{"title":"An economy and ecosystem symbiosis: barrier systems for water conservation and pollution control","authors":"K. Legge","doi":"10.36487/ACG_REP/1910_0.02_LEGGE","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_0.02_LEGGE","url":null,"abstract":"An awareness of the rate at which water resource development took place in South Africa being supply driven, until relatively recent times, leads to an appreciation of the changing philosophy in respect of water conservation and pollution control, as well as essential amendment to principles and procedures. Reconciling water demand and supply in catchments requires concurrent consideration of available water quantity and quality. This stimulates the need for change in the way we view water uses and brings about business opportunities in the sector. The review of infrastructure designs in support of water use and mining applications for industrial and mining waste has developed and transformed along with improved technology and changes in legislation since 1994 in South Africa. A containment barrier system comprises of both filter protected drains and low permeability liners which are visible in the short term until covered. They are required to perform effectively after initial use and are often inaccessible for the operating period and subsequent service life of decades or even centuries. This paper presents a regulator’s perspective of commonly repeated deviation from accepted norms and standards in the engineering profession, as applied to pollution control facilities. Emphasis is placed on the standards of today with experience reflecting on the past five years of design reviews, leading to conclusions and recommendations for facility owners and practitioners. Examples of procedure, mechanisms, performance, specifications and socio-economic benefits are addressed. It is postulated that in the near future many mining and industrial developers will choose to improve containment standards of barrier systems as a component of reengineering water demands and for economic advantage while embracing contributions from ecosystem services.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75811856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Practical thoughts regarding filtered tailings","authors":"B. Ulrich","doi":"10.36487/ACG_REP/1910_01_ULRICH","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_01_ULRICH","url":null,"abstract":"Filtered tailings technology has been successfully implemented only at a limited number of relatively lowproductionrate mining operations. The technology, however, may be poised to make a dramatic leap forward as it is being proposed for use at several high-throughput operations. Demands from increasing regulatory scrutiny and decreasing water availability are likely to drive further adoption of the technology. This paper presents a recommended approach to select a tailings disposal method and summarises several filtered tailings design concepts and considerations that the author has found useful in his practical experience.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84143990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of a non-Newtonian two-layer model for high concentration suspensions","authors":"C. Fraser, P. Goosen","doi":"10.36487/ACG_REP/1910_40_GOOSEN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_40_GOOSEN","url":null,"abstract":"High concentration thickened tailings slurries that appear to be homogeneous mixtures often contain coarse particles that settle in the pipeline under laminar flow conditions. During pipeline transport, these coarse particles may eventually settle to the pipe invert. Frequently, these high concentration suspensions are misclassified as homogeneous slurries, leading to the use of incorrect models for predicting the pressure gradient and flow behaviour. \u0000This paper discusses the use of a non-Newtonian two-layer model to predict the pressure gradient of a high concentration suspension with a sliding bed in laminar flow conditions. The success of the model is measured by comparing the results obtained by applying the model to experimental results for a typical iron ore tailings slurry. It was found that the model predicted the laminar flow pressure gradient with less than 10% error for slurries with carrier fluid yield stresses above 10 Pa.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86167081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. McPhail, Roxana Ugaz Palomino, Francisco Garcia Araujo
{"title":"Practical tailings slurry dewatering and tailings management strategies for small and medium mines","authors":"G. McPhail, Roxana Ugaz Palomino, Francisco Garcia Araujo","doi":"10.36487/ACG_REP/1910_15_MCPHAIL","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_15_MCPHAIL","url":null,"abstract":"Recent tailings facility failures and the resulting emphasis on ensuring that the best available technology is applied when designing a tailings management system, together with a need to reduce water consumption, have brought about a need for wider evaluation of tailings management approaches. A key determining issue is the extent to which tailings slurry can be cost-effectively dewatered. This issue often drives the selection between high-density slurry, paste and filtered tailings management approaches. Commonly, the focus is purely on thickening, where production rates exceed 30,000 t per day, or filtration, which is most suitable for production rates below 30,000 t per day due to the number of units required, as the means for separating the solids and the liquids. However, there are alternative approaches, suitable for small and medium sized mines, that are not only competitive in terms of capital and operating cost but that may also be significantly more robust and accommodating of variations in ore mineralogy and process plant upsets. These entail the application of hydrocyclones and/or vibratory dewatering screens in conjunction with thickening and/or filtration, sometimes treating only a part of the tailings stream in order to more reliably achieve dewatering targets. The alternative approaches can facilitate more balanced optimisation between the broader drivers of water recovery, slope stability, seepage control and post-closure relinquishment. This paper describes a range of alternative dewatering approaches (in addition to pure thickening or filtration) that merit consideration. It provides insight into the methods of testing and evaluation for selection and sizing of the equipment, describes tailings placement and storage methods associated with varying degrees of dewatering, and discusses the related benefits in terms of robustness of dewatering, water recovery, slope stability, seepage control and post-closure relinquishment.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87419526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The underdog mechanical alternative for tailings dewatering: the screw press","authors":"W. Wimmler, S. Whitton, L. Wimmler","doi":"10.36487/ACG_REP/1910_24_WIMMLER","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_24_WIMMLER","url":null,"abstract":"“Given the increasing scrutiny of the mining industry and its relatively poor record with regards to mine tailings management, increased requirements to minimise water usage (often accompanied by very high costs of water) and the need to demonstrate achievable long-term closure strategies, it is likely that the option of a filtered tailings system will need to be considered in many operations in future.” (Australian Centre for Geomechanics 2018). \u0000Given such a statement as a conference introduction, it is only appropriate that a range of potential technologies are investigated and compared, to create awareness for even underrated but appropriate technologies. The advantages and disadvantages of all technologies need to be considered and analysed. Suppliers are swift to promote their technologies advantages, however aspects of sustainability are not always fully understood and comprehended. Perhaps a combination of two filtration technologies is appropriate. This paper delves into the technical details, good or bad, of four mechanical dewatering technologies in tailings dewatering and provides insight on an undervalued and, in the author’s opinion, young technology – the screw press.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90666842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Paste backfill reticulation optimisation using high shear mixing at DeGrussa Mine","authors":"N. Steward, G. Allen, K. Tiedermann","doi":"10.36487/ACG_REP/1910_29_STEWARD","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_29_STEWARD","url":null,"abstract":"This paper investigates the work carried out by DeGrussa Mine and the Weir Technical Centre (WTC) of Weir Minerals Australia, in developing a process to produce a consistent cemented paste backfill that is fully sheared and presents the lowest possible yield stress and pressure gradients during the underground transport phase. \u0000The existing twin shaft paste mixer on DeGrussa Mine was not providing sufficient shear or time of shear to deliver a fully homogenised product. The project to improve the paste backfill rheology involved quantifying the performance of the twin shaft mixer as well as the required rheological parameters of yield stress and pressure gradient of the paste backfill product. In order to achieve the required outcome, a centrifugal pump was installed after the mixer to provide the shear energy required to produce a fully sheared paste backfill rapidly and continuously. \u0000A fully sheared consistent paste backfill is required to ensure predictable transport of the paste backfill throughout the DeGrussa Mine reticulation system. This predictability of paste backfill performance results in a safe and robust reticulation system, together with ensuring pipeline integrity. The lower pressure gradients, manifest by the fully sheared paste backfill, also allow DeGrussa Mine to fill stopes that are at a distance that would otherwise require a positive displacement pumped system.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90340315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Advancements of fluid fine tailings treatment technologies through fundamental research","authors":"X. Yuan, H. Li, J. Zhou, L. Zhao","doi":"10.36487/ACG_REP/1910_22_YUAN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_22_YUAN","url":null,"abstract":"Fluid fine tailings (FFT) management is one of the main challenges that oil sand developers continue to face. Syncrude Canada Ltd, independently or in collaboration with Canada’s Oil Sands Innovation Alliance (COSIA) member companies, has developed various technologies to accelerate FFT dewatering to meet progressive mine closure and reclamation objectives. One of the technologies is FFT clay treatment that targets the problematic clays in FFT. The basis of this step-out technology is the use of a polymeric flocculant to enlarge the effective size of clays and a collector to change the clay surfaces from hydrophilic to hydrophobic. In this way, the treated FFT dewaters very fast. An effective, easy to use collector is key to the success of this technology. Collectors are chemical compounds added to FFT that change the clay hydrophobicity, promote aggregation of clay particles and assist in FFT dewatering. Theoretically, it is possible to directly use a cationic collector or a combination of a metal ion and an anionic collector to make the negatively charged FFT clays hydrophobic. Building on this concept, several process technology scenarios have been developed and tested. This paper demonstrates how fundamental research provides a simple and cost-effective method for screening collectors for operational FFT clay treatment.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91422742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Wu, Z. Ruan, Y. Shao, Wang Jiandong, S. Yin, Shaoyong Wang, Cui-ping Li
{"title":"Friction losses of cemented unclassified iron tailings slurry based on full-scale pipe-loop test","authors":"A. Wu, Z. Ruan, Y. Shao, Wang Jiandong, S. Yin, Shaoyong Wang, Cui-ping Li","doi":"10.36487/ACG_REP/1910_44_RUAN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_44_RUAN","url":null,"abstract":"Friction losses is a key parameter in the design of pipeline transportation in paste backfill. A full-scale pipeloop test was conducted in the JCHX Paste Backfilling laboratory to investigate the friction losses of cemented unclassified iron tailings slurry. Friction losses in upward sloping pipe, vertical downward pipe, vertical upward pipe, 90° long radius elbow, horizontal straight pipe and downward sloping pipe were tested simultaneously under different solid fractions. The results indicated that friction losses always increase with flow rate and solid fraction. Friction losses in the elbows are about 1.55–2.16 times that in the horizontal straight pipe, which is about 2.7–10.0 kPa·m-1. The pipe-loop test data can be used to analyse the rheological priorities of cemented unclassified tailings slurry. Based on the Buckingham rheological equation, an empirical formula for friction losses was established and applied to a pipe with the optimal diameter of DN 150 mm. It can be concluded that the full-scale pipe-loop test is an effective way to investigate friction losses and the economics of design pipeline transportation.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83143813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tailings dewatering with increased filtration rates and lowest filter cake moisture for filtered tailings stacking","authors":"J. Hahn","doi":"10.36487/ACG_REP/1910_16_HAHN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_16_HAHN","url":null,"abstract":"The most commonly used dewatering technologies for the filtration of tailings from ore processing are pressure filters, filter presses, belt filters and rotary vacuum disc filters. The vacuum disc filter type in around 80% of all applications is the most economical of these technologies in terms of capital and operating cost, especially when modern high performance disc filters are used. \u0000The Boozer disc filter is a big diameter high performance vacuum disc filter that has set the pattern in a multitude of applications including the alumina industry and in dewatering coal slurries. In the past decade, this type of disc filter has established itself in applications of tailings dewatering, such as tailings from gold/copper, zinc and gold/silver mines. The reasons for its successful operation in tailings dewatering are: (a) high throughput and dewatering performance, (b) operational reliability even in the case of varying feed conditions, (c) simple and robust design, (d) ease of maintenance, (e) a small footprint. To achieve higher solids throughput rates, or to achieve the lowest possible filter cake moisture, HiBar filtration and HiBar steam pressure filtration offer new solutions in tailings dewatering. HiBar filtration and the HiBar steam pressure filtration are advanced continuous pressure filtration processes realised on rotary disc filters that are installed in a pressure vessel. The application of hyperbaric pressure of up to 6 bar (instead of a vacuum) ensures a high filtration rate and dewatering capability even with filter cakes of fine particles where high cake resistance and capillary forces in the cake must be overcome. With HiBar steam pressure filtration, the use of steam under special conditions improves demoisturing to the furthest extent, leading to the lowest values of moisture content. The drier HiBar filter cake improves the cake handling and disposal with steeper dumping slopes, resulting in reduced disposal area and improved safety of the disposal site.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90233823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of coarse tailings and dry ash disposal facilities","authors":"A. Copeland, J. Teixeira","doi":"10.36487/ACG_REP/1910_04_COPELAND","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_04_COPELAND","url":null,"abstract":"The diamond industry has been disposing of its coarse tailings using conveyor and stacker systems for many years. The process plant typically generates two tailings products, a grit fraction (sand) and a coarse fraction (gravel), which are often combined on one dump. In some cases, the dump is stable with a single steep slope angle. However, in other situations a composite slope forms with settlement and intermittent slumping behaviour, this impacts on both design and operation. \u0000The thermal coal industry has also been disposing of dry ash for many years using either conveyor/stacking systems or haul trucks. Both systems work well, but the costs, deposition plans and stability aspects differ. Management of water and dust are also key factors. \u0000There are a number of key design and operational aspects that are similar between these diamond tailings and ash facilities, and would apply equally to filtered and dry stacked tailings. This paper aims to examine these similarities and show how these learnings could be built into new filtered tailings designs and operations to make them more efficient and stable.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91469465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}