New research will help mining companies better understand the negative societal and environmental impacts of mine-waste disasters, known as tailings flows, and hopefully avoid them.
Researchers created a database as part of a study that presents the first global picture of the occurrence rates, behaviours and physical impacts of tailings flows, which are rapid downstream movements of mine waste following failures of tailings impoundments.
The study, led by the University of Waterloo, involves researchers from across Canada and reports detailed information on 63 tailings flows that have occurred worldwide since 1928. Catastrophic tailings flows have happened once every two to three years on average since 1965, with many of these events causing death, long-lasting environmental contamination and severe infrastructure damage over distances that can span tens of kilometres. Hazardous weather and inadequate drainage systems have been the most frequent triggers for tailings flows since 1996.
"Despite the strict engineering requirements, tailings impoundments can fail, sometimes catastrophically, so our research raises awareness of the potential downstream effects for public safety purposes," said Nahyan Rana, a PhD student of earth and environmental sciences at Waterloo, and lead researcher on this project. "This study is especially relevant when we consider the global rise in mining activity."
The database will help mining engineers compare the conditions for previous incidents to those of existing sites. The researchers used historical satellite imagery to map dozens of cases of tailings flows since 1965.