The global mining industry produces billions of tonnes of tailings each year. This waste material is contained in tailings dams and storage facilities, which are among some of the world’s largest engineering structures.
These large structures are at constant risk of failure due to the physical pressure applied by liquid and solid products, posing a serious threat to their surrounding communities. Despite a basic understanding of the mechanisms that cause tailings dam failures, and the data collected, tailings dams have consistently failed over the past 50 year.
This article explores the known risks, the catastrophic consequences of failure and the monitoring solutions that are improving safety and monitoring standards in the mining industry.
The primary hazards and causes of tailings dams failures are slope instability, foundation failure, overtopping, as well as uncontrollable external factors such as earthquakes and seepage. These potential geohazards require targeted identification and assessment during both the dam construction and closure stage while a continuous safety monitoring program is needed throughout the entire lifecycle of the dam.
There are a reported 18,000 tailings dams around the world, with a failure rate estimated at 1.2%. To put this into perspective, traditional water storage dams fail at a rate of 0.01%. Tailings dams are more susceptible to damage due to lack of reasonable regulations and design standards, poor embankment construction using soil, coarse waste and mining residual materials, and the overall cost of monitoring. Tailings dams are also dynamic in nature, often requiring expansion, raising of the dam height or the addition of subsequent dams.
In the last 50 years, 63 major tailings dam failures have been recorded worldwide. Alarmingly, the failure rate has increased in the last 20 years, with five to six failures reported annually.
The Severe Consequences
The impacts of failures are severe. It is estimated that between 1961 and 2019, 2375 people lost their lives due to a tailings dam failure.
In 2019, a catastrophic collapse of the tailings dam at the Córrego do Feijão iron ore mine in Brumadinho, Brazil killed more than 230 people and destroyed large sections of agricultural land. The live footage of the devastation, share globally, sparked major public scrutiny of the potential risks and resulted in greater demand for safety transparency of tailings storage facilities around the world.
In addition to the great public safey riskand long-term environmental impact thattailings dam failures pose, there is also the substantial cost to the mining industry including high compensation costs and extensive environmental rehabilitation reconstruction.
It is therefore critical that these dams are continuously monitored to ensure the highest level of safety.
The Solutions to Preventing Tailings Dam Failures
To increase and maintain a high level of integrity and safety, tailings dams require meticulous design and operation, along with ongoing and geotechnical monitoring. GroundProbe’s cost-effective monitoring systems are critical to mitigating the risks associated with such disastrous failures.
GroundProbe’s focus is simple – reliability and precision. Their systems are ideal for both real-time predictive and reactive monitoring of tailings dams and can be adapted to suit the specific monitoring needs of any tailings dam globally.
Tactical, targeted solution. The SSR-XT is designed to critically monitor known movements that pose a potential or immediate threat to the safety or productivity of mining operations, the SSR-XT monitors slope movements within a targeted area. A 3D Real Aperture Radar (RAR), its fine pencil beam scans in a raster pattern to provide full 3D imaging, guaranteeing every targeted area of concern is monitored in real-time.
Strategic, broad-area solution. The SSR-FX detects new risks and hazards across extensive mine areas over longer periods of time. The 2D RAR uses a thin, vertical stripe to monitor mine walls, detecting hotspots of movement, even in non-critical areas.
High resolution-long-range solution. Featuring a 2D Synthetic Aperture Radar, SSR-SARx is capable of monitoring areas from a long-range to detect new risks and hazards. It uses wall imagery to produce high-resolution targets. When combined with the longer integration time, this imaging can detect small movements over many months.
Full-coverage, high-resolution solution. The SSR-Omnidetects movement through a fast and comprehensive high-resolution scan. A rotational RAR, it monitors 360° around the walls of the mine site through a thin, vertical stripe, producing real aperture measurements that are less susceptible to contamination.
A tactical, highly-mobile solution. SSR-Agilis is a standalone vehicle monitoring system designed to protect personnel and valuable equipment in active working areas of a mine site. It transmits visual and audible warnings to operational crews in real time.
A reactive monitoring and alarming solution. The RGR-Velox (Reactive Geohazard Radar), is a high-precision reactive monitoring and alarming tool for tailings dam breaches, landslides, avalanches, and large slope failures. It is the highest precision, fastest scanning and longest range doppler radar currently available.
A large area, high-precision service. The Insar Service, in partnership with 3vGeomatics, detects and monitors surface movement via the combination of bothsatellite and ground-based radars to create an integrated, multi-source monitoring solution.
High-volume, high-risk tailings dams will continue to be built due to the increasing demand for metals and the resulting mine waste. Understanding the risks and establishing and maintaining comprehensive safety systems are key to reducing the risk of future failures.
GroundProbe understands the risk factors that tailings dams pose and have the advanced suite of technologies available to mitigate those risks.
Proudly, GroundProbe has never missed a failure. GroundProbe’s products have effectively detected the amount, shape, and degree of wall movement for hundreds of mines, including tailings dams, across the globe, for more than 20 years. They are committed to empowering safer and more sustainable mine operations, now and into the future.