Flexible focus: the tailings management system at Teck’s QB2 mine
Effective tailings management remains one of the crucial parts of a mining operation. Giles Crosse asks if Teck's $5bn Quebrada Blanca Phase 2 mine can ensure safe operations?
uebrada Blanca Phase 2 (QB2) is a copper project being built by Teck and project partners WSP in northern Chile. It features a flexible tailings management system, which could, if done right, set a precedent for sophisticated tailings management at some of the world’s biggest mines.
Circumstances haven't helped the project; the Covid-19 pandemic has pushed back timelines amid rising costs, disrupted supply chains and shaky global economics. Indeed, deeply unpleasant memories plague the industry as a whole surrounding the Brumadinho dam disaster on 25 January 2019.
Set against this legacy, today the Global Industry Standard on Tailings Management (GISTM) exists, while the Investor Mining and Tailings Initiative draws together over 100 investors, with more than $20tn collectively ,to press for positive change. Further, a Global Tailings Portal exists, offering open access to detail on some 1,800 tailings dams around the world, as the mining industry looks to entrench its knowledge of critical tailings management.
A standard, albeit voluntary, is now here and Teck, Anglo American and Freeport-McMoRan, among others, have agreed to meet it. By 8 April 2022, 45% of the mining companies contacted, 65% by market capitalisation, had agreed to at least review the GISTM and its applicability across their operations, but half had yet to respond.
Globally, reports suggest that some 12 tailings incidents have taken place at mine sites in Angola, Brazil, India, Mexico, Peru and Turkey since Brumadinho. Can Teck’s latest project help set a precedent for more responsible tailings management in the industry?
The tailings partnership
WSP personnel across six countries contributed to the design of the tailings management facility (TMF) for Teck’s QB2. The project’s operation incorporates extensive environmental measures, including the use of desalinated seawater and a tailings management plan that maximises water recovery in challenging terrain.
The project required several in-depth designs and various analyses to specify a facility capable of handling 140,000 tonnes of tailings per day, transported by gravity to the TMF for separation into fine and coarse fractions. The coarse sand fraction will be used for construction of the storage embankment, while the finer fraction will be deposited into the tailings impoundment.
“Responsible management of mine tailings is an important part of our business,” explains Paul Bedell, engineering manager. “Having the opportunity to work on a high-profile project like this and leverage our best practices from various disciplines to design this facility is a true honour.
"The entire team takes this responsibility very seriously, and we are all proud of what has been accomplished: a sound tailings management facility design, aligned with the industry imperative of ensuring safety," he continues.
“This was the result of collaboration with our clients and across our internal international teams, work environments and languages.”
This was the result of collaboration with our clients and across our internal international teams, work environments and languages.
Teck is optimistic that QB2 will be built to industry-leading standards for safety and security to ensure safe management and storage. Utilities constructed to service the mine will include the concentrate and desalinated water transport systems, high-voltage power lines and access roads.
Furthermore, over 50% of operational energy at QB2 will stem from renewable sources, eliminating some 800,000 tonnes of GHG emissions. In 2021, Teck announced formal commitment to the Copper Mark, a voluntary assurance framework to promote responsible production practices, and this certification is due to expand to QB2 in 2023.
Teck's 2021 Sustainability Report notes its strong track record of tailings management, with zero “significant” incidents at its tailings storage facilities. All its facilities performed as intended, with their inspections and assorted internal and external reviews conducted as scheduled, with the exception of a single tailings governance review, which was deferred due to Covid-19.
Teck also says it has expanded the use of advanced monitoring systems across tailings, including satellites, drones, autonomous robots and real-time monitoring platforms.
“We have tested new types of sensors that are able to non-intrusively and continuously monitor water levels within a tailings facility,” explains the company.
A key player
Teck helped create the original GISTM and chairs the MAC Tailings Working Group, responsible for best practice guidance and key industry documents. Dr Michael Davies was chosen as the industry’s representative expert, serving as an advisor to Teck and contributing to the development of the GISTM.
The company also seems candid; its news resources note that for the industry as a whole, tailings facility failures are relatively rare, but when they do fail they pose big health and safety, environmental and community risks.
“Two catastrophic tailings facility failures in Brazil - Mariana in 2015 and Brumadinho 2019 - emphasised that while tailings management has come a long way, there are still improvements that the mining industry can make,” says Teck.
While tailings management has come a long way, there are still improvements that the mining industry can make.
Combine this open stance with membership, support and leadership of the key standardisation processes driving better practice and Teck gives every appearance of a company putting its money where its mouth is on tailings safety. Certainly, should Teck suffer any future tailings incidents, they would contrast drastically against its promises.
“I’m enthusiastic about the GISTM coming into effect,” says Davies, who works as the company’s senior advisor for tailings and mine waste management.
“At Teck, we have already met about 75% of the GISTM requirements across our sites and we will have it fully implemented and met by August 2023 across our active sites, as well as having it embedded in our development projects.”
What comes next?
“We’re always looking to do better,” continues Davies. “Part of that in this case is having a third-party assessor check our work and confirm that we’re in alignment with GISTM and I look forward to having that third-party perspective on our work and processes.
“Teck is already well-developed in the area of tailings management, having centralised our expertise within our corporate tailings working group and fully engaging senior management in those activities.”
Teck's stance and promises give every indication that the work it is doing in Chile could prove industry-leading.
It remains true that no single standardisation process guarantees safety. Yet Teck's stance and promises give every indication that the work it is doing in Chile could prove industry-leading, and it has the clout and kudos to share that knowledge and drive the industry as a whole to safer, more sustainable operations.
“At the level of the working group, we have interactions across all areas of sustainability among site and corporate practitioners; tailings is also folded into our cross-cutting corporate sustainability strategy,” concludes Davies. “The GISTM has crystallised the expectations of cross-functional best practices across the industry, and further reinforced the concept for Teck.”
// Main image: An activist standing next to a polluted river. Credit: Stefan Milivojevic / Shutterstock.com