There are growing expectations of mining companies to operate in a more sustainable manner, with a strong business case for improving waste management and reducing environmental impacts. As the stewardship of tailings come under increasing scrutiny, decision-makers are urged to adopt a robust approach to the selection of a tailings management strategy that encompasses design for closure, and leading practices to lower the risk of catastrophic dam failures, optimise the use of resources, and mitigate environmental impacts on climate change. An integrated analysis, considering economic, environmental, social, and risk aspects of the operation can therefore provide decision-makers with balanced information to ensure the right projects proceed with an optimal business case so that the most cost-effective solution, that does not externalise costs, can be selected. However, literature review revealed that fundamental shortcomings exist within traditional evaluation approaches used for economic comparisons. This paper reports on life cycle cost analyses conducted for comparing various tailings management options under different scenarios. A conceptual case study for the disposal of gold tailings in Western Australia as a slurry, as thickened, or as filtered tailings, was considered. This was done for examining the extent to which potentially hidden costs impact on the total cost of a project. It is suggested that the proposed approach will lead to selection of a tailings management alternative that ensures sound economic, environmental, and social performance is achieved.
The new Technical Bulletin: Application of Dam Safety Guidelines to Mining Dams, complements the Dam Safety Guidelines re-published by CDA in 2013 by providing additional explanation of how the concepts described in the guidelines apply to mining dams. The Bulletin identifies some specific issues that should be considered during the design and safety evaluation of both tailings dams and water retention dams used in the mining industry. Available in hard copy only.
CDA's Annual Conference is a national forum for dam owners and operators, engineers, geoscientists, regulators, and others. Share ideas and knowledge on management, maintenance and design of water dams and mining dams.
One of the methods that has been studied for the disposal of tailings by the mining industry is dry stacking. Several studies have indicated that the use of filtered tailings is feasible under certain technical and operational conditions. The requirements for deposition, and characterisation of the tailings properties, must be obtained through a wide range of field and laboratory tests. These parameters are key to determining the behaviour of the material during the dewatering process, the optimum moisture content and the maximum density of the tailing cake, as well as the physical and environmental stability of the projected geotechnical structure. The operational aspects related to the handling of the material are also vital to determine the placement of the filtered tailings on the facility. In addition, the advantages with respect to water consumption, reduced and/or flexible stack footprints and geometries, seepage control requirements, closure/reclamation costs and public perception of risk can result in dry stacking being selected as an economically beneficial alternative, particularly if life-of-mine risks and costs are appropriately considered. As with any conventional tailings management approach, careful and diligent planning, engineering and operational controls, quality assurance/quality control (QA/QC), instrumentation and monitoring are required to manage risks and uncertainties. This paper presents the criteria that need to be evaluated in the evaluation of filtered tailings as a business case, based on the experience of the authors developing such projects within the minerals industry.
This paper reviews the progressive growth of awareness, adoption and practices with respect to geotechnical risk in mining in Australia over the last four decades, with a particular focus on underground mining. Initial experience in the 1980s was drawn from other high-risk industries such as nuclear and petrochemical sectors, and whilst the mining industry recognised the issue of a changing hazard and risk environment, it did not change practices significantly. Subsequent growth in understanding of the evolving discipline of risk management, coupled with major changes in mining legislation to a more enabling legislative framework, have led to a far more risk-aware industry where risk assessment and risk management practices have become a fundamental component of the overall mining management systems. In underground mining, geotechnical risk is at, or close to, the top of the risk priority list for proactive mine management today. The recognition of what are referred to as core risks associated with particular mining methods was a further development in the maturity of the industry management systems, with implications for all levels of management, right from feasibility through to design, planning and operations. One of the problems with the growth of risk-based management practices in Australia is that because we do so many risk assessments and develop so many hazard plans, we have, in some cases, become too blasé about them and do not give due recognition and priority to the ongoing management of important risks with the potential for serious consequences through lack of attention to detail and lack of integration of risk management into the mine management system. In an effort to overcome this issue and place higher priority on the most critical risks facing a mining operation, the International Council of Mining and Metals (ICMM) Critical Control Management (CCM) system, for focusing on the most critical risks, and then directing more attention to the actual control practices required to manage them, has been a valuable trend in recent years. In the Australian coal sector over the last 10 years, the industry-funded RISKGATE system has also been an extremely useful documentation of industry experience and a tool to assist operators either investigate incidents or plan risk assessments on new topics or areas. Geotechnical topics make up at least three of the 18 major topic areas covered by RISKGATE. This paper will briefly outline how RISKGATE operates and is applicable to the industry in the geotechnical space.
Component 3 of the Oil Sands Tailings Technology Deployment Roadmap. This report intended to develop a method to evaluate the identified tailings technologies to determine their strengths and weaknesses, in light of specific criteria provided by Component 2, and then to evaluate the technologies using the developed methodology. Eight categories of technologies (mining, extraction and bitumen recovery, tailings processing, deposition and capping, water treatment, reclamation, and technology suites) were sub-divided into three categories (commercial, development, and research).
Copmonent 4 of the Oild Sands Tailings Technology Deployment Roadmap. This report intends to identify technologies and/or suites of technologies which could improve the ability of tailings management practices to meet the previously defined goals, and the pathways by which they could be brought through the research and development process to commercial implementation.
It took five years to bring mining with paste backfill to Maaden Barrick Copper Companys (MBCC) Jabal Sayid Mine in Saudi Arabia. The work involved various studies, multiple test programs, site visits for benchmarking and detailed engineering before the paste system was commissioned in October 2017. Barrick is a world leader in paste backfill and drew on international teams to conceptualise, design and construct this 225 m3/hr cemented paste backfill system. Value engineering, peer reviews and risk management workshops were held throughout the process to ensure MBCC received value for money and a reliable system. The paste plant was required to handle a tailings stream that was originally planned to produce hydraulic fill (the coarse fraction) but through the reintroduction of fine tailings was able to generate a good paste product that met mining needs. Challenges involved getting the most out of the tailings dewatering circuits (both fine and coarse streams), the local conditions (temperatures >50°C), large bulk stopes fed by a gravity system and the capital cost associated with building a high throughput system with significant cement storage. This paper presents the history of the project, test work, engineering design and construction, commissioning, and training required to fill the first stope. More recent backfill monitoring, data logging, improvements and ongoing optimisation of the system that have continued through the first year of paste production are also presented.
Thin spray-on liners (TSLs) provide areal support to rock excavation surfaces, and have been implemented in the mining sector for over 20 years. However, scepticism over their usage still prevails, despite the results of laboratory research that has been carried out indicating their effectiveness for use in mines. The study described in this paper aims to highlight TSL performance as viewed by the mining industry. Some underground cases of practical performance have been singled out and compared with the expected performance based on information from suppliers and from laboratory testing perspectives, and the causes of the resulting quality of performances were categorised. Among the causes of the discrepancies between expectations and observations is the lack of inclusion of parameters such as temperature and humidity in the laboratory tests, which could have significant effects on the liner performance since, based on results from Brazilian indirect tensile tests on coated samples, their inclusion doubles the probability of failure and therefore, increases the predicted geotechnical risk of failure. Consequently, to take into account potential performance discrepancies, some existing recommendations and further potential recommendations are suggested in the paper. If later validated, these suggestions could be included in a good practice guideline for TSL application in underground mines.
This webpage includes links to online content from the Mining Engineering, Tunneling and Underground Construction, and Mining, Metallurgy & Exploration magazines published by SME. Occasionally the Mining Engineering magazine includes tailings specific technical papers. SME Publications cover the full range of the mining, mineral processing and underground construction industries. Read timely news, peer-reviewed papers and opinion from some of the leading experts in the world and be a leader in your office.