All information is valid as at 5 August 2024.
The physical activities of extracting and processing ore to separate valuable metals and minerals often result in significant quantities of mineral residue material – including tailings.
As the world’s demand for many mined products has grown at an accelerating pace in recent decades, and as the grades of many orebodies have decreased as they have been mined over time, so the volumes of this residue material have increased.
There is a clear imperative to use all possible endeavours to ensure that Tailings Storage Facilities (TSFs) are managed to the highest standards of safety so that our industry can build and sustain trust with all our stakeholders. Anglo American employs best-practice standards and we manage our TSFs with the utmost care through rigorous governance and stewardship.
Transparency is central to how we approach engagement and our disclosure provides stakeholders with valuable information and an update on our ongoing progress across this key area of our operations.
In 2019, in response to the Investor Mining and Tailings Initiative (IMTSI) led by the Church of England Pensions Board and the Swedish Council on Ethics, Anglo American made disclosures in relation to identified tailing dams. In 2023, Anglo American voluntarily updated its 2019 disclosures. Although the data which was made available in response to the IMTSI is now outdated, we have, in the interest of transparency, taken the decision to retain it on this platform for the time being.
Since then, there have been significant developments in the context of tailings data disclosure including the introduction of the comprehensive Global Industry Standard on Tailings Management (GISTM), an important step forward for the global mining industry. Anglo American played an active role in the multi-stakeholder process of developing the GISTM, which covers standards and practices over the entire tailings facility lifecycle and sets a high bar for the mining industry to achieve strong social, environmental and technical outcomes.
In 2022, we continued the work to align with the technical requirements of the GISTM and the social aspects that are already encompassed in our Social Way 3.0.
In August 2023, for tailings facilities with ‘extreme’ or ‘very high’ potential consequences, we disclosed our work and progress in line with other ICMM members. We are now, in 2024, releasing updates on our work and progress for those facilities.
In relation to other tailings facilities we will disclose our work and progress in August 2025 in line with our ICMM member commitments.
We are also incorporating tailings related data in our CDP water security scoring reports. To ensure integrated disclosure, the applicable data from those reports is now also being captured on this platform. This process does take time and we ask that you please bear with us as we make these updates.
Our definition
After the completion of mining and processing, we are left with mineral residue that is generally made up of two principal components:
Our definition
A TSF is a structure specifically engineered and tailored to deal with the physical nature of the tailings materials, as well as local climate, topography and seismic activity. The purpose of a TSF is to receive deposits of tailings and allow water to separate from the fine waste particles – either naturally or through a mechanised process – so that the water can be recycled back into mining processes.
At Anglo American, we upgraded our technical standard for Processed mineral residue safety management in early 2014, going beyond established regulatory and industry standards in many respects at that time.
In 2022 we aligned our technical standard to include all additional technical requirements as called for under the Global Industry Standard on tailings management (GISTM) inclusive of guidelines to augment the implementation process of GISTM.
In support of the technical standard and other non-technical disciplines, we have developed Processed mineral residue a Policy document approved by the Board of Directors that is available on our website.
There are six fundamental types of tailings dams, each constructed using different techniques:
The upstream method starts with the construction of a starter dam. Tailings will naturally separate so that coarse material settles closest to the starter dam, while liquid and fine material settles furthest away. As the level of the materials rises, the crest of the dam is raised “upstream”, using the support of the previous dam raise and the tailings beach area.
Its stability is dependent on the in-situ strength of the tailings material itself. This method is more suitable in dry climates with limited seismic activity, low deposition rates, and flat topography.
The downstream method begins in most cases with a starter dam that has a low permeability zone or liner to control and minimise water loss.
In some cases, it also serves to initially store water for start-up of the plant. 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” or away from the starter dam. A liner or membrane can be used on the upstream slope of the dam to prevent erosion and limit infiltrations.
Downstream tailings dams require more material to build than upstream constructed dams, but are considered more stable, making them better suited for areas with seismic activity and more intense rainfall or water management requirements.
The centreline method sits between the upstream and downstream construction methods. Like the upstream method, the tailings are discharged on top of the dam to form a beach behind the dam wall.
When the dam is raised, material is placed on both the tailings beach and the existing embankment.
The embankment crest is being raised vertically on the “centreline” and does not move in relation to the upstream and downstream directions.
The centreline design is suitable in areas with moderate rainfall and moderate to high seismic risk.
A hybrid dam is a combination of the tailings dam types that are defined as either Downstream, Upstream or Centreline. Some tailings dams have changed construction type in the past and now are defined as ‘hybrid’ or ‘mixed’ type. In addition, some hybrid dams may incorporate waste rock materials in their structure.
A landform is one that is typically a very old legacy tailings dam that has dried out to the point where it does not constitute a wet dam anymore, nor is considered to be a containment structure. The main features, such as the outer wall slopes, may also be altered or flattened by erosion to the point that the facility is unrecognisable in comparison to its previous engineered state.
Water retaining type of dams are built using selected imported fill materials from designated borrow areas and quarries, placed in a controlled manner in lifts, typically resulting in an embankment structure that is designed to store water and tailings in direct contact with the outer wall. Water retaining structures may have specific engineered structural features, such as riprap, a low permeability liner or core zone, internal filters, and drainage system, to safely manage stored water and seepage flow through the dam body.
Water retaining structures are similar to downstream structures in that the outer wall is self-supporting. A key difference is that a downstream facility is not always designed to allow water to pond against the outer wall.
Of the *57 Processed mineral residue facilities currently managed by Anglo American, 27 are in active use, 22 are inactive or in care and maintenance, and 8 are closed or rehabilitated.
*The 2023 count of 62 came down to 57 due to the divestment of the De Beers Namaqualand operations.