Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings最新文献

{"title":"Thickened tailings loop test to corroborate the hydraulic Hanks model and Buckingham equation","authors":"L. Vilela, Daniele Pinto, Gabriel Ramos de Oliveira","doi":"10.36487/acg_repo/2115_12","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_12","url":null,"abstract":"","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128037690","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":"Optimisation of backfill operations at Mavres Petres mine","authors":"Evangelos Palatos, M. Yumlu","doi":"10.36487/acg_repo/2115_27","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_27","url":null,"abstract":"Mavres Petres mine is an underground mine, located in Chalkidiki, northern Greece, that is owned and operated by Hellas Gold; a wholly owned subsidiary of Eldorado Gold Corporation. The mine extracts a high-grade lead and zinc orebody using drift and fill mining method. Backfill is an integral part of mining cycle at Mavres Petres mine. Filtered coarse tailings mixed with cement are used for making cemented hydraulic backfill in a surface batching plant. The paper will discuss and present an overview of the backfill optimisation efforts at Mavres Petres mine, which includes recent changes and upgrades in the backfill plant, improved mix design, backfill quality control, and backfill delivery and placement in order to improve the operational efficiency, product consistency, safety and economic viability of the mine.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127603537","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":"Achieving the design intent, reducing risk and saving costs of tailings storage facilities","authors":"Jarrad Coffey, John Plunkett, Alpesh Patel, Josh Oliver, M. Gunner, A. Carneiro","doi":"10.36487/acg_repo/2115_01","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_01","url":null,"abstract":"The mining industry continuously strives to increase the effectiveness of tailings management practices to minimise impacts on people and the environment. A commonly stated objective of operations is to achieve the design intent, but is this clearly communicated by designers and understood by stakeholders? Planning, operating, monitoring and closing a tailings storage facility (TSF) can present many challenges, especially in dynamic mining environments where site conditions vary spatially and with time. However, big impacts can be made at relatively small cost once the tailings management system, design and performance are well defined and understood. This paper presents various examples of initiatives aimed at achieving the design intent that have been adopted by Rio Tinto Iron Ore, which also reduce risks and improve tailings management performance. Examples presented include development and communication of short-term, long-term and life-of-facility deposition plans, implementation of simple deposition management tools, monitoring and managing slurry density, development and continual oversight of water balance models, and sound investment in water management infrastructure extending to safe performance in emergency situations. Regular governance was also implemented to provide assurance that these controls remain effective. These improvements also provide a financial benefit in the form of deferred capital expenditure due to the achievement of greater in situ densities of tailings deposits; a fortuitous by-product of following the principles within the Global Industry Standard on Tailings Management (GISTM) (Global Tailings Review 2020) and other industry guidance documents. As such, this paper aims to illustrate the benefits of continually improving tailings management practices with a focus on simple and in some cases novel approaches.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124626898","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":"Thickener feedwell internal trough slurry distribution method","authors":"S. Viduka, B. Henriksson","doi":"10.36487/acg_repo/2115_07","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_07","url":null,"abstract":"This paper presents a numerical and experimental investigation of an innovation in thickener feedwell technology. A feedwell plays a leading role in the robust operation of a thickener. Its multifunctional duties include slurry feed momentum dissipation, solids and liquor mass fraction preparation, flocculation, and symmetrical aggregate delivery to the tank. The testing of new concepts in the pursuit of developing a next generation feedwell presented an opportunity to create an improvement in process performance. An alternative method of using a feedwell trough, populated by a multitude of vertically directed nozzles, is adopted. These deliver slurry into a flocculation chamber before dispersing through an exit gap into the thickener tank. The trough most innovatively ensures flash mixing, and highly uniform solids dispersion inside the aggregate growth chamber. Initial examination adopted a multiphase Eulerian mathematical model to explore geometric configurations under various process scenarios. Numerical modelling indicated that when quantitatively compared to an equivalently sized diluting Vane Feedwell TM the design provides a large improvement in solids hold-up, mixing, exit distribution, and more. Modelling advanced to onsite testing of a non-diluting small 2 m diameter prototype in an industrial mineral processing plant. The retrofitted feed system improved thickener performance when compared to the pre-existing feedwell and at a newly higher throughput duty. The first occurrence of a networked bed was observed, underflow densities improved by 6.5% w/w, flocculant consumption reduced by 5%, and overflow clarity largely improved. Underpinned by this positive result, modelling has shown even greater benefits may be found in application of the new technology to self-diluting feedwells.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116465356","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":"Strain localisation behaviour of cemented paste backfill","authors":"Yue Zhao, Li Jie Guo, A. Taheri, Murat Karakuş, A. Deng","doi":"10.36487/acg_repo/2115_30","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_30","url":null,"abstract":"Mine tailings are the most significant and most problematic sources of solid waste globally in the mining industry. The developing concept of sustainable mining warrants reusing mine wastes, particularly tailings. Cemented paste backfill (CPB) is a backfill method composed of dewatered tailings, a cementitious binder, and processed mine water. CPB reuses tailings in underground mine excavations, and as such, reduces the amount of surface-disposed tailings, mitigates the potential environmental impacts, and assists waste management. In this study, the strain localisation behaviour of a South Australian copper–gold underground mine CPB system was evaluated through a comprehensive experimental programme. Understanding the strain localisation behaviour helps evaluate CPB damage evolution and failure mechanism under real-life loading regimes. The three-dimensional digital image correlation (DIC) technique was used to measure the full-field of strain development on the surface of CPB samples during unconfined compressive strength (UCS) tests. With the use of several virtual extensometers, the axial and lateral strains of CPB samples, with and without strain localisation, in both pre-peak and post-peak regimes are characterised. Overall, the DIC technique provides more accurate stress–strain relations of CPB samples than conventional external measurement devices. The DIC test results indicate that strain localisation of CPB samples initiates in the pre-peak regime at around 80% of the UCS. The greater the binder content and the longer the curing time, the higher the axial stress level required to initiate localisation to the UCS, thus emulating the failure mechanism of quasi-brittle materials – rock and concrete. Finally, with the increase of curing time, the difference between strain values at the localised and non-localised zones became less significant in the pre-peak regime and more pronounced in the post-peak regime.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116952628","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":"Revaluing paste and thickened tailings for large tonnage applications","authors":"A. Vietti","doi":"10.36487/acg_repo/2115_20","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_20","url":null,"abstract":"A decade ago, paste and thickened tailings (P&TT) disposal was regarded as a potential technology for eliminating so-called wet tailings dams. Despite numerous very successful examples of both surface and backfill applications, by 2015, confidence in the technology had waned after the technical difficulties encountered at two high-profile, large tonnage copper tailings projects in South America. The recent spate of deadly tailings dam disasters has refocused public and private sector attention on conventional tailings disposal. The knee-jerk reaction from the mining industry has been to ignore P&TT and focus on dry stacking as the solution to the problem, which itself is still a relatively immature technology for large tonnages. This paper attempts to explain the apparent lack of recognition that P&TT as a legitimate and safe tailings disposal method has received. A chronological review of P&TT technology implementation and possible reasons for its loss of favour, particularly in large tonnage applications, is provided.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115592152","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":"Numerical modelling of dry stacking tailings heaps","authors":"G. Vizcarra","doi":"10.36487/acg_repo/2115_19","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_19","url":null,"abstract":"In the practice of geotechnical engineering applied to mining, dry stacked tailings heap projects are analysed by limit equilibrium methods and stress-strain analyses. These methods and model assumptions do not consider the influence of the partially drained conditions, strain softening, and transition from over-consolidated to normally consolidated behaviour of the foundation. This situation can lead to calculations of deterministic safety factors that are often overestimated, according to the nature of the foundation. This article proposes a methodology for numerical modelling of the foundation during staged construction of a heap, and considers loading time as a critical variable in calculating the Factor of Safety of the heap dry stacked of elaborating a numerical model considering the foundation and construction. The physical and geotechnical properties of the materials were derived through the model, and are the interpretation of data obtained from a geotechnical investigation and laboratory testing campaign. Stress-strain analyses are performed for different stacking speed scenarios to assess its influence on the safety factor at each loading stage. The analyses are coupled, where the distribution of stresses and deformations within the foundation and the dissipation of porewater pressures over time are simulated. The results show the evolution of the Factor of Safety, the spatial distribution of the regions with excess porewater pressure, allowing the optimisation of both the rate of rise of the dry stack and external batter slope for the project to minimise ground improvement. It is observed that there is a strong dependence of the coefficient of permeability of the foundation soils on the porewater pressure dissipation time. Numerical modelling considering partially drained conditions allows greater understanding of foundation behaviour and performance during the development of the dry stacked heap. The analysis is considered applicable to both soft soil foundation conditions and conversion of existing wet disposal tailings facilities to dry stacking atop, referred to as ‘piggybacking’ within the mining industry.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114889745","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}