{"title":"Paste thickener benefits for soda ash: liquor recovery, mine backfill and surface stack","authors":"J. Johnson, L. Webb","doi":"10.36487/ACG_REP/1910_25_JOHNSON","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_25_JOHNSON","url":null,"abstract":"The benefit of paste and thickened tailings (P&TT) was used for decades in the trona industry with a highdensity type thickener installed as early as 1994. The extraction process produced supersaturated liquor, which makes liquor recovery paramount. The insoluble material consisting largely of clays and silts produces the common problem of safe containment of the tailings. Both mine backfill and surface stacking of the tailings are being used. \u0000This paper provides a commodity review for trona, discussing the benefit of paste-type thickeners in the soda ash circuit. The topics include recovery from counter current decantation (CCD) circuits versus dilution washing; before and after retrofit data establishing improved underflow density and clarity from the latest thickener designs and operation; and the difficulties of surface stacking and drying due to residual soda ash forming a decahydrate crust sealing the stack and preventing drying. \u0000The trona industry provides a good review of paste-type thickeners and their benefits.","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":"78478812","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":"Applying image classification to develop artificial intelligence for tailings storage facility hazard monitoring using site-based cameras","authors":"J. Engels, H. Gonzalez, G. Aedo","doi":"10.36487/ACG_REP/1910_12_ENGELS","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_12_ENGELS","url":null,"abstract":"Image classification is a process whereby the spectral information of an image, based on its digital numbers, attempts to classify individual pixels to a theme or specific object (e.g. vegetation, water, vehicles, people, etc.). The output is generally an image map or mosaic of pixels, each of which belong to a particular theme or identification to produce an independent overlay of the original image. This overlay can be used to provide a post analysis regarding changes that are occurring in a sequence of images or, for example, identify a potential hazard that can trigger an action for human intervention. \u0000The accuracy of image classification is based on having enough information to train a model to identify the theme or object of interest. This paper presents the results of a supervised machine learning technique whereby target objects were identified and models run to train the classification algorithm to identify changes in supernatant pond size, rates of rise, detection of inflows of water to an area and presence of mobile equipment. Training images were acquired from site-based static time-lapse cameras that have been taking images since early 2017 of different areas of a tailings storage facility in the north of Chile.","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":"76309757","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":"Advances in non-Newtonian dam break studies","authors":"N. Moon, M. Parker, H. Boshoff, D. Clohan","doi":"10.36487/ACG_REP/1910_09_BOSHOFF","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_09_BOSHOFF","url":null,"abstract":"Tailings dam failures have and continue to cause large-scale devastation and environmental impacts. Historically these impacts have largely been predicted using Newtonian hydrodynamic modelling principles resulting in a general overestimation of potential consequences. However, since about 2014 the collective mining industry began developing complex tools to better predict the likely impacts of these failures. The industry has focused on leveraging the latest in computational flow dynamics modelling software and computational hardware to preform non-Newtonian tailings dam break assessments. However, as our tools become more sophisticated so does the requirement on input data. This paper discusses the past modelling approaches and the development of non-Newtonian tailings dam break models. The sensitivity of the flow behaviour is presented through four case studies, showing how this selection influences the outcomes and how previous approaches assuming Newtonian characteristics may present an overly conservative result. It is noted that additional knowledge and expertise will become available as non-Newtonian tailings dam break studies become the norm. In the interim, the uncertainty of these analysis needs to be analysed.","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":"86191063","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":"Dry stacking of high-grade flake graphite tailings: Tanzania","authors":"P Moshi, J. deVries, C. Hogg, C. Lane","doi":"10.36487/ACG_REP/1910_07_LANE","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_07_LANE","url":null,"abstract":"This paper presents some details of the feasibility study for a proposed dry stacked tailings management system for the Mahenge Graphite Project, in Tanzania. Black Rock Mining Limited is focused on developing its Mahenge Graphite Project, which holds the largest high-grade flake graphite resource reserve in Tanzania – the fourth largest graphite resource in the world. Several potential graphite processing operations are being proposed at various locations around the world and tailings management is a unique challenge given the geochemical characteristics of the graphite tailings and the topographical constraints of the site. Dry stacking of the graphite tailings offers a solution which minimises the environmental risks associated with conventional wet tailings and permits water reuse as part of the tailings management process. The project is located in a tropical savannah environment with a distinct difference between wet and dry seasons. Dry stacking offers a unique and innovative approach to minimising potentially large volumes of excess water during periods of high rainfall. At least 80% of the process water can be recycled.","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":"81127306","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":"Review of the potential role of electrokinetics technology in tailings dewatering and minerals recovery","authors":"D. Kalumba, S. Mudenge","doi":"10.36487/ACG_REP/1910_17_KALUMBA","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_17_KALUMBA","url":null,"abstract":"Water is employed as a cost-effective media of transporting tailings; a mixture of ground waste ore, water and chemicals used in metal extraction processes. Tailings are conveyed in pipelines from the plant to the tailings dam. From the dam, the water should be recycled back to the processing plant but herein lies the challenge. The hydraulic conductivity of fine-grained tailings is very low such that instead of draining, the water tends to accumulate in the dam. Not only does this led to pore water pressure build up which undermines the dam’s stability, but it also causes massive water losses by evaporation more so in arid regions. \u0000Dewatering of tailings prior to disposal has emerged as a solution that can be used to conserve water by producing paste or thickened tailings. Thickened tailings have higher shear strength, lower volume and they reduce dam closure costs. Filtered tailings can also be used as underground backfill for mine cavities or transported with conveyor belts and trucks to a designated point. The main limitation is that the benefits of dewatering are mainly technical and they do not yield a direct financial return. Processes that increase mineral production are vital in mine operations. Apart from the residue of the targeted metal, most tailings contain base metals like copper, nickel and zinc. Some mines have already established systems to extract valuable minerals from tailings; these include DRDGold, Lonmin and Sibanye mines in South Africa. Dewatering systems are designed to be in close contact with tailings and if they can perform the dual function of recovering water while extracting metals, they would fully meet the demands of the mining industry. \u0000One of the most efficient techniques which can harness both dewatering and metal extraction is electrokinetics. Electrokinetics involves the application of an electrical current to induce the flow of water from the anode to the cathode in a process called electroosmosis. Electrokinetics also induces the migration of ions in a phenomenon termed electro migration. The metal cations precipitate at the cathode where they are collected and dried. This paper evaluates the viability of using an electrokinetic system to dewater and extract metals from tailings. Introducing a mineral extracting function could well be the key to increase the usage of tailings dewatering techniques by mines.","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":"88610628","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":"Underground paste fill reticulation management of system flow-loss","authors":"M. Griffiths","doi":"10.36487/ACG_REP/1910_41_GRIFFITHS","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_41_GRIFFITHS","url":null,"abstract":"An underground paste fill system will inevitably experience a system flow-loss event during its operational life. In a flow-loss event, the underground reticulation design, flow-control hardware, instrumentation specification and system recovery methods can greatly impact the time taken to safely and effectively achieve a full system clearance and recommence backfilling activities. \u0000In addition, the learnings and methods discussed in this paper minimise the opportunity cost of using valuable underground work crew resources to rectify the blocked pipe work and the associated paste plant downtime. This deficit of paste filling will further impact the mining production schedule by increasing mining activity interaction and disrupting the extraction sequence. Direct costs of a blockage may include piping replacement and work crew labour as well as an increased risk of injury and equipment damage during a time-critical activity. \u0000The management of a flow-loss event must consider each of the following three flow-loss conditions experienced: \u0000A case study (Scenario 1) is presented to demonstrate the management of a flow-loss event, which includes system blockage and stalling due to insufficient available head pressure being overcome by system segmentation. Segmentation highlights the advantages of the ability to carry out safe and effective system isolation from underground in a time-critical situation. \u0000Reticulation failure response is also discussed in this paper, with an explanation of the recovery method and the requirement of an adaptive approach as the flow-loss condition can transition from one type to another during the recovery effort.","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":"77215613","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":"Rehabilitation of the Hillendale Mine’s residue storage facility","authors":"J. Beukes, M. Vlok, F. Khosa","doi":"10.36487/ACG_REP/1910_35_BEUKES","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_35_BEUKES","url":null,"abstract":"The Tronox KZN Sands Hillendale Mine is located in Zululand – close to Richards Bay. Mining activities commenced in 2001 and the mine’s production came to an end in 2013. At Hillendale, dunes with a high fines content were mined to recover the valuable minerals of ilmenite Zircon and rutile. The fine fraction consisting mainly of fine clay minerals was managed by storage in a residue storage facility (RSF). Following the cessation of mining activities several actions have been implemented towards achieving mine closure. This paper will firstly give some basic background on the operation of the residue facility as part of the Hillendale Mine. Secondly the paper will focus on mine closure activities planned and implemented at the RSF. The learnings and experience gained from the Hillendale Mine will form the basis of future closure plans for RSFs operated as part of Tronox’s newly established mine at Fairbreeze.","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":"88098157","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":"Mine fines dewatering trials using amphibious vehicles at the Tronox KZN Sands Fairbreeze Mine","authors":"Bld Cocks","doi":"10.36487/ACG_REP/1910_36_COCKS","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_36_COCKS","url":null,"abstract":"The Tronox KZN Sands Fairbreeze Mine is located in Zululand, south of Mtunzini on the east coast of South Africa. Mining activities commenced in 2015 and the declared life of the mine is 15 years. \u0000Fairbreeze Mine is beneficiating an orebody that is part of the Berea Red dune system and the fines content is known to approach 30% in some areas of the deposit. The definition of ‘fines’ in the mineral sands industry is classified as any particle passing 75 µm and consists predominantly of clays and some traces of silica particles of silt size. \u0000Historically, the mining industry has made use of sub-aerial deposition to dewater fines that do not drain freely. The only tools available to the processing facilities using the sub-aerial deposition dewatering method, has been: \u0000In order to minimise the risk and to reduce the sterilisation of large tracts of land, mining companies are being forced to consider alternative dewatering techniques. \u0000The use of amphibious vehicles, or mud-crawlers, is a well-documented alternative in the alumina industry but little is known about the performance of amphibious scrollers on mineral sands fines residue. This paper investigates the effects of mechanical scrolling performed by mud-crawlers on the dewatering and the ultimate final dry density of Fairbreeze fines. The investigation looks at ways that mud-crawlers can be applied as a financially viable alternative to sub-aerial deposition.","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":"83680419","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":"Conversion of a conventional tailings storage facility to a perimeter discharge central decant configuration using Nalco WaterShed polymer","authors":"F. Verdoorn, K. Gibbs","doi":"10.36487/ACG_REP/1910_21_GIBBS","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_21_GIBBS","url":null,"abstract":"In 2012, SIMEC Mining commenced a detailed investigation into changing the way the magnetite tailings storage facility (Mag TSF) operates at the South Middleback Ranges (SMR) to increase water recovery and provide a sustainable cost-base for tailings management. Changes were also necessary to support the Magnetite Expansion Project (MEP) that was destined to be commissioned in October 2013. A feasibility study was performed with Golder Associates to understand the technical and commercial influences and provide a capital estimate for several options. The selected option from the study was a redesign of the current dual discharge TSF to a perimeter discharge, central decant (PDCD) design. \u0000Application of Nalco WaterShed polymer at the Big Baron Pit (Verdoornet al. 2018) revealed the technology would greatly assist in the successful conversion of the TSF to a PDCD configuration. Expectation was high that WaterShed polymer treatment would allow greater beach angle control, improved water recovery, and a reduction in surface water pooling across the TSF with water pooling concentrated around the central decant allowing for efficient removal prior to loss via evaporation or seepage. \u0000A conceptual design for the polymer tailings dewatering application was developed in collaboration with Nalco Water and dosing commenced in October 2013. Due to unknown risks associated with dewatering magnetite tailings, the project was split into two stages, namely, phase 1: a proof of concept trial to establish the applicability of Watershed on the magnetite tailings prior to commissioning of MEP; and phase 2: fully operationalise the PDCD configuration. \u0000Golder was engaged to develop a life-of-mine plan for the TSF at SMR that could be safely operated to a planned final height of RL 199 m. Throughout 2013 and 2014, design and construction occurred to convert the Mag TSF to a PDCD facility. A master plan was developed to manage tailings storage for five years from March 2014, referred to as the ‘First 5 Year Plan’. This involved six wall raises that would eventually fill the three voids near the western embankment and bring the height of the TSF to RL 172 m. \u0000The civil concept selected was based on an alternatives assessment that presented three options. SIMEC Mining chose the lowest cost approach of filling the voids with WaterShed polymer treated tailings to provide a base for 3 m wall raises upstream. Strict deposition and water recovery models were followed to ensure sufficient dewatering and the subsequent drying of the tailings layers. There was also extensive test work completed prior to each of the individual embankment raises to ensure that the dewatered tailings had the appropriate density and strength properties to support the raises before commencing with the lifts. \u0000During the first five years of operation, water recovery was around 60% and the volume utilisation was in line with the deposition model. The high percentage of water recovered enabled the proc","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":"88494539","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 dam safety: going beyond technical","authors":"C. Priscu","doi":"10.36487/ACG_REP/1910_0.03_PRISCU","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_0.03_PRISCU","url":null,"abstract":"The criticality of effective stewardship of tailings facilities has recently gained increasing recognition and triggered much effort on the part of the many mining companies across the world. The world of mining, and in particular the mine waste management practice area, is changing dramatically after the recent tragic events following the tailings dam failure in Brazil in January 2019. Investors, communities, shareholders, nongovernmental organisations, regulators and insurance companies are looking to the tailings storage facilities and their management through a completely different lens; one that focuses on the need for implementing best available practices (BAP), best applicable technologies (BAT), and how the zero repeats commitment of the mining industry will be achieved. \u0000This presentation outlines Anglo American’s approach to building a world-class tailings storage facilities practice, which includes a number of key must-have ingredients: \u0000A solid and strict governance framework for the oversight of a large portfolio of tailings and water dams in a global environment, where stringent minimum technical standards are implemented with non-negotiable requirements. \u0000The need for people with the right set of skills, competencies, and technical knowledge, but also the mindset on safety and the ‘do the right thing’ approach that needs to be part of their DNA. \u0000The critical controls definition and implementation to ensure each facility is planned, built and managed safely to design requirements, minimising the presence of the ‘surprise’ effect, and in particular the minimisation of the human error element factor. \u0000Pushing the boundaries of technology and innovation in tailings production, deposition, and management of such facilities. From minimising the tailings production, to high tech near \u0000real-time monitoring instrumentation and surveillance technologies, all are key ingredients in building a global success story. \u0000Implementing the Anglo American dam safety management program at a global level does not come without challenges. The presentation will discuss the strategy and share some of the success stories, as well as lessons learned along the Anglo American journey since 2014, when the company transformed its internal technical requirements, raising the bar to a whole new level.","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":"81800277","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}