14 October 2021
A responsible approach to business is crucial in the mining industry. Mining companies now need to balance the need for minerals with the call for sustainability. There have already been significant breakthroughs by applying digital technology to improve the safety and sustainability of mines. In this post, we will be discussing the risks of tailings dams, and how to decrease those risks with technology.
What are tailings?
Tailings are materials leftover from mineral processing. Mineral processing involves crushing and grinding ore into fine particles and mixing with water to extract the metals or minerals. Once separated, a mixture of fine particles and water remain. This tailings mixture is then stored in a tailings storage facility or tailings dam.
What are tailing dams?
Tailings storage facilities, or tailings dams, are dams built to hold waste from mining operations.
There are three common types of tailings dams:
Upstream tailings dams
Upstream tailings dams are less expensive but have a higher risk of failure. The upstream method starts with the construction of a starter dam. Tailings will naturally separate and the coarser material will settle closer to the dam. This essentially pushes the water upstream, using the support of the previous dam raise and the tailings beach area. Upstream tailings dams are more suited to climates with limited seismic activity and flat topography.
Downstream tailings dams
Downstream tailings dams are more stable, with minimal risk of collapse. However, they are more expensive. The downstream method begins with a starter dam that has a low permeability zone or liner to control and minimise water loss. In short, tailings are placed behind the dam and the embankment is raised by building the new wall on the downstream slope of the previous section. The crest of the dam thereby moves “downstream”. As a result, downstream tailings dams are better for high rainfall and seismic areas.
The centreline method is a combination of the upstream and downstream methods. As with upstream tailings dams, tailings flow from the top of the dam to form a beach behind the wall. When the dam is raised, the material is placed on the tailings beach and the existing embankment. The centreline design is more suitable for areas with moderate rainfall and moderate to high seismic activity.
There is an estimate of 3500 tailings dams worldwide, with South Africa having the highest number of dangerous tailings dams. As a result, tailings dams can pose a major threat to the communities surrounding them, wildlife, and the environment as a whole.
What are the tailings dam risks?
The collapse of tailings dams has occurred every 2 – 3 years since 1965, resulting in death, destruction of the environment and infrastructure damage. The devastating failure of a tailings dam in Brazil on 25 January 2019 lead to the loss of 300 people.
There are also concerns about the safety of legacy tailing dams. These tailings dams are no longer in use, but still pose a considerable threat to life and the environment if they fail. It has therefore become imperative to prevent these failings, but also to focus on more sustainable waste management systems.
Decreasing tailings dam risks with technology
Over the last few years, we’ve seen incredible advancements in mobile technologies, connectivity, satellite data, data storage and more. By using innovative technology, mining companies now have access to relevant data that generates actionable insights. Additionally, these insights can improve decision-making and reduce risks.
By strategically using digital technologies, such as remote surveillance, IoT connected devices, sensors, satellite data and drone footage, mines can continuously survey their tailings dams. Similarly, near real-time data from IoT devices can be aggregated and used to build predictive models and mitigate potential hazards.
In the event of a tailings dam failure, a digital alerting system using social media platforms and mobile technology can help save lives and protect the environment.
Digital technologies at Integrove
At Integrove we are currently developing a view that provides data-driven insights to improve maintained protocols to manage safety and risks through digital alerting. Remote monitoring eliminates the need for ground teams going into inaccessible and dangerous areas.
Furthermore by aggregating multiple streams of data, from weather conditions, hydrology, structural measurements to seismic events, our view can help protect lives, the environment and infrastructure. Data-driven insights can also ensure mines meet regulatory compliance and take preventative action rather than reactive.
Let us help you with your digital mining technology needs.