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Tailings dams design and experience

Lately several tailings dam failures rocked the mining world. Despite the relative high frequency of these events we have heard engineers qualify the failures as “one in a million”, “extremely rare” or even “black swans”. Today we want to discuss a few concepts on tailings dams design and experience. In particular, we will focus on some disconcerting qualifiers like the ones we just cited above. For example, given the experience of tailings dams catastrophic failures  resulting from combinations of various…

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Not all risk assessments are created equal

The UNEP “Mine tailings storage: safety is no accident” report asks mining companies to make environmental and human safety a priority. To ensure mining companies meet that result in management actions and ground operations, a residual risk assessment should be performed. For clarity, residual risk assessments are those that intervene after mitigations or critical controls.  However not all risk assessments are created equal so let’s explore the differences. What are the requirements for a good risk assessment? Risk assessments are…

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Catastrophic failures forensic analyses

Catastrophic failures forensic analyses are, most of the time, left in the hand of experiences engineers. At least, that’s the case for tailings dams failures and other catastrophes like major infrastructural accidents and for instance, aviation. Are we sure that is the best way? Normalization of deviance, management and decision-making are oftentimes ingredients of the catastrophic failure buildup, not only “engineering”. So, we dare to say, Independent Panels should include social scientists. They seem to be the most qualified to…

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Quantifying Tailings Dam Risks at MIRA

Quantifying Tailings Dam Risks at MIRA (Mining Insurance and Risk Association) one hour session took place on June 11th 2020. The talk presented a comprehensive approach to address how to quantify and prioritize tailings dam risks, especially in the context of large dams’ inventories. In this blogpost we summarize the Q/A session that followed the talk, classified by theme. The full talk is viewable on Youtube    At the end we present a synthesis before some closing remarks. Understanding geology and…

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Tailings Dams Review Boards and Inspection Reports

Tailings dams review boards and inspection Reports exist because of a voluntary effort by the mining industry to improve and mitigate dams “issues”. In addition, mining companies are under pressure to be more transparent on their “issues”. We discuss below the term “issue”.   UNEP 2017 report and more recently Church of England initiative and ICMM “global code” are all expressions of this growing pressure. Thus, mining companies are requesting the publication of Tailings dams review boards and inspection Reports. Publication…

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Slope Failure Definition

Slope Failure definition is the second step of a slope risk assessment. The first step is, of course, system definition. It is indeed paramount to clearly state what is considered the success of the slope under consideration. Indeed, unless one clearly defines success, failure remains an ambiguous term (Adams, 2015). Generally we define the success of a slope as the fact that: it stands as built and does not afflict operations (traffic, ore recovery, business interruption, H&S). it features slow…

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Marcus Aurelius stoicism and COVID-19 epidemic

Marcus Aurelius stoicism and COVID-19 epidemic reactions are deeply linked. As famously stated by Marcus Aurelius, Roman Emperor and philosopher: “Things do not touch the soul.” Also, for example: “Focus on what you can act, the rest is negative noise.” These deceptively simple statements are keystones of the Stoic philosophy. Marcus Aurelius meant that we are not victims of events, people, or things, but by the opinions we form of them. As he put it, “our perturbations come only from…

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Light on Tailings dams failures

The Church of England Pensions Board and the Council of Ethics of the Swedish National Pension Funds published some recently collected numbers shedding some light on Tailings dams failures.   How many active dams in the world did we assume earlier? In the literature we oftentimes see the number 3500 to characterize the total tailings dam inventory in the world. We used that number in both the following papers: Oboni, C., Oboni F., Factual and Foreseeable Reliability of Tailings Dams and…

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