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By T Alexieva

Since the early 1900s the geotechnical community has investigated every significant failure of a tailings dam, improved our knowledge of the behaviour of the tailings storage facilities, developed analysis methods, compiled lessons learned, and committed to zero failures. The rate of occurrence of tailings dam failures has reduced since the 1980s, however, failures continue to occur and continue to surprise us. At BHP, we have decided to take an approach to the tailings management that is similar to the approach to safety. We are looking at ways to eliminate, substitute, separate or engineer around the hazard (tailings dam failure). As such, our ultimate long term goal would be to eliminate the need for new tailings facilities. Unfortunately, we have not developed yet technologies for extracting many of the common metals and minerals without producing tailings. Our shorter term goal is to substitute the current conventional slurry tailings facilities with less risky dryer facilities. We are working with vendors and research organizations to develop technologies that can be efficiently applied on a large scale. At the same time, we are committed to using the best available engineering to reduce the risks associated with our existing and new conventional tailings facilities. The best engineering can be achieved by people with the appropriate education, experience, attention to detail, discipline and authority. We have implemented a system of governance to make sure, we have the best engineering applied to all our facilities, considering the specific conditions at each site.This paper presents the current tailings governance process at BHP, and the initiatives that were undertook towards achieving a zero failure goal. CITATION:Alexieva, T, 2018. Tailings governance, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 2–7 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By T Baumgartl, T Huynh, K Tungpalan, E Wightman, M Edraki, M Tayebi-Khorami, L Huang, S Palaniandy, E Manlapig

With the increasing rate of tailing production worldwide there is a growing concern about the hazards of tailings storage facilities (TSF). Past and current mining, processing and waste disposal strategies that focus on the extraction of the valuable minerals, and an economic assessment only, are no longer suitable. Social implications and environmental legacies must be included for effective evaluation. This is possible by using an integrated assessment framework to evaluate more alternatives, including the production of additional saleable and benign streams, alternative tailings treatment and disposal as well as options for reuse, recycling and preprocessing of existing tailings. Tailings are not viewed as a final waste product but as part of the resource. From the sustainability perspective the models developed in integrated research programs will contribute to more effective methods for assessing different scenarios and potential processes and lead to better environmental management, increased production of benign tailings and improved efficiency of water and energy use and thus more responsible resource stewardship of the ore resource.This paper presents preliminary results from a multiyear research program on integrated tailings management at the Sustainable Minerals Institute (SMI), The University of Queensland, called ‘Designer Tailings’. The project involves the gathering of experimental and observational information on tailings biogeochemical processes to design and modify the range of activities within mineral processing plants, upstream characterisation ore and gangue, and downstream tailings management for desired tailings properties and outcomes. This information will assist the development of new total integrated value chain CITATION:Edraki, M, Huynh, T, Baumgartl, T, Huang, L, Andrusiewicz, M, Tungpalan, K, Tayebi-Khorami, M, Wightman, E, Palaniandy, S, Manlapig, E, Evans, C, Farrokhpay, S, Bradshaw, D and Vink, S, 2014. Designer tailings – an integrated model for tailings management, in Proceedings Life-of-Mine 2014 , pp 599–608 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By J Boshoff

The management and operation of tailings storage facilities (TSFs) are often neglected until the process plant has to shut down as a result of this negligence or as a result of a catastrophic failure as was the case during the recent TSF failure in North America.TSFs are often regarded as non-assets and do not receive the attention they deserve in terms of technical expertise and financial provision. A TSF is not a simple structure but a complex and dynamic structure that changes throughout its operational life. The operational life of a TSF is the period in which there is the greatest opportunity for risks to occur. The failure of a TSF is normally not as a result of a single event but as a result of a consequence of events. These events are often not recognised in time due to a number of factors.Process plants and slurry pumping systems are operated at suboptimal conditions in order to maintain throughput. At the same time, the tailings properties are compromised in terms of slurry density and particle size distribution amongst other things. Tailings deposition cycles and drying cycles are not well understood and the tailings management strategy is not well tuned in terms of maximising consolidation and improving in situ densities. Pond control is also neglected. These are aspects that form the keystone to the effective utilisation of available deposition area as well as the frequency and cost of future embankment raises.Apart from operational issues, forward planning in terms of budget requirements, increases in tailings throughput, embankment raises, pipe replacements, etc are normally put on the back burner. Available deposition space at the time seems to render this planning obsolete.The bottom line is that responsible tailings management and proper forward planning can limit liability and reduce the bottom line in terms of cents per ton if correctly implemented by suitably qualified tailings managers and engineers.The aspects that need to be considered as part of responsible tailings management are highlighted in this paper.CITATION:Boshoff, J, 2015. Responsible tailings management, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 317–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By S H. Burgmans, B Anderson

This paper aims to define the specific challenges relating to dredging fine tailings from an above ground storage facility for transferral to a mined-out pit. In addition, it compares dredging and mining perspectives on dredging of fine tailings.

Jul 1, 2021

By T Baumgartl, D Bradshaw, B Forsyth, M Edraki

In a tailings storage facility, the chemistry of pore water is a function of oxidation and dissolution of sulfide minerals, containing metals and metalloids, the neutralising effect of gangue minerals and the geochemical processes controlling solute equilibria such as pH, redox potential, precipitation, ion exchange and adsorption. On the other hand, the changes in geochemical composition of tailings feed over time is a function of spatial variability within the orebody and modifications in processing method. Tailings properties such as pyrite content, pH, concentration of deleterious elements, surface chemistry, pore water chemistry and particle size are already shaped in the dynamic environment of a process plant.To engineer desired environmental outcomes, a new research framework is needed. The new approach should follow the physical and geochemical processes of tailings feed and construct models that can be used for the prediction of seepage water quality and dust propagation and evaluate the potential re-processing of tailings or production of tailings with desirable surface chemistry, particle size and internal structure. The challenge of developing tailings engineering model is not in laboratory techniques, but more of the overall communication of results and establishing the link between disciplines. It requires investigating geochemistry across mining and processing for improved environmental outcomes at tailings storage facilities.The paper reviews the current tailings management practices by comparing the geochemistry and mineralogy of tailings and the chemistry of seepage water from three Australian case studies in the context of geology, mineral processing and climate. Some alternative methods of tailings management are also reviewed and it is concluded that a proactive multi-disciplinary approach is needed with respect to tailings management, based on a novel integrated research framework.CITATION:Edraki, M, Forsyth, B, Baumgartl, T and Bradshaw, D, 2012. Geochemistry of tailings and seepage from three tailings storage facilities in Australia - Uncapped, capped and active tailings, in Proceedings Life-of-Mine 2012 , pp 269-278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By B P. Wrench, N R. Steward, C Wu

A gold mine in southern China has transitioned from an open pit operation to a fully underground mine. An overhand mining method is used which requires the mined stopes to be filled with backfill having an unconfined compressive strength of at least 0.35MPa. Tailings from the process plant is deposited into separate flotation and Carbon in Leach (CIL) tailings storage facilities. The tailings has a high fines content and the thickener on site could only produce a dilute flotation tailings at a solids content of about 30 wt%. This resulted in two undesirable outcomes: the density of flotation tailings in the Tailings Storage Facility (TSF) was significantly lower than planned so that the TSF could not store the life of mine tailings and that the backfill product had to include a high percentage of manufactured aggregate and increased cement content to achieve the required strength. This paper presents results of a tailings study which identified that the flotation TSF would be capable of storing the remaining life of mine tailings if an amended backfill product made up of 100% of flotation tailings could be introduced. A 100% tailings backfill with the addition of 8% cement was developed by classifying the tailings and using the coarser fraction in the backfill. This backfill allowed 60% of the flotation tailings to be placed underground and only the remaining 40% in the flotation TSF. A new thickener was designed and installed to thicken the tailings and rheological testing of the tailings, using a closed loop pilot plant, provided parameters to upgrade the underground reticulation system to deliver cemented backfill to stopes throughout the mine and to deliver thickened tailings to the TSF. The revised design was implemented and has resulted in considerable cost savings. CITATION:Steward, N R, Wrench, B P and Wu, C, 2018. Optimisation of surface tailings storage and tailings backfill – a case study, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 454–464 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By R Jia, J T. Waldram

"The Caijiaying lead zinc mine is located in China, north-west of Beijing, in Hebei Province. The region experiences severe winters, below -35°C, and warm summers, up to 30°C. The mine and concentrator commenced operations in the second half of 2005 with a conventional tailings disposal system consisting of a tailings dam with peripheral ring main discharge and central water recovery. A second similar dam sharing one common wall was added later. In view of the extreme winter conditions tailings lines and ring mains plus spigots, together with return water lines, require insulation and electrical trace heating. The volume of process water trapped as ice in the tailings dam ponds each winter is significant. This seasonal variation presents a major difficulty in the management of process water availability. Although Caijiaying is an underground mine there was no backfill plant at the start of operations. As plant throughput increased more quickly than originally anticipated, tailings storage capacity became a prime concern. The construction of a backfill plant in 2007 reduced the pressure on surface tailings storage area requirements, but as suitable land on which to construct further tailings storage was both expensive and difficult to acquire, a more efficient use of the available area was required. Dry tailings storage, where flotation tailings are filtered to provide an immediate return of process water plus ‘dry’ tailings filter cake for stacking, provided an answer to both the land area required, and the water management difficulties. The paper details the reasoning behind the change and the benefits obtained at Caijiaying by moving from ‘wet’ tailings storage to ‘dry’ tailings storage.Citation:Waldram, J T and Jia, R, 2016. Caijiaying Dry Tailings Storage, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 379–382 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By H Jones

The paper outlines the adoption and evolution of ‘sustainable development’ as a concept in tailings management practices in the mining industry over the last 30 years. Over 500 lives have been lost in tailings facility accidents since World War 2. The paper outlines commonalities in many of these accidents, particularly the role of excess water. It considers the role effective tailings management can play in enhancing the social acceptability of mining in the future.Tailings management is a major operating cost at many mines while the cost of successfully closing tailings facilities is also very high. Current tailings management practices in the industry are outlined. The technical and engineering challenges of reducing potential risks associated with tailings by reducing water entrainment are described. The successful development of practical techniques to better manage tailings and reduce water consumption and wastage are described. For example, water removal in the alumina industry to produce a paste for dry stacking is now a reality.The future adoption of these new risk reducing techniques by the industry is discussed and the implications of the adoption or non-adoption of these techniques on the industry’s future ‘social licence’ is considered.

Nov 22, 2011

By G M. Mudd

Mine tailings represent one of the two largest sources of mine waste from the minerals industries (the other being waste rock). Given the problems of declining ore grades and growing production, tailings generation is increasing exponentially across the global mining industry. Common practice is for mines to build large containment dams to store tailings during operations, which are then rehabilitated following mine closure. At some sites, however, the controversial practices of riverine or marine dumping of tailings is still practiced. As recent tailings dam failures have shown, there are legitimate questions being raised about the long-term viability of leaving tailings above ground due to the risks of collapse and failure. At present, it is rare for mines to emplace tailings back into former mine voids following mine closure, most commonly into a former open pit mine void (although a fraction of the tailings may be used for underground mine backfill, this is minor in scale). The approach of in-pit tailings has numerous advantages, such as inherent physical stability, low to negligible acid and metalliferous drainage (AMD) risks, as well as allowing more productive use of formerly mined land. In tropical areas where surface repositories are prone to leakage with potential for AMD and widespread dispersal of radionuclides (in the case of uranium mining), in-pit management provides particularly strong advantages – thorough hydrogeological studies are required, however, to address residual groundwater contamination risks and to establish sound, long-term environmental monitoring regimes for groundwater quality and subsidence issues. This paper presents a study of in-pit tailings management and compares it with surface repositories established in a tropical climate. The comparisons lead to the conclusion that, at least under tropical conditions, in-pit tailings management should be considered as world’s best practice – especially for radioactive uranium tailings.

Aug 8, 2011

By C J. Hogan

Increasing demand for fine grinding to improve mineral liberation and metal recovery and the need for stricter control of the environmental impact of tailings deposition poses problems for tailings disposal. This has led to an increasing number of investigations of properties of tailings and their disposal. This paper describes laboratory model testing undertaken on Macraes mine flotation tailings to provide information on tailings behaviour under conditions of subaerial deposition. The in-place density or 'dry density' of the impounded tailings and the impoundment depth relationship are important for utilisation of the available impoundment storage facility and results of dry density to depth relationships are given for the Macraes mine tailings impoundment.

Jan 1, 1993

The Kaltails Project is situated close to the city of Kalgoorlie-Boulder in Western Australia. Located on the south-eastern fringe of the Golden Mile, Kaltails has been in operation since June 1989. The tailings forming the reserve for Kaltails have been derived from 100 years of underground mining on the Golden Mile, but, some of the re.;erve has been retreated in the past. A map of the tailings reserves and treatment plant site is presented as Figure 1. The gold project is a joint venture between Poseidon 90 per cent and Gold Corporation (ten per cent) and is managed by Poseidon Gold Kaltails.

Jan 1, 1992

By D Brett

The Paper presents the authors thoughts on how the mining industry should be improving the education of site personnel so they can provide a greater level of effective control of tailings dam safety including empowerment to develop their own documentation, monitoring and surveillance systems and to better liaise with specialist external technical staff or consultants.

Jul 1, 2021

By Madgwick J. C

Microaerobic biodegradation oflow-grade manganese dioxide slurry tailings was demonstrated in enrichment cultures treated with dilute molasses at 30°C and pH 5·8. Supplementary nitrogenous nutrients, yeast extract addition and pH adjustment were not required.Continuously stirred, air-limited reactors were superior to still intermittently agitated cultures, in that, at 5 per cent (w/v) MnOz tailings and 5 per cent (w/v) molasses, the yield of 0.12 g Mn++/g molasses, the rate ofleaching of 1·06 g Mn++/l/d and a recovery of Mn++ of 58 percent from MnOz were 2·8 times, 1·7 times and 1·9 times greater, respectively. The best compromise in yield (0·45 g Mn++/g molasses) and rate ofdissolution (0·73 gMn++/l/d) was at 1 per cent (w/v) molasses in a stirred reactor.Where leaching organisms were separated from sterile ore by a bacteria impermeable membrane leaching was shown to be some 20 per cent due to diffusible metabolites and 80 per cent due to a direct contact between the bacteria and the ore particle's surfaces.

Jan 1, 1986

By M Jones

Legacy tailings storage facilities exist within operating mine sites across Australia. These tailings storage facilities are often viewed as rehabilitation liabilities but with considered assessment may prove to be a resource. Extraction of such a resource might add value to operations by providing cash flow during the development of new mines; providing supplementary mill feed for existing mines undergoing step changes in operations; and supporting mine closure activities. Hellyer Gold Mines is successfully extracting and reprocessing sub-aqueous material from legacy tailings storage facilities at their Hellyer operation in north-west Tasmania. The Hellyer tailings storage facilities contain poly-metallic material from the Hellyer and Fossey underground deposits dating back to the 1980s as well as material from tailings reprocessing activities by other operators of the Hellyer site. Hellyer Gold Mines is reclaiming sub-aqueous material using cutter-suction dredgers and reprocessing on-site. Hellyer is the only operation of its type in Australia and few such operations exist worldwide. Key learnings around the estimation of a resource for legacy tailings storage facilities have been acquired at Hellyer that can be applied to the assessment of other tailings storage facilities. The application of dredging as a mining method at Hellyer is delivered through collaboration with experts from outside the mining industry under the direction of a mining engineer. Key elements required for the planning and delivery of safe and efficient dredging inside tailings storage facilities have been identified at Hellyer and are presented to provide a road map to the development of other dredging operations.

Sep 1, 2024

By D Luppnow, C Hore

In-pit tailings storage can provide many advantages when compared to typical above-ground tailings storage facilities (TSFs). As regulations become more restrictive and existing mines expand into new pits, the motivation and opportunities for in-pit tailings disposal is increasing.The Langer Heinrich uranium orebody follows a palaeo-river channel and is mined as an open pit operation. The mine pits intersect two main aquifer systems, one at the surface and one at the base of the orebody/pits. The tailings storage methodology is full in-pit disposal in multiple TSFs for the life-of-mine. Continuity of the initial hydrogeological conditions is incorporated in the design by the use of the pervious surround concept and the reinstatement of the lower aquifer (palaeochannel aquifer) at the base of the pit. Containment embankments are required to facilitate the staging of the TSFs development and are constructed using waste rock liberated during the mining of the pits. All of the TSFs are equipped with decant structures and an underdrainage system is included to improve water recovery, enhance consolidation and increase tailings density.This paper presents the design of a unique in-pit tailings storage solution for the Langer Heinrich mine in Namibia owned by Paladin Energy Ltd.CITATION:Hore, C and Luppnow, D, 2015. In-pit tailings disposal at Langer Heinrich – tailings storage facilities in a unique hydrogeological setting, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 373–380 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By D J. Williams

The majority of surface tailings storage facilities continue to employ sub-aerial tailings slurry deposition. Surface TSFs are typically sized and operated in a way to minimise the initial capital cost of the facility, driven largely by the net present value approach to accounting. This generally leads to too small a storage, too fast a rate of rise of the tailings, and difficulties in managing supernatant water. In turn, this results in wet and soft tailings deposits of high moisture content and low density, and the need for frequent and costly tailings dam raises. Further, such tailings deposits often do not facilitate closure and rehabilitation of the facility. Globally, there are on average over two failures annually of such tailings dams, resulting in loss of life, damage to infrastructure and environmental impact downstream, and the loss of company shareholder value and reputation. Recent high profile tailings dam failures are threatening the mining industry’s financial and social licence to operate.Among the physical processes that tailings undergo on sub-aerial deposition are beaching, hydraulic sorting down the beach according to particle size and specific gravity, settling, consolidation, and desiccation on exposure to the sun and wind. Beaching and hydraulic sorting have proved difficult to test at laboratory scale and difficult to model, and are best assessed in the field. Settling, consolidation and desiccation may be assessed at laboratory scale, but to date there has been an absence of tests to form the basis for the design and management of tailings deposition, and ultimate closure and rehabilitation. The paper describes recent advances in tailings testing methods, including a purpose-built slurry consolidometer that tests the settling and consolidation of tailings from a slurry consistency, simulating increasing tailings depth to about 50 m; and a purpose-built instrumented column that tests the settling, self-weight consolidation and desiccation of a surface layer of tailings, also from a slurry consistency. Selected test results from these two apparatus are presented in the paper, together with brief descriptions of how they may be used to better design tailings slurry deposition. In addition, planned further advances in tailings testing methods are briefly described.CITATION:Williams, D J, 2018. Recent advances in tailings testing methods, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 8–37 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By S Thacker, M Noakes

The Newmont Tanami Operations (NTO), formerly the Granites Gold Mine, commenced operation in the mid-1980s with tailings deposition evolving over the past three decades as production has increased and the operation has expanded. Paddock-style tailings storage facilities (TSFs) and in-pit tailings deposition have fulfilled the tailings requirements for NTO over its lifetime with the technical specifications of these facilities improving over time in line with the positive development of standards, guidelines and best practice.This paper reviews the options for tailings storage facilities at NTO and the many considerations that have been analysed and deliberated upon before settling on specific TSF types and designs. It also explains the operating philosophies of the tailings deposition and how the facilities have always strongly maintained the optimum capture and retrieval of water. The current TSF design and criteria is presented, along with the introduction of dry tails harvesting for use in paste production as a backfill product for the underground mine. Tailings deposition and recovery remains a critical function of the Granites process to ensure long-term operation and gold production.CITATION:Thacker, S and Noakes, M, 2015. Newmont Tanami Operations – tailings storage facilities, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 305–314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By G Simpson, S Dressler, A E. Levett

Tailings storage facilities often represent a mining operation’s most significant liability, posing serious environmental, social and safety risks. Almost all mining operations dispose of wet tailings (Valenta et al, 2023), which represents a risk of failure due to the potential for a rapid strength reduction of the unconsolidated materials leading to static liquefaction and subsequent dam wall failure. As a waste stream, tailings disposal, decommissioning and relinquishment aim to be inexpensive processes, ruling out many highly engineered solutions. Advantageously, tailings consolidation does not need to be immediate, opening the door for relatively passive, inexpensive consolidation methods that aim to gradually increase the strength of tailings over extended periods (ie years). In this paper, we present the prospect of novel in situ tailings stabilisation, learning from studies that have investigated the most erosion-resistant landforms on Earth.

Aug 2, 2023

By G B. Smith, G M. Marshall, A Querzoli

The South Australian mining regulatory framework has adopted a performance based approach to the management of risk. This approach has been in place in South Australia for more than 10 years and is increasingly being implemented in mining jurisdictions in Australia and around the world. Performance based regulation focuses on setting appropriate environmental outcomes to be achieved based on an assessment of the potential impacts associated with the development, operation and closure of mining projects. Measurable compliance criteria, including completion criteria, are set to demonstrate achievement of the outcomes. It is the responsibility of the proponent to propose designs and strategies that will achieve the regulated environmental outcomes and to demonstrate the implementation of their designs and strategies will achieve the outcomes into the future. Tailings Storage Facilities (TSFs) are significant elements of many major mines and each is unique with site specific factors such a materials to be stored, design, size, location, climate, sensitive receptors, operating history of the facility (i.e. changes to design), site culture and company capability amongst a range of other factors. Consequently a fit-for purpose approach is a key principle of best practice regulation of tailings management as it takes the site specific factors into account in setting appropriate outcomes for mitigating the identified impacts associated with a proposed development. Achievement of those outcomes through fit-for purpose, well designed management strategies would ensure safe, stable and economic storage of tailings in a manner that complies with all legislative requirements and presents negligible public health and safety risks. Tailings storage must also have acceptably low social and environmental impacts, both on and off site, during operation and indefinitely post closure. Achievement of environmental outcomes during operations and at mine completion can then be demonstrated to the regulator and community through public reporting of compliance with measurement criteria which establish the appropriate level of impact for each individual operation. A number of new mining proposals including tailings storage facilities (TSF) have recently been assessed and approved in South Australia. The location, size, design, sensitive receptors, public interest and therefore risk profiles of these TSF’s have varied substantially between these new mining proposals. These considerations were reflected in the assessment of the TSFs and the resulting mining lease conditions of approval including the environmental outcomes to be achieved over the life of the facilities. This paper and the accompanying presentation will provide case studies of recently approved TSFs within South Australia and the regulatory framework for each case.CITATION:Smith, G B, Querzoli, A and Marshall, G M, 2018. Tailings regulation – a South Australian perspective, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 166–177 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998