Dam cross section optimization: Collahuasi Copper Project, Chili

Unlike water retention dams, tailings dams typically are constructed in stages over the operating life of a mining project. The selection of an optimal design cross section for a tailings dam therefore is highly dependent on the operating requirements of the mine as well as the characteristics of the site and the tailings, amongst other factors. The Collahuasi Copper Mine is located in the Andean Cordillera in northern Chile, at an elevation of over 4,100m a.m.s.l. The open pit mine is designed to ultimately supply ore to the concentrator facility at a rate of 120,000 metric tonnes per day. The tailings dam will be raised in stages to an ultimate height of over 100m and is designed to safely accommodate 1.8 Billion metric tonnes of mine tailings over the expected 45 year operating life of the mine. This paper describes how the dam cross section was optimized to make the most cost-effective use of locally available borrow materials, mine waste rock and cycloned sand tailings for dam construction over the 45 year operating life of the mine.