An insight into failure of iron ore mine tailings dams

ABSTRACT Mine tailings dams are surface impoundment structures consisting of raised embankments that are built to contain mine tailings and mill effluents. In the past, many failures of these iron ore mine tailings storage facilities/dams have been reported worldwide in different forms. In this paper, an attempt has been made to review the failure modes, mechanisms and possible solutions to enhance the stability and safety of iron ore tailings dams. A comprehensive investigation has been carried out on 16 failure cases of such dams that were reported from 1917 to the current period. Additionally, mineralogy of iron ore tailings has been provided. The analysis of the past failures shows that most failures took place as a result of slope instability, overtopping, liquefaction-related instability, foundation movement and some form of structural failure. It has been found that 31.25% of iron ore mine tailings dams collapsed due to slope instability, 18.75% due to overtopping, 6.25% due to liquefaction-related instabilities, 6.25% due to foundation failure, 6.25% due to erosion, and 6.25% due to structural failure. In 25% of the failure cases, the causes have been unknown. An attempt is also made here to present prevention and remediation measures for avoiding failures and the associated negative environmental impacts in future.