Sustainability website / Case Studies 2003 / Xstrata copper / Alumbrera Capping Simulations - Tailings Dam and Waste Rock

Alumbrera Capping Simulations - Tailings Dam and Waste Rock

Alumbrera capping simulations for the tailings dam and top surface of the waste rock dump were completed. It is proposed to cap the waste rock dump with non-acid forming run-of-mine material, while alluvial materials that exist naturally upstream of the tailings dam will be used to cap the tailings dam. Modelling determined that 0.5m of the respective potential capping materials is considered sufficient to prevent the infiltration of rainfall into the final landforms. A total of four capping trials were constructed based on results from mathematical modelling for final capping designs. Two trials were established on the waste rock dump with a capping thickness of 0.5m and 1.5m respectively, and two were installed in the tailings dam area, one with a 0.5m cap, and the other without a cap. The final objective of the capping design is to prevent the infiltration of rainfall into the waste rock dump and the tailings dam after mine closure.