Safe storage

What is a tailings storage facility and what does it do?
Copper doesn’t exist in huge blocks underground for us to remove. It is embedded with all the other materials in the rock.

Tailings is the name we give to everything that is not of economic value when we’re extracting copper from the ground. It’s the rest of the rock that has been processed and, because it has been through the processing systems, it comes in a slurry of rock mixed with water. Depending on the composition of the ground and the material that you have extracted, this slurry can have varying levels of toxicity, so it is really important that you dispose of it correctly. The tailings storage facility is where that happens. At each operation, we design and build unique storage solutions that allow us to manage these tailings and ensure they remain safe for the long-term.

Historically, tailings facilities have not been given as much time, thought and innovation as they should have by the wider mining industry. Now that the spotlight has been shone on what happens when it is not done properly, our entire industry is making great strides in improving the technology and giving it the required focus to create truly fantastic tailings storage facilities as well as long term plans for the land which they occupy.

Often, that is quite a lot of land. When the rock is in the ground it is a very dense material, and so the particles are all close together. As it is broken down through processing – so that we can access and remove the copper – it becomes far less dense and can reach almost twice the size that it was before. So, in many cases, Tailings storage facilities will in fact take up far more space at a mining operation than the mining pits themselves.

Unique facilities
Each tailings facility is relatively unique, as there are many factors that have to be considered when you create your storage facility. The design traits that are built into the final product are defined by extensive analytical work to ensure that these facilities are built as strongly as possible and will not negatively impact the surrounding environment or communities. Before any job begins, there is a long process of analysis to ensure that the facility you build is able to manage any dangers inherent in the local environment.

Long term management
Each operation must create a plan for the long-term management and maintenance of a tailings facility. This plan must ensure, through monitoring, that it remains safe for its entire lifecycle, including monitoring the facilities in terms of their physical and chemical stability until a new land use has been established. At the same time, the end goal is to either return the tailings facility to nature or find a new use for it. At our Pyhasalmi operation, the tailings facilities have been developed into solar farms that provide renewable energy to our operation, whilst in Cobre Panama the tailings will one day be rehabilitated into the natural rainforest, returning it to the state it was before we arrived.

A varied team
As with so many parts of mining, it takes a varied team to come together to create a tailings facility, in many roles that might not initially become apparent. Of course there are people who work on the construction, but there are also environmental and safety managers, geotechnical engineers, hydrologists and hydrogeologists, QAQC engineers, data analysts, and tailings facility specialists who each work on their own area of specialism to ensure that when we’re creating a mine, we’re also trying to minimize potential negative impacts. Beyond our own people, there are also highly qualified independent auditors who regularly monitor the facilities.