EXECUTIVE SUMMARY
(Download the full paper below)
The mining industry generates roughly 13 billion tonnes of tailings each year (ICMM, 2025). The majority of that is stored in facilities that are, by volume, approximately half water. Over the past decade, more than 20 tailings dam failures across four continents have killed more than 400 people, released more than 25 million cubic metres of tailings and water, and caused severe environmental harm. The failure rate remains unacceptably high. This white paper, prepared under CEEC's Global Tailings Initiative, asks why incremental improvements to containment practice have not significantly moved the curve, and what must change upstream of the dam to achieve better outcomes.
The white paper's central hypothesis is that the industry should move away from considering tailings as a single stream and should instead match dewatering technology to much narrower particle size ranges. Permeability scales with the square of particle size, so a whole-of-stream design is dictated by the finest 20% to 40% of the feed even when the remainder could be dewatered with simpler and lower-cost equipment. Splitting the stream ahead of dewatering and choosing equipment that suits each fraction is the single largest lever available for reducing the capital cost, the operating cost, and the stored-water risk of a tailings facility. To take but one example: for a 100 kt/d operation, a circuit comprised of hydrocycloning, horizontal
belt filter pressing, and centrifuging has the potential to reach the same tailings moisture as whole-of-stream pressure filtration at roughly half the capital and operating costs.
Three findings support this hypothesis and frame the rest of the document:
- The dominant driver of dewatering difficulty is the minus 20 μm fraction, not the bulk particle size distribution (PSD)—a point that is neither well understood nor leveraged by the industry.
- Clays cannot be treated as "small particles"; their surface charge, water chemistry interactions (conductivity, sodium adsorption ratio, pH), and dispersive state determine whether any given dewatering equipment can work at all.
- Once these two variables are understood, the feasible solution space is much wider than contemporary industry's predominantly binary choice between conventional wet storage and wholesale pressure filtration. Sand separation, codisposal, layered horizontal belt filter precoating, centrifuges, and hydraulic dewatered stacking are all viable intermediate pathways worthy of consideration.
Moving away from a single tailings stream is somewhat challenged due to the lack of:
- a common classification framework so that metallurgical and geotechnical engineers describe the same material in the same terms, and
- a silo-busting, cross-disciplinary collaboration between process, geotechnical, and mine planning teams. These disciplines often make decisions with different success metrics and rarely see each other's constraints.
Without greater cross-disciplinary integration, rethinking tailings management may optimise for one discipline at the expense of another, and the overall optimum solution may not be realised in practice.
The white paper closes with a call to action for the industry to use CEEC's community of practice to seed research, peer-review emerging solutions, and share case studies (in particular, operating data from the handful of sites already running split-stream dewatering at scale). Solving tailings at a positive internal rate of return (IRR) is achievable with today's equipment and the right approach.
Key message
The central insight of this white paper is that tailings management can be materially improved by moving away from treating tailings as a single stream and instead matching dewatering technologies to specific particle size ranges. By separating the stream before dewatering, particularly by addressing the minus 20 μm fraction and clay behaviour, operators can reduce stored water risk, capital and operating costs, and reliance on either conventional wet storage or whole-of-stream pressure filtration. Achieving this requires a common classification framework and stronger collaboration between process, geotechnical, and mine planning disciplines so that tailings solutions are optimised across the full system, not within individual technical silos.