Commercial activity in the Collahuasi mining district dates back to 1880 when its systems of high-grade copper and silver veins began to be exploited. These operations continued for fifty years until their interruption by the Great Depression. Work in the area resumed in 1978 with the identification of the key components of the Rosario deposit. A series of satellite, aerophotogrametric and onsite studies followed, along with drilling activities, and in 1991 the Ujina deposit was discovered.

The feasibility and environmental impact studies for the Collahuasi project were approved in 1995 and, at the end of 1996, once financing and marketing agreements had been signed, the development and construction phase began.