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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 498-504页

作者： Kichakeswari Tudu Sagar Pal N.R.Mandre Department of Fuel and Mineral Engineering Indian Institute of Technology (Indian School of Mines) Polymer Chemistry Laboratory Department of Applied ChemistryIndian Institute of Technology (Indian School of Mines)

This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acrylic acid(PAA), and a graft copolymer(AP-g-PAA). The obtained results were analyzed; they indicate the enhancement of the iron ore grade from 58.49% to 67.52% using AP-g-PAA with a recovery of 95.08%. In addition, 64.45% Fe with a recovery of 88.79% was obtained using AP. Similarly, using PAA, the grade increased to 63.46% Fe with a recovery of 82.10%. The findings are also supported by characterizing concentrates using X-ray diffraction(XRD) and electron probe microanalysis(EPMA) techniques.

关键词： low grade iron ore fines selective flocculation graft copolymer amylopectin(AP) poly acrylic acid(PAA)

Cyclic liquefaction screening of sand with non-plastic fines:Critical state approach

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Geoscience Frontiers 2020年第2期11卷 429-438页

作者： Md.Mizanur Rahman TGSitharam Natural and Built Environments Research Centre(NBERC) School of Natural and Built EnvironmentsUniversity of South AustraliaMawson LakesSA 5095Australia Department of Civil Engineering Indian Institute of Science(IISc)BangaloreIndia

There have been significant advances in the application of critical state,CS,in liquefaction potential *** was done by comparing state parameter,j with estimated characteristic cyclic stress ratio,CSR due to an earthquake.A cyclic resistance ratio,CRR curve,which can be determined from cyclic liquefaction tests,separates historical liquefied and non-liquefied data points(j,CSR).On the other hand,the concepts of equivalent granular state parameter,j*,which was developed for sands with fines,can be used in lieu j to provide a unifying framework for characterizing the undrained response of sands with non/low plasticity fines,irrespective of fines content(fc).The present work combines these two propositions,and by merely substituting j*for j into the aforementioned CS approach to capture the influence of fc.A series of static and cyclic triaxial tests were conducted,separately and independently of the concept of j*,for sand with up to fc of 30%.The clean sand was collected from Sabarmati river belt at Ahmedabad city in India which was severely affected during the Bhuj earthquake,*** experimental data gave a single relation for CRR and j*which was then used to assess liquefaction potential for a SPT based case study,where fc varies along the *** prediction matched with the field observation.

关键词： Critical state State parameter Liquefaction Sands fines Constitutive model

Importance of Double Layer Force between a Plat and a Nano-Particle in Restricting fines Migration in Porous Media

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Advances in Nanoparticles 2014年第3期3卷 99-105页

作者： Saeed Sourani Mohammad Afkhami Yousef Kazemzadeh Houman Fallah Department of Petroleum Engineering Islamic Azad University of Lamerd Lamerd Iran Department of Petroleum Engineering Islamic Azad University of Firoozabad Firoozabad Iran Department of Petroleum Engineering Islamic Azad University of Marvdasht Marvdasht Iran Department of Petroleum Engineering Shiraz University Shiraz Iran

fines migration is defined as separation of a Nano-sized particle by fluid flow in porous media and its migration along some distances and its entrapment in a narrow pore throat or its settlement on pore wall. Although this phenomenon happens in scales of Nano-meters, it can lead to sever irretrievable damages. This damage includes permeability reduction that causes drastic oil recovery reduction. There are several forces impacting a fine that is placed on a pore wall. Some of most important forces affecting settlement of a fine in porous media in presence of a fluid are electrical forces. Electrical forces consist of several long and short range forces. This study focuses on a long range force called Double Layer Force (DLF) that beside Van der Waals is one of most powerful electrical forces. DLF is a repulsive force that can repel a particle from pore wall and result separation of a Nano-sized solid which subsequently moves along with flowing fluid and clogs a throat. The DLF depends on the solid material (reservoir rock and fine) and fluid properties (i.e. ionic strength, pH). This study investigates how each of these parameters affects DLF and introduces proper conditions for reservoir water flooding for controlling fines migration.

关键词： Water Flooding Reservoir Damage fines Migration EOR Double Layer Force Inter-Particle Forces

Origins of the Problematic Substances in fines, for Their Acceptance at Inert Landfills

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Journal of Geoscience and Environment Protection 2018年第5期6卷 237-246页

作者： Soukaina Oujana Denis Sanchez Université Grenoble Alpes CNRS G-SCOP Grenoble France

Integrated solid waste management (ISWM) involves approaching solid waste in a comprehensive manner with careful selection of appropriate technology. The aim of good waste management is to push waste up the hierarchy with landfill as a last resort. However given the current sorting technology, heterogeneous residues called fines are created, they are considered at the present time as non-sortable and non-recoverable sent to second class landfills. A previous conducted study has revealed that fines contain several problematic substances for an inert classification. This article summarizes the most important problematic substances in fines for their acceptance inert landfills. These substances were identified by analyzing several samples collected from a siting of non-hazardous solid waste in the region of Rhône-Alpes in France. Eluate Analysis and fines analysis were conducted in order to identify the presence of any component that could prevent the classification of fines in an inert landfill. The obtained results were compared with the limit values for waste acceptance in an inert landfill. The study concluded that the six top-ranking problematic substances are Copper, Mercury, Antimony, Chloride, Fluoride and Sulfates, this study gives additional information on the origins of these substances that deserves particular attention to better limit their presence in the input of fines stream.

关键词： fines Heavy Metals Inert Waste Landfill Non-Hazardous Waste

Collaborative Effect of fines on Changes in Grain Distribution in the Process of Improving the Geotechnical Properties of an Alluvial Gravel 0/14

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Geomaterials 2024年第3期14卷 29-48页

作者： Adolphe Ekouya Louis Ahouet Sylvain Ndinga Okina Higher National Polytechnic School (ENSP) Marien Ngouabi University Brazzaville Congo Higher Institute of Architecture Urbanism Building and Public Works Denis Sassou Nguesso University Brazzaville Congo Control Office for Building and Public Works (BCBTP) Brazzaville Congo

The technical and economic optimization of road projects has led to research into the use of materials obtained by mechanical stabilization for pavement construction. This research has enabled us to outline a solution capable of giving the sub-base layer the necessary and sufficient capacity to support the induced loads forecast for the traffic. This work evaluates the effect of adding fine silty clay (Cl) and clayey silt (Csp), two corrective materials to alluvial gravel (0/14), the main material, in the process of improving its cohesion and geotechnical properties. The results obtained show that the optimum mix is obtained with 10% by weight of Cl and 15% Csp. The granulometry of the mixes is spread out, but poorly calibrated. The Ag-Cl mixtures made at 10%, 15%, 20%, 25% 30% and Ag-Csp at 15%, 20%, 25%, 30%, and 35%, do not obey the law of mixtures. Mixing with 10% Cl reduces the sand equivalent of alluvial gravel by 60.23%, while mixing with 15% Cl reduces the sand equivalent by 6.82%. The addition of correctors increases the optimum water content and fine sand content of the mixes. Increasing the fine sand content reduces the optimum dry density, CBR index and static modulus. Mixes containing 10% Cl and 15% Csp have CBR values of CBRCl (96%) and CBRCsp (84%) and are not suitable for pavement base layers. In fact, the hardness of the grains has a Los Anges value of 41%, higher than the maximum permitted by the standard of 35%. The mixes obtained can be used as pavement base layers for traffic levels in a cumulative number of heavy goods vehicles 5 × 105 6 for an approximate life of 15 years.

关键词： Alluvial Gravel Cubitermes Sp Termite fines Mechanical Treatment Corrector

燃油中CATALYST fines超标引起船舶柴油机故障浅析与排除

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中国水运（下半月） 2008年第6期8卷 129-,131页

作者：孙玉孟王福奎中远航运股份有限公司广东广州510061 青岛海事局山东青岛266071

本文以实船故障为例阐述了船舶燃油中CATALYST fines含量超标的原因及引起的后果,并提出了在实船管理过程中降低燃油中CATALYST fines含量行之有效的措施。

关键词： CATALYST fines 分油机磨料磨损

Mobile silencing in plants:what is the signal and what defines the target

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Frontiers in Biology 2011年第2期6卷 140-146页

作者： Dacheng LIANG E.Jean FINNEGAN Elizebeth S.DENNIS Peter M.WATERHOUSE Ming-Bo WANG CSIRO Plant Industry Clunies Ross StreetCanberraACT 2601Australia School of Molecular Bioscience University of SydneySydney NSW 2006Australia

RNA-mediated silencing in plants can spread from cell to cell and over a long distance,and such mobile silencing has been extensively studied in the past ***,major questions remain as to what is the exact nature of the mobile silencing signals,how the components of the RNA-directed DNA methylation pathway are involved,and why systemic spread of silencing has only been observed for transgenes but not endogenous *** this review,we provide an overview of the current knowledge on mobile gene silencing in plants and present a model where systemic silencing involves long nuclear RNA transcripts that serve as a template to amplify primary siRNA signals.

关键词： endogenous template fines

When Design Defines a City

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China Today 2024年第7期73卷 38-40页

作者： MARIA JOSÉMASNOU Cátedra China

Both Spain and China’s practices in urban design show how urban governance,local social development,and people’s needs shape a city’s *** the 20th century,China and Spain faced the common challenge of urban *** China,it began with the urbanization and revitalization process with the inception of the reform and opening-up in 1978,and in Spain.

关键词： transition. urban fines

Intergrain contact density indices for granular mixes——Ⅱ: Liquefaction resistance

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Earthquake Engineering and Engineering Vibration 2007年第2期6卷 135-146页

作者： S. Thevanayagam Dept. of Civil Struct. & Env. Eng. State Univ. of New York Buffalo NY 14260 USA

Whether the presence of non-plastic silt in a granular mix soil impact its liquefaction potential and how to evaluate liquefaction resistance of sand containing different amounts of silt contents are both controversial issues. This paper presents the results of an experimental evaluation to address these issues. Two parameters, namely, equivalent intergranular void ratio （ec）eq and equivalent interfine void ratio （ef）eq, proposed in a companion paper （Thevanayagam, 2007） as indices of active grain contacts in a granular mix, are used to characterize liquefaction resistance of sands and silty sands. Results indicate that, at the same global void ratio （e）, liquefaction resistance of silty sand decreases with an increase in fines content （Cv） up to a threshold value （Crth）. This is due to a reduction in intergrain contact density between the coarse grains. Beyond Crth, with further addition of fines, the interfine contacts become significant while the inter-coarse grain contacts diminish and coarse grains become dispersed. At the same e, the liquefaction resistance increases and the soil becomes stronger with a fttrther increase in silt content. Beyond a limiting fines content （CrL）, the liquefaction resistance is controlled by interfine contacts only. When Cr〈Crth, at the same （e）eq, the liquefaction resistance of silty sand is comparable to that of the host clean sand at a void ratio equal to （ec）eq. When CF〉CFth, at the same （ef）eq, the cyclic strength of a sandy silt is comparable to the host silt at a void ratio equal to （ef）eq.

关键词： Sand silt fines silty sand liquefaction cyclic strength

Effects of various parameters on the attrition of bed material in a recirculating fluidized bed with a draft tube

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Particuology 2018年第3期16卷 61-70页

作者： Shivali Chourasia Babu J. Alappat Department of Civil Engineering Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India

We performed an experimental study to investigate the effects of various parameters on the attrition of bed material and its size distribution with increasing operation time in a recirculating fluidized bed （RCFB）. The studied parameters included superficial velocity of fluidizing air, bed inventory, and spacing between the jet top and draft tube bottom （spacer height）. The bed material was prepared from Indian Standard （IS） Grade I sand from sieves with a size range of 2.20-1.00 mm. Experiments were performed at ambient conditions, with the superficial air velocity ranging from 7.13-9.16 m/s, a bed inventory of 7-10 kg, spacing of 0.085 and 0.045 m between the jet top and draft tube bottom, and an operating time of 40 h. We investigated the influence of these parameters in terms of changes in the size distribution of particles, changes in the %-weight of particles of different size ranges, generation of particles with smaller diameters, the decrease of the downcomer bed height, variations in the coefficient of uniformity and coefficient of curvature, and material loss from entrainment of fines with increasing operation time. The mode of attrition was abrasion in all experiments. We found that with increasing operation time and other parameters （bed inventory, superficial air velocity, and spacer height） attrition of the bed material also increased. Generation and elutriation of fines were more pronounced at higher superficial air velocity, bed inventory, and spacer height.

关键词： Attrition Recirculating fluidized bed (RCFB) Fluidization Elutriation fines