The paper presents the design adopted for the tailings impoundment of La Candelaria mine, located in the North of Chile in a semidesert zone next to a highly developed agricultural region. The design of this impoundment is characterized by having integrated in a harmonious way, the environmental, operational and economical aspects both for the operation, and abandonment phases, for which the planning studies of the mine, particularly in regards to the location of the waste rock dumps, had to be incorporated from the beginning. The final result will be an impoundment that fully complies with the current standards and requirements for this type of civil work as regards to environmental, economic, and safety requirements.
The design, construction and abandonment of a large tailings impoundment represents an enormous challenge while trying to reconcile the economical, environmental, and operational aspects, and, at the same time obtain a safe, economic and environmentally-friendly design. This reconciliation of very different interests is not always possible to obtain. What follows is a description, first in general terms and then in detail, of the tailings deposit of the La Candelaria copper mine, owned by Phelps Dodge and Sumitomo. The mine is located in Chile, approximately 800 km north of Santiago, in a semidesert and mountainous area next to the fertile agricultural valley of Copiap... The region has historically supported an important mining activity, which currently coexists with very valuable vineyards in the main valley. Currently with a production of 60,800 tons of copper sulfide mineral per day, the mine is exploited by open pit mining with an average stripping ratio in the order of 3:1. The process plant is located immediately upstream of the pit in one of the neighboring streams.