RISK TAILINGS II - Sustainable mine tailings

Offentlig prosjektsammendrag

Mine tailings are a mixture of sand, silt and clay with high content of metals, chemical reagents and process water employed during raw material extraction. Tailings are usually stored in a Tailings Storage Facility (TSF) retained by embankments or dams. Tailings dams are built incrementally, usually without interruption of the mining activities. While mining technology over the past 100 years have made it economically feasible to increase excavated volumes, there has not been similar progress in the management and risk assessment of TSFs. The uncertainties on the physical and chemical characteristics of tailings together with varying dam management practices are of great concern. The poor performance of tailings dams have resulted in disastrous dam failures. The challenge of safely storing mine waste is growing in scale and complexity and exacerbated by extreme weather events due to climate change. NGI initiated in 2019 research on "Sustainable and safe tailings dams", focusing on (1) sulphidic tailings and their potential valorisation; (2) geochemical and geomechanical tailings characterization; (3) numerical modelling of tailings behaviour; (4) use or remote sensing for early warning; and (5) risk assessment and management for TSFs. The objective of the project is to reduce the risk associated with failure of TSFs. Given earlier failures and their catastrophic consequences, there is an urgent need to understand and model the behaviour and mobility after failure of tailings materials to establish potential precursors of failure, develop suitable material models for tailings materials and enable a reliable prediction of potential failure and runout of tailings materials to evaluate impending risk. Such efforts are required to prevent future failures and reduce the risk of human, property and environment losses. The project contributes to reduced number of failures, improved safety and make mine tailings more sustainable.