Tailings management is the handling, treatment and disposal of mine waste, known as tailings, generated after the ore of interest has been extracted and processed. A good tailings management system that complies with current environmental regulations and global best practices is crucial to achieve stable and safe mining infrastructure, allowing us to achieve the goal of zero harm to people and the environment. If not properly managed, they could generate problems in the use of water, affect the existing flora and fauna or, in the worst case, generate structural and non-structural failures in the facilities, which could cause disasters that could even lead to human fatalities.
At Ausenco, we understand that tailings management goes beyond waste disposal. Our approach is based on a comprehensive model, ranging from identifying the best tailings location and technology, to designing a stable, safe and environmentally friendly facility, to ensuring the proper implementation of the construction, operation, closure and remediation stages of all facilities attached to the tailings deposit.
Navigating tailings management challenges
The mining industry faces numerous challenges, as each deposit presents unique characteristics in terms of the size of the operation, accessibility, climatic conditions, the socio-environmental environment and the regulations of the country where the mining operation is located. This requires tailings management solutions to be tailored to the specific needs of each project.
Regarding tailings management specifically, the main challenges include the efficient use and recovery of water, the availability of areas for the disposal of tailings, as well as the safety and stability of the deposits.
Water scarcity in many mining regions makes it imperative to adopt more sustainable measures and practices. The safety of tailings impoundments is another crucial challenge. If not properly managed, they can pose significant risks to the environment and communities. The implementation of best practices and international standards from the design stage to closure are essential to avoid catastrophic incidents. The goal is to achieve stable conditions throughout the life of the repository by ensuring a safe facility that can remain stable in perpetuity despite internal and external conditions that may affect the stability of the tailing’s impoundment.
At Ausenco, we focus on solutions that not only meet the most stringent regulations but are also sustainable over the long term. We are currently collaborating with our mining clients to develop new technologies including tailings dewatering methods for increased water recovery and tailings impoundment safety.
Innovative tailings dewatering solutions
Dewatering seeks to recover water from the tailings slurry to make them safer facilities. By converting the slurry into a more stable material with less water, a large dam or wall is not required to contain the tailings, at least not in the conventional way. This not only reduces the risk of failure, such as dam collapse, but also allows us to recover water for reuse in mining operations, which is critical in arid areas. Another advantage is that the work in the closure and remediation stages becomes less complex and more environmentally friendly.
Filtered tailings systems use mechanical equipment to press, dewater and transport the material by belts or conveyor belts and is an alternative used today in some gold-silver and polymetallic mining operations.
We also have the co-disposal method, where filtered tailings are disposed of together with the mine waste to deposit them in a single location. This results in the efficient use of the space in the mine for the disposal of mine waste, reducing the impacts of the project's footprint.
There are other methods for dry stacking of tailings which are still being developed. However, the challenge is bringing them to industrial scale, especially for large copper mining operations, where large volumes of production and the investment in mechanized systems make, until today, its use economically unfeasible as a unique solution for tailings management.
Tailings management: Challenges in Peru and Chile
Each country has its own challenges and regulations. One of the key factors in mining is relationships with communities. Establishing an early and continuous dialogue allows for a correct and timely understanding of the impacts and benefits of mining projects.
Water is another key factor and is directly related to tailings management. Peru has a positive water balance in some mining regions, which means that managing excess water can be a challenge for tailings management. In Chile, water scarcity in the north of the country has led to the adoption of seawater alternatives along with long-distance pipeline water supply systems.
In both countries, environmental regulations are becoming increasingly stringent, challenging us to be innovative and to seek solutions that minimize the use of our natural resources.
A community-focused approach to managing social and environmental aspects
At Ausenco, we not only design tailings management facilities, but also provide solutions to our clients in social and environmental management. Currently, we have been developing with our clients in Peru, Chile and Argentina several environmental impact studies and closure plans that involve tailings management systems.
We work hand-in-hand with mining companies and local communities from the initial stages of the project, including early planning for closure. We involve the communities in citizen participation workshops, where we explain in detail the mining project, field data collection activities, tailings management plans, social management plans, among other topics. In addition, as part of the environmental impact studies, we develop surveillance programs that allow continuous monitoring of water resources, air quality, biological ecosystems and other environmental components.
Our team is experienced in identifying and designing measures to address socio-environmental risks in a timely manner, which allows us to build trusting relationships with communities. This not only facilitates permitting, but also ensures that operations are conducted in a responsible and sustainable manner.
What sets us apart from other tailings management providers?
Our main differentiator is our ability to offer integrated solutions. Not only do we assist in obtaining environmental permits, we provide services across the entire lifecycle of the project, from initial planning and design to construction and operations, to closure and post-closure of the mine. We have a multidiscipline team that includes geotechnicians, hydrologists, hydrogeologists, geochemists, process engineers, permitting and socio-environmental experts that allows us to develop customized solutions for each client, considering both technical aspects and non-technical aspects of a project.
Contact us with any questions.
Article first published in ProActivo magazine, October 2024.