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Integrating geometallurgical ball mill throughput predictions into short-term stochastic production scheduling in mining complexes

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International Journal of Mining Science and Technology 2023年第2期33卷 185-199页

作者： Christian Both Roussos Dimitrakopoulos COSMO–Stochastic Mine Planning Laboratory Department of Mining and Materials EngineeringMcGill UniversityMontreal H3A 0E8Canada

This article presents a novel approach to integrate a throughput prediction model for the ball mill into short-term stochastic production scheduling in mining *** datasets for the throughput prediction model include penetration rates from blast hole drilling(measurement while drilling),geological domains,material types,rock density,and throughput rates of the operating mill,offering an accessible and cost-effective method compared to other geometallurgical ***,the comminution behavior of the orebody was geostatistically simulated by building additive hardness proportions from penetration rates.A regression model was constructed to predict throughput rates as a function of blended rock properties,which are informed by a material tracking approach in the mining ***,the throughput prediction model was integrated into a stochastic optimization model for short-term production *** way,common shortfalls of existing geometallurgical throughput prediction models,that typically ignore the non-additive nature of hardness and are not designed to interact with mine production scheduling,are overcome.A case study at the Tropicana Mining Complex shows that throughput can be predicted with an error less than 30 t/h and a correlation coefficient of up to *** integrating the prediction model and new stochastic components into optimization,the production schedule achieves weekly planned production reliably because scheduled materials match with the predicted performance of the *** to optimization using conventional mill tonnage constraints reveal that expected production shortfalls of up to 7%per period can be mitigated this way.

关键词： Geometallurgy Stochastic optimization Short-term open pit mine production scheduling Measurement while drilling Non-additivity Hardness

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Effect of some operational variables on bubble size in a pilot-scale mechanical flotation machine

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Journal of Central South University 2014年第3期21卷 1077-1084页

作者：张炜 J.E.Nesset J.A.Finch Mining and Mineral Resources Division Department of Business AdministrationChinalco China Copper Corporation Limited Department of Mining and Materials Engineering McGill University

This work aims to provide a relationship of how the key operational variables of frother type and impeller speed affect the size of bubble （D32）. The study was performed using pilot-scale equipment （0.8 m^3） that is up to two orders of magnitude larger than equipment used for studies performed to date by others, and incorporated the key process variables of frother type and impeller speed. The results show that each frother family exhibits a unique CCC95-HLB relationship dependent on n （number of C-atoms in alkyl group） and m （number of propylene oxide group）. Empirical models were developed to predict CCC95 from HLB associated with other two parameters a and ft. The impeller speed-bubble size tests show that D32 is unaffected by increased impeller tip speed across the range of 4.6 to 9.2 m/s （representing the industrial operating range）, although D32 starts to increase below 4.6 m/s. The finding is valid for both coalescing and non-coalescing conditions. The results suggest that the bubble size and bubble size distribution （BSD） being created do not change with increasing impeller speed in the quiescent zone of the flotation.

关键词： flotation bubble size operational variables critical coalescence concentration hydrophile-lipophile balance impellerspeed

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Bubble size as a function of some situational variables in mechanical flotation machines

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Journal of Central South University 2014年第2期21卷 720-727页

作者：张炜 Jan E.Nesset James A.Finch Mining and Mineral Resources Division Department of Business AdministrationChinalco China Copper Corporation Limited Department of Mining and Materials Engineering McGill University

The specific results of the work investigating the effect of gas density and water temperature on bubble size were *** were surrogate variables designed to investigate the effect of viscosity(varying water temperature) and altitude(varying gas density).The results show that there is a measurable but relatively small effect of gas density on bubble *** D32 is revealed to increase proportionally as(ρ0/ρg)*** projected impact on flotation kinetics at 4500 m versus sea level is small,of the order of 0.5% recovery loss for a bank of eight flotation *** effect of water temperature(4-40 °C) on bubble size is more significant than gas *** relationship correlates with water viscosity values quite closely.A finding that D32 increases proportionally as(μ/μ20)0.776 highlights the importance of accounting for viscosity effects if,for example,large process temperature fluctuations or deviation from design/test conditions are expected.

关键词： flotation frother bubble size viscosity altitude

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Emerging and re-emerging human infectious diseases:A systematic review of the role of wild animals with a focus on public health impact

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Asian Pacific Journal of Tropical Medicine 2020年第3期13卷 99-106页

作者： Marli C Cupertino Michely B Resende Nicholas AJ Mayers Lorendane M Carvalho Rodrigo Siqueira-Batista Medical School Faculdade Dinamica do Vale do Piranga.Ponte Nova.Minas GeraisBrazil Laboratory of Epidemiological and Computational Methods in Health Department of Medicine and NursingUniversidade Federal de Vicosa.Minas GeraisBrazil Department of Veterinary Medicine Universidade Federal de Vicosa.Vicosa.Minas GeraisBrazil

Infectious diseases continue to impose unpredictable burdens on global health and economies, a subject that requires constant research and updates. In this sense, the objective of the present article was to review studies on the role of wild animals as reservoirs and/or dispersers of etiological agents of human infectious diseases in order to compile data on the main wild animals and etiological agents involved in zoonotic outbreaks. A systematic review was carried out using PRISMA guidelines, using the PubMed, Scopus and SciELO platforms as data banks. The descriptors used were "zoonosis", "human infectious diseases" and "wild animals". The results show that wild animals(mainly bats, birds and primates) play an important role in the dissemination of etiological agents(mainly viruses, as a new coronavirus called 2019 Novel Coronavirus) in extensive geographic regions. Moreover, these wild animal organisms can act as the site for essential biotic synergy among several pathogenic microorganisms, promoting a higher rate of adaptation, mutation and even genetic recombination, with consequent stimulation of new strains and subtypes, inducing new infectious agents with unknown virulent potential. In conclusion, the monitoring of these diseases and adequate preparation for possible epidemics and pandemics are fundamental conditions for the mitigation of their future impact. The zoonotic threat of these etiological agents and the impact on public health can be enormous as shown by the ongoing epidemic of 2019 novel coronavirus(2019-nCoV) infections.

关键词： Zoonosis Epidemics 2019-nCoV Virology Epidemiology

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Effect of solids on pulp and froth properties in flotation

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Journal of Central South University 2014年第4期21卷 1461-1469页

作者：张炜 James A.Finch Mining & Mineral Resources Division Department of Business Administration Chinalco China Copper Corporation Limited Department of Mining and Materials Engineering McGill University

Froth flotation is a widely used process of particle separation exploiting differences in surface properties. It is important to point out that overall flotation performance(grade and recovery) is a consequence of the quality and quantity of the solid particles collected from the pulp phase, transported into the froth phase, and surviving as bubble-particle aggregates into the overflow. This work will focus on studying these phenomena and will incorporate the effects of particle hydrophobicities in the 3-phase system. Solids are classed as either hydrophilic non-sulphide gangue(e.g. silica, talc), hydrophilic sulphide(e.g. pyrite), or hydrophobic sulphide(e.g. sphalerite). Talc is a surface-active species of gangue that has been shown to behave differently from silica(frother adsorbs on the surface of talc particles). Both are common components of ores and will be studied in detail. The focus of this work is to investigate the role of solids on pulp hydrodynamics, froth bubble coalescence intensity, water overflow rate with solids present, and in particular, the interactions between solids, frother and gas on the gas dispersion parameters. The results show that in the pulp zone there is no effect of solids on bubble size and gas holdup; in the froth zone, although hydrophilic particles solely do not effect on the water overflow rate, hydrophobic particles produce higher intensity of rates on water overflow and bubble coalescence, and many be attributed to the water reattachment.

关键词： flotation frothers bubble size coalescence gas holdup hydrophobicity

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Natural enemies depend on remnant habitat size in agricultural landscapes

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Journal of Forestry Research 2015年第2期26卷 469-477页

作者： Mainara Xavier Jordani erica Hasui Vinicius Xavier da Silva Laboratorio de Ecologia Animal Departamento de Zoologia e BotanicaUniversidade Estadual Paulista-UNESPRua Cristovao Colombo2265Jardim NazarethSao Jose Do Rio PretoSP CEP 15054-000Brazil Laboratorio de Ecologia de Fragmentos do Sul de Minas Gerais-ECOFRAG Instituto Ciencias da NaturezaUniversidade Federal de Alfenas-UNIFAL–MGRua Gabriel Monteiro da Silva700CentroAlfenasMG CEP 37130-000Brazil

In recent decades,the consequences of habitat fragmentation have been of growing concern,because it is particularly important to understand how fragmentation may affect biodiversity,an ecological *** tested two hypotheses：（1） that natural fragment size in agricultural landscapes indirectly affects the herbivore through effects on natural predator populations;and（2） predator activity into the crop reduces along the distance from the natural fragment *** 2008 and 2009,we conducted our study in seven forest remnants and in surrounding coffee plantations（fragments ranged from 6 to 105 ha,mean 49.28 ± 36.60 ha） in Southern Minas Gerais,*** were sampled by point counts,and insect predation was evaluated by using an artificial insect model（Koh and Menge 2006）.Our results suggest that although there were many potential predators（e.g.,wasps,ants,birds,and mammals）,birds were the most important taxon *** covariance analysis supported the hypothesis that patch size affected the number of larvae predation by overall taxi,but there was no support for a distance *** findings suggest that natural enemies’ ecological service（mainly from birds） declined with remnant reduction,which has implications not only for human welfare,but also in strengthening the economic justifications for conserving the remaining natural habitats and biodiversity in agricultural landscapes.

关键词： Ecosystem service Fragmentation Isolation Insectivore Predation

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A novel approach to prevent bubble coalescence during measurement of bubble size in flotation

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Journal of Central South University 2014年第1期21卷 338-343页

Effect of frothers in preventing bubble coalescence during flotation of minerals has long been *** evaluate the performance of a frother,an apparatus to measure the bubble size is a basic *** Bubble Size Analyzer(MBSA) or bubble viewer that has been developed and completed by McGill University's Mineral Processing Group during the last decade is a unique instrument to serve this *** parameters which are thought to influence the bubble size measurements by McGill bubble viewer include water quality and frother concentration in the *** show that there is no difference in Sauter mean(D32) when tap or de-ionized water was used instead of process ***,the frother concentration,in this research DowFroth 250(DF250),inside the chamber exhibited a pronounced effect on bubble *** concentration below a certain point can not prevent coalescence inside the chamber and therefore caution must be taken in plant *** was also noted that the frother concentration which has been so far practiced in plant measurements(CCC75-CCC95) is high enough to prevent coalescence with the bubble viewer.

关键词： flotation frother bubble size bubble coalescence

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Morphological and molecular diversity of arbuscular mycorrhizal fungi in revegetated iron-mining site has the same magnitude of adjacent pristine ecosystems

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Journal of Environmental Sciences 2018年第5期30卷 330-343页

作者： Caroline Krug Vieira Matheus Nicoletti Marascalchi Arthur Vinicius Rodrigues Rafael Dutra de Armas Sidney Luiz Stürmer Universidade Regional de Blumenau(FURB) Programa de Pos-Graduacao em Engenharia Ambiental89030-903 BlumenauSCBrazil Universidade Regional de Blumenau(FURB) Departamento de Ciencias Naturais(DCN)89030-903 BlumenauSCBrazil Uniuersidade Regional de Blumenau(FURB) Programaa de Pos-Graduacao em Engenharia Florestal89030-903 BlumenauSCBrazil Centro Universitario-Catolica de Santa Catarina 89203-005 JoinvilleSCBrazil

Arbuscular mycorrhizal fungi（AMF） are important during revegetation of mining sites, but few studies compared AMF community in revegetated sites with pristine adjacent ecosystems. The aim of this study was to assess AMF species richness in a revegetated iron-mining site and adjacent ecosystems and to relate AMF occurrence to soil chemical parameters. Soil samples were collected in dry and rainy seasons in a revegetated iron-mining site（RA） and compared with pristine ecosystems of forest（FL）, canga（NG）,and Cerrado（CE）. AMF species were identified by spore morphology from field and trap cultures and by LSU r DNA sequencing using Illumina. A total of 62 AMF species were recovered, pertaining to 18 genera and nine families of Glomeromycota. The largest number of species and families were detected in RA, and Acaulospora mellea and Glomus sp1 were the most frequent species. Species belonging to Glomeraceae and Acaulosporaceae accounted for 42%–48% of total species richness. Total number of spores and mycorrhizal inoculum potential tended to be higher in the dry than in the rainy season, except in RA. Sequences of uncultured Glomerales were dominant in all sites and seasons and five species were detected exclusively by DNA-based identification. Redundancy analysis evidenced soil p H,organic matter, aluminum, and iron as main factors influencing AMF presence. In conclusion, revegetation of the iron-mining site seems to be effective in maintaining a diverse AMF community and different approaches are complementary to reveal AMF species, despite the larger number of species being identified by traditional identification of field spores.

关键词： Community structure Glomeromycota Illumina LSU rDNA Spore morphology Taxonomic distinctness index

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Analysis of rockburst in tunnels subjected to static and dynamic loads

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1031-1040页

作者： Amin Manouchehrian Ming Cai Bharti School of Engineering Laurentian University Sudbury P3E 2C6 Canada MIRARCO Laurentian University 935 Ramsey Lake Road Sudbury P3E 2C6 Canada State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071Hubei China

The presence of geological structures such as faults, joints, and dykes has been observed near excavation boundaries in many rockburst case histories. In this paper, the role of discontinuities around tunnels in rockburst occurrence was studied. For this purpose, the Abaqus explicit code was used to simulate dynamic rock failure in deep tunnels. Material heterogeneity was considered using Python scripting in Abaqus. Rockbursts near fault regions in deep tunnels under static and dynamic loads were *** tunnel models with and without faults were built and static and dynamic loads were used to simulate rock failure. The velocity and the released kinetic energy of failed rocks, the failure zone around the tunnel, and the deformed mesh were studied to identify stable and unstable rock failures. Compared with models without discontinuities, the results showed that the velocity and the released kinetic energy of failed rocks were higher, the failure zone around the tunnel was larger, and the mesh was more deformed in the models with discontinuities, indicating that rock failure in the models with discontinuities was more violent. The modeling results confirm that the presence of geological structures in the vicinity of deep excavations could be one of the major influence factors for the occurrence of rockburst. It can explain localized rockburst occurrence in civil tunnels and mining drifts. The presented methodology in this paper for rockburst analysis can be useful for rockburst anticipation and control during mining and tunneling in highly stressed ground.

关键词： Rockburst Numerical modeling Geological structure Static load increase Dynamic disturbance Tunnel

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Design of rock support system under rockburst condition

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Journal of Rock Mechanics and Geotechnical Engineering 2012年第3期4卷 215-227页

作者： Peter K. Kaiser Centre for Excellence in Mining Innovation Sudbury Ontario Canada

As mining and civil tunneling progresses to depth, excavation-induced seismicity and rockburst problems increase and cannot be prevented. As an important line of defense, ground control measures and burst-resistant rock support are used to prevent or minimize damage to excavations and thus to enhance workplace safety. Rock support in burst-prone ground differs from conventional rock support where controlling gravity-induced rockfalls and managing shallow zones of loose rock are the main target. Rock support in burst-prone ground needs to resist dynamic loads and large rock dilation due to violent rock failure. After reviewing the rockburst phenomenon, types of rockbursts, damage mechanisms, and rockburst support design principles and acceptability criteria, this paper describes that the support selection process in burst-prone ground is iterative, requiring design verification and modification based on field observations. An interactive design tool for conducting rockburst support design in underground tunnels is introduced to facilitate cost-effective design.

关键词： rockburst rockburst damage rock support design

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