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Priscu, Caius. "Behavior of mine tailings dams under high tailings deposition rates." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0024/NQ50240.pdf.
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Knutsson, Roger. "Tailings Dam Performance : Modeling and Safety Analysis of a Tailings dam." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18084.
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Storage and management of mine waste are both needed in the mining industry. After mineral extraction of the ore, there are generally leftovers with insufficient economical value that need to be taken care of. The finest grained fractions are referred to as tailings. Since every mine site and every tailings impoundment is unique, there is unfortunately not an universal answer to proper management that can be applied everywhere. Even though local guidelines and regulations can be considered to give a best practice in terms of design, there is correspondingly a need for dam safety stewardship on an operational level. Without such stewardship, not even the best designed dams or facilities would be fully controlled in terms of safety. Conversely, even badly designed dams can be operated in safe manners with good stewardship and surveillance programs. The coupling between design and stewardship is therefore important in order to reach proper tailingsmanagement.In the design of tailings dams, a certain value of the factor of safety for slopes of the dams is normally striven for to secure stability. The value is generally based on national regulations and/or guidelines. In Sweden the factor of safety should not be lower than 1.5 under normal conditions. In the guidelines, recommendations are often given on dam surveillance and field measurements of e.g. pore water pressure, deformations and seepage. Field measurements are taken, but are generally assessed in terms of trends (change with time) and not by comparison to anticipated performance.In this study, numerical modeling has been used for stability analyses and dam performance, as predictions of deformations and pore water pressure levels. An upstream tailings dam located in northern Sweden has been used as a case. The granular materials being part of the model based were described based upon geotechnical investigations (field and lab). The tailings material was modeled, on a constitutive level, by the Hardening Soil model. Good agreement betweensimulated behavior and laboratory tests was achieved. Other dam materials were simulated by the Mohr-Coulomb model.The model was built as a staged construction model where historical events between 1992 and 2013 were simulated. The historical events included dam raises, increased beach elevations, remedial works etc. The simulations of historical events were used for facilitating comparison with field measurements. By means of inclinometer data, horizontal deformations were measured and evaluated for a period of six years. These deformations were accurately simulated, which was considered to verify the numerical model. By this verification, the model is considered accurate enough to be used for simulating future events. Both stability and corresponding dam performance were computed, by simulating a period of 10 years. The stability analyses were used for the set-up of rockfill support plans, i.e. where and when remedial works are needed in order to maintain a certain safety level. The corresponding values in deformations and pore water pressures were used for the set-up of alert levels for each measuring unit. These alert levels will help the engineer in field with data interpretation, where the simulated values are compared with field measurements taken. The proposed methodology is recommended for tailings dams in general, which reduces the gap between design and stewardship. Hence, one step closer to proper tailings management is taken.Godkänd; 2015; 20151026 (rogknu); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Roger Knutsson Ämne: Geoteknik/Soil Mechanics Uppsats: Tailings Dam Performance Modeling and Safety Analysis of a Tailings Dam Examinator: Professor Sven Knutsson Institutionen för samhällsbyggnad och naturresurser Avdelning Geoteknologi Luleå tekniska universitet Diskutant: Technical Director Annika Bjelkevik Tailings Consultant Scandinavia AB Stockholm Tid: Fredag 27 november 2015 kl 13.00 Plats: F1031, Luleå tekniska universitet
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Bhanbhro, Riaz. "Mechanical Behavior of Tailings : Laboratory Tests from a Swedish Tailings Dam." Doctoral thesis, Luleå tekniska universitet, Geoteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62534.
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Tailings is leftover material from mining industry and is produced in huge quantities approximately 70-99% of the ore production. Tailings material is stored as impoundments by constructing tailings dams which are often constructed with tailings material itself. Tailings are artificial material and the mechanical behavior of tailings material upon loading is different as compared to natural soil materials. There are number of dam failures reported every year which has severe impact on inhabitants and environment nearby. Considering the failures of tailings dams and consequences there is a need to understand the tailings material in depth for safe existence of these dams. The confident dam design can assure the safe existence of tailings dams for long term as these dams are presumed to function for generations to come. The material properties in tailings dams can change during operation due to raising of new layer. Raised new layer can change stress level, which in turn may change the material properties in terms of strength, pore pressures, grain sizes etc. Today mostly tailings dam are designed by performing analysis for safety for existing and future rasings as well. These analyses are based upon a for certain factor of safety. Not very much can be done with design and analysis for tailings material if the material is not described very well. Understanding of tailings material in depth can provide help for detailed material parameters which later can be used in safety assessment for future raising and changed conditions in dam. This study presents the work carried out on tailings material from a Swedish tailings dam. The study is conducted on undisturbed and disturbed tailings material. The undisturbed tests are carried out to understand material properties as per in-situ conditions. Whereas disturbed materials are used to created different materials with different particles sizes. Initially in this study the basic properties of tailings materials are studied e.g. specific gravity, phase relationships, particle sizes, particle shapes and shear behavior on collected samples at various depths. During direct shear tests, the unexpected vertical height reductions were observed, these results are presented in this study. The comparison of strength parameters by direct shear and triaxial tests on material from various depths is also done and presented. Based on results from direct shear, triaxial and oedometer tests on uniform sized tailings material; the evaluation of primary and secondary deformations and particle breakage and effect of vertical loads is also carried out and presented. The study also includes the comparison of strength parameters for each particles size. The breakage of particles is analyzed by sieving the material after direct shear tests followed by a particle shape study. The effect of deposition on shear strength parameters is also studied by construction of samples with different angle of deposition of material. The strength parameters of uniform sized particles in triaxial tests are also evaluated and discussed.
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Bhanbhro, Riaz. "Mechanical Properties of Tailings : Basic Description of a Tailings Material from Sweden." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16952.
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Tailings dams are constructed to store waste material from mining industry and usually these dams are raised with time depending upon production rate. Tailings material is sometimes used in construction of tailings dams. Tailings are artificial material and the behavior of tailings material upon loading is different compared to natural soil materials. The mechanical properties of tailings have influence on the performance of a tailing dam. Since the tailings dams are constructed to withstand for long times, it is essential to understand tailings materials in depth in order to assure safe existence of the dams in short term as well as in long term perspective. This licentiate thesis describes the present work carried out on sulphide rich tailings from one mine in Sweden. The material presented is based upon material from three different papers. The first paper describes the basic characteristics of tailings which includes; specific gravity, phase relationships, particle size, particle shape and direct shear behavior. The second paper discusses direct shear tests carried out on tailings from one Swedish mine. Shear strength parameters are evaluated and results from 27 tests (15 drained and 12 undrained tests) are discussed. This paper also describes the vertical height reductions observed during direct shear tests. The third paper focuses on the laboratory results from triaxial tests conducted on tailings materials. This paper shows the drained behavior of tailings under application of different consolidation pressures.The results from particle analysis showed that smaller particles were very angular and bigger particles were sub angular. The material was classified as silt and silty sand. The average particle density (ρs) is 2.83t/m3. The dry density and void ratios were found to be 1.18–1.65 t/m3 and 0.72–1.41 respectively. During direct shear tests vertical height reductions were observed with slight increment in pore pressures. The strain hardening behavior was observed in both drained and undrained conditions in direct shear tests. The strength parameters determined in triaxial test were higher than of those calculated in direct shear tests. Friction angle ϕ' in triaxial tests were found to be 39 to 41degrees and it did not showed any effect with relation to depth. The cohesion and friction angle in direct shear test at 0.15radian, in drained tests were found as in range of 9.7-33.7kPa and 12.5-18.3 degrees respectively. The same parameters for undrained tests were found as 7.1-16.1 kPa and 16.0-20.4 degrees for cohesion and friction angle respectively.Godkänd; 2014; 20140818 (riabha); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Riaz Bhanbhro Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Uppsats: Mechanical Properties of Tailings Basic Description of a Tailings Material from Sweden Examinator: Professor Sven Knutsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Adjungerande professor Peter Viklander, Vattenfall AB, Luleå Tid: Torsdag den 18 septemebr 2014 kl 10.00 Plats: F1031, Luleå tekniska universitet
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Brisson, Patrick. "Unsaturated flow in tailings." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27229.
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The work presented in this document is two-fold. The major part of the work described herein, involved designing and building an apparatus to determine the unsaturated coefficient of permeability of mine tailings in a laboratory environment. The Modified Permeameter was built based on a permeameter used by Meerdink et al (1996) which was used with compacted clay samples.
The modifications include using a large size sample; the ability to accommodate mobile sensors to alleviate the problems associated with the formation of water pockets and to use the same test specimen and determine the SWCC and unsaturated coefficient of permeability of the tailings over a large range of saturation.
Mobility of the sensors was achieved with a system of counterweights, which also retained the water-tightness of the apparatus. Although Time Domain Reflectometry (TDR) sensors did not yield any results during this research program, the Modified Permeameter includes counterweight system to provide mobility for three TDR probes to measure volumetric water content. During the experimental work, water content was measured with sampling tools developed and built for use in the Modified Permeameter. Negative pore water pressures were measured with tensiometers.
Two gradations of tailings were tested with the Modified Permeameter. The two gradations were the overflow (fine) and the underflow (coarse) samples. Prior to laboratory experimentation with the tailings, numerical predictions of soil-water characteristic curves (SWCC) and conductivity curves were computed. These predictions were obtained using the SoilVision software package.
The predicted curves were compared with the laboratory values. The estimated SWCC for both tailings gradations and the laboratory results show good agreement. In regards to the conductivity curves, insufficient laboratory data was gathered to compute the unsaturated coefficient of permeability of the coarse underflow sample. The laboratory results for the overflow sample show important scatter around the predicted conductivity curve.
Due to the differences observed between the laboratory results and the predicted conductivity curve, the numerical modeling portion of this research, which constitutes the second portion of this research, was conducted using typical permeability values.
The modeling portion consisted of producing a generic model of an upstream tailings dam on which individual factors were analysed. The factors considered were as follows: (1) Effect of beach length; (2) Effect of pervious foundation; (3) Effect of blanket drain; (4) Effect of segregation along the beach, (5) Effect of anisotropy; (6) Combined effect of segregation along the beach and blanket drain.
The numerical analysis showed that maintaining a good beach length throughout the construction period of the upstream dam helps to prevent saturation of the fine tailings underlying the shell. The addition of a blanket drain to a good beach length provided the desired effect, which was to lower the phreatic surface away from the fines closest to the dam's shell.
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Fitton, Timothy, and tfitton@hotmail com. "Tailings beach slope prediction." RMIT University. Civil, Environmental and Chemical Engineering, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080212.120813.
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Tailings (mining waste) disposal is a significant consideration for the mining industry, with the majority of the ore processed in most mining operations ending up as tailings. This creates large volumes of tailings, which must be handled and stored responsibly to avoid potential environmental catastrophes. The most common form of tailings storage facility is the impoundment, where tailings are contained within a basin, with beaches forming around the perimeter of the impoundment and a pond standing in the middle. A relatively new method of tailings storage is to create a 'stack', whereby the tailings solids form a large heap, with the discharge of tailings slurry from the apex of the heap. It is of significant value for mine operators and tailings engineers to be able to predict the shape of the beach that forms in either of these disposal scenarios. The key to being able to do this relies on a method of prediction of the beach slope. The aim of this work is to develop a method of tailings beach slope prediction for tailings slurries that are sub-aerially discharged from a pipe. In this thesis a literature review is undertaken, investigating existing methods for the prediction of tailings beach slopes. These methods are validated against relevant industrial and experimental data. Two separate phases of experimental work have taken place in an effort to investigate tailings deposition behaviour, one at mine sites and the other in a laboratory on a small scale. Three new tailings beach slope prediction models are presented; a simple empirical model enabling quick approximate predictions; an a priori tailings beach slope prediction model based on existing theories of open channel flow, sediment transport and rheology, which is more powerful due to the greater degree of theory in its foundation; and a new semi-empirical model that shares some of the theoretical aspects of the a priori model but offers better predictions due to its empirical calibration to the experimental data. The experimental results, along with 3 other independently collected sets of relevant industrial and experimental data, are used to validate the beach slope prediction models found in the literature, as well as the new beach slope models presented in this thesis. Statistical evaluation of the performance of all of these models is presented to enable comparison. Finally, a new beach shape model is presented for the three dimensional geometric forecasting of the beach surface of a tailings stack. Historic tailings discharge data is run through the beach shape model, and the shapes predicted by the model are compared with aerial survey data of a real tailings stack for validation of the shape model. This work not only presents a new method of tailings stack shape prediction, but also a plausible theory for explaining the concavity of tailings beaches. The stack shape model also has the potential to be developed further for the three dimensional modelling of tailings beaches formed in other types of storage facilities, such as impoundments or valleys.
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Durve, C. "Flow through tailings dams." Thesis, Open University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375642.
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This thesis deals with the study of flow through tailings dams. Examination of the current practices led to the construction of a valid experimental model. A unique system of instrumentation was developed, which was employed successfully to measure pore water pressures accurately and thus provide the necessary information to locate the position of the phreatic surface. Using the developed technique, models of tailings dams were constructed and monitored and it was discovered that a major deviation in the expected position of the phreatic surface occurred in a tailings dam. Further investigation by the construction of various types of dams led to the redefining of the phreatic surface and thus the flow regime. A computer programme based on the use of the finite difference technique was applied to water retention dams and found to locate the position of the phreatic surface accurately.
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Anchiraico, Anthony, José Bazo, Vidal Aramburú, and Carlos Raymundo. "Reuse method for deposits of polymetallic tailings in a state of abandonment through the application of mineral flotation." Springer Science and Business Media Deutschland GmbH, 2019. http://hdl.handle.net/10757/656289.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.In the mining industry, due to the extraction and processing of ore, a significant amount of tailings are produced which are discharged into deposits. In some cases, these are in contact with effluents and generate acid waters that pollute the environment and affect the health of the inhabitants. Additionally, these tailings within their composition contain valuable metals that can be reused through a process of mineral flotation. As a part of this research, a study based exclusively on laboratory tests was performed on the tailings deposit located in the Recuay–Peru district, where the presence of concentrations of Pb, Zn, and Ag at 48.36% was obtained, 23% and 250 g/TM. Thus, this study aims to take advantage of polymetallic tailings deposits that are in an abandonment state by extracting valuable ore through the flotation process based on their chemical composition and mineralogical characterization.
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Van, den Berg Mader J. "Western limb tailings reclamation project." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-07272005-100249.
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Tang, Juliana. "Fundamental behaviour of composite tailings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq22680.pdf.
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Welch, Jonathan Paul. "Water flow through tailings dams." Thesis, Durham University, 1993. http://etheses.dur.ac.uk/5523/.
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Water levels in tailings dams are generally lower than those of standard earth dams. Previously, other authors have shown that embankment geometry and variation in permeability can be responsible for a concave upwards steady state seepage line. These factors are investigated in greater detail using a finite element program to model flow in the saturated portion of the embankment. It is shown that the angle of the upstream slope only has an appreciable effect on the form of the seepage line if the pond is close to the downstream face of the dam. An increasing permeability in the direction of flow and seepage path length are responsible for reducing the height of the seepage line. This effect is demonstrated for both a continuous variation of permeability and a step jump in permeability between the tailings deposit and the dam. Anisotropy of tailings and dam permeability is also investigated. Transient analyses of saturated flow are performed for tailings dams constructed of dry compacted waste. For this case, the seepage line is straight for a constant pond level, and concave upwards for a rising pond and a low dam permeability. The simple computer model also predicts that for a constantly rising pond level, the seepage line advances at a constant rate dependent on the rate of pond rise, and the material properties of the dam. A fully automatic finite element program has been written, combining an adaptive mesh regeneration algorithm and a variable mesh technique. The program is shown to provide both an accurate and precise solution of the free surface problem. A method of automatically generating "square" flow nets by post-processing the finite element data is presented for the first time. Flow nets provide a visual proof of the correctness of the computer model and are a useful aid to other workers.
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Chernoloz, Oleksiy, and Oleksiy Chernoloz. "Cataloging Tailings Dams in Arizona." Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/625329.
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Tailings storage facilities (TSFs) and conventional water retaining dams are the largest manmade structures on Earth. Statistics show that TSFs are more likely to fail than water retaining dams.Recent catastrophic failures of TSFs have led to the loss of lives (Germano mine, Brazil), environmental damage (Mount Polley, Canada), contamination of drinking water (Baia Mare, Romania), and the destruction of property (Kingston Fossil Plant, USA). As the scale of mining increases, TSFs increase in height and volume, therefore increasing the consequence of failure. To help mitigate risk associated with large TSFs mining companies empanel expert groups to review operations of TSFs and conduct regular visual inspections. In the US the Mine Safety and Health Administration has regulatory responsibility for the safety of TSFs. As population centers expand nearer to existing and proposed TSFs, the public requires assurance of the integrity of these structures. A pro-active approach to public safety is more desirable than a post-mortem analysis after a major failure.
We have examined both the regulatory practices, the industry practices, and public data on TSFs in Arizona. In this thesis paper we address inadequacies of the official government records on TSFs in the two largest publicly accessible databases of dams inthe US – the National Inventory of Dams (NID), and the National Performance of Dams Program (NPDP). Both databases contain numerous errors and omissions, including descriptions and geographic coordinates of TSFs that are inaccurate by many kilometers. Several large TSFs in Arizona are not included in either database.We address these shortcomings with a pilot project for Arizona that demonstrates recording accurate information in a database is neither expensive nor onerous, communicating best practices for operation can help alleviate community concerns, and continuous monitoring technology can resolve shortcomings with visual inspections.
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Yang, Fenghua. "Geopolymerization of Copper Mine Tailings." Thesis, The University of Arizona, 2012. http://hdl.handle.net/10150/268596.
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Geopolymerization is a chemical reaction process, reacting SiO₂ and Al₂O₃ with alkaline solutions, which can transform aluminosilicate solids or particles to polymer materials. Geopolymers have many engineering applications such as cementation binders for construction and solidification or encapsulation of hazardous heavy metals. Mine tailings mainly consist of SiO₂ and Al₂O₃. Theoretically, mine tailings can be used as source materials for geopolymerization. However, for most researchers, they use fly ash, metakaolin or furnace slag as source minerals, because these minerals are much more reactive with alkaline solutions. Mine tailings are naturally-forming minerals and are considered to be inert in geopolymerization. How are mine tailings to be activated through different reaction conditions? We conducted several tentative or preliminary experiments to study the geopolymerization process step by step. We tried different methods to react mine tailings with alkaline solutions. Mine tailings were submerged into alkaline solutions in a plastic bucket for 6 days in room temperature (20-25 °C). We wanted mine tailings to be activated by soaking. The results were not satisfying. Then we tried to react mine tailings with alkaline solutions at 60 °C and 90 °C. After analyzing, we found that the results were not satisfying either. So, we conducted simplified geopolymerization experiments in order to better understand the chemical reaction mechanism. Pure SiO2 and Al2O3, which were two major reactants, were employed to simplify and simulate the geopolymerization process. We drew some useful conclusions such as that geopolymerization took place at elevated temperatures; Al₂O₃ almost did not react with alkaline solutions at low temperatures, etc. We conducted experiments at elevated temperatures (150 °C, 180 °C, 210 °C). Different levels of pressure (5 MPa, 10 MPa, 20 MPa) were applied to make compact specimens. After many attempts, the results were successful. The highest mechanical strength was about 20 MPa. Most importantly, we obtained polymers produced from geopolymerzation, which could be seen by naked eyes. The experiment techniques such as scanning electron microstructure (SEM) imaging and X-ray diffraction (XRD), inductively-coupled plasma mass spectrometry (ICP-MS), and unconfined compression tests (UCS) were applied to study the geopolymerization reaction mechanism and the feasibility of using mine tailing-based geopolymers as construction materials.
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Tisch, Bryan. "Studies on the use of depyritized tailings, gold tailings, sewage incinerator ash and granulated slag as cover alternatives for the reclamation of sulphide tailings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ31472.pdf.
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Hussain, Fida 1956. "THE RELATIVE EFFECTS OF INSITU DRYING AND SAMPLE PREPARATION DISTURBANCE ON THE COMPRESSIBILITY OF A COPPER MINE TAILING." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/275562.
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BELLA, GIANLUCA. "Hydro-Mechanical Behaviour of Tailings in Unsaturated Conditions." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2685795.
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Many geotechnical problems are related with soils and structures in unsaturated conditions. Among them, a significant role is played by tailing dams that represent complex geotechnical systems. Because of their wide extension, tailing storage facilities are subjected to many external actions and interactions with the atmosphere, whose effects governing the position of phreatic surface. Hence, the low permeability deposited tailings are subjected to drying-wetting processes, leading variation in the extensions of the unsaturated zone above the phreatic surface with a significant role in stability of the embankment.
The current research is aimed to study the hydro-mechanical behaviour and the water retention response of unsaturated silt and silt-sand tailings mixtures, respectively, in order to extend a previous characterization of the same soil performed in saturated conditions. This research is also aimed at investigating the occurrence of the critical state in unsaturated conditions, showing the range of state variables leading the static liquefaction. Finally, irradiation by means of gamma rays is proposed as an accelerated technique in order to simulate the natural ionizing radiations acting on stored tailings that, in many countries, are beginning to be re-used as backfill, landscaping material or feedstock for cement and concrete. Wet and dry silty samples were exposed to gamma rays and then characterized in order to study any possible physical and chemical modifications of the exposed matter.
The starting point of this research is an available hydro-mechanical characterization of saturated tailings coming from Stava tailing dams collapsed in 1985 (Italy). The first series of experimental tests was carried out to study the hydraulic behaviour of the Stava tailings by means of water retention tests. To account for the heterogeneity of the tailing material within the basin, the dependency of the water retention relationship on grain size distribution and void ratio was investigated. In order to extend the limited range of matrix suction allowed by the axis translation technique, the water retention curves were also implemented with data obtained by indirect soil suction measurement and soil suction controlling methods, dew point technique and vapour equilibrium technique, respectively.
Since the pre-shearing state of the soil has a relevant effect on the behaviour shown during shearing before reaching the critical state conditions, a second campaign of experimental tests, consisting in five mono-dimensional compression tests, was performed. Results were compared with those in saturated conditions obtained by Carrera (2008) in order to investigate the dependency of preconsolidation stress and stiffness of the soil on suction. Aimed to extend the hydraulic characterization and to approach the possible critical state in unsaturated conditions from drying and wetting sides, a third campaign of experimental tests was carried out by using a suction controlled triaxial cell and imposing different hydro-mechanical stress paths. Statically compacted silty samples were subjected at different suction levels, then isotropically consolidated at different net stresses, and finally sheared at constant water content or constant suction level by means of the axis translation technique or the vapour equilibrium technique.
Finally, due to the importance of the static liquefaction phenomena in stability problems of tailing dams, a fourth series of experimental tests was performed by means of a triaxial cell. Silt specimens were tested in unsaturated or close to saturated conditions, in order to investigate some of the main factors (degree of saturation, initial density and preparation technique) that are supposed to influence the liquefaction response.
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Johnson, Lawrin Von. "THE DESIGN OF STABLE AGGLOMERATES FOR MINE TAILING LEACH HEAPS." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275239.
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Solgi, Narjes. "Water balance of metal mining tailings management facilities : influence of climate conditions and tailings management options." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61315.
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The objective of this research was done to review and compare available methods for Tailings Management Facilities (TMFs) water balance; to develop deterministic and probabilistic models; and to compare the impacts of different tailings management options and climate conditions.
The developed models were spreadsheet based. Mount Polley operational data were used. Water balance models were created for lined and unlined impoundments in both wet and dry climates. Wet condition climate data were extracted from ClimateBC (a University of British Columbia Software Program) using the location of the Kerr-Sulphurets-Mitchell (KSM) project in British Columbia. Climatic data from the Cerro Negro mine site in Argentina were used to simulate the dry condition.
After developing a deterministic model, Monte Carlo simulation computational algorithm was used to develop the probabilistic evaluations. Simulations were carried out using the Oracle Crystal Ball Excel add-in. Evaluations were done on four management options (slurry, thickened, paste, and filtered tailings) by changing the tailings solids content.
Results confirmed that entrainment and evaporation were the biggest water losses in TMF. For slurry tailings, entrainment loss was more than 80% of the total water loss in the wet condition and more than 50% of the total water loss in the dry condition.
The reported average mine water consumption for slurry tailings in arid climate is between 0.4 and 0.7 m³/tonne. The estimated mean required make up water from the developed model in this reaserch was 0.70 m³/tonne. Water withdrawal in dry climate conditions can decrease to 0.18m³/tonne when a filtered tailings option is implemented.
The average water surplus in wet climate conditions for an unlined impoundment varied between 0.83 and 1.12 m³/tonne for solids contents between 45% (slurry tailings) and 80% (filtered tailings). The corresponding values for a lined impoundment were 0.86 and 1.16 m³/tonne.
Implementing dewatered tailings is not recommended in wet climates. In contrast, paste tailings and filtered tailings are good options in arid areas for proper-size operations.
TMFs are site-specific complex systems. Results presented here are only examples to outline how the mining industry can work toward reducing water losses by using dewatering and tailings management technologies.Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate
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McIntosh, Bruce John. "A SIMPLIFIED PROBABILITY APPROACH TO THE DESIGN AND ANALYSIS OF URANIUM TAILINGS IMPOUNDMENTS." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276414.
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Oz, Ekrem Eser. "Evaluation Of Kosovo-artana Concentrator Tailings." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613236/index.pdf.
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In this study, evaluation of Kosovo-Artana Concentrator tailings with flotation and
leaching method is aimed. The minerological analysis of sample showed that
sphalerite, galena, chalcopyrite and their oxidised forms are the main ore minerals
in the sample, while pyrite, illite, quartz, calcite and gypsum are the gangue
minerals. The metal contents of the sample are 1.2% Zn, 0.75% Pb, and 0.06% Cu.
Flotation tests to produce bulk concentrate of copper-lead and lead-zinc were
unsatisfactory. The recovery of the zinc with H2SO4 leaching were conducted both
at room temperature and at elevated temperature. The effects of various parameters
such as leaching duration, concentration of H2SO4, pulp density and temperature on
the zinc metal recovery were examined. The maximum extraction of zinc was 80%
and 89% at room temperature and at 80 °C respectively for 120 minutes leaching period.
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Simms, P. H. "Engineered covers for reactive tailings management." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0004/MQ32508.pdf.
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Stewart, Douglas Michael Charles Carleton University Dissertation Chemistry. "An investigation of uranium mill tailings." Ottawa, 1987.
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Carlsson, Erik. "Sulphide-rich tailings remediated by soil cover : evaluation of cover efficiency and tailings geochemistry, Kristineberg, northern Sweden /." Luleå : Luleå tekniska univ, 2002. http://epubl.luth.se/1402-1544/2002/44.
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Hagström, Patrik. "Determination of dry density in tailings with a Dynamic Cone Penetrometer :." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-66993.
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Today mines produce metals which are used for everyday products by people worldwide. When metals are produced, waste products known as tailings are generated. These tailings are commonly stored in impoundments, surrounded by embankment dams. The demands from the society are constantly increasing regarding the quality and safety of dams. One step in development towards a better control regarding safety and quality of tailing dams, could be to compact the beach. Today there is a lack of methods to easy check the dry densities over large areas for a compacted material. Since these dams can be large structures with embankment lengths of several kilometers, it is necessary to be able to check the density with a fast method. In this thesis it was investigated if the dry density, and correspondingly the compaction, can be checked with a Dynamic Cone Penetrometer (DCP). In the thesis the dry density of tailings was compared with penetration rate of the DCP. A laboratory setup was made with a test box filled with tailings provided by Boliden AB from the Aitik mine. Six different box tests were performed, each test with different compaction. From the tests a trend was observed, for which the tailings increased in density as the DCP indexes showed an increased resistance. A relationship between DCP index and dry densities was found. Though a relationship was found, it is important to emphasize that the tests were carried out in an environment that was easy to control. One test with high water content showed that water was influencing the DCP index results. Therefore it was concluded that if the DCP will be used in field, the water content also has to be checked.
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Landine, Patrick G. "Weathering and diagenesis of Saskatchewan potash tailings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1993. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq23919.pdf.
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Qiu, Yunxin. "Optimum deposition for sub-aerial tailings disposal." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0008/NQ59656.pdf.
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Mainali, Ganesh. "Monitoring of tailings dams with geophysical methods." Licentiate thesis, Luleå : Luleå university of Technology, 2006. http://epubl.luth.se/1402-1757/2006/07.
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Priestley, Daniel. "Modeling multidimensional large strain consolidation of tailings." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/39809.
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Mine sites generate large volumes of tailings materials, requiring storage in tailings impoundments. Large strain consolidation of tailings materials represents a major factor in determining how a tailings impoundment will behave over time. Being able to accurately model these phenomena ensures that the effects of long term consolidation may be considered in the design of future tailings impoundments. SoilVision Systems has created an internal version of the SVOFFICE 2009 finite element modeling software capable of evaluating these scenarios. Prior to this research, preliminary benchmarks have been established, but the software had not yet been applied to multidimensional scenarios to benchmark the results. The goal of this research was to first benchmark the software against literature case studies. Following this, the software could then be applied to multidimensional tailings impoundments to study how the modeling could be performed and what factors require further consideration. Benchmarking of the software showed that the software is capable of recreating a wide variety of case studies from the literature. Further test were used to determine the effects of various material parameters on the material. Applications to multidimensional scenarios show that the software is capable of analyzing a wide variety of scenarios and considering numerous factors not found in other software packages. While the software does require additional functionality, it has been found to be a viable tool for examining multidimensional consolidation effects in tailings impoundments.
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El, Husseini Bassam. "Streaming potential measurements in sulfide rich tailings." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115872.
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In general, tailings dams are expected to seep. Anomalous seepage, especially when induced by internal erosion, is a major concern for owners and operators. The long established techniques for monitoring water seepage provide sparse information which may not be sufficient to detect and map the seepage path. Hence, there exists a great need for non-invasive techniques that would be sensitive to changing seepage conditions. The non-invasive nature of the techniques is particularly important because drilling and other penetrating (invasive) investigation methods are normally avoided.Non-invasive techniques such as self-potential and high-resolution resistivity have been significantly improved in the past decade and have been successfully used for water retention dam investigation and monitoring. The main difficulty in the use of these techniques in monitoring sulfide rich tailings dams is the presence of electrochemical potentials that renders the interpretation of the acquired self-potential data difficult.
Numerical modelling is one of the latest methods in interpreting self-potential anomalies induced by liquid flow. But, in order to model streaming potentials several parameters need to be measured or estimated; (1) the hydraulic driving force and the hydraulic conductivity are required to solve for the hydraulic pressure distribution; (2) the cross-coupling conductivity distribution is needed to calculate the conduction current source parameter; and (3) the resistivity distribution is needed to determine the resulting potential distribution.
The zeta-potential and the resistivity of three pyrite rich tailings from the Abitibi region in Quebec were measured over the pH range 2 to 5 in different KCl aqueous solutions for the purpose of estimating the magnitude of electrokinetic effect induced by mine water seepage and the electrical resistivity variation induced by particle migration. The experimental and theoretical results obtained in the present study are pertinent to the interpretation of self-potential data. The zeta-potential was found to vary from -27 to -2 mV and the resistivity of the tailings was found to increase when fine particles are eroded.
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Bernier, Luc Warren Lesley A. "Sulphur biogeochemistry in a mine tailings lake." *McMaster only, 2007.
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Vermeulen, Nicolaas Johannes. "The composition and state of gold tailings." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-03102006-122937/.
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Gan, Princess Rochelle. "Flotation of Yxsjöberg historical tungsten ore tailings." Thesis, Luleå tekniska universitet, Mineralteknik och metallurgi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75844.
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Tailings dams, due to their sheer size and metal content, pose safety and environmental hazards. The Småltjarnen repository, which hosts material from the largest known tungsten mineralization in Sweden named the Yxsjöberg deposit, is estimated to contain 2.2 million tons of material from previous operations when recovery rates of scheelite, chalcopyrite, and fluorite were low. The repository is also observed to contain at least four of the listed critical raw materials by the European Commission in 2017, namely tungsten, fluorite, beryllium, and bismuth. The amenability of this tailings repository as secondary sources for valuable minerals and metals supports the Raw Material Initiative and the drive of the European Union towards a more circular economy. This masters thesis is part of the REMinE (Improve Resource Efficiency and Minimize Environmental Footprint) project that aims to evaluate the amenability of historical mining waste for re-processing from the technical, economical, and environmental perspectives. The study focuses on work package 3 of the project: Identification of new processing methods for mine waste. Previous work on this repository includes geochemical characterization and physical separation through magnetic and gravity separation tests. Since scheelite, the main mineral of the deposit, is commonly recovered through combinations of gravity separation and flotation methods, it is imperative to investigate the response of the material to flotation tests. Further characterization work and flotation tests were rendered on samples from sampling location 6 (60°02'33.6"N 14°46'30.8"E). Previous work was done on samples from and near sampling location 1, which is southwest from location 6. Characterization methods performed on the material included elemental analysis through ICP-SFMS, X-ray diffraction measurements, and mineral liberation analysis as well as physical characterization through particle size distribution analysis and determination of specific gravity. Based on MLA, the material from the main samples showed good liberation by free surface which is important for flotation processes. Mineral association also showed low percentages between scheelite and other Ca-bearing minerals which is a main concern for scheelite flotation. Comparison of characterization work between the two sampling locations allows information on the repository at a larger scope. The common scheelite flotation collector sodium oleate, as well as novel formulations Atrac 2600 and Berol 8313 from Nouryon were tested in combination with the depressant sodium silicate. Based on mass recovery, grade and recovery, selectivity, required dosage, and the degree to which it is environmentally safe, Atrac 2600 at 400 g/t is deemed to produce the most positive results. Based on characterization of the material and flotation tests, an estimated 222,200 tons of -75 µm can go directly into the flotation circuit with an average grade of 0.2768% WO3 and 0.195% Cu. Approximately 15,000 tons at 0.50% WO3 and 14,000 tons at 0.224% Cu can be recovered at a single flotation. Rough mass balance of the process flowsheet indicates a Cu concentrate at 30% Cu will produce 880.50 tons, while a saleable scheelite concentrate at 65% WO3 will yield 672.16 tons from only the original -75 µm fraction of the material. Including the gravity separation tails intended to join the flotation circuit after grinding, an estimated 1,205.54 tons of scheelite at 65% WO3 and 1.860.20 tons of 30% Cu concentrate can be produced. Aside from this, the gravity separation circuit will still be able to yield 188,000 tons of 0.92% WO3 concentrate, which can be further studied if it can be beneficiated to a saleable product. Value estimation of the products for the recommended flowsheet indicate a total of US$ 17 million for the WO3 and Cu concentrates to be produced from the readily amenable -75 µm fraction to be treated directly by flotation. Inclusion of the gravity separation tails mass into the flotation feed yields a value estimated at US$32 million.
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Aida, Farkish. "SAP Based Rapid Dewatering of Oil Sands Mature Fine Tailings." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24251.
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Mature fine tailings (MFT), as a mixture of residual bitumen, sand, silt, fine clay particles and water, are a byproduct of oil sands extraction. The large volume, and poor consolidation and water release ability of MFT have been causing significant economic and environmental concerns. Therefore, several studies have been implemented on finding innovative dewatering/disposal techniques. As a result, different methods have been introduced and tested at a laboratory or a field scale, yet very few of these are commercially used in the oil sands industries. Despite the extensive research, an optimal solution has not been found due to the lack of technical or economic feasibility.
In the present study, a novel approach that consists of the rapid dewatering of MFT by using a super absorbent polymer (SAP) to produce dense MFT is proposed. A comprehensive laboratory investigation on the geotechnical characteristics and behavior before and after treatment of MFT is conducted. The effects of SAP based dewatering and freeze/thaw cycles on the undrained shear strength of dewatered MFT by using a vane shear apparatus are studied. Furthermore, the ability of recycled SAP to dewater and densify MFT is assessed. Finally, this study provides the results of consolidation and hydraulic conductivity testing to evaluate the void ratio versus effective stress and hydraulic conductivity of MFT. The effects on the behavior and characteristics of MFT after amendment with usage of recycled SAP are also investigated.
The results indicate that SAP has the ability to significantly dewater, densify and increase the undrained shear strength of MFT. Furthermore, when subjected to freeze/thaw cycles, the MFT dewatered with SAP shows an additional increase in strength and solid content. It is also found to be possible to regenerate the polymer (still within sachets) through light thermal drying, and the regenerated SAP can still significantly dewater and thus increase the shear strength and solid content of the MFT. In addition, the obtained high solid content affects and improves the compressibility of the material, thus resulting in low initial void ratios. On the other hand, low hydraulic permeability that is derived from low initial void ratios and consolidation is improved by the freeze/thaw process due to the interconnected voids created during the freezing process.
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Westraad, Delme. "Suction induced shear strength of gold mine tailings." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-06102005-092115.
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Rohde, Michael D. "Recovery of silver from lead/zinc flotation tailings /." [St. Lucia, Qld], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18254.pdf.
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Van, der Merwe Josias Willem. "Dissolution of sphalerite minerals from Rosh Pinah tailings." Pretoria : [s.n.], 2003. http://upetd.up.ac.za/thesis/available/etd-04282005-124139.
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Zardari, Muhammad Auchar. "Stability of tailings dams : focus on numerical modelling." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18427.
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Upstream tailings dams may experience slope stability problems when the rate of raising is too fast. Tailings consolidate slowly due to low hydraulic conductivity. The excess pore pressures can build up due to accelerated rate of raising. The cumulative increase in excess pore pressures due to successive raisings can endanger slope stability of a tailings dam. The stability of a tailings dam is closely related to the consolidation process. The consolidation process and associated stability of an upstream tailings dam during staged construction was modelled with the finite element program PLAXIS. The analysis indicated that the stability of the dam reduced during raising due to increase of excess pore pressures. The safety of the dam was improved by adding rockfill banks on the downstream side. The volume of the rockfill banks was minimized with an optimization technique. This technique involves (i) construction of a rockfill bank on the downstream side when the factor of safety is less than a permissible limit, (ii) utilization of a minimum volume of the rockfill that is necessary to stabilize the slope. This technique can be practicable when the rate of raising is moderate, and partial consolidation occurs between consecutive raisings. Numerical analysis was also performed on a curved embankment of an upstream tailings dam in order to investigate the possible risk of hydraulic fracturing and internal erosion in a corner of the dam. The analysis showed that low compressive stresses occurred above the phreatic level, near the zones of filter and rockfill banks. These zones contain coarse material, and are, therefore, not susceptible to hydraulic fracturing and internal erosion. An increase in the radius of the corner is suggested in order to prevent large reductions in compressive stresses that may occur due to future raisings. Presently the curved dam section is stable. However, an additional rockfill bank on the downstream side will be required for future raisings. Static liquefaction is considered as a common cause of disastrous flow failures of tailings dams. These flow failures can be predicted with numerical modelling using suitable constitutive models. In this context, some constitutive models capable of simulating static liquefaction behaviour of loose saturated sands are reviewed. It is generally concluded that the finite element method can be a helpful tool for modelling stability of tailings dams.Godkänd; 2011; 20110404 (muhauc); LICENTIATSEMINARIUM Ämnesområde: Geoteknik/Soil Mechanics and Foundation Engineering Examinator: Professor Sven Knutsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Professor Anders Sellgren, Luleå tekniska universitet Tid: Fredag den 6 maj 2011 kl 10.00 Plats: F1031, Luleå tekniska universitet
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Durrant, Adrian Michael. "A computer-aided simulation of hydraulic tailings disposal." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/28025.
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Computer-aided tools appropriate to architecture, engineering and construction have been Summarised, including digital terrain modelling (DTM), computer-aided design and draughting (CADD) and database management systems (DBMS). DTM and CADD techniques have been applied to simulating the hydraulic filling of tailings, or mine waste dams. A relational DBMS was used to structure and manage filling and terrain data relevant to hydraulic tailings disposal at the Wheal Jane mine in Cornwall.
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Hamberg, Roger. "Characterization and solidification of arsenic-rich cyanided tailings." Licentiate thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17804.
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Information on the occurrence of As species and iron sulphide minerals in tailings is essential for predicting therelease of As over extended period of time. Tailings originating from a goldmine in northern Sweden with low content of trace elements except for As were used for this purpose. The dominating sulphides were pyrrhotite and arsenopyrite. The samples used in the study were post-cyanided, tailings slurries treated with Fe2(SO4)3 and H2O2 to form arsenates and Fe-hydrates for effective As-immobilization. Speciation of the As in ore and tailings samples revealed that mining processes have dissolved the majority of the arsenopyrite in the ore, causing secondary As phases to co-precipitate with newly formed Fe-hydrates. A minor part of the As retained in the tailings was assumed to be As (III)-species. Weathering cell tests (WCT) involving 32 weekly cycles of wetting and air exposure were conducted to assess the effect of weathering on the stability of As in the tailings. As-bearing Fe-hydrates remained intact during the early stages of the WCT; the low release of As during this period was probably due to the dissolution of solubleAs(III)-phases. During the later stages of the WCT, the release of As, Fe and S increased due to pyrrhotite oxidation and the destabilization of As-bearing Fe-hydrates. The majority of the originally present As was still associated with the tailings by the end of the test, but additional pyrrhotite oxidation with the pH falling to >3 could further destabilize these As-bearing Fe-hydrates. In the second part of the study,cyanided tailings were converted into a monolith by using a method called cemented paste backfill (CPB). Two mixtures of CPB were tested; CE with 1 wt. % of cement and CE-FA consisting 2 weight (wt.) % of cement together with 1 wt. % of biofuel fly ash. The stability of As in CPB-masses andun-amended tailings were evaluated using tank leaching tests (TLT) and WCT: s. TheTLT results showed that the CPB mixtures were not suitable for use inunderground backfilling because the As content of the CPB leachates increasedcontinuously over the course of the tests. The proportion of binders inCPB-materials is usually 3-7% because such loadings are required to create amonolithic mass that physically and chemically stabilizes arsenic species intailings. The addition of small quantities of binders in CE and CE-FA maytherefore have been insufficient to ensure that the monoliths were highly saturated, which is required to prevent the transport of oxygen and water through the CPB material. In the WCT, crushed CPB materials were used and the addition of binders caused only a minor increase in the leaching of As relative to that seen with unmodified tailings. The addition of binders has re-located a minor proportion of As in As-bearing Fe-hydrates into less acid-tolerant species. During the later stages of the WCTs, the CPB mixtures were treated with acid in order to consume the buffering minerals and simulate the formation of acid mine drainage (AMD). When acid was added to crushed CPB-materials, As-release increased due to the dissolution of Fe-hydrates. The addition of binders into tailings could pose more resistance to sulphide oxidation, which in turn means that the stability of As-bearing Fe-hydrates could be prolonged on long term. Results from the WCT suggested that the addition of low proportions of binders could have a positive effect on As-leaching in a long term perspective. A relatively new method called “Surfacepaste disposal” (SPD), where mixtures of low proportions of binders and tailings is placed as a cover on the un-amended tailings has shown promising results in terms of decreasing As-leaching and the generation of AMD. Future research will, therefore, focus on the stability of As in SPD-applications.Godkänd; 2014; 20141015 (rogham); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Roger Hamberg Ämne: Tillämpad geologi/Applied Geology Uppsats: Characterization and Solidification of Arsenic-rich Cyanided Tailings Examinator: Biträdande professor Lena Alakangas, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Fil. lic / Enhetschef Bergteknik Lena Sultan, Ramboll Sverige AB Tid: Torsdag den 4 december 2014 kl 13.00 Plats: E246, Luleå tekniska universitet
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Silva, Marvin Jose. "Plant dewatering and strengthening of mine waste tailings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0015/NQ46918.pdf.
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Steinert, Aaron. "Development of hardpans on Hypersaline Tailings Kalgoorlie, W.A. /." Adelaide, 1998. http://web4.library.adelaide.edu.au/theses/09SB/09sbs822.pdf.
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Nudo, Vince. "Scavenging iron ore tailings with the Reichert cone." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66257.
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Tompkins, David Stuart. "Sandy tin tailings in Malaysia : characterization and rehabilitation." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/2309.
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Cassiterite extraction in West Malaysia has left a legacy of some 80,000 hectares of nutrient-poor, drought-prone, quartz sandy tailings. Their proximity to urban centres has long made them a target for agricultural and forestry enterprises, and various techniques have been developed to overcome their intractability, including amendment with bulky organic matter and replacement with natural soils. Although reasonably successful, these approaches have often failed to acknowledge that a percentage of the original heavy mineral suite remains in sandy tailings, exerting possible phytotoxic effects and certainly raising concerns about the suitability of sandy tailings for agronomic crop production. To determine the nature and extent of trace element contamination of sandy tailings, ten different areas were identified and sampled in the states of Selangor and Perak. Preliminary analyses failed to corroborate earlier discoveries of elevated mercury and cadmium status, but lead, zinc, arsenic, uranium and rare earth elements were all common. However, greater concentrations of all these elements were found in clay (slime) tailings, which had been colonized by dense vegetation cover. This indicated that levels of trace elements in sandy tailings were not of themselves phytotoxic, but in the context of reduced nutrient availability, might exert a disproportionate influence on their colonization by plants. The colonization of sandy tailings by Melastoma malabathricum was therefore examined, revealing that in two of four sites, water contents were greater in colonized areas than the rest of each site. Macronutrient concentrations were also greater in colonized tailings, as were concentrations of zinc and manganese, but whether these were the cause or result of plant establishment could not be determined conclusively. Overall, trace element distribution in sandy tailings did not influence colonization by Melastoma, although in three of four populations, foliar concentrations of uranium were greater than those of a population growing on a natural soil. This has serious implications for the agronomic use of sandy tailings. The effects of bulky organic and clay amendment of sandy tailings on the availability and uptake of trace elements has never before been examined. A tropical greenhouse experiment was undertaken to examine the effects of peat and clay on the growth and trace element chemistry of Panicum miliaceum and Pueraria phaseoloides. The use of symbiotic mycorrhizal fungi was also included, since although these often improve the phosphorus nutrition of their hosts, they might also increase trace element uptake from pools sorbed by organic matter. Neither clay nor peat improved the growth of either plant species. However, addition of clay substantially increased the availability of aluminium and trace elements, and its use in rehabilitation attempts cannot be recommended. In contrast, peat reduced the availability of Co, Cu, As, La, Ce and U, whilst simultaneously improving the ECEC of sandy tailings. The effects of mycorrhizal inoculation were difficult to interpret, since the carrier medium used (predominantly zeolite) drastically altered the chemistry of soils to which it was added. Growth of Panicum and Pueraria was equally poor on two of three naturally sandy soils. Adding peat to sandy tailings produced plants with similar foliar chemistry to those grown on natural soils, suggesting that plant communities established on these natural siliceous media could act as models for the sustainable rehabilitation of anthropic mine tailings - something which has never before been suggested. A range of native species are recommended as having potential for further research into naturalistic rehabilitation.
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Ould-Hamou, Malek. "Beneficiation of Algerian phosphate tailings by electrostatic methods." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277859.
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Törnqvist, Sofie, and Amanda Lindquist. "Stability analysis on a planned Mexican tailings dam." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-275797.
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If mine waste materials are stored in dams, the dams are referred to as tailings dams. Tailings dam failures can lead to massive destruction in nearby areas because of the large amount of water and slurry tailings stored in the dams. Tailings dams are large constructions which therefore endure great stresses. If the stresses become higher than what the materials of the dam can tolerate there is a risk that the embankment will collapse. This master thesis is the result of a collaboration between Vattenfall, Elforsk, Uppsala University and Tsinghua University. The purpose has been to evaluate a design suggestion for a tailings dam located in Mexico, and this was done from a strain stress perspective which also included a seepage and displacement analysis. The results indicated that the maximum stresses that occurred in the dam were within the stability region for the fine tailings, but adjustments have to be made regarding the coarse tailings. These results also need to be supplemented with an additional earthquake simulation before a final evaluation can be made.
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Engels, Jonathan. "An expert management system for surface tailings storage." Thesis, University of Leeds, 2006. http://etheses.whiterose.ac.uk/4622/.
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This thesis outlines the general design, management and operating parameters that influence the safety and stability of a surface tailings storage facility. A critique of current tailings storage practices, research, regulations, guidelines and the day to day management principals of a storage facility are discussed. Weaknesses and recommendations are presented with a view to reducing the associated risk of surface tailings storage. In the past, the majority of tailings research has focused on the design components to reduce operational costs and the closure methods to establish the most suitable sustainable cover system. The day to day operations and the management strategies of an active tailings storage facility have been somewhat overlooked. Considering that the majority of tailings impoundment failures have been caused by poor operational management, a need for this research was identified. The fundamentals of tailings management are discussed as well as the necessity for training and competency testing of tailings related personnel. The goal of this research is to develop a systematic tailings management system that can be established at any mine site to enhance the consistency of day to day management, reduce risk and increase safety. Accompanying this thesis is an interactive online database that is designed to increase awareness of safe storage practices. This database compliments the managerial components of this thesis by ensuring that the tailings personnel are confident and can implement a tailings management system effectively. In summary, this research provides a novel approach to improving tailings management and provides an interactive training tool focused on increasing a user's ability, awareness and competency on a wide range of tailings storage scenarios. This online tool is supported by a thesis that identifies the fundamentals of today's tailings storage practices, as well as the challenges and managerial requirements to reduce operational risk.
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Adiansyah, Joni Safaar. "A life cycle assessment of mine tailings management." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/59656.
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This study of life cycle assessment and environmental valuation of mine tailings management combines rheology analysis, and computer simulations. Three strategies were assessed: thickened tailings, tailings paste, and filtered tailings. Technology improvement and renewable energy were introduced in order to improve the sustainability performance of the mine tailings methods investigated. Alternative Tailings Disposal methods with filter belt press and stack cell flotation together with renewable energy helped to reduce the environmental impact and costs associated with coal tailings disposal.
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Wortmann, Heid. "Sedimentation and desiccation of gold mines." Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-11052007-152710.
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Alshawmar, Fahad Abdulaziz. "Shaking Table Testing of Geotechnical Response of Densified Fine-Grained Soils to Cyclic Loadings: Application to Highly Densified Tailings." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/41892.
Full textAbstract:
Liquefaction is a major challenge in geotechnical engineering in which soil strength and stiffness are compromised due to earthquake activity. Understanding and predicting the behaviour and liquefaction susceptibility of soils under cyclic loading is a critical issue in civil engineering, mining and protective engineering. Numerous earthquake-induced ground failure events (e.g., substantial ground deformation, reduced bearing capacity) or liquefaction in natural fine-grained soils or manmade fine-grained soils (i.e., fine tailings) produced by mining activities have been observed and reported in the literature. Tailings are manmade soils that remain following the extraction of metals and minerals from mined ore in a mine processing plant. Traditionally, such tailings are stored in surface tailings impoundments at the mine’s surface. However, geotechnical and environmental risks and consequences related to conventional tailings impoundments have attracted the attention of the engineering community to develop novel methods of tailings disposal and management to minimize geotechnical and environmental risks. Thus, engineers have introduced and implemented innovative tailings technologies—thickened tailings and paste tailings—as cost-effective means for tailings management in mining operations. As both thickened tailings and paste tailings have lower water content and higher solid content than tailings in conventional impoundments, these tailings may be more resistant to liquefaction. However, it should be noted that the seismic or cyclic behaviour of these thickened and paste tailings, with and without heavy rainfall effects, are not fully understood. There is little technical information or data about the behaviour and liquefaction of thickened and paste tailings under seismic or cyclic loading conditions.
The objective of the present PhD research is to investigate the response of layered thickened and paste tailings deposits, with and without heavy rainfall effects, to cyclic loads by conducting shaking table tests. To simulate the field deposition of thickened and paste tailings, tailings were deposited in three thin layers in a flexible laminar shear box (FLSB) attached to the shaking table equipment. A sinusoidal seismic loading at a frequency of 1 Hz and peak horizontal acceleration of 0.13g was applied at the bottom of the layered tailings deposits. Acceleration, displacement and pore water pressure responses to the cyclic loading were monitored at the middle depth of each layer of the tailings deposits. Regarding the acceleration response of these thickened and paste tailings deposits (without the effect of heavy rainfall), there was no difference between the middle of the bottom and middle layers or at the base of the shaking table. However, the acceleration at the middle of the top layer differed from the acceleration at the base of the shaking table. Throughout shaking, the layered tailings deposits (with and without the effect of heavy rainfall) exhibited contraction and dilation responses. The excess pore water pressure ratios of the layered thickened tailings deposit that was not exposed to heavy rainfall prior to shaking were found to exceed 1.0 during shaking. However, for the layered paste tailings deposit that was not exposed to the effect of heavy rainfall prior to shaking, the excess pore water pressure ratios were found to be lower than 0.85 during shaking. This reveals that without the effect of heavy rainfall, the layered thickened tailings deposit was susceptible to liquefaction, whereas the layered paste tailings deposit was resistant to liquefaction during shaking. The excess pore water ratios of the layered thickened and the paste tailings deposits that were exposed to heavy rainfall prior to shaking were found to be lower than 0.8 during shaking. This reveals that with the effect of heavy rainfall, the layered thickened and paste tailings deposits were resistant to liquefaction during shaking. The results and findings of this PhD research thus provide valuable information for the implementation of tailings in earthquake-prone areas.
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Fernando, Kapila Chemical Sciences & Engineering Faculty of Engineering UNSW. "The treatment of cyanidation tailings using ion exchange resin." Awarded by:University of New South Wales. Chemical Sciences & Engineering, 2007. http://handle.unsw.edu.au/1959.4/40697.
Full textAbstract:
This thesis explores the behaviour of metal cyanide complexes under oxidative acid conditions in ion exchange systems, with the objective of developing an ion exchange based process for the treatment of gold cyanidation tailings. The novel cyanide detoxification process developed from this study employs strong base ion exchange resins to extract cyanide from tailings. Variations in the stability of cyanide complexes are exploited to concentrate, recover, or destroy cyanide species loaded on the resin, through the use of an oxidative acid eluent containing H2O2 and H2SO4. This eluent removes all base metal cyanide complexes from strong base resins, while regenerating the resin. The spent eluent, containing the base metals recovered from the tailings, can be used as a source of such base metals. Copper can be recovered separately from other base metals if necessary. Low levels of precious metals present in the tailings are accumulated on the resin as the ion exchange bed is cycled between loading and elution stages. They can be recovered economically, so as to offset the cost of the tailings detoxification. Cyanide is initially concentrated as an alkaline solution, which can be detoxified within the process or recovered for recycling. This process was successfully tested at pilot scale by treating approximately 14,000 m3 of cyanide contaminated tailings solution, over 14 loading/elution cycles on a standard strong base ion exchange resin bed. This treatment reduced the total cyanide concentration of the contaminated solution from approximately 50 mg/L to an average of 1.5 mg/L. The reagent cost was approximately ADD 0.50 per m3 of treated liquor. When the resin was repeatedly loaded with mixed metal cyanide species and eluted with the oxidative acid eluent, a gradual deterioration of the ion exchange resin performance was noted. The reduction of net operating capacity of the columns due to resin deterioration was in the order of 1-3% per loading/elution cycle. The oxidation of resin catalysed by copper, the precipitation of metal hexacyanoferrates on the resin and the oxidation of Au(CN)2- to Au(CN)4- were identified as possible factors giving rise to the reduction of resin loading capacity.