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

{"title":"In situ backfilll monitoring database","authors":"J. Oke, A. Hashemi","doi":"10.36487/acg_repo/2115_29","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_29","url":null,"abstract":"The history of backfilling underground mined-out voids dates back to the beginning of mining several centuries ago using rockfill. Currently, there are three major types of backfill: rock, hydraulic, and paste fill. When backfill is required to be exposed from mining beside or underneath, cement binder is added. Cemented hydraulic fill is the most commonly used backfill as it has existed for over 80 years. In the early 1960s, a series of field instrumentations were initiated by the US Bureau of Mines on hydraulic fill. These studies were conducted in order to better understand the characteristics of hydraulic backfill. \u0000Cemented paste backfill (CPB) has gained wider acceptance in the mining industry and the number of operations utilising CPB has expanded significantly. One of the earliest attempts at field measurement in CPB occurred over 20 years ago. Since then, extensive scientific research has been conducted on CPB material in order to provide mines with a rational design process; however, there has been limited published instrumentation programs. The authors’ affiliated company has been involved with in-stope backfill instrumentation programs at numerous operations. Because of the data collection and field experience, the authors have a better understanding of how in situ backfill behaves, and how operations can use this information to safely improve the efficiency of their backfilling operation. In order to improve the safety and efficiencies of backfilling for other mines and other practitioners, a collection of published data along with additional case studies are provided. This paper summarises both hydraulic and CPB instrumentation results focusing on the important mechanical properties of backfill: time to onset of effective stresses and hydrostatic loading (i.e. fluid backfill to soil‐like material), influences of flushes, thermal expansion and contraction, and influences of seismic and blast events.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133314448","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":"Lessons learned from thickening and filtering tailings for dry stacking","authors":"D. Connelly","doi":"10.36487/acg_repo/2115_04","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_04","url":null,"abstract":"The metallurgical testwork for a new gold project indicated acceptable settling rates and filtration rates. The equipment was sized, and the plant constructed. Subsequently, commissioning of the thickening and filtration for dry stacking of tailings indicated serious deficiencies with the design and a much lower achievable throughput. The throughput was some 30% of design and cash flow considerations were that the project throughput was restricted by poor performance of the thickeners and tailings filtration acting as a bottleneck. \u0000Mineral Engineering Technical Services Pty Ltd was commissioned with the task of increasing filtration throughput and removing the bottleneck. \u0000For the thickeners, new flocculants were evaluated, changes to the flocculant dilution were made, and thickener underflow pump speeds were increased. An additional filter feed storage tank was installed to allow for short-term filter shutdowns. \u0000With the two belt filters, various flocculants, guar and diatomaceous earth were evaluated. Also, more permeable filter cloths were evaluated in order to increase filtration rates. The single biggest improvement achieved was with the use of coagulants. \u0000This paper describes how the task was managed and what steps were taken to achieve design throughput.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"2012 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128008616","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":"Dam break analysis for BRDA 5 at Worsley Alumina Refinery","authors":"G. McPhail, Peter DiDonna, Roxana Ugaz Palomino","doi":"10.36487/acg_repo/2115_16","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_16","url":null,"abstract":"South32 Worsley Alumina Pty Ltd operates several bauxite residue storage facilities at their refinery in Western Australia. The bauxite residue slurry is thickened and pumped onto the storage facilities which are constructed on an upstream basis using compacted earthfill embankments. BRDA 5 is the newest of the residue storage facilities, established in 1999, and has a current maximum height of embankment slope of 42 m, of which a compacted earthfill starter embankment makes up the first 22 m. Since 2010, the residue has been treated after deposition using amphirols, which assist in dewatering and compacting the residue. As part of their residue management commitments, Worsley undertook a dam break analysis entailing a review of all available geotechnical testing data, a fault-event analysis to evaluate the probability of removal of support to the residue through slope instability, overtopping, geotechnical piping or failure of a buried structure leading to liquefaction of the residue and a dam break. To model the flow of the liquefied residue, pilot-scale dam break testing was carried out from which estimates of the rheology of the residue were made. The rheology has been incorporated into a flow slide model that applies stream power entropy theory to define the energy changes due to viscous effects and frictional resistance. Benchmarking of the results against modelling using computational fluid dynamics has been made. This paper presents an overview of the dam break assessment process and results that covers a liquefaction potential assessment, a semi-quantified risk assessment based on a fault-event analysis approach, rheological testing of liquefied consolidated residue in a specially developed box rheometer and probabilistic modelling of the dam break, the outflow hydrograph, and the flow inundation areas. It is concluded that incorporation of rheology representative of liquefied consolidated residue in dam break modelling results in significantly reduced prediction of inundation area.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"195 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115483745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailings storage facility surface moisture mapping for prediction of dusting events – and other benefits","authors":"James Thompson, L. McDonald, Joshua Kelcey, J. Dixon","doi":"10.36487/acg_repo/2115_25","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_25","url":null,"abstract":"The fine-grained nature of some tailings materials can lead to dusting on tailings storage facilities (TSFs). Dusting has the potential to negatively affect the health of workers, nearby communities, and the surrounding environment which may adversely affect a mining operator’s ability to operate. Mitigation measures to prevent dusting can be expensive and aren’t always successful. Advances in monitoring systems allow the relative surface moisture of tailings beaches to be monitored during operations providing the opportunity to identify and forward plan the depositional strategy to minimise the risk of dusting. This paper presents the outcomes of a study that utilised predictive methods based on advanced synthetic aperture radar and multispectral data coupled with Google Earth Engine to develop a model for particular TSFs based on historical records, observations, and material types. \u0000Google Earth Engine brings the first opportunity to use a systematic and comprehensive combination of radar and visual-infrared satellite data. It was found that the synergy between the two data types could be used to offset the individual ambiguities of each, and the resulting method delivered a predictive dryness probability map and visual moisture/water depth/presence indicators that were able to be verified and made operational almost immediately. \u0000On-ground visual records and aerial imagery provided qualitative verification of the approach. The methodology allows TSF operators a free, open source platform with which to monitor and map surface moisture, enabling proactive deposition decision-making to mitigate the risk of tailings dusting. Additional benefits realised include increased data on beach formation, channel and pond location (extent and to some degree depth), improving the accuracy of the TSF water balance. For the particular TSFs studied, the water balance is a critical control from a safety perspective to mitigate potential failure mechanisms, and from an operational perspective to maximise tailings density and water return to the plant.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131752539","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":"Safety and efficiency benefits from using automated backfill diverter valves on Kirkland Lake Gold Fosterville mine’s paste reticulation systems","authors":"R. Evans, Gary Trinker, M. Carrière","doi":"10.36487/acg_repo/2115_22","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_22","url":null,"abstract":"As backfill systems become a more common method for managing tailings and enhancing ore recovery, safe and efficient methods for handling the backfill are adding value for mine owners. At Kirkland Lake Gold Fosterville mine (Victoria, Australia), automated diverter valves were installed at distribution switching points to direct paste to the intended stopes. The valves are operated remotely from a control room, removing the human element at the transition point during diversion. The other option for making changes in paste distribution is a manual operation where long sweep elbows are disconnected from the piping network and reconnected to a different downstream pipe. This process is tedious and time consuming, requiring many man hours and equipment that is not always readily available, resulting in much down time. \u0000This paper will discuss how using automated diverter valve operation in place of manual diversion of the paste at Kirkland Lake Gold’s reticulation system delivered dramatic uptime and minimised physical safety risks. Safety benefits not only eliminated the manual movement of piping components but include localised lockout access, safe evacuation of paste from upstream borehole (and piping) resulting from downstream blockage and diversion of flush water to a suitable collection area.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125105325","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":"Pulsation reduction system for positive displacement pumps","authors":"Tony Hendriks, Roman Jansen","doi":"10.36487/acg_repo/2115_23","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_23","url":null,"abstract":"Positive displacement pumps are a crucial part of the entire process of a tailings and storage facility. Any pump downtime or unplanned maintenance directly affects the productivity. Therefore, increasing the reliability of the piston diaphragm pumps leads to a more stable process. \u0000When operating piston diaphragm pumps, the oscillating movement of the pump pistons results in asymmetrical flows, both in the suction side and at the discharge side of the pump. These asymmetrical flow rates lead to pressure pulsations and to vibrations in the pump itself and the adjacent piping system, having a negative impact on the pump operation. In the suction side of the pump, these pulsations can cause cavitation that reduces the pump reliability and poses a risk for damages, not only for the pump, but also for the entire system. \u0000The paper will present a new pulsation reduction system (PRS) invented by MHWirth. This PRS is— in contrast to conventional pulsation dampers—suitable to eliminate high-frequency pulsation of reciprocating diaphragm pumps. \u0000Brief description of functionality: \u0000The new damper is connected to the propelling fluid chamber of the diaphragms. The propelling fluid, a hydraulic oil, is used as a damping medium, converting the pulsation energy described above into heat by throttle effects. This effect is similar to a shock absorber. \u0000The paper will also explain the PRS effects, present operational data from field application and address the following benefits by using it in a tailings and storage facility:","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127018729","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":"Assessing oil sands tailings consolidation using a modified benchtop filter press","authors":"Taimur A. Qureshi, Yunhui Li, A. Sedgwick, H. Kaminsky, Jason K. Ng","doi":"10.36487/acg_repo/2115_05","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_05","url":null,"abstract":"Open pit surface mining generates process effluents known as tailings. These mixtures accumulate in large impoundment structures typically termed as tailings ponds, which serve as storage structures where water from the tailings is separated and recycled back into the process. With the continuous accumulation of material in tailings ponds, and to comply with reclamation and water-use regulations, the industry is constantly seeking new technologies that can accelerate the tailings consolidation and dewatering process. Preliminary tools and techniques to screen potential consolidation technologies are valuable to quickly understand the effectiveness of the technology on the bench-scale before larger-scale testing. At present, settling tests have been the ideal medium for bench-scale study, however, this process can be time-intensive. This study compares a potential tool for short-term testing of consolidation, a benchtop filter press, with a standard settling test. The benchtop filter press is commonly used for the generation of specific resistance to filtration (SRF) data, however, the application for use in understanding consolidation is not. In this study, a benchtop filter press was modified to remove the limitation on the dewatering time due to the filter cake cracking, thus allowing dewatering past the liquid limit of the material. Two types of synthetic tailings were developed using a kaolinite and bentonite mix in synthetic process water, with varying solids content, methylene blue indices (MBI) and water chemistries, to mimic the conditions in actual mining samples. \u0000The study shows that the modified benchtop filter press results produce similar trends to settling tests and perform as expected with and without polymer addition. The modified benchtop filter press provides data in a course of hours to days, as compared to the settling test data that can take weeks to months to generate. Additionally, work conducted with oil sands fluid fine tailings (FFT) after various treatments, demonstrates that SRF curves from actual mining samples show trends in dewatering time consistent with observed field performance.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122278942","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":"Some considerations when preparing thickened tailings for shear strength testing in the laboratory from a slurry","authors":"D. Reid, R. Fanni, Andries Fourie","doi":"10.36487/acg_repo/2115_17","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_17","url":null,"abstract":"Preparation of tailings in the laboratory to simulate the likely range of densities and resulting behaviour that will occur under load in situ is challenging. A number of issues of relevance include whether effects such as subaqueous deposition can be reproduced at all in the laboratory, and the potential importance of in situ layering of segregating tailings. These issues may have (thus far, largely unquantified) effects on mechanical behaviour in ways that are difficult to predict with element tests that are usually intentionally prepared homogeneously. Thickened tailings testing is conceptually easier, as issues such as segregation and the potential for subaqueous deposition are often not relevant. Despite this relative simplicity, a number of important considerations remain. While it is trivial to pour a thickened slurry into various forms of moulds or vessels to prepare for element testing, questions remain over whether the density that is reproduced will be relevant to in situ conditions. In particular, preparation of triaxial samples from thick slurries is particularly challenging as a number of steps are required to enable such samples to be ‘free-standing’, with each one of these steps potentially leading to slight disturbance and thus densification of the sample. Where such densification occurs, it would result in the element test results being non-conservative. This could have important implications with respect to expectations of the contractive (and potentially liquefiable) or dilative response of the tailings in situ. \u0000To investigate these issues, a series of slurry-deposited triaxial tests was carried out using a non-segregating slurry. As test methods were refined during the program, the amount of disturbance applied to the specimen was reduced. However, comparison of the triaxial tests to slurry consolidometer tests indicated that, regardless of efforts made, the triaxial tests achieved denser states at a given amount of consolidation stress. This was found to be the case using any conceivable range of assumed geostatic stress ratio to interpret the slurry consolidometer results. This outcome is speculated to be a result of the quiescent conditions used in the preparation of a slurry consolidometer specimen, which only requires pouring and then application of vertical load, first using weights, then a load frame. The implications of the increased density seen in triaxial tests compared to the likely more realistic value seen from the slurry consolidometer are discussed. Alternative preparation methods to target this looser density range are briefly discussed.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131976278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The development and practice of new quick-setting filling materials prepared by total industrial wastes","authors":"Aixiang Wu, Guanzhao Jiang, Yi-ming Wang, Z. Ruan","doi":"10.36487/acg_repo/2115_32","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_32","url":null,"abstract":"Traditional paste filling materials adopt industrial solid wastes such as unclassified tailings and waste rocks as filling aggregates, but the binder used is dominantly commercial cement, which raises the filling cost. Hemihydrate phosphogypsum (HPG) is one of the main by-products of the phosphorus chemical industry, and the high-efficiency utilisation technology of HPG has been a problem worldwide. The potential gelling property of HPG is found in the laboratory at first. It is then modified by appropriate chemical and physical methods to produce new filling binder with the purpose of replacing cement completely. A lot of experiments show that the modified HPG (MHPG) has outstanding properties of quick setting (setting time less than 90 minutes), high early strength (UCS for three days more than 8 MPa) and good flowability (yield stress less than 50 Pa). In addition, MHPG can bind different aggregates according to the filling needs to prepare a homogeneous, non-settling, and non-bleeding filling paste. In the past three years, two mines in Guizhou, China have adopted the underground paste backfill technology and surface open pit cemented filling technology based on MHPG paste materials. In practice, this new technology reduces the material cost by 30%, increases the flow capacity by 50%, and has a solid wastes rate of more than 98% compared to traditional methods.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117095546","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":"A comparison of cemented paste backfill shotcrete barricade design methods","authors":"R. Veenstra, Xu Zhao, Andries Fourie, J. Grobler","doi":"10.36487/acg_repo/2115_33","DOIUrl":"https://doi.org/10.36487/acg_repo/2115_33","url":null,"abstract":"The use of cemented paste backfill (CPB) is becoming increasingly more common at underground mines worldwide. Part of any CPB design includes the specification of the (typically) shotcrete barricades that retain the CPB within the stope during filling. Newmont’s Tanami Operations (NTO) has started an in situ barricade stress monitoring program. The data from this program will provide a basis for comparison of several models that can be used to model the capacity of these barricades. These models vary in complexity from analytical solutions to 3D numerical models. Part of the comparison will include a discussion detailing the required material inputs and how these inputs were obtained. Analysis of this comparison will provide additional understanding on what parameters affect the ultimate capacity of a shotcrete barricade.","PeriodicalId":410057,"journal":{"name":"Paste 2021: 24th International Conference on Paste, Thickened and Filtered Tailings","volume":"226 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121350071","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}