Regulations, risk management and experience about tailings dams in Chile

Abstract

Chile is the biggest copper producer in the world, the production of fine copper in 2018 was approximately 5.5 Mton and it is estimated that in 2025, 7.2 Mton of copper will be produced. This production, added to copper grades of less than 1%, causes 99% of the material that is processed to become mine waste such as tailings storage, heap leach pads and rubble deposits. Tailings are classified as high risk environmental waste, and these tailings are also located in a country of high seismicity. Due to this, Chile has a regulatory framework that allowed the improvement of the standards in the design, construction and operations of tailings deposits based on the know-how about the behaviour of these structures. Currently, a risk management system is being implemented to identify the risks and take decisions and actions to ensure the physical and chemical stability of these different types of storage. This article describes the Chilean experience about the behaviour of tailings storage under high magnitude seismic events. A summary about the regulatory framework and the recently implemented risk management is also presented.