Anglo American has announced the delivery of the first copper production on schedule from its Los Bronces expansion project in central Chile, visited by IM Editor Paul Moore on November 22. The expansion is expected to more than double (on average over the first three years of full production), the mine’s existing production of 220,000 t/y and is the second of Anglo’s four major strategic growth projects to begin production in 2011. John Mackensie, CEO of Anglo’s copper business commented: “We have delivered this major expansion of Los Bronces on schedule thanks to the admirable hard work and dedication of the entire team of up to 16,000 people who have been working on the project over the last three years. We have a 12-month ramp up period ahead until we reach full production, during which time we will be increasing processing plant throughput from 61,000 t/d to 148,000 t/d.”

The expansion has seen a lot of investment in new equipment, including a 40 ft diameter SAG mill and two large ball mills from Metso, all with Siemens gearless drives. The 44-strong haul truck fleet of mainly Komatsu 930Es has also been expanded, though interestingly the mine is also testing the Caterpillar 795F AC. A new primary crusher was also installed near the open pit with the crushed ore fed by conveyor through a 4.4 km tunnel to the new Confluencia milling facility. At that plant there is also a new covered stockpile, thickeners and other associated equipment to produce copper ore slurry. This is then transported through a 56 km pipeline to a new copper and molybdenum concentrator plant known as Las Tortolas. It is adjacent to the existing plant and consists mainly of large FLSmidth Wemco flotation cells. A detailed article on the Los Bronces operations will appear in IM in early 2012.