such as copper, zinc, molybdenum, silver and lead occurs.
Also, this process is carried out within specific time periods determined by the stages defined within the mining plan.
Antamina’s extraordinary tailings dam – the highest of its kind in the world – has the capacity to story 570 million metric tons of waste rock material or 330 Million m3 over the duration of its useful life. Antamina’s tailings dam is designed to provide guaranteed security. It has a technical risk control system that utilizes key instrumentation to ensure efficient operation.
Located in the Huincush Ravine and three kilometers from the concentrator plant, this tailings tank has a starter dam that is 135 meters high and lined with a sheet of reinforced concrete. This top level is simultaneously protected by a high density geo-membrane to prevent potential filtration from the tailings tank moving outward to the exterior.
Drainage tunnels, concrete injections of up to 80 meters in the abutments, and rain water collection channels, with a final capacity of 25 m3 /second – supplement a high technology construction project that guarantees both environmental protection and structural stability.
The Dam is built to be structurally fault-free and retain its stability in the event of a Maximum Credible Earthquake (MCE) and is designed to contain extreme heavy rainfall. The design includes the installation of geotechnical controls used to constantly monitor settlements, deformations, and changes in water levels as well as filtrations.
The Dam has also received the approval by international experts and is being continuously monitored by them as well as by Peruvian agencies such as the OEFA (Agency for Environmental Assessment and Enforcement) and OSINERGMIN. The tailings dam is not only used to dispose of unmarketable parts of the material processed in the mill, it is also used to recirculate 98.5% of the water used by the concentrator. This way, Antamina has no impact whatsoever on bodies of water located high in the Andes Mountains; instead, it uses fresh water in its operation.
The discharges that take place from the tailings dam toward the Ayash Valley reach a level of compliance of over 98%, according to monitoring test observations recorded since the year 2004, and ensure the free availability of this natural resource in the valley as an ecological flow throughout the year at a volume of flow of 150 liters / second.
The slurry pipeline is a reinforced pipeline that runs underground and is monitored over its entire route. Thus, this pipeline has been designed using state of the art technology which includes a fiber optic cable extending from the mine to Huarmey. This reinforced metallic pipe transports copper or zinc concentrates from the Mine (San Marcos) to the port: Puerto Punta Lobitos (Huarmey).
The slurry pipeline has three layers:
1. Exterior plastic coating (Polyethylene)
2. Steel pipe
3. Internal thick plastic protective lining (HDPE)
The diameter of this pipeline does not exceed 25 cm and has 4 valve stations in the Fortaleza Valley and a terminal station in the Port. This mechanism is designed to protect the environment in the event of any accident.
Port Punta Lobitos – Huarmey
Port Punta Lobitos was designed to filter the copper and zinc concentrates that originate from the concentrator located in Yanacancha, and export the mineral to different international shipping ports. The port has coastal and marine shipping facilities and equipment to receive, filter, and store the concentrates, as well as a 271 meter long dock that supports a hermetically enclosed conveyor belt used for loading operations.
Port Punta Lobitos is located 1 kilometer to the west of Puerto Huarmey, 140 kilometers to the south of the city of Chimbote and 300 kilometers to the north of Lima.