Abstract
Bulletin 194 Tailings Dam Safety has been prepared by the International Commission on Large Dams (ICOLD) to document recommended technical practices for the planning, design, construction, operation, and closure of tailings dams, with the overarching goal of supporting the safe design and assessment these structures. The Bulletin was produced by ICOLD Technical Committee L on Tailings Dams and Waste Lagoons. It drew on previously developed Bulletins by ICOLD and guidelines produced by member countries, including Australia (Australian National Committee on Large Dams – ANCOLD) and Canada (Canadian Dam Association – CDA), and other documents developed by industry groups such as the Mining Association of Canada (MAC) and the International Council on Mining and Metals (ICMM). The preparation of the Bulletin was led by Mr. Harvey McLeod of Klohn Crippen Berger, and he was supported by the experience and technical knowledge of the Committee members.
The ICOLD Bulletin considered and supports the principles and practices outlined in the Global Industry Standard for Tailings Management (GISTM, Global Tailings Review, 2020), and also the United Nations Economic Commission for Europe (UNECE) Safety Guidelines and Good Practices for tailings management facilities.
The focus of the Bulletin is on the technical aspects of the safety of tailings dams since they form the most significant component of most tailings storage facilities (TSFs), and which could have a direct impact on communities and the environment if not properly managed. Nevertheless, the Bulletin provides guidance on the overall TSF when appropriate and may also be relevant to certain TSFs that do not include a structure that meets the accepted definition of a dam (such as filtered tailings “stacks”). The technical and governance principles described in this Bulletin are to be applied throughout the life phases of a tailings dam, from concept to post-closure.
The Bulletin also summarizes key aspects of governance, providing guidance to support mining companies, tailings engineers, regulatory personnel, and other professionals who are involved in tailings management, but it defers to the GISTM , and to the Tailings Management Good Practice Guide by ICMM for details.
This presentation will discuss the key technical aspects of the Bulletin, released in final draft in November 2022, and indicates how this guidance can help the mining industry in improving the safe design and assessment TSFs over their life. The presentation will also highlight the guidance on advanced technical concepts related to the understanding and applying the critical concepts of shear strength and deformation behavior of tailings and other particulate materials, as well as shedding some light on the concepts surrounding the contractive shearing behaviour. The latter topics are a real problem faced by many mining companies who may have inherited old facilities that were designed, constructed, and operated without the benefit of understanding the highlighted principles and latest scientific and engineering advances in this field of practice.