Tailings facility disclosures reveal stability risks

Abstract

Tailings facility failures represent a significant risk to the environment and communities globally, but until now little data was available on the global distribution of risks and characteristics of facilities to ensure proper governance. We conducted a survey and compiled a database with information on tailings facilities disclosed by extractive companies at the request of institutional investors. Despite limitations in the data, this information disclosure request represents the most comprehensive survey of tailings facilities ever undertaken. The compiled dataset includes 1743 tailings facilities and provides insights into a range of topics including construction method, stability, consequence of failure, stored volume, and the rate of uptake of alternative technologies to dewater tailings and reduce geotechnical risk. Our analysis reveals that 10 per cent of tailings facilities reported notable stability concerns or failure to be confirmed or certified as stable at some point in their history, with distinct trends according to construction method, governance, age, height, volume and seismic hazard. Controversy has surrounded the safety of tailings facilities, most notably upstream facilities, for many years but in the absence of definitive empirical data differentiating the risks of different facility types, upstream facilities have continued to be used widely by the industry and a consensus has emerged that upstream facilities can theoretically be built safely under the right circumstances. Our findings reveal that in practice active upstream facilities report a higher incidence of stability issues (18.3%) than other facility types, and that this elevated risk persists even when these facilities are built in high governance settings. In-pit/natural landform and dry-stack facilities report lower incidence of stability issues, though the rate of stability issues is significant by engineering standards (> 2 per cent) across all construction methods, highlighting the universal importance of careful facility management and governance. The insights reported here can assist the global governance of tailings facility stability risks.

Revaluing paste and thickened tailings for large tonnage applications

“…A tailings disclosure document was issued to 726 publicly listed mining companies and detailed information regarding the location, age, construction method, etc. of tailings storage facility (TSF) sites was collected and electronically published in the Global Tailings Portal (www.tailing.grida.no), and more recently in a paper summarising the stability risks of various TSF construction methods (Franks et al 2021). Although several construction methods are defined in the portal and the paper, they appear to cover only two tailings dewatered states:…”

Strength Characteristics of Iron Tailings Blended Soil as a Road Base Material

“…The elevated levels of the tailing ponds are largely attributed to the increase of ITS discharge. The tailings accumulation exhibits fluidity which tends to collapse and thus poses a serious threat to the environment [4][5][6][7]. Therefore, the rational utilization of ITS resources is of immense significance.…”

Métodos avançados para avaliação da natureza reológica de suspensões concentradas aplicados ao escoamento pós-colapso de barragens de rejeito.

“…Os rejeitos produzidos são comumente armazenados em estrutura de contenção como as barragens. Atualmente, no Brasil, há 880 barragens de mineração (ANM, 2021;SNISB, 2021), sendo que nos últimos anos foi observado um crescimento no número de barragens: em média 10 barragens por ano desde o início do século XXI (FRANKS et al, 2021;GLOBAL TAILINGS PORTAL, 2020).…”

“…No entanto, faltam estudos que analisem o processo de rompimento das barragens, a possibilidade de escoamento dos rejeitos e a evolução do fluxo TANG;CHEN, 2020b) Estimativas empíricas, que relacionam os principais parâmetros hidrológicos à características físicas pré-ruptura, com base no histórico de acidentes de barragens de rejeitos, podem oferecer uma alternativa para a quantificação dos danos associados ao colapso de uma barragem. Contudo, essa relação se mostra limitada para barragens de rejeitos devido à escassez de dados confiáveis (FRANKS et al, 2021). Além disso, essas relações empíricas requerem dados geotécnicos detalhados dos rejeitos, bem como a geometria do vale a jusante, que nem sempre está disponível (Rico et al 2008).…”