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Plant growth and metabolism of exotic and native Crotalaria species for mine land rehabilitation in the Amazon

Journal of Forestry Research 2024年第1期35卷 143-154页

作者： Hemelyn Soares das Chagas Rafael Silva Guedes Markus Gastauer Paula Godinho Ribeiro Allan Klynger da Silva Lobato Cecílio Frois Caldeira Fabrício William deÁvila AndréRodrigues dos Reis Silvio Junio Ramos Instituto Tecnológico vale Rua Boaventura da Silva955BelémPA 66055-090Brazil Universidade Federal do Sul e Sudeste do Pará XinguaraPABrazil Núcleo de Pesquisa Vegetal Básica e Aplicada Universidade Federal Rural da AmazôniaParagominasPABrazil Departamento de Engenharia Florestal Universidade Estadual do Centro-Oeste/UNICENTROIratiPRBrazil School of Sciences and Engineering São Paulo State University(UNESP)TupãSP.CEP 17602-496Brazil

Despite its enormous benefits,mining is respon-sible for intense changes to vegetation and soil ***,after extraction,it is necessary to rehabilitate the mined areas,creating better conditions for the establishment of plant species which is *** study evaluated mineral and organic fertilization on the growth,and carbon and nitrogen(N)metabolism of two Crotalaria species[Cro-talaria spectabilis(exotic species)and Crotalaria maypu-rensis(native species from Carajás Mineral Province(CMP)]established on a waste pile from an iron mine in CMP.A control(without fertilizer application)and six fertilization mixtures were tested(i=NPK;ii=NPK+micronutrients;iii=NPK+micronutrients+organic compost;iv=PK;v=PK+micronutrients;vi=PK+micronutrients+organic compost).Fertilization contributed to increased growth of both species,and treatments with NPK and micronutrients had the best results(up to 257%***),while organic fertilization did not show *** Crotalaria had a greater number of nodules,higher nodule dry mass,chlorophyll a and b contents and showed free ammonium as the predominant N form,reflecting greater increments in biomass compared to native *** having lower growth,the use of this native species in the rehabilitation of mining areas should be considered,mainly because it has good development and meets current government legislation as an opportunity to restore local biodiversity.

关键词： Biological nitrogen fixation Mining Nitrogen metabolism Plant nutrition

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Ground support design for dynamic loading conditions:A quantitative data-driven approach based on rockburst case studies

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 909-919页

作者： Philippe Morissette John Hadjigeorgiou Agnico Eagle Mines Limited 10 200route de PreissacRouyn-NorandaJ0Y 1C0Canada University of Toronto TorontoM5S 3E3Canada

There are considerable challenges associated with the design of ground support for seismically-active underground *** is extremely difficult to establish the demand on ground support as well as the capacity of a ground support *** resulting dynamic or impact loads caused by mining-induced seismicity are difficult to anticipate and *** performance of a ground support system is defined by the load distribution and interaction between several reinforcement and surface support ***,the design of ground support in seismically-active mines tends to evolve,or be modified based on qualitative assessments of perceived performance or response to significant seismic events or *** research is motivated by a need to provide quantitative and data-driven design guidelines for ground support systems subjected to dynamic-loading *** data were collected from three deep and seismically-active underground mines in the Sudbury basin in *** constructed database comprises 209 seismic events that resulted in damage to mine excavations and ground *** events were associated with damage at 324 locations within the three *** developed ground support design strategy,based on these documented case studies,identifies areas where the use of dynamic or enhanced support should be *** developed design methodology provides guidelines for the zoning of mine locations in which installation of enhanced support is recommended,the specifications for an optimal ground support system,and the timing or sequence of installation.

关键词： Ground support design Mining-induced seismicity Rockburst

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Structural Optimization of Metal and Polymer Ore Conveyor Belt Rollers

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Computer Modeling in Engineering & Sciences 2022年第12期133卷 601-618页

作者： Joao Pedro Ceniz Rodrigo de Sá Martins Marco Antonio Luersen Tiago Cousseau Department of Mechanical Engineering Federal University of Technology-Parana(UTFPR)Curitiba81280-340Brazil

Ore conveyor belt rollers operate in harsh environments,making them prone to premature *** service lives are highly dependent on the stress field and bearing misalignment angle,for which limit values are defined in a *** this work,an optimization methodology using metamodels based on radial basis functions is implemented to reduce themass of twomodels of *** a structural point of view,one of the rollers ismade completely of metal,while the other also has some components made of polymeric *** objective of this study is to develop and apply a parametric structural optimization methodology to minimize the mass of the two models of *** represent the mechanical behavior of the rollers,simulations were performed using the finite element *** the numerical optimization process,the variable parameters were the dimensions of the shaft and external *** geometric configuration that corresponded at the same time to the lowest mass and acceptable ranges for the stress and bearingmisalignment angle was *** the proposed methodology,a 32.3% reduction in mass was obtained for a metal roller design and an 18.9% reduction for a polymer *** both cases,the constraints were not *** the all-metal roller,the safety factors for the maximum stress and bearingmisalignment angle were 1.44 and 1.75,respectively,while for the polymer roller the corresponding figures were 1.50 and *** work describes a low-computational-cost optimization methodology for roller designs that have been little studied in the ***,the methodology could be adapted for use with other types of rollers and rollers made of different materials.

关键词： Conveyor belt rollers structural optimization surrogate models radial basis functions

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Optimization of room-and-pillar dimensions using automated numerical models

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International Journal of Mining Science and Technology 2019年第5期29卷 797-801页

作者： Gian Franco Napa-García Tais Renata Camara Vidal Félix Navarro Torres Mining Instituto Tecnológico ValeSanta LuziaMG 33040-900Brazil Exploration and Mineral Projects VALE S.A.Santa LuziaMG 33040-900Brazil

This paper presents an optimization methodology for the geometric configuration of a room–and–pillar mining project,considering safety and operational restrictions while maximizing ore *** underground manganese mine was chosen as a case study to investigate the capabilities of the presented methodology.A software package(OPTIMINE)was implemented to address the computational demand in an automated ***–dimensional finite difference analyses were performed in FLAC3D and used as implicit functions to consider safety in terms of the factor of safety and room *** obtained results showed that recovery could be increased from 44%to more than 80%in a safe manner.

关键词： Optimization Safety Room and pillar mining Ore recovery 3D numerical modeling

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Geomechanical effects of stress shadow created by large-scale destress blasting

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1085-1093页

作者： Isaac Vennes Hani Mitri Department of Mining and Materials Engineering McGill UniversityMontrealH3A 0E8Canada

This study aims to determine if large-scale choked panel destress blasting can provide sufficient beneficial stress reduction in highly-stressed remnant ore pillar that is planned for production. The orebody is divided into 20 stopes over 2 levels, and 2 panels are choke-blasted in the hanging wall to shield the ore pillar by creating a stress shadow around it. A linear-elastic model of the mining system is constructed with finite difference code FLAC3 D. The effect of destress blasting in the panels is simulated by applying a fragmentation factor(α) to the rock mass stiffness and a stress reduction factor(β) to the current state of stress in the region occupied by the destress panels. As an extreme case, the destress panel is also modeled as a void to obtain the maximum possible beneficial effects of destressing and stress *** stopes are mined in the stress shadow of the panels in 6 lifts and then backfilled. The effect of destress blasting on the remnant ore pillar is quantified based on stress change and brittle shear ratio(BSR) in the stress shadow zone compared to the base case without destress blasting. To establish realistic rock fragmentation and stress reduction factors, model results are compared to measured stress changes reported for case studies at Fraser and Brunswick mines. A 1.5 MPa immediate stress decrease was observed 20 m away from the panel at Fraser Mine, and a 4 MPa immediate stress decrease was observed 25 m away at Brunswick Mine. Comparable results are obtained from the current model with a rock fragmentation factor α of 0.2 and a stress reduction factor α of 0.8. It is shown that a destress blasting with these parameters reduces the major principal stress in the nearest stopes by 10-25 *** yields an immediate reduction of BSR, which is deemed sufficient to reduce volume of ore at risk in the pillar.

关键词： Destress blasting Preconditioning Rockbursts Strainbursts Numerical modeling Rock failure

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Large-scale destress blasting for seismicity control in hard rock mines:A case study

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International Journal of Mining Science and Technology 2020年第2期30卷 141-149页

作者： Isaac Vennes Hani Mitri Damodara Reddy Chinnasane Mike Yao Department of Mining and Materials Engineering McGill UniversityMontrealQuebec H3A 0E8Canada Copper Cliff Mine Vale Canada LtdSudbury P0M 1N0Canada

Destress blasting is a rockburst control technique where highly stressed rock is blasted to reduce the local stress and stiffness of the rock,thereby reducing its burst *** technique is commonly practiced in deep hard rock mines in burst prone developments,as well as in sill or crown pillars which become burst-prone as the orebody is ***-scale destressing is a variant of destress blasting where panels are created parallel to the orebody strike with a longhole,fanning blast pattern from cross cut drifts situated in the host *** aim of panel destressing is to reduce the stress concentration in the ore blocks or pillars to be *** paper focuses on the large-scale destress blasting program conducted at vale's Copper Cliff Mine(CCM)in Ontario,*** merits of panel destressing are examined through field measurements of mining induced stress changes in the *** destressing mechanism is simulated with a rock fragmentation factor(a)and stress reduction/dissipation factor(b).A 3D model is built and validated with measured induced stress *** is shown that the best correlation between the numerical model and field measurements is obtained when the combination of a and b indicates that the blast causes high fragmentation(a=0.05)and high stress release(b=0.95)in the destress *** is demonstrated that the burst proneness of the ore blocks in the panel stress shadow is reduced in terms of the brittle shear ratio(BSR)and the burst potential index(BPI).

关键词： Destress blasting Preconditioning Rockbursts Strainbursts Numerical modeling

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Mechanical behavior of iron ore tailings under standard compression and extension triaxial stress paths

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第7期15卷 1883-1894页

作者： Alexia Cindy Wagner João Paulo de Sousa Silva João Vítor de Azambuja Carvalho Ana Luisa Cezar Rissoli Pedro Pazzoto Cacciari Helder Mansur Chaves Hugo Carlos Scheuermann Filho Nilo Cesar Consoli Universidade Federal do Rio Grande do Sul Porto Alegre90035-190Brazil Mineral Development Centre Vale S.A.Santa Luzia33040-900Brazil Department of Civil Geological and Mining EngineeringPolytechnique MontrealMontrealH3C 3A7Canada

The disposal of mining tailings has increasingly focused on the use of dry *** structures offer more security since they use filtered and compacted *** of the construction method and the heights achieved,the material that compounds the structure can be subjected to different stress paths along the failure *** theoretical framework considered in the design of these structures generally is the critical state soil mechanics(CSSM).However,the data in the literature concerning the uniqueness of critical state line(CSL)is still controversial as the soil is subjected to different stress *** respect to tailings,this question is even more *** paper studies two tailings with different gradings due to the beneficial processes over extension and compression paths.A series of drained and undrained triaxial tests was conducted over a range of initial densities and stress *** the q-p'plane,different critical stress ratio(M)values were obtained for compression and extension stress ***,the critical state friction angle is very similar with a slightly higher critical state friction angle for extension *** stress path dependent CSLs were obtained in the n-lnp0 plane with the extension tests below the CSL defined in *** the fines content,the studied tailings presented very similar M and critical state friction angle ***,the fines content af-fects the volumetric behavior of the studied tailings and the CSLs on the n-lnp0 plane shift downwards with the increasing fines content for compression and extension *** relation to dilatancy analysis,the fines content did not present an evident influence on the dilatancy of the ***,different values of mean stress ratio N were obtained between compression and extension tests and can corroborate the existence of non-unique CSLs for these materials.

关键词： Iron ore tailings(IOTs) Dry stacking Critical state soil mechanics Extension tests Stress path

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Iron toxicity resistance strategies in tropical grasses:The role of apoplastic radicular barriers

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Journal of Environmental Sciences 2019年第4期31卷 257-266页

作者： Advanio Inacio Siqueira-Silva Camilla Oliveira Rios Eduardo Gusmao Pereira Institute of Biological and Health Sciences Federal University of Vicosa (UFV)Campus Florestal Minas Gerais Brazil Federal University of Western Para (UFOPA) University Campus of JurutiPara Brazil Postgradute Program in Management and Conservation of Natural and Agrarian Ecosystems UFV Campus Florestal Florestal Minas Gerais Brazil

The revegetation of mined areas poses a great challenge to the iron ore mining *** initial recovery process in degraded areas might rely on the use of Fe-resistant *** grasses, such as Paspalum densum and Echinochloa crus-galli, show different resistance strategies to iron toxicity; however, these mechanisms are poorly *** Fe-resistance mechanisms and direct iron toxicity as a function of root apex removal were investigated. To achieve this purpose, both grass species were grown for up to 480 hr in a nutrient solution containing 0.019 or 7 mmol/L Fe-EDTA after the root apices had been removed or maintained. Cultivation in the presence of excess iron-induced leaf bronzing and the formation of iron plaque on the root surfaces of both grass species, but was more significant on those plants whose root apex had been removed. Iron accumulation was higher in the roots, but reached phytotoxic levels in the aerial parts as well. It did not hinder the biosynthesis of chloroplastidic pigments. No significant changes in gas exchange and chlorophyll a fluorescence occurred in either grass when their roots were kept intact; the contrary was true for plants with excised root apices. In both studied grasses, the root apoplastic barriers had an important function in the restriction of iron translocation from the root to the aerial plant parts, especially in E. crus-galli. Root apex removal negatively influenced the iron toxicity resistance mechanisms(tolerance in P. densum and avoidance in E. crus-galli).

关键词： Paspalum densum Echinochloa crus-galli Apoplastic barrier Iron toxicity

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Cerium alleviates drought-induced stress in Phaseolus vulgaris

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Journal of Rare Earths 2020年第3期38卷 324-331页

作者： Olívia Graziela Gelioli Salgado Jéssica Cristina Teodoro Joyce Pereira Alvarenga Cynthia de Oliveira Teotonio Soares de Carvalho Débora Domiciano Paulo Eduardo Ribeiro Marchiori Luiz Roberto Guimaraes Guilherme Department of Soil Science Federal University of LavrasCP 3037Campus UFLALavras37200-000Brazil Department of Biology Federal University of LavrasCP 3037Campus UFLALavras37200-000Brazil

Extreme drought events are expected to be one of the main challenges for tropical agriculture and,consequently,for global food *** this reason,it is urgent to develop strategies to increase water use efficiency,as well as to increase crops’ ability to cope with *** rare earth elements(REEs) are known to alleviate damages in plants under abiotic stresses,we hypothesized that addition of Ce^3+to nutrient solution would promote the growth of common bean,especially under simulated drought *** test this hypothesis,we conducted an experiment evaluating the effect of six Ce^3+concentrations on the development and physiological traits of common bean grown in nutrient solution under normal condition and under induced drought stress,caused by the addition of polyethylene glycol6000 to the nutrient *** results show that Ce^3+alleviates water stress in common bean plants,increasing their survival rate and *** addition,Ce^3+application increases photosynthesis rate,chlorophyll content and water use efficiency under water ***,we observe no significant effect of Ce^3+on plants growing under normal ***,Ce3+seems to be a promising attenuator of drought stress for common bean.

关键词： Water stress Polyethylene glycol Rare earth elements Cerium nitrate Mitigation Common bean

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Plant growth and nutrient use efficiency of two native Fabaceae species for mineland revegetation in the eastern Amazon

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Journal of Forestry Research 2020年第6期31卷 2287-2293页

作者： Silvio J.Ramos Markus Gastauer Simone K.Mitre Cecı´lio F.Caldeira Joyce R.Silva Antonio E.Furtini Neto Guilherme Oliveira Pedro W.M.Souza Filho Jose´O.Siqueira Instituto Tecnolo´gico vale Rua Boaventura da Silva955Belem 66055-090Brazil Departamento de Ciencia do Solo Universidade Federal de LavrasLavras 37200-000Brazil

The primary challenge of mineland revegetation is the establishment of species able to cope with low availability of nutrients,especially in steep slopes such as of mine *** evaluated plant growth response and nutrient use efficiency(NUE)of two promising native Fabaceae species(Dioclea apurensis—liana from metalliferous savannas;Bauhinia longipedicellata—tree from Amazon rainforest)from the Caraja´s Mineral Province,eastern *** were grown separately in 2-kg pots filled with mining *** were fertilized with nitrogen,phosphorus,potassium(NPK),lime,and *** results showed increments on growth of both species when nutrients were applied to the mining *** showed increases in leaf area,plant height,stem diameter,and shoot dry mass production when NPK or NPK?micronutrients were applied,while *** was responsive to application of NPK?lime or NPK?lime?***,*** showed higher NUE than ***,especially at the lowest doses of N,P and *** findings may indicate a substantial advantage of *** for mineland revegetation,as this species may require lower nutrient inputs,being,therefore,a more sustainable way to revegetate degraded areas.

关键词： Fertilizer application Mining soil Tropical forest Nutrient use efficiency

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