Why mines should look at total life to achieve tailings facility closure

Abstract

Dewatering tailings is typically given only a nominal assessment and eliminated as too expensive as a tailings management option because of its perceived upfront capital cost. In fact, there is often a compelling business case for constructing a dry tailings storage facility if the value of reduced risk throughout the operating life and achieving closure are considered holistically. It is common practice for mines to store tailings waste as a fluid slurry behind earthen embankments or in depleted mine pits. Looked at purely from an upfront cost perspective, this is generally the most economical option. However, look at the same facility long-term and it is a different story. Unless mine owners view tailings management from a total cost/benefit perspective from cradle to grave, their risk analysis of what is considered an appropriate tailings management solution for start-up could be very short-sighted. A dewatering approach that extracts most of the liquid and changes tailings from a fluid to a soil product, offers many mine sites substantial long-term benefits. Dewatering facilities can be introduced at the start of a project or during operations to transition away from slurry management, and each site should be considered on a case-by-case basis. As public expectations for standards of remediation and mine closure get higher, mining executives would be remiss if dewatering tailings is not considered as an option when deciding tailings management and closure strategies.