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Sample records for agglomerating ash process

  1. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983

    Energy Technology Data Exchange (ETDEWEB)

    None

    1987-07-31

    KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

  2. Automated Manufacture of Fertilizing Agglomerates from Burnt Wood Ash

    Energy Technology Data Exchange (ETDEWEB)

    Svantesson, Thomas

    2002-12-01

    In Sweden, extensive research is conducted to find alternative sources of energy that should partly replace the electric power production from nuclear power. With the ambition to create a sustainable system for producing energy, the use of renewable energy is expected to grow further and biofuels are expected to account for a significant part of this increase. However, when biofuels are burned or gasified, ash appears as a by-product. In order to overcome the problems related to deposition in land fills, the idea is to transform the ashes into a product - agglomerates - that easily could be recycled back to the forest grounds; as a fertilizer, or as a tool to reduce the acidification in the forest soil at the spreading area. This work considers the control of a transformation process, which transforms wood ash produced at a district heating plant into fertilizing agglomerates. A robust machine, built to comply with the industrial requirements for continuous operation, has been developed and is controlled by an industrial control system in order to enable an automated manufacture.

  3. Agglomeration processes in aging societies

    OpenAIRE

    Theresa Grafeneder-Weissteiner; Klaus Prettner

    2010-01-01

    This article investigates agglomeration processes in aging societies by introducing an overlapping generation structure into a New Economic Geography model. Whether higher economic integration leads to spatial concentration of economic activity crucially hinges on the economies' demographic properties. While population aging as represented by declining birth rates strengthens agglomeration processes, declining mortality rates weaken them. This is due to the fact that we allow for nonconstant ...

  4. Biomass ash - bed material interactions leading to agglomeration in fluidised bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Visser, H.J.M.; Hofmans, H.; Huijnen, R.; Kastelein, R.; Kiel, J.H.A. [ECN Biomass, Petten (Netherlands)

    2000-07-01

    The present study has been aimed at improving the fundamental understanding of mechanisms underlying agglomeration and defluidisation in fluidised bed combustion and gasification of biomass and waste. To this purpose dedicated lab-scale static heating and fluidisation experiments have been conducted with carefully selected and prepared ashes and bed materials, viz. straw ash/sand and willow ash/sand mixtures, mullite subjected to straw gasification and artificially coated mullite. The main conclusion is that ash/bed material interaction processes are very important and often determine the bed agglomeration and defluidisation tendency. In the static heating experiments with both ash/sand mixtures, partial melting-segregation of ash components and dissolution/reaction with the bed material are processes that determine the melt composition. This melt composition and behaviour can deviate considerably form expectations based on ash-only data. Artificially coated bed materials prove to be very useful for systematic studies on the influence of coating composition and thickness on agglomeration tendency. For the coated mullite samples, different stages in the defluidisation process are identified and the influence of coating properties (thickness, composition, morphology) and operating parameters is elucidated. The behaviour of the mullite appears to be dominated by a remnant glass phase. On the one hand, this glass phase accounts for an alkali-getter capability, while on the other hand it is mainly responsible for agglomeration at temperatures {>=} 800C. 3 refs.

  5. Development of a Gas-Promoted Oil Agglomeration Process

    Energy Technology Data Exchange (ETDEWEB)

    C. Nelson; F. Zhang; J. Drzymala; M. Shen; R. Abbott; T. D. Wheelock

    1997-11-01

    The preliminary laboratory-scale development of a gas-promoted, oil agglomeration process for cleaning coal was carried out with scale model mixing systems in which aqueous suspensions of ultrafine coal particles were treated with a liquid hydrocarbon and a small amount of air. The resulting agglomerates were recovered by screening. During a batch agglomeration test the progress of agglomeration was monitored by observing changes in agitator torque in the case of concentrated suspensions or by observing changes in turbidity in the case of dilute suspensions. Dilute suspensions were employed for investigating the kinetics of agglomeration, whereas concentrated suspensions were used for determining parameters that characterize the process of agglomeration. A key parameter turned out to be the minimum time te required to produce compact spherical agglomerates. Other important parameters included the projected area mean particle diameter of the agglomerates recovered at the end of a test as well as the ash content and yield of agglomerates. Batch agglomeration tests were conducted with geometrically similar mixing tanks which ranged in volume from 0.346 to 11.07 liters. Each tank was enclosed to control the amount of air present. A variable speed agitator fitted with a six blade turbine impeller was used for agitation. Tests were conducted with moderately hydrophobic Pittsburgh No. 8 coal and with more hydrophobic Upper Freeport coal using either n-heptane, i-octane, or hexadecane as an agglomerant.

  6. Important characteristics of a gas-promoted oil agglomeration process

    Energy Technology Data Exchange (ETDEWEB)

    Shen, M.; Wheelock, T.D. [Iowa State University, Ames, IA (United States)

    1998-12-31

    The characteristics of a gas-promoted oil agglomeration process for cleaning coal particles in an aqueous suspension were determined by conducting a large number of agglomeration tests with scale model mixing systems of different sizes with controlled amounts of air present. The tests were conducted with both high-volatile and medium-volatile bituminous coals using iso-octane as an agglomerant. The results indicated that the process can be characterized by the minimum time required to produce spherical agglomerates t{sub E} the mean diameter d{sub p} of the agglomerates produced in a specific time, coal recovery, and product ash content. Among these parameters t{sub E} appears to hold the key for size scale-up of an agglomeration mixing system, and an appropriate scale-up rule is proposed. 8 refs., 3 figs., 1 tab.

  7. Frequency comparative study of coal-fired fly ash acoustic agglomeration

    Institute of Scientific and Technical Information of China (English)

    Jianzhong Liu; Jie Wang; Guangxue Zhang; Junhu Zhou; Kefa Cen

    2011-01-01

    Particulate pollution is main kind of atmospheric pollution.The fine particles are seriously harmful to human health and environment.Acoustic agglomeration is considered as a promising pretreatment technology for fine particle agglomeration.The mechanisms of acoustic agglomeration are very complex and the agglomeration efficiency is affected by many factors.The most important and controversial factor is frequency.Comparative studies between high-frequency and low-frequency sound source to agglomerate coalfired fly ash were carried out to investigate the influence of frequency on agglomeration efficiency.Acoustic agglomeration theoretical analysis,experimental particle size distributions (PSDs) and orthogonal design were examined.The results showed that the 20 kHz high-frequency sound source was not suitable to agglomerate coal-fired fly ash.Only within the size ranging from 0.2 to 0.25 μm the particles agglomerated to adhere together,and the agglomerated particles were smaller than 2.5 μm.The application of low-frequency (1000-1800 Hz) sound source was proved as an advisable pretreatment with the highest agglomeration efficiency of 75.3%,and all the number concentrations within the measuring range decreased.Orthogonal design L16 (4)3 was introduced to determine the optimum frequency and optimize acoustic agglomeration condition.According to the results of orthogonal analysis,frequency was the dominant factor of coal-fired fly ash acoustic agglomeration and the optimum frequency was 1400 Hz.

  8. Agglomeration in Stripper Ash Coolers and Its Possible Remedial Solutions: a Case Study

    Science.gov (United States)

    Singh, Ravi Inder

    2016-04-01

    The bottom ash of circulating fluidized bed (CFB) boiler contains large amounts of physical heat. When low quality coals are used in these types of boilers, the ash content is normally more than 40 % and the physical heat loss is approximately 3 % if the bottom ash is discharged without cooling. Bottom ash cooler (BAC) is often used to treat the high temperature bottom ash to reclaim heat, and to facilitate the easily handling and transportation of ash. The CFB boiler at BLA Power, Newari, MP (India) is facing problems of clinker formation in strip ash coolers of plant since the installation of unit. These clinkers are basically agglomerates, which leads to defluidization of stripper ash cooler (BAC) units. There are two strip ash coolers in unit. Each strip ash cooler is capable of working independently. The proper functioning of both strip coolers is very important as it is going to increase the combustion efficiency of boiler by stripping of fine unburnt coal particles from ash, which are injected into the furnace. In this paper causes, characterization of agglomerates, thermo gravimetric analysis of fuel used, particular size distribution of coal and sand and possible remedial solution to overcome these agglomerates in strip ash coolers has also been presented. High temperature in compact separators, non uniform supply of coal and not removing small agglomerates from stripper ash cooler are among main causes of agglomeration in stripper ash cooler. Control of compact separator temperature, replacing 10-12 % of bed material and cleaning stripper ash cooler periodically will decrease agglomeration in stripper ash cooler of unit.

  9. Agglomeration behaviour of high ash Indian coals in fluidized bed gasification pilot plant

    International Nuclear Information System (INIS)

    Although gasification of high ash Indian coals is gaining importance, the resultant uncertainties associated with agglomerate formation are still unresolved. To address this, a suitable pilot scale Fluidized Bed Gasifier was utilized in this study. Stabilized operating conditions in terms of coal feed rate, air feed rate, bed temperature, etc., already identified for maximum possible carbon conversion, were maintained in all experiments and the steam flow rate was only varied. Though the ash fusion temperature of the coals were above 1200 °C, agglomerate was formed during gasification at 950 °C with ‘steam to coal ratio’ less than 0.15 (kg/kg). On increasing this ratio above 0.2 local heat-concentration and agglomeration could be avoided with certainty. Chemical composition alone was not sufficient to explain the relative strength of ash-agglomerates. Compositional variation and state of iron within the matrix were assessed through SEM-EDX and electron paramagnetic resonance (EPR) study, respectively. The probing also required the ash-loading and iron-loading factors to be freshly defined in the context of gasification. Localized heat, large compositional variation, presence of iron in Fe2+ state, ash-loading/iron-loading factors influenced intensity of agglomerate formation. Finally, low temperature agglomerate formation was explained by SiO2–Al2O3–FeO phase diagram. - Highlights: • Pilot plant studies on agglomerate formation during high ash coal gasification. • AFT, chemical analysis of coal ash could not give proper indication. • Ash-/iron-loading factors, compositional variation, Fe2+ leads to agglomeration. • Steam to coal ratio was controlled judiciously to avoid agglomeration. • Cause for agglomeration investigated in depth and remedial adjustment was focused

  10. Engineering development of selective agglomeration: Task 5, Bench- scale process testing

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    Under the overall objectives of DOE Contract Engineering Development of Selective Agglomeration,'' there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

  11. Engineering development of selective agglomeration: Task 5, Bench- scale process testing

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    Under the overall objectives of DOE Contract ``Engineering Development of Selective Agglomeration,`` there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

  12. [Sonic Enhanced Ash Agglomeration and Sulfur Capture]. [Quarterly technical progress report, September 27, 1993--January 2, 1994

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a ``hot flue gas cleanup`` subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which slagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process. The goal of the program is to support the DOE mission in developing coal-fired combustion gas turbines. In particular, the MTCI proprietary process for bimodal ash agglomeration and simultaneous sulfur capture will be evaluated and developed. The technology embodiment of the invention provides for the use of standard grind, moderately beneficiated coal and WEM for firing the gas turbine with efficient sulfur capture and particulate emission control upstream of the turbine. The process also accommodates injection of alkali gettering material if necessary. This is aimed at utilization of relatively inexpensive coal fuels, thus realizing the primary benefit being sought by direct firing of coal in such gas turbine systems.

  13. Biomass-Ash-Induced Agglomeration in a Fluidized Bed. Part 1: Experimental Study on the Effects of a Gas Atmosphere

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang;

    2016-01-01

    . The agglomerates are analyzed by scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) for morphology and elemental composition. Significant differences are observed on the defluidization temperature (Td) and agglomeration mechanisms in different gas atmospheres. Td in H2 and steam....... Understanding of the agglomeration in various atmospheres is crucial to optimize the design and operation conditions. This study focuses on the effects of gases on agglomeration tendency with different types of biomass, including corn straw, rice straw, and wheat straw. The biomass ash samples are mixed...... atmospheres are much lower than that in air. It appears that, in a steam atmosphere, the agglomeration of corn straw and rice straw ash is predominantly coating-induced. The agglomeration in both H2 and air atmospheres are melting-induced. In a H2 atmosphere, K2SO4 in the ash samples disappears, caused...

  14. Automated Manufacture of Fertilizing Agglomerates from Burnt Wood Ash

    OpenAIRE

    Svantesson, Thomas

    2002-01-01

    In Sweden, extensive research is conducted to find alternative sources of energy that should partly replace the electric power production from nuclear power. With the ambition to create a sustainable system for producing energy, the use of renewable energy is expected to grow further and biofuels are expected to account for a significant part of this increase. However, when biofuels are burned or gasified, ash appears as a by-product. In order to overcome the problems related to deposition in...

  15. Analysis and synthesis of solutions for the agglomeration process modeling

    Science.gov (United States)

    Babuk, V. A.; Dolotkazin, I. N.; Nizyaev, A. A.

    2013-03-01

    The present work is devoted development of model of agglomerating process for propellants based on ammonium perchlorate (AP), ammonium dinitramide (ADN), HMX, inactive binder, and nanoaluminum. Generalization of experimental data, development of physical picture of agglomeration for listed propellants, development and analysis of mathematical models are carried out. Synthesis of models of various phenomena taking place at agglomeration implementation allows predicting of size and quantity, chemical composition, structure of forming agglomerates and its fraction in set of condensed combustion products. It became possible in many respects due to development of new model of agglomerating particle evolution on the surface of burning propellant. Obtained results correspond to available experimental data. It is supposed that analogical method based on analysis of mathematical models of particular phenomena and their synthesis will allow implementing of the agglomerating process modeling for other types of metalized solid propellants.

  16. Theoretical studies on aerosol agglomeration processes

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, K.E.J. [VTT Energy, Espoo (Finland). Energy Use

    1997-12-31

    In this thesis, theoretical modeling of certain aerosol systems has been presented. At first, the aerosol general dynamic equation is introduced, along with a discretization routine for its numerical solution. Of the various possible phenomena affecting aerosol behaviour, this work is mostly focused on aerosol agglomeration. The fundamentals of aerosol agglomeration theory are thus briefly reviewed. The two practical applications of agglomeration studied in this thesis are flue gas cleaning using an electrical agglomerator and nanomaterial synthesis with a free jet reactor. In an electrical agglomerator the aerosol particles are charged and brought into an alternating electric field. The aim is to remove submicron particles from flue gases by collisions with larger particles before conventional gas cleaning devices that have a clear penetration window in the problematic 0.1-1{mu}m size range. A mathematical model was constructed to find out the effects of the different system parameters on the agglomerator`s performance. A crucial part of this task was finding out the collision efficiencies of particles of varying size and charge. The original idea was to use unipolar charging of the particles, and a laboratory scale apparatus was constructed for this purpose. Both theory and experiments clearly show that significant removal of submicron particles can not be achieved by such an arrangement. The theoretical analysis further shows that if the submicron particles and the large collector particles were charged with opposite polarity, significant removal of the submicron particles could be obtained. The second application of agglomeration considered in this thesis is predicting/controlling nanoparticle size in the gas-to-particle aerosol route to material synthesis. In a typical material reactor, a precursor vapor reacts to form molecules of the desired material. In a cooling environment, a particulate phase forms, the dynamics of which are determined by the rates of

  17. Biomass ash-bed material interactions leading to agglomeration in FBC

    DEFF Research Database (Denmark)

    Visser, H.J.M.; van Lith, Simone Cornelia; Kiel, J.H.A.

    2008-01-01

    describes a fundamental study on the mechanisms of defluidization. For the studied process of bed defluidization due to sintering of grain-coating layers, it was found that the onset of the process depends on (a) a critical coating thickness, (b) on the fluidization velocity when it is below approximately......-scale installations is "coating-induced" agglomeration. During reactor operation, a coating is formed on the surface of bed material grains and at certain critical conditions (e.g., coating thickness or temperature) sintering of the coatings initiates the agglomeration. In an experimental approach, this work...... four times the minimum fluidization velocity, and (c) on the viscosity (stickiness) of the outside of the grains (coating)....

  18. Ash related bed agglomeration during fluidized bed combustion, further development of the classification method based on CCSEM; CCSEM-luokitusmenetelmaen jatkokehittaeminen tuhkan aiheuttaman agglomeroitumisen tutkimisessa leiju- ja kiertopetipoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, R.; Patrikainen, T.; Heikkinen, R.; Tiainen, M.; Virtanen, M. [Oulu Univ. (Finland). Inst. of Chemistry

    1997-10-01

    The scope of this project is to use the information and experience gained from the development of classification method to predict ash related problems like bed agglomeration during fluidised combustion. If boilers have to be shut down due to slagging or agglomeration of the bed material may cause significant economic losses for the entire energy production chain. Mineral classification methods based on the scanning electron microscopy are commonly used for coal ash investigation. In this work different biomass, peat, and peat-wood ash, fluidised-bed materials, and bed agglomerates were analysed with SEM-EDS combined with automatic image analysis software. The properties of ash particles are different depending on the fuel type. If biomass like wood or bark are added to peat the resulting ash has different properties. Due to the low mineral content in the original peat and to the fact that the majority of inorganic material is bound to the organic matrix, the classification has turned out to be less informative than was hoped. However, good results are obtained the by use of quasiternary diagrams. With these diagrams the distribution of particle composition is easily illustrated and thus meaningful prediction can be made of the slagging and agglomerating properties of ash. The content of ten different elements are determined for each particle by SEM-EDS combined with Link AIA software. The composition of the diagram corners can be varied Freely within these ten elements. (orig.)

  19. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  20. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  1. Prevention of the ash deposits by means of process conditions in biomass gasification; Biomassapolttoaineiden tuhkan kuonaantumiskaeyttaeytymisen estaeminen prosessiolosuhteiden avulla

    Energy Technology Data Exchange (ETDEWEB)

    Moilanen, A.; Laatikainen-Luntama, J.; Nieminen, M.; Kurkela, E.; Korhonen, J. [VTT Energy, Espoo (Finland)

    1997-10-01

    In fluidised-bed gasification, various types of deposits and agglomerates may be formed by biomass ash in the bed, in upper zones of the reactor, for instance in cyclones. These may decisively hamper the operation of the process. The aim of the project was to obtain data on the detrimental fouling behaviour of the ash of different types of biomass in fluidised-bed gasification, and on the basis of these data to determine the process conditions and ways of preventing this kind of behaviour. Different types of biomass fuel relevant to energy production such as straw, wood residue were be used as samples. The project consisted of laboratory studies and fluidised-bed reactor tests including ash behaviour studied both in the bed and freeboard. In laboratory tests, the sample material was characterised as a function of different process parameters. In fluid-bed reactors, the most harmful biomasses were tested using process variables such as temperature, bed material and the gasification agents. Bubbling fluidised-bed gasification tests with wheat straw showed that agglomerates with different sizes and structures formed in the bed depending on the temperature, the feed gas composition and bed material. Agglomerates consisted of molten ash which sintered with bed material and other solids. In all BFB tests, freeboard walls were slicked by ash agglomerates (different amounts) which, however, were easily removable. The results of this project and the earlier pilot-scale gasification experience obtained with the same feedstocks showed that useful characteristic data about ash behaviour can be obtained using laboratory tests and small scale reactors. (orig.)

  2. Fabrication of agglomerate-free nanopowders by hydrothermal chemical processing

    OpenAIRE

    Schmidt, Helmut K.; Nass, Rüdiger; Burgard, Detlef; Nonninger, Ralph

    1998-01-01

    A chemical processing technique for the fabrication of nanopowders has been developed. The route is based on precipitation processes in solutions, either within aqueous droplets in microemulsions in the presence of surface modifiers like surfactants or by direct precipitation in solutions in the presence of theses surface modifiers or small organic molecules directly bonded to the particle surface. In order to obtain well crystallized or densified particles, a continuous flow hydrothermal pro...

  3. Prediction of powder stickiness along spray drying process in relation to agglomeration

    OpenAIRE

    Gianfrancesco, Alessandro; Turchiuli, Christelle; Dumoulin, Élisabeth; Palzer, S.

    2009-01-01

    The spray drying process consists of a fast convective drying of liquid droplets by hot air. Initially, the water activity (aw) of a drop is close to 1. During drying, the drop surface aw decreases while viscosity increases until reaching a sticky rubbery state before further drying. This can be observed for products such as carbohydrates, leading to particles sticking on walls (product losses) or to adhesion between particles leading to agglomeration. In this study, particle stickiness was i...

  4. Simulation of Solid Particle Agglomeration Process in Gas Enhanced by High Intensity Sound Field%Simulation of Solid Particle Agglomeration Process in Gas Enhanced by High Intensity Sound Field

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    There are two mechanisms in the particle agglomeration process enhanced by the high intensity sound field in the gas-solid system: the orthokinetic interaction mechanism and hydrodynamic interaction mechanism. The orthokinetic interaction mechanism, hydrodynamic interaction mechanism and the acoustic agglomeration process which included the both two mechanisms were investigated by modeling method and MATLAB program. The results showed: the value of acoustic agglomeration kernel function (AAKF) based on the orthokinetic interaction mechanism was zero when the size of two particles in the pair was the same.

  5. Encapsulation of hazardous wastes into agglomerates

    International Nuclear Information System (INIS)

    The objective of this study was to investigate the feasibility of using the cementitious properties and agglomeration characteristics of coal conversion byproducts to encapsulate and immobilize hazardous waste materials. The intention was to establish an economical way of co-utilization and co-disposal of wastes. In addition, it may aid in the eradication of air pollution problems associated with the fine-powdery nature of fly ash. Encapsulation into agglomerates is a novel approach of treating toxic waste. Although encapsulation itself is not a new concept, existing methods employ high-cost resins that render them economically unfeasible. In this investigation, the toxic waste was contained in a concrete-like matrix whereby fly ash and other cementitious waste materials were utilized. The method incorporates the principles of solidification, stabilization and agglomeration. Another aspect of the study is the evaluation of the agglomeration as possible lightweight aggregates. Since fly ash is commercially used as an aggregate, it would be interesting to study the effect of incorporating toxic wastes in the strength development of the granules. In the investigation, the fly ash self-cementation process was applied to electroplating sludges as the toxic waste. The process hoped to provide a basis for delisting of the waste as hazardous and, thereby greatly minimize the cost of its disposal. Owing to the stringent regulatory requirements for hauling and disposal of hazardous waste, the cost of disposal is significant. The current practice for disposal is solidifying the waste with portland cement and dumping the hardened material in the landfill where the cost varies between $700--950/ton. Partially replacing portland cement with fly ash in concrete has proven beneficial, therefore applying the same principles in the treatment of toxic waste looked very promising

  6. Processing of Sugarcane Bagasse ash and Reactivity of Ash-blended Cement Mortar

    Science.gov (United States)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad

    Sugarcane bagasse ash (SCBA), a sugar-mill waste, has the potential of a partial cement replacement material if processed and obtained under controlled conditions. This paper discusses the reactivity of SCBA obtained by control burning of sugarcane bagasse procured from Punjab province of India. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to ascertain the amorphousness and morphology of the minerals ash particles. Destructive and non-destructive tests were conducted on SCBA-blended mortar specimens. Ash-blended cement paste specimens were analyzed by XRD, thermal analysis, and SEM methods to evaluate the hydration reaction of SCBA with cement. Results showed that the SCBA processed at 600°C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

  7. Evaluation of Vitrification Processing Step for Rocky Flats Incinerator Ash

    Energy Technology Data Exchange (ETDEWEB)

    Wigent, W.L.; Luey, J.K.; Scheele, R.D.; Li, H.

    1999-04-08

    In 1997, Pacific Northwest National Laboratory (PNNL) staff developed a processing option for incinerator ash at the Rocky Flats Environmental Technology Sites (RFETS). This work was performed with support from Los Alamos National Laboratory (LANL) and Safe Sites of Colorado (SSOC). A description of the remediation needs for the RFETS incinerator ash is provided in a report summarizing the recommended processing option for treatment of the ash (Lucy et al. 1998). The recommended process flowsheet involves a calcination pretreatment step to remove carbonaceous material followed by a vitrification processing step for a mixture of glass tit and calcined incinerator ash. Using the calcination pretreatment step to remove carbonaceous material reduced process upsets for the vitrification step, allowed for increased waste loading in the final product, and improved the quality of the final product. Figure 1.1 illustrates the flow sheet for the recommended processing option for treatment of RFETS incinerator ash. In 1998, work at PNNL further developed the recommended flow sheet through a series of studies to better define the vitrification operating parameters and to address secondary processing issues (such as characterizing the offgas species from the calcination process). Because a prototypical rotary calciner was not available for use, studies to evaluate the offgas from the calcination process were performed using a benchtop rotary calciner and laboratory-scale equipment (Lucy et al. 1998). This report focuses on the vitrification process step after ash has been calcined. Testing with full-scale containers was performed using ash surrogates and a muffle furnace similar to that planned for use at RFETS. Small-scale testing was performed using plutonium-bearing incinerator ash to verify performance of the waste form. Ash was not obtained from RFETS because of transportation requirements to calcine the incinerator ash prior to shipment of the material. Because part of

  8. Advanced physical fine coal cleaning spherical agglomeration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    The project included process development, engineering, construction, and operation of a 1/3 tph proof-of-concept (POC) spherical agglomeration test module. The POC tests demonstrated that physical cleaning of ultrafine coal by agglomeration using heptane can achieve: (1) Pyritic sulfur reductions beyond that possible with conventional coal cleaning methods; (2) coal ash contents below those which can be obtained by conventional coal cleaning methods at comparable energy recoveries; (3) energy recoveries of 80 percent or greater measured against the raw coal energy content; (4) complete recovery of the heptane bridging liquid from the agglomerates; and (5) production of agglomerates with 3/8-inch size and less than 30 percent moisture. Test results met or exceeded all of the program objectives. Nominal 3/8-inch size agglomerates with less than 20 percent moisture were produced. The clean coal ash content varied between 1.5 to 5.5 percent by weight (dry basis) depending on feed coal type. Ash reductions of the run-of-mine (ROM) coal were 77 to 83 percent. ROM pyritic sulfur reductions varied from 86 to 90 percent for the three test coals, equating to total sulfur reductions of 47 to 72 percent.

  9. Influences of Different Components on Agglomeration Behavior of MoS2 During Oxidation Roasting Process in Air

    Science.gov (United States)

    Wang, Lu; Zhang, Guo-Hua; Wang, Jing-Song; Chou, Kuo-Chih

    2016-08-01

    An agglomeration of the furnace charge always takes place during the oxidation roasting process of molybdenite concentrate (with the main component of MoS2) in multiple hearth furnaces, which greatly affects the production process and furnace service life. In the present work, a preliminary study about the influence of various components on the agglomeration phenomenon of pure MoS2 have been carried out. The results show that reaction temperature, impurity content, and air flow rate have significant effects on the agglomeration extent. Meanwhile, the impurity type added into the pure MoS2 plays a crucial role. It was found that CaO and MgO have a stronger sulfur-fixing effect and that the desulphurization of the roasted product was uncompleted. It was also concluded that the agglomeration is due to the formation of low-melting-point eutectics, including that between MoO3 and impurities and that between MoO3 and Mo4O11. It is suggested that decreasing the impurities contents, especially K, Cu, Pb, and Fe, is an effective method for reducing the extent of agglomeration.

  10. Influences of Different Components on Agglomeration Behavior of MoS2 During Oxidation Roasting Process in Air

    Science.gov (United States)

    Wang, Lu; Zhang, Guo-Hua; Wang, Jing-Song; Chou, Kuo-Chih

    2016-05-01

    An agglomeration of the furnace charge always takes place during the oxidation roasting process of molybdenite concentrate (with the main component of MoS2) in multiple hearth furnaces, which greatly affects the production process and furnace service life. In the present work, a preliminary study about the influence of various components on the agglomeration phenomenon of pure MoS2 have been carried out. The results show that reaction temperature, impurity content, and air flow rate have significant effects on the agglomeration extent. Meanwhile, the impurity type added into the pure MoS2 plays a crucial role. It was found that CaO and MgO have a stronger sulfur-fixing effect and that the desulphurization of the roasted product was uncompleted. It was also concluded that the agglomeration is due to the formation of low-melting-point eutectics, including that between MoO3 and impurities and that between MoO3 and Mo4O11. It is suggested that decreasing the impurities contents, especially K, Cu, Pb, and Fe, is an effective method for reducing the extent of agglomeration.

  11. Hydrothermal processing of new fly ash cement

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, W.; Roy, D.M. (Materials Research Lab., Pennsylvania State Univ., University Park, PA (United States))

    1992-04-01

    The recent Mount Pinatubo volcanic eruption in the Philippines, in which at least 268 people died, shows that volcanic eruptions can be highly destructive. The eruption shot ash and debris over the countryside; six towns near the volcano faced a high risk of devastating mudslides, and nearly 2000 U.S. service members and their families were evacuated from two nearby military bases. However, this paper reports that not all the consequences of volcanic eruptions are bad. Under hydrothermal conditions, volcanic ash can be transformed into zeolitic tuff and, eventually, into clay minerals that constitute agricultural soils. The Materials Research Laboratory (MRL) has recently used some artificial pozzolanas (fly ash) that when mixed with lime, under hydrothermal conditions, also produced a new type of cementitious material. This was categorized as a new fly ash cement. The formation of a new hydrothermally treated wood-fiber-reinforced composite has also been demonstrated. It is apparent, however, that with respect to concerns about detailed knowledge of the reactivity of calcium silicate-based materials under hydrothermal conditions, the application of the technology far outweighs the understanding of the underlying principles of reactivity. It would seem that an understanding of reactions on the molecular level is just beginning, and that work on hydrothermal reactions is still a potentially lucrative area of research.

  12. Behaviour of peat ash in high-temperature processes

    Energy Technology Data Exchange (ETDEWEB)

    Moilanen, A.

    1986-01-01

    The ash-forming constituents are in peat as minerals and bound in the organic framework. The kind of binding is dependent on peat type, plant species composition, acidity of the peatland, etc. Studies carried out with brown coal have indicated that the forms of ash occurrence in the fuel have an influence on the slagging ehaviour of ash in the process. The behaviour is also dependent on the reactor type and conditions in the reactor, for example, on the composition of gas atmosphere, on temperature, and gas flows. For example, the reducing conditions affect especially the occurrence of iron in different oxidation degrees in gasification, and this affects further the melting behaviour of ash. In brown coal gasification, as much as a third of the iron content was found to be reduced to metallic iron in the fluid-bed gasifier. To forecast the slagging behaviour of ash, the melting temperatures of ash are measured. Fouling or partial melting of ash cannot always be monitored with standard measuring methods, as these phenomena may start already at temperatures 200 deg C lower than the lowest melting temperature. THey can be studied for example with thermochemical methods.

  13. The problem of providing food resources in urban agglomerations (the case study of the Kuzbass agglomeration)

    OpenAIRE

    ZOBOVA L.L.; SHABASHEV V.A.

    2016-01-01

    Urban agglomerations are the result of a process of spatial competition for resources. To analyze the functioning of specific urban centers, it is necessary to make a distinction between the process of agglomeration and the state of agglomeration in the spatial structure. This paper shows the interrelation of the process of urban agglomeration and the agglomeration of the production activity as its economic foundation. The study reveals the connection between the urban agglomeration process a...

  14. Reduced ash related operational problems (slagging, bed agglomeration, corrosion and fouling) by co-combustion biomass with peat; Minskade askrelaterade driftsproblem (belaeggning, slaggning, hoegtemperatur-korrosion, baeddagglomerering) genom inblandning av torv i biobraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Marcus; Boman, Christoffer; Erhardsson, Thomas; Gilbe, Ram; Pommer, Linda; Bostroem, Dan; Nordin, Anders; Samuelsson, Robert; Burvall, Jan

    2006-12-15

    Combustion studies were performed in both a fluidized bed (5 kW) and in an under-feed pellets burner (20 kW) to elucidate the responsible mechanisms for the positive effects on ash related operational problems (i.e. slagging, fouling, corrosion and bed agglomeration) during co-combustion of several problematic biomass with peat. Three typical carex-containing Swedish peat samples with differences in e.g. silicon-, calcium- and sulfur contents were co-fired with logging residues, willow and straw in proportions corresponding to 15-40 weight %d.s. Mixing of corresponding 20 wt-% of peat significantly reduced the bed agglomeration tendencies for all fuels. The fuel specific agglomeration temperature were increased by 150-170 deg C when adding peat to the straw fuel and approximately 70-100 deg C when adding peat to the logging residue- and the willow fuel. The increased level of calcium in the inner bed particle layer caused by the added reactive calcium from the peat and/or removing alkali in the gas phase to a less reactive particular form via sorption and/or reaction with reactive peat ash (containing calcium, silica etc.) during which larger particles (>1{mu}m) are formed where collected potassium is present in a less reactive form, is considered to be the dominated reason for the increased agglomeration temperatures during combustion of logging residues and willow. During straw combustion, the ash forming matter were found as individual ash sticky particles in the bed. The iron, sulphur and calcium content of these individual ash particles were significantly increased when adding peat to the fuel mix thereby decreasing the stickiness of these particles i.e. reducing the agglomeration tendencies. Adding peat to the relatively silicon-poor fuels (willow and logging residues) resulted in higher slagging tendencies, especially when the relative silicon rich peat fuel (Brunnskoelen) was used. However, when co-combusting peat with the relatively silicon and potassium

  15. Effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor.

    Science.gov (United States)

    Varol, Murat; Atimtay, Aysel T

    2015-12-01

    This study aimed to investigate the effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor. The tests included co-combustion of 50-50% by wt. mixtures of Bursa-Orhaneli lignite+olive cake and Denizli-Kale lignite+olive cake, with and without limestone addition. Ash samples were subjected to XRF, XRD and SEM/EDS analyses. While MgO was high in the bottom ash for Bursa-Orhaneli lignite and olive cake mixture, Al2O3 was high for Denizli-Kale lignite and olive cake mixture. Due to high Al2O3 content, Muscovite was the dominant phase in the bottom ash of Denizli Kale. CaO in the bottom ash has increased for both fuel mixtures due to limestone addition. K was in Arcanite phase in the co-combustion test of Bursa/Orhaneli lignite and olive cake, however, it mostly appeared in Potassium Calcium Sulfate phase with limestone addition.

  16. Processing and Sintering of Agglomerate-free CaO-ZrO2 Powder

    Institute of Scientific and Technical Information of China (English)

    Liping LIANG; Shu'e DANG; Dong WU; Yuhan SUN

    2004-01-01

    Coprecipitation supercritical fluid drying technology has been employed to synthesize calcia-stabilized zirconia ultrafine powder with low-cost inorganic salts as the starting materials. The sintering behaviors of these powders were also investigated. The results showed that supercritical fluid drying could effectively alleviate the hard agglomeration of grains during the gel drying process, and the morphology of the powder retained the network texture of the original gel.The resulting particles were characterized by small particle size (5~20 nm), better monodispersity and high surface area, which gave rise to high activity and sinterability. Consequently, these powders could readily be compacted into the desired shape and their densification could be carried out in shorter time and at lower temperatures. For instance,nanometer-sized powder calcined at 600℃ for 2 h could be cold-pressed into a green body and sintered at 1100° for 0.5 h to attain a dense body with bulk density of 5.9718 g/cm3 and specific pore volume of 0.0008 cm3/g.

  17. Temperature-Switchable Agglomeration of Magnetic Particles Designed for Continuous Separation Processes in Biotechnology.

    Science.gov (United States)

    Paulus, Anja S; Heinzler, Raphael; Ooi, Huey Wen; Franzreb, Matthias

    2015-07-01

    The purpose of this work was the synthesis and characterization of thermally switchable magnetic particles for use in biotechnological applications such as protein purification and enzymatic conversions. Reversible addition-fragmentation chain-transfer polymerization was employed to synthesize poly(N-isopropylacrylamide) brushes via a "graft-from" approach on the surface of magnetic microparticles. The resulting particles were characterized by infrared spectroscopy and thermogravimetric analysis and their temperature-dependent agglomeration behavior was assessed. The influence of several factors on particle agglomeration (pH, temperature, salt type, and particle concentration) was evaluated. The results showed that a low pH value (pH 3-4), a kosmotropic salt (ammonium sulfate), and a high particle concentration (4 g/L) resulted in improved agglomeration at elevated temperature (40 °C). Recycling of particles and reversibility of the temperature-switchable agglomeration were successfully demonstrated for ten heating-cooling cycles. Additionally, enhanced magnetic separation was observed for the modified particles. Ionic monomers were integrated into the polymer chain to create end-group functionalized particles as well as two- and three-block copolymer particles for protein binding. The adsorption of lactoferrin, bovine serum albumin, and lysozyme to these ion exchange particles was evaluated and showed a binding capacity of up to 135 mg/g. The dual-responsive particles combined magnetic and thermoresponsive properties for switchable agglomeration, easy separability, and efficient protein adsorption.

  18. 灰融聚流化床粉煤气化技术应用及节能减排措施%Use of Agglomerating Ash Fluid Bed Pulverized Coal Gasification Technology and Measures for Energy Saving and Discharge Reduction

    Institute of Scientific and Technical Information of China (English)

    毕可军

    2011-01-01

    The agglomerating ash fluid bed pulverized coal gasification technology is described, its special features, process flow and the measures taken for energy saving and discharge reduction, with results. A comparison is given of the gasifiers at atmospheric and 1. 0 Mpa pressures for the production of 1 000 m3 of gas with the UGI oxygen-enriched gasifier, and the results show that the energy consumption of the atmospheric fluid bed gasifier is slightly lower than that of the UGI oxygen-enriched gasifier, while the 1.0 Mpa pressurized one is more advantageous than the atmospheric one in terms of energy saving.%介绍了灰融聚流化床粉煤气化技术的特点、工艺流程及采取的节能减排措施和效果.对常压和加压1.0 MPa灰融聚流化床粉煤气化炉生产1 000m3煤气的能耗分别与UGI富氧气化炉进行比较,结果表明:常压灰融聚流化床粉煤气化技术的能耗略低于UGI富氧气化技术,而加压1.0 MPa灰融聚流化床粉煤气化技术比常压灰融聚流化床粉煤气化技术在节能方面更具优势.

  19. Phosphorus recovery from sewage sludge ash through an electrodialytic process

    DEFF Research Database (Denmark)

    Guedes, Paula; Couto, Nazare; Ottosen, Lisbeth M.;

    2014-01-01

    The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB...

  20. Computational prediction of the refinement of oxide agglomerates in a physical conditioning process for molten aluminium alloy

    Science.gov (United States)

    Tong, M.; Jagarlapudi, S. C.; Patel, J. B.; Stone, I. C.; Fan, Z.; Browne, D. J.

    2015-06-01

    Physically conditioning molten scrap aluminium alloys using high shear processing (HSP) was recently found to be a promising technology for purification of contaminated alloys. HSP refines the solid oxide agglomerates in molten alloys, so that they can act as sites for the nucleation of Fe-rich intermetallic phases which can subsequently be removed by the downstream de-drossing process. In this paper, a computational modelling for predicting the evolution of size of oxide clusters during HSP is presented. We used CFD to predict the macroscopic flow features of the melt, and the resultant field predictions of temperature and melt shear rate were transferred to a population balance model (PBM) as its key inputs. The PBM is a macroscopic model that formulates the microscopic agglomeration and breakage of a population of a dispersed phase. Although it has been widely used to study conventional deoxidation of liquid metal, this is the first time that PBM has been used to simulate the melt conditioning process within a rotor/stator HSP device. We employed a method which discretizes the continuous profile of size of the dispersed phase into a collection of discrete bins of size, to solve the governing population balance equation for the size of agglomerates. A finite volume method was used to solve the continuity equation, the energy equation and the momentum equation. The overall computation was implemented mainly using the FLUENT module of ANSYS. The simulations showed that there is a relatively high melt shear rate between the stator and sweeping tips of the rotor blades. This high shear rate leads directly to significant fragmentation of the initially large oxide aggregates. Because the process of agglomeration is significantly slower than the breakage processes at the beginning of HSP, the mean size of oxide clusters decreases very rapidly. As the process of agglomeration gradually balances the process of breakage, the mean size of oxide clusters converges to a

  1. DOES EU-INTEGRATION CHANGE AGGLOMERATION PROCESS? THE IMPACT OF EU MEMBERSHIP PROCESS ON THE CITY-SIZE DISTRIBUTION OF TURKEY

    Directory of Open Access Journals (Sweden)

    Engin Sorhun

    2013-02-01

    Full Text Available This paper aims to reveal the eventual impacts of European Union (EU membership process and other conventional factors on the city-size distribution of a candidate country (Turkey. I can state main results as follows: Analyzing from different estimation methods the direct effect of the EU reforms on agglomerating forces rather than congesting forces are revealed to be dominant for Turkey. However, the main impact of the EU membership process has positive but modest coefficient that indicate the weak willingness of the country for EU reforms.Keywords: Economic itegration, agglomeration, city-size distribution, EU, Turkey.JEL Classification: F15, F22, R12, R23

  2. IMPACT OF PARTICLE SIZE AND AGGLOMERATION ON SETTLING OF SOLIDS IN CONTINUOUS MELTERS PROCESSING RADIOACTIVE WASTE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    HRMA PR

    2008-12-18

    The major factor limiting waste loading for many waste compositions in continuous waste glass melters is the settling of crystalline materials. The currently used constraints, i.e., the minimum liquidus temperature or the maximum fraction of equilibrium crystallinity at a given temperature, are based on thennodynamic equilibria. Because of the rapid circular convection in the melter, these constraints are probably irrelevant and cannot prevent large crystals from settling. The main factor that detennines the rate of settling ofindividual crystals, such as those ofspinel, is their size. The tiny crystals of RU02 are too small to settle, but they readily fonn large agglomerates that accelerate their rate ofsettling by severalorders ofmagnitude. The RU02 agglomerates originate early in the melting process and then grow by the shear-flocculation mechanism. It is estimated that these agglomerates must either be ofhundreds micrometers in size or have an elongated shape to match the observed rates ofthe sludge-layer fonnation. PACS: 47.57.ef, 81.05.Kj, 81.10.Fg

  3. Comparison of reduction disintegration characteristics of TiO2-rich burdens prepared with sintering process and composite agglomeration process

    Science.gov (United States)

    Yu, Zheng-wei; Li, Guang-hui; Liu, Chen; Zhou, Feng; Peng, Zhi-wei; Jiang, Tao

    2016-04-01

    To reveal the impact of the composite agglomeration process (CAP) on the reduction disintegration properties of TiO2-rich ironmaking burden for a blast furnace, the reduction disintegration indices (RDIs), mineral constituents, and microstructure of the products prepared by the CAP and the traditional sintering process (TSP) were investigated. The results showed that, compared to the sinter with a basicity of 2.0 prepared by the TSP, the RDI+6.3 and the RDI+3.15 of the CAP product with the same basicity increased by 28.2wt% and 13.7wt%, respectively, whereas the RDI-0.5 decreased by 2.7wt%. The analysis of the mineral constituents and microstructure of the products indicated that the decreasing titanohematite content decreased the volume expansion during reduction. Meanwhile, the decreasing perovskite content decreased its detrimental effect on the reduction disintegration properties. In addition, the higher silicoferrite of calcium and aluminum (SFCA) content improved the strength of the CAP product. Together, these factors result in an improvement of the RDI of the CAP products. In addition, compared to the sinter, the reduced CAP products clearly contained fewer cracks, which also led to mitigation of reduction disintegration.

  4. Recent Advances in the Development and Application of Power Plate Transducers in Dense Gas Extraction and Aerosol Agglomeration Processes

    Science.gov (United States)

    Riera, E.; Cardoni, A.; Gallego-Juárez, J. A.; Acosta, V. M.; Blanco, A.; Rodríguez, G.; Blasco, M.; Herranz, L. E.

    Power ultrasound (PU) is an emerging, innovative, energy saving and environmental friendly technology that is generating a great interest in sectors such as food and pharmaceutical industries, green chemistry, environmental pollution, and other processes, where sustainable and energy efficient methods are required to improve and/or produce specific effects. Two typical effects of PU are the enhancement of mass transfer in gases and liquids, and the induction of particle agglomeration in aerosols. These effects are activated by a variety of mechanisms associated to the nonlinear propagation of high amplitude ultrasonic waves such as diffusion, agitation, entrainment, turbulence, etc. During the last years a great effort has been jointly made by the Spanish National Research Council (CSIC) and the company Pusonics towards introducing novel processes into the market based on airborne ultrasonic plate transducers. This technology was specifically developed for the treatment of gas and multiphasic media characterized by low specific acoustic impedance and high acoustic absorption. Different strategies have been developed to mitigate the effects of the nonlinear dynamic behavior of such ultrasonic piezoelectric transducers in order to enhance and stabilize their response at operational power conditions. This work deals with the latter advances in the mitigation of nonlinear problems found in power transducers; besides it describes two applications assisted by ultrasound developed at semi-industrial and laboratory scales and consisting in extraction via dense gases and particle agglomeration. Dense Gas Extraction (DGE) assisted by PU is a new process with a potential to enhance the extraction kinetics with supercritical CO2. Acoustic agglomeration of fine aerosol particles has a great potential for the treatment of air pollution problems generated by particulate materials. Experimental and numerical results in both processes will be shown and discussed.

  5. Cold Agglomeration of Ultrafine Oxidized Dust (UOD from Ferromanganese and Silicomanganese Industrial Process

    Directory of Open Access Journals (Sweden)

    María Ordiales

    2016-08-01

    Full Text Available Different wastes are generated in ferromanganese and silicomanganese alloy production. One of them is the ultrafine oxidized dust (UOD produced in the collection and control of flying dusts in the ferroalloy industry. This waste has fairly high manganese content (20%–40% Mn, making it suitable to be a secondary raw material for the ferromanganese industry. This research proposes a method for the transformation of UOD into a useable raw material. Cold agglomeration is the best option, due to its low energy consumption. Portland cement and refractory cement are compared as suitable candidates in the management of the UOD for their reuse in the electric arc furnace feed.

  6. A high temperature granulation process for ecological ash recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Sundqvist, Thomas

    1999-07-01

    This thesis is a summary of three papers dealing with new technologies for facilitating ecological biomass ash recirculation back to forest and farm lands. The present outtake of biomass for paper and energy production may be incompatible with a sustainable forestry. The cycle of nutrients contained in the biomass extracted must be closed by ash recirculation in an environmental compatible way. This implies stabilization of the loose ashes/rest-products to a product with low heavy metal contents, controlled leaching properties and a high spreadability. In the present work, two different techniques were evaluated for the possibilities to separate heavy metals from the nutrient elements by utilizing high process temperatures to vaporize the unwanted metals from the condensed bulk materials. The results indicated that direct in-situ separation in fluidized bed combustion systems is possible, but requires too high process temperatures to be practically attractive. On the other hand, the new proposed high temperature treatment method for granulated raw materials was found to significantly separate As, Cd and Pb, with separation efficiencies exceeding 90 % at optimal operating conditions. In addition, the results indicated that the treatment method could be used to significantly delay and control the leaching characteristics, as well as the content of products of incomplete combustion of the produced granules.

  7. Relationship between attachment probability and surface energy in adhesion process of gold particles to oil-carbon agglomerates

    Institute of Scientific and Technical Information of China (English)

    WU Xi-qing(伍喜庆); A.J. Monhemius; R.J. Gochin

    2003-01-01

    Based on the theoretical analyses, the adhesion process of fine gold particles to oil-carbon agglomerates in a dynamic system was quantitatively investigated in terms of the relationship between the attachment probability and the surface energy. The proposed way to establish this relationship is to firstly theoretically derive the formula to evaluate the surface energy change of the system by analyzing the adhesion process of a gold particle on an oil-carbon agglomerate in a mathematic and thermodynamic way. The obtained formula of the maximum energy change of unit surface area is, △ω'max =-1/2σhw (cosθ-1), which involves two measurable elements: interfacial tension and contact angle. In a well-quantified system, based on the related model it is also possible to calculate the complicated concept, namely, the attachment probability by transferring other measurable indices. In this way, after some adhesion experiments and measurements of relevant parameters, the empirical relationship between the attachment probability and the surface energy change was established in an exponential function, Pa =Aexp(-△Gsurf/k).

  8. What Controls the Sizes and Shapes of Volcanic Ash? Integrating Morphological, Textural and Geochemical Ash Properties to Decipher Eruptive Processes

    Science.gov (United States)

    Liu, E. J.; Cashman, K. V.; Rust, A.

    2015-12-01

    Volcanic ash particles encompass a diverse spectrum of shapes as a consequence of differences in the magma properties and the magma ascent and eruption conditions. We show how the quantitative analysis of ash particle shapes can be a valuable tool for deciphering magma fragmentation and transport processes. Importantly, integrating morphological data with ash texture (e.g. bubble and crystal sizes) and dissolved volatile data provides valuable insights into the physical and chemical controls on the resulting ash deposit. To explore the influence of magma-water interaction (MWI) on fine ash generation, we apply this multi-component characterisation to tephra from the 2500BC Hverfjall Fires, Iceland. Here, coeval fissure vents spanned sub-aerial to shallow lacustrine environments. Differences in the size and morphology of pyroclasts thus reflect fragmentation mechanisms under different near-surface conditions. Using shape parameters sensitive to both particle roughness and internal vesicularity, we quantify the relative proportions of dense fragments, bubble shards, and vesicular grains from 2-D SEM images. We show that componentry (and particle morphology) varies as a function of grain size, and that this variation can be related back to the bubble size distribution. Although both magmatic and hydromagmatic deposits exhibit similar component assemblages, they differ in how these assemblages change with grain size. These results highlight the benefits of characterising ash deposits over a wide range of grain sizes, and caution against inferring fragmentation mechanism from a narrow grain size range. Elevated matrix glass S concentrations in hydromagmatic ash (600-1500 ppm) compared to those in magmatic ash and scoria lapilli (200-500 ppm) indicate interrupted vesiculation. In contrast to the subaerial 'dry' deposits, fragmentation during MWI likely occurred over a greater range of depths with quench rates sufficient to prevent post-fragmentation degassing. High

  9. Merging two waste streams, wood ash and biowaste, results in improved composting process and end products.

    Science.gov (United States)

    Fernández-Delgado Juárez, M; Gómez-Brandón, M; Insam, H

    2015-04-01

    A trial was carried out to evaluate the influence of wood ash admixture on biowaste composting. The aim was to find the optimal dosage of ash addition to enhance the composting process without endangering the final compost characteristics and use. Six treatments including an unamended control (K0) and composts with additions of 3% (K3), 6% (K6), 9% (K9), 12% (K12) and 15% (K15) of wood ash (w/w) were studied. The composting process was monitored in situ for 49days, by measuring temperature, CO2, O2, and CH4 in the piles and pH, electric conductivity (EC), and inorganic N in the laboratory. At the end of the process, the products were tested for Reifegrad (maturity), toxicity and quality. The addition of up to 15% of wood ash to biowaste did not negatively affect the composting process, and the initial differences found between both the low and high ash-treated composts were attenuated with the ongoing process development. Nevertheless, and mainly due to Cd level, composts with higher ash amendment did not comply with the highest quality standards established by the Austrian Compost Ordinance. The failure of obtaining class A+ quality after ash amendment emphasizes the need for a rigid quality selection of (bottom) ashes and thus reducing environmental risks related to high pollutant loads originating from the ashes. PMID:25536175

  10. Agglomeration of ash during combustion of peat and biomass in fluidized-bed reactors. Development of image analysis technique based on scanning electron microscopy; Tuhkan muuntuminen leijukerroskaasutuksessa ja -poltossa. Haitallisten hivenmetallien vapautuminen ja alkalien kaeyttaeytyminen

    Energy Technology Data Exchange (ETDEWEB)

    Kauppinen, E. [VTT Chemistry, Espoo (Finland); Arpiainen, V.; Jokiniemi, J. [VTT Energy, Espoo (Finland)] [and others

    1996-12-01

    The objective of the project is to study the behaviour of alkali metals (Na and K) and hazardous trace elements (Sb, As, Be, Cd, Cr, Co, Pb, Mn, Ni, Se and Zn) during fluidized bed combustion and gasification of solid fuels. The areas of interest are the release of elements studied from the bed and the behaviour of gaseous and particle-phase species after the release from the bed. During 1995 combustion and gasification experiments of Polish coal in bubbling bed were carried out with a laboratory scale fluidized bed gasifier in atmospheric pressure. Flue gas samples were drawn from the freeboard of the reactor and cooled quickly using a dilution probe. Ash particle size distributions were determined using low pressure impactors and differential mobility analyser. The morphology of the ash particles was studied with a scanning electron microscope (SEM) and will be further studied with transmission electron microscopy (TEM). The ash matrix elements (Si, Al, Fe, Ca and Mg) and the alkali metals (Na and K) were not significantly vaporized during the combustion process. More than 99 % of each of these elements was found in ash particles larger than 0.4 {mu}m. In Polish coal the alkali metals are bound mainly in silicates. The alkali metals were not released from the silicate minerals during the combustion process. A significant fraction of As, Cd and Pb was vaporized, released as gaseous species from the fuel particle and condensed mainly on the fine ash particles. 20 - 34 % of cadmium was present in fly ash particles smaller than 0.6 {mu}m (during combustion in 950 deg C), whereas only 1 % of the total ash was in this size fraction. All of the hazardous trace elements studied (As, Be, Cd, Co, Cr, Mn and Zn) were enriched in ash size fraction 0.6 - 5 {mu}m. The enrichment of Co, Cr, Mn, Ni, Pb and Sb was more significant during combustion in 950 deg C than in lower temperature (850 deg C)

  11. Physical cleaning of high carbon fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Gray, McMahan L.; Champagne, Kenneth J.; Soong, Yee; Killmeyer, Richard P. [National Energy Technology Laboratory, US Department of Energy, P.O. Box 10940, Cochran Mills Roads, 15236 Pittsburgh, PA (United States); Maroto-Valer, M. Mercedes; Andresen, John M. [The Energy Institute, The Pennsylvania State University, 405 Academic Activities Building, 16802-2308 University Park, PA (United States); Ciocco, Michael V.; Zandhuis, Paul H. [Parson Project Services Inc, National Energy Technology Laboratory, P.O. Box 618, 15129 Library, Pittsburgh, PA (United States)

    2002-04-20

    An industrial fly ash sample was cleaned by three different processes, which were triboelectrostatic separation, ultrasonic column agglomeration, and column flotation. The unburned carbon concentrates were collected at purities ranging up to 62% at recoveries of 62%. In addition, optical microscopy studies were conducted on the final carbon concentrates to determine the carbon forms (inertinite, isotropic coke and anisotropic coke) collected from these various physical-cleaning processes. The effects of the various cleaning processes on the production of different carbon forms from high carbon fly ashes will be discussed.

  12. Decay of Metastable State with Account of Agglomeration and Relaxation Processes

    Directory of Open Access Journals (Sweden)

    Victor Kurasov

    2016-01-01

    Full Text Available Theoretical description of the metastable phase decay kinetics in the presence of specific connections between the embryos of small sizes has been given. The theory of the decay kinetics in the presence of relaxation processes is constructed in analytical manner. The m-mers nucleation is investigated and the global kinetics of decay is also constructed in this case analytically.

  13. The simulation of incineration ash in a burning process

    International Nuclear Information System (INIS)

    The paper first provides some problems of taking the radioactive wastes contaminated with cesium 137 in municipal waste incineration facilities. For analyzing the behaviors of cesium in an incinerator, a computer code was developed and the results presented. Ash concentration and distribution of particulate radius are used from incineration conditions, added circumstances from consideration of the chemical reaction between cesium compounds and ashes including chemical forms and using DEM model so as applicable to a real burning facility. (S. Ohno)

  14. Processes of Defragmentation, Thermocapillary Extraction and Agglomeration of Ultradispersed Gold from Mineral Raw Materials and Technogenic Products within Laser Radiation Field

    Directory of Open Access Journals (Sweden)

    A.P. Kuzmenko

    2013-10-01

    Full Text Available According to the analysis of the results of complex studies of mineral raw materials and man-handle products containing ultra-dispersed gold, silver, and platinum before and after laser treatment, a qualitative physical model which explains the origin of thermal processes occurring under the action of laser radiation is proposed. It is noted that laser treatment of those materials generates processes of defragmentation, thermocapillary extraction, and agglomeration of micro-and nanoinclusions of these metals.

  15. Amenability of Muzret bituminous coal to oil agglomeration

    Energy Technology Data Exchange (ETDEWEB)

    Sahinoglu, E.; Uslu, T. [Karadeniz Technical University, Department of Mining Engineering, 61080 Trabzon (Turkey)

    2008-12-15

    Laboratory scale agglomeration tests were undertaken to investigate the amenability of Muzret (Yusufeli-Artvin) bituminous coal to oil agglomeration. Kerosene was extensively used as oil in the tests. In addition, fuel oil, diesel oil, and hazelnut oil were also used in order to determine the effect of oil type. The effects of the parameters including coal content, kerosene content, agglomeration time, coal particle size, pH, oil type, and agitation rate, on the combustible matter recovery, ash reduction and pyritic sulphur reduction, were investigated. It was found that Muzret bituminous coal could be readily cleaned by oil agglomeration with substantial reductions in ash and pyritic sulphur content. Maximum combustible matter recovery, ash reduction and pyritic sulphur reduction were achieved to be 85.54%, 59.98%, and 85.17%, respectively. (author)

  16. Amenability to dry processing of high ash thermal coal using a pneumatic table

    Institute of Scientific and Technical Information of China (English)

    Dey Shobhana; Gangadhar B.; Gopalkrishna S.J.

    2015-01-01

    High ash thermal coal from India was used to conduct the dry processing of fine coal using a pneumatic table to evolve a techno-economically novel technique. The fine as-received sample having 55.2%ash was subjected to washability studies at variant densities from 1.4 to 2.2 to assess the amenability to separa-tion. The experiments were conducted using a central composite design for assessing the interactive effects of the variable parameters of a pneumatic table on the product yield and ash content. The perfor-mance of the pneumatic table was analyzed in terms of clean coal yield, recovery of combustibles, separation efficiency (Esp) and useful heat value of clean coal. The combustibles of clean coal obtained through a single stage operation at 35% and 38.7% ash were 40% and 63% respectively. However, the two stage processing was more effective in reducing the ash content in the clean coal. The rougher con-centrate generated at higher ash level was subsequently processed in different conditions at 35% ash level, and 58%combustibles could be recovered. Hence, two stage processing increases the combustibles by 18 units and the useful heat value of clean coal increases from 1190 kcal/kg to 3750 kcal/kg.

  17. Trace and major element pollution originating from coal ash suspension and transport processes.

    Science.gov (United States)

    Popovic, A; Djordjevic, D; Polic, P

    2001-04-01

    Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport. PMID:11341293

  18. Trace and major element pollution originating from coal ash suspension and transport processes

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, A.; Djordjevic, D.; Polic, P. [University of Belgrade, Belgrade (Yugoslavia). Faculty of Science, Dept. of Chemistry

    2001-07-01

    Coal ash obtained from Nikola Tesla A power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. It is concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

  19. Trace and major element pollution originating from coal ash suspension and transport processes.

    Science.gov (United States)

    Popovic, A; Djordjevic, D; Polic, P

    2001-04-01

    Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

  20. Agglomeration patterns in the Polish manufacturing industry

    Directory of Open Access Journals (Sweden)

    Tomasz Brodzicki

    2012-01-01

    Full Text Available External liberalization should affect regional agglomeration patterns in manufacturing industry. In Poland, the largest CEE economy, economic transition was marked by accelerated restructuring associated with relatively rapid external trade and capital flows liberalization. The process of economic transition was reinforced by accession to the EU. Economic transition could potentially have a sizeable impact on industrial agglomeration patterns. Using sectoral agglomeration indices we examine changes in the agglomeration patterns of the Polish manufacturing industry. The analysis is carried out on a disaggregated data set on employment for 2 and 3-digit NACE manufacturing industry sectors at the level of local administrative districts (LAD4 level. The data set covers the period 1999-2006. The overall agglomeration index for Polish manufacturing industry decreased only by 0.5 percent within the analyzed period of time. The patter of agglomeration remained largely unaffected despite of significant structural adjustments in other areas.

  1. Stabilization and separation of heavy metals in incineration fly ash during the hydrothermal treatment process.

    Science.gov (United States)

    Hu, Yuyan; Zhang, Pengfei; Li, Jianping; Chen, Dezhen

    2015-12-15

    In the paper, hydrothermal treatment (HT) of MSWI fly ashes was performed to stabilize and separate heavy metals. Influences of pre-treatment, types of ferric and/or ferrous additives, and subsequent heavy metal stabilization procedure by adding phosphate were investigated. The chemical stability of hydrothermal products was examined by solid waste extraction procedure with acetic acid buffer solution. Mineralogical investigation of selected hydrothermal product was carried out by XRD. FEGE SEM- -EDX was used to study the morphology and surface compositions of the ash particles. Experimental results revealed that HT process facilitated heavy metal exposure to leaching solution. FEGE SEM-EDX images revealed that fly ash particles were re-organized during hydrothermal process and that the minerals with special shapes and containing high levels of heavy metals were formed. A mild acid washing treatment with final pH around 6.20 could remove soluble heavy metals. Therefore, it may be a proper pre- or post-treatment method for fly ash particles for the purpose of reducing heavy metal contents. For the purpose of stabilizing heavy metals, the addition of ferric/ferrous salts in the HT process or phosphate stabilization after HT is recommended. The HT process may be applied to realize the environmentally sound management of MSWI fly ash or to recover and utilize MSWI fly ash. PMID:26100935

  2. Defining urban agglomerations to detect agglomeration economies

    CERN Document Server

    Cottineau, Clementine; Hatna, Erez; Arcaute, Elsa; Batty, Michael

    2016-01-01

    Agglomeration economies are a persistent subject of debate among economists and urban planners. Their definition turns on whether or not larger cities and regions are more efficient and more productive than smaller ones. We complement existing discussion on agglomeration economies and the urban wage premium here by providing a sensitivity analysis of estimated coefficients to different delineations of urban agglomeration as well as to different definitions of the economic measure that summarises the urban premium. This quantity can consist of total wages measured at the place of work, or of income registered at the place of residence. The chosen option influences the scaling behaviour of city size as well as the spatial distribution of the phenomenon at the city level. Spatial discrepancies between the distribution of jobs and the distribution of households at different economic levels makes city definitions crucial to the estimation of economic relations which vary with city size. We argue this point by regr...

  3. Acidification - neutralization processes in a lignite mine spoil amended with fly ash or limestone

    Energy Technology Data Exchange (ETDEWEB)

    Seoane, S.; Leiros, M.C. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Edafologia y Quimica Agricola

    2001-08-01

    A laboratory experiment was conducted to investigate the long-term effects of amending sulfide-rich lignite mine spoil with fly ash (originating from a coal-fired power station and largely comprised of aluminosilicates) and/or agricultural limestone. The experiment was carried out with soil moisture maintained at field capacity or alternate cycles of wetting and drying. Results obtained suggest that the principal acidification processes were oxidation of sulfide and formation of hydroxysulfate (FeOHSO{sub 4}), whereas the main neutralization processes were weathering of aluminosilicates in fly ash-treated samples. The highest dose of limestone rapidly raised the pH of the spoil, but this increase was not maintained throughout the one-year experiment. In contrast, fly ash-treated samples showed a more sustained increase in pH, attributable to the gradual weathering of aluminosilicates. The best results (i.e., good short- and long-term neutralization) were obtained in samples treated with both fly ash and limestone. The low liming capacity of the fly ash (47.85 cmol kg{sup -1}) means that it must be used in large quantities, an advantage in achieving the further aim of disposing of the fly ash. 33 refs., 5 figs., 4 tabs.

  4. Co-composting of biowaste and wood ash, influence on a microbially driven-process.

    Science.gov (United States)

    Fernández-Delgado Juárez, Marina; Prähauser, Barbara; Walter, Andreas; Insam, Heribert; Franke-Whittle, Ingrid H

    2015-12-01

    A trial at semi-industrial scale was conducted to evaluate the effect of wood ash amendment on communal biowaste in a composting process and on the final composts produced. For this purpose, three treatments including an unamended control (C0) and composts with additions of 6% (C6), and 12% (C12) of wood ash (w/w) were studied, and physico-chemical parameters as well as microbial activity and community composition were investigated. At the end of the process, composts were tested for toxicity and quality, and microbial physiological activity. The influence of ash addition on compost temperature, pH, microbial activity and composition was stronger during the early composting stages and diminished with time, whereby composts became more similar. Using the COMPOCHIP microarray, a reduction in the pathogenic genera Listeria and Clostridium was observed, which together with the temperature increases of the composting process helped in the hygienisation of composts. Lactobacillus species were also affected, such that reduced hybridisation signals were observed with increased ash addition, due to the increased pH values in amended composts. Organic matter mineralisation was also increased through ash addition, and no negative effects on the composting process were observed. The nutrient content of the final products was increased through the addition of ash, and no toxic effects were observed. Nonetheless, greater concentrations of heavy metals were found in composts amended with more ash, which resulted in a downgrading of the compost quality according to the Austrian Compost Ordinance. Thus, regulation of both input materials and end-product quality is essential in optimising composting processes. PMID:26394680

  5. Treatment process for MSW combustion fly ash laboratory and pilot plant experiments.

    Science.gov (United States)

    Wilewska-Bien, M; Lundberg, M; Steenari, B-M; Theliander, H

    2007-01-01

    Fly ash from combustion of municipal solid waste sometimes contains large amounts of soluble salts, such as NaCl, even though the content of soluble toxic metal compounds is relatively low. Removal of the salts by washing with water has been suggested as a method to increase the stability of this type of ash. In the work presented here, a simple washing process was studied and evaluated. The process includes three steps: leaching with water, filtration and displacement washing. Basic data were obtained in laboratory experiments and used in the construction of pilot plant equipment at a full size fluidized bed boiler, where a side-stream of the cyclone ash was treated. The process was designed to minimize the water consumption while obtaining an effective removal of salts and a stable ash residue. In order to achieve this, recirculation of leaching liquor was used and the displacement washing was adjusted to become close to ideal. The results showed that an ash/water slurry with a liquid to solid ratio as low as 3 could be handled without difficulty in the mixing, pumping and filtration units. Washing of the filter cake at a liquid to solid ratio of 0.5 removed the major part of the remaining dissolved salts in the pore liquid. About 90% of the chloride content was removed from the ash, whereas the contents of Na, K, Ca, Cd, Pb and a number of other minor elements were removed by 10-30%. Before treatment, the results of ash leaching tests were sometimes too high for chloride (2003/33/EC), but the treatment reduced the amount of soluble chlorides to far below the limit values. The leachability of most metals was reduced or unaffected by the ash treatment. For Na, K and Cl, it was less than 10% of the value for the untreated ash. However, the results showed that some ash components may be mobilized by the washing. Antimony is the most important due to its toxicity. PMID:17157492

  6. Experimental evidence for de novo synthesis of PBDD/PBDF and PXDD/PXDF as well as dioxins in the thermal processes of ash samples

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, K.; Ishikawa, N. [National Inst. for Environmental Studies, Tsukuba (Japan)

    2005-07-01

    Fly ash in gasification-melting plants and conventional incineration plants can form dioxins through a process known as de novo synthesis. This paper investigated the de novo synthesis of dioxins formed as a result of fly ash catalysis activities. Thermal experiments using fly ash were performed using a flow-through reactor to investigate the formation of brominated and chlorinated-brominated dibenzodioxins (PBDD/F) and dibenzofurans (PXDD/F). Ash samples were collected at conventional stoker incineration and gasification-melting plants. Samples included ash from a bag filter (Ash A); ash from a fluidized gasification and melting furnace plant (Ash C); boiler ash (Ash B); and ash containing tetrabromobisphenol (Ash D). Samples were subjected to a thermal treatment at 300 degrees C. Results showed that dioxin levels were very high for Ash A, which suggested that temperature had a significant influence on de novo synthesis. Dioxin concentrations for Ash C had a relatively low carbon content. Considerable concentrations of PXDD/PXDF were determined for Ash A. High PBDD, PBDF, PXDD and PXDF were observed for Ash D and Ash B. The total amount of dioxins in Ash A were relatively slow to change before and after the thermal treatment of the sample. The homologue distribution patterns of PCDD and PCDF in Ash A showed significant alterations after treatment. It was concluded that de novo dioxin synthesis occurred during the experimental procedure. Results suggested that carbon content plays an important role in the production of dioxins. 3 refs., 2 tabs., 4 figs.

  7. Evaluation of an accelerated mineralization process for ashes - feasibility study; Evaluering av jordmaansbildande askbehandlingsprocess (EJA) - foerstudie

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Holger; Bjurstroem, Henrik

    2005-03-01

    In Japan, expenses for landfilling yield about 400 USD per ton of ash, which gives an incentive to reduce the amount of landfilled ash. At NIES (National Institute for Environmental Studies) in Tsukuba, Japan, the AMT process (Accelerated Mineralization Technology) was developed aiming at the treatment of ashes and production of soil-like material for reuse. The objective of the project EJA was to evaluate the AMT process on the basis of available information and the possibilities the process could offer with respect to the conditions present in Sweden. With support of researchers at NIES, available literature including unpublished manuscripts on the AMT process was compiled, translated and evaluated. During treatment, the ashes are washed, aged and mixed with up to 5 % by weight of biodegradable organic matter. The material is stabilized at landfill. During up to several decades, metals are demobilized through a combination of three mechanisms, viz. carbonation, clay formation, and humification. Also persistent organic pollutants (POP) are demobilized due to humification products or they are degraded anaerobically. When the treatment is completed, the reuse of the material is envisaged. Due to the long treatment period, the AMT method might not be favored by ash producers in Sweden. In the future, landfill companies could be interested in the technology, since they are experienced to handle waste at long sight. This, however, requires that the legislation does not pose any hindrance for the implementation of the method, e.g. regarding the requirement to add organic matter to the ash. Above all, it remains several years of research on the AMT process to fully understand and evaluate the underlying biological and chemical processes as well as their interaction.

  8. The effect of wash cleaning and demagnetization process on the fly ash physico-chemical properties

    Directory of Open Access Journals (Sweden)

    A. Baliński

    2007-04-01

    Full Text Available Problems related in this study concern the possibility of improving the physico-chemical properties of fly ash used as a base granular material in moulding mixtures. The investigations were carried out mainly to evaluate the process of the fly ash modification performed in order to stabilize its mineralogical and chemical composition. Changes in chemical composition, specific surface and helium density of fly ash after the process of its wash cleaning and demagnetization were examined. The analysis of the data has proved that the process of wash cleaning considerably reduces the content of sodium and potassium. Calcium and magnesium are washed out, too. The wash cleaning process of fly ash reduces also its true density. This fact can be due to the washing out of illite as well as some fractions of haematite (the grains weakly bonded to the glassy phase. The process of demagnetization allows removing about 25.7% of the magnetic phase calculated in terms of Fe2O3. The process of demagnetization is accompanied by a decrease in the content of aluminium, sodium, potassium and calcium, and a reduction in the size of the specific surface by over one half. The possible processes of transformation have also been discussed.

  9. An SEM/EDX study of bed agglomerates formed during fluidized bed combustion of three biomass fuels

    International Nuclear Information System (INIS)

    The agglomeration behaviour of three biomass fuels (exhausted and virgin olive husk and pine seed shells) during fluidized bed combustion in a lab-scale reactor was studied by means of SEM/EDX analysis of bed agglomerate samples. The effect of the fuel ash composition, bed temperature and sand particle size on agglomeration was investigated. The study was focused on the main fuel ash components and on their interaction with the bed sand particles. Agglomeration was favoured by high temperature, small sand size, a high fraction of K and Na and a low fraction of Ca and Mg in the fuel ash. An initial fuel ash composition close to the low-melting point eutectic composition appears to enhance agglomeration. The agglomerates examined by SEM showed a hollow structure, with an internal region enriched in K and Na where extensive melting is evident and an external one where sand particles are only attached by a limited number of fused necks. Non-molten or partially molten ash structures deposited on the sand surface and enriched in Ca and Mg were also observed. These results support an ash deposition-melting mechanism: the ash released by burning char particles inside the agglomerates is quantitatively deposited on the sand surface and then gradually embedded in the melt. The low-melting point compounds in the ash migrate towards the sand surface enriching the outermost layer, while the ash structure is progressively depleted of these compounds

  10. Flocculation, hydrophobic agglomeration and filtration of ultrafine coal

    Science.gov (United States)

    Yu, Zhimin

    In coal preparation plant circuits, fine coal particles are aggregated either by oil agglomeration or by flocculation. In a new hydrophobic agglomeration process, recently developed hydrophobic latices are utilized. While the selectivity of such aggregation processes determines the beneficiation results, the degree of aggregation has a strong effect on fine coal filtration. The aim of this research was to study the fundamentals and analyze the common grounds for these processes, including the potential effect of the coal surface properties. The selective flocculation tests, in which three types of coal, which differed widely in surface wettability, and three additives (hydrophobic latices, a semi-hydrophobic flocculant and a typical hydrophilic polyelectrolyte) were utilized, showed that coal wettability plays a very important role in selective flocculation. The abstraction of a hydrophobic latex on coal and silica revealed that the latex had a much higher affinity towards hydrophobic coal than to hydrophilic mineral matter. As a result, the UBC-1 hydrophobic latex flocculated only hydrophobic coal particles while the polyelectrolyte (PAM) flocculated all the tested coal samples and minerals, showing no selectivity in the fine coal beneficiation. The oil agglomeration was tested using kerosene emulsified with various surfactants (e.g. cationic, anionic and non-ionic). Surfactants enhance not only oil emulsification, hence reducing oil consumption (down to 0.25--0.5%), but also entirely change the electrokinetic properties of the droplets and affect the interaction energy between oil droplets and coal particles. Consequently, the results found in the course of the experimental work strongly indicate that even oxidized coals can be agglomerated if cationic surfactants are used to emulsify the oil. Oil agglomeration of the Ford-4 ultrafine coal showed that even at extremely low oil consumption (0.25 to 0.5%), a clean coal product with an ash content around 5% at over

  11. Agglomeration and Market Interaction

    OpenAIRE

    Fujita, Masahisa; Thisse, Jacques-François

    2002-01-01

    The most salient feature of the spatial economy is the presence of a large variety of economic agglomerations. Our purpose is to review some of the main explanations for this universal phenomenon, as they are proposed in urban economics and modern economic geography. We first show why the competitive framework can hardly be the foundation for the economics of agglomeration. We then briefly review the alternative modelling strategies. In the hope of making our Paper accessible to a broad audie...

  12. SPHERICAL AGGLOMERATION – DIRECT TABLETTING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Patil Pradnya B.

    2011-11-01

    Full Text Available Direct tabletting technique is the modern and the most efficient process used in tablet manufacturing and has been successfully employed for various poorly soluble and poorly compressible drugs. Spherical agglomeration is particle engineering technique which involves the transformation of fine crystals into spherical shape particles which enhances the powder properties such as particle size, shape, flow properties, solubility and bioavailability of pharmaceutical drug substances. This technique can also be applied to sustain the drug release from solid dosage forms. The present article is on the detailed comprehensive review about advantages and disadvantages, mechanism, different manufacturing methods of spherical agglomerates and characterization of spherical agglomerates.

  13. Synthesis and characterization of nanocrystalline silver coating of fly ash cenosphere particles by electroless process.

    Science.gov (United States)

    Shukla, S; Seal, S; Schwarz, S; Zhou, D

    2001-12-01

    Electroless nanocrystalline Ag coating of fly ash cenosphere particles utilizing a Sn-Pd catalyst system is demonstrated in this article. The deposition of pure metallic nanocrystalline Ag on the fly ash cenosphere particle surface is confirmed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. Under the described conditions of electroless coating, average nanocrystalline Ag-coating thickness is observed to be approximately 220 nm, using a focused ion beam technique, which is less than that observed by transmission electron microscopy (TEM) (260-360 nm). TEM observation further reveals that the Ag-coating is made up of 50 nm Ag nanocrystallites, which is comparable with the size of approximately 37 nm obtained from the XRD data. The mechanism of the electroless Ag-coating process is discussed. Ag-coated fly ash particles find applications in manufacturing conducting polymers for electromagnetic interference shielding applications. PMID:12914083

  14. Experiments on gas-ash separation processes in volcanic umbrella plumes

    Science.gov (United States)

    Holasek, Rick E.; Woods, Andrew W.; Self, Stephen

    1996-03-01

    We present a series of analogue laboratory experiments which simulate the separation of ash and gas and the formation of secondary intrusions from finite volcanic umbrella plumes. We examined the lateral spreading of mixtures of freshwater and particles released into a laboratory tank containing a uniformly stratified aqueous solution. For times smaller than the sedimentation time of particles through the intrusion, the current remains coherent and intrudes laterally. As some of the particles settle into the underlying ambient fluid, a layer of particle-depleted fluid develops below the upper surface of the current and the density of the residual fluid is reduced. Over longer times, the intrusion ceases to be coherent, with small fingers of relatively buoyant, particle-depleted fluid rising from the upper part of the intrusion into the overlying fluid. Meanwhile, the lateral motion of the injected solution induces a return flow in the ambient fluid which sweeps some of the particles sedimenting from the lower surface of the intrusion inwards. As a result, relatively dense particle-laden fluid collects below the intrusion and then sinks into the underlying fluid. Eventually this fluid reaches a new neutral buoyancy height, where it intrudes to form a second laterally spreading current below the original intrusion. The process then repeats to form further weaker intrusions below. These results of the separation of the ash and volcanic gas in an umbrella plume are consistent with field observations at Sakurajima volcano where positively charged plumes, thought to consist of volcanic gas, have been observed above negatively charged plumes of ash. This work also suggests that volcanic aerosols may form up to a kilometer above the original injection height of the ash. In a strong wind shear, this could result in very different trajectories of the ash and gas and so be important for evaluating the impact of ash plumes on both aviation safety and volcanic aerosol formation

  15. Process identification and model development of contaminant transport in MSWI bottom ash

    NARCIS (Netherlands)

    Dijkstra, J.J.; Sloot, van der H.A.; Comans, R.N.J.

    2002-01-01

    In this work we investigate to what extent we are able to predict experimental data on column leaching of heavy metals from municipal solid waste incinerator (MSWI) bottom ash, using the current knowledge on processes controlling aqueous heavy metal concentrations in combination with a multicomponen

  16. Agglomeration of coal fines for premium fuel application

    International Nuclear Information System (INIS)

    This paper reports on fine coal in liquid suspension, which can be agglomerated in a number of ways. One of the oldest procedures involves the addition of electrolyte to the suspension to cause a reduction in the zeta potential and allow colliding particles to agglomerate. A second method involves the use of polymeric flocculants to bridge between particles. Both of these technologies are being used in the wastewater treatment plants for removal of fine waste particles from contaminated water. A third method involves the addition of a second immiscible liquid preferentially to wet the particles and cause adhesion by capillary interfacial forces. While the bonding forces in the first two methods are small and result in rather weak and voluminous agglomerates, the third method is postulated to produce more dense and much stronger agglomerates. In the case of fine coals, the carbonaceous constituents can be agglomerated and recovered from the aqueous suspension with many different coagulants. Inorganic or ash-forming constituents are also agglomerated along with the fine coal particles. As the froth floatation, agglomeration using coal and colloidal dust to effect a separation. Froth floatation, however, becomes less effective where extremely fine particles of cal must be treated or if there is considerable clay-size particle present. In contrast, there appears to be virtually no lower limit on the particle size suitable for agglomeration uses

  17. A Novel Process and Appratus for the manufacture of precipitated silica from rice husk ash

    OpenAIRE

    Mukunda, Hanasoge Suryanarayana Avadani; Dasappa, Srinivasaiah; Paul, Palkat Joseph; Subbukrishna, Dibbur Nagesh Rao; Rajan, Nagamangala Krishnaiyengar Sriranga

    2004-01-01

    A novel process for the manufacture of precipitated silica from rice husk ash, having a surface area ranging from $50-400m^2/g$ and tap density of $80-600kg/m^3$ having multiple applications in the field of rubbers and plastics, paints, toothpastes, catalyst, carrier agent, insulation, stabilizing and desiccants. The process method for silica precipitation is novel, where in the chemicals used are regenerated making it a closed loop operation. The extraction process through digestion, prec...

  18. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin, E-mail: leeam@dlut.edu.cn

    2015-04-15

    Highlights: • Glass ceramic composite is prepared from oil shale fly ash and MSWI bottom ash. • A novel method for the production of glass ceramic composite is presented. • It provides simple route and lower energy consumption in terms of recycling waste. • The vitrified slag can promote the sintering densification process of glass ceramic. • The performances of products decrease with the increase of oil shale fly ash content. - Abstract: Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2 h) showed the properties of density of 1.92 ± 0.05 g/cm{sup 3}, weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced

  19. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite

    International Nuclear Information System (INIS)

    Highlights: • Glass ceramic composite is prepared from oil shale fly ash and MSWI bottom ash. • A novel method for the production of glass ceramic composite is presented. • It provides simple route and lower energy consumption in terms of recycling waste. • The vitrified slag can promote the sintering densification process of glass ceramic. • The performances of products decrease with the increase of oil shale fly ash content. - Abstract: Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2 h) showed the properties of density of 1.92 ± 0.05 g/cm3, weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared

  20. Advances in food powder agglomeration engineering.

    Science.gov (United States)

    Cuq, B; Gaiani, C; Turchiuli, C; Galet, L; Scher, J; Jeantet, R; Mandato, S; Petit, J; Murrieta-Pazos, I; Barkouti, A; Schuck, P; Rondet, E; Delalonde, M; Dumoulin, E; Delaplace, G; Ruiz, T

    2013-01-01

    Food powders are used in everyday life in many ways and offer technological solutions to the problem of food production. The natural origin of food powders, diversity in their chemical composition, variability of the raw materials, heterogeneity of the native structures, and physicochemical reactivity under hydrothermal stresses contribute to the complexity in their behavior. Food powder agglomeration has recently been considered according to a multiscale approach, which is followed in the chapter layout: (i) at the particle scale, by a presentation of particle properties and surface reactivity in connection with the agglomeration mechanisms, (ii) at the mechanisms scale, by describing the structuration dynamics of agglomerates, (iii) at the process scale, by a presentation of agglomeration technologies and sensors and by studying the stress transmission mode in the powder bed, and finally (iv) by an integration of the acquired knowledge, thanks to a dimensional analysis carried out at each scale.

  1. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite.

    Science.gov (United States)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-04-01

    Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2h) showed the properties of density of 1.92 ± 0.05 g/cm(3), weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared to conventional vitrification and sintering method. Chemical resistance and heavy metals leaching results of glass ceramic composites further confirmed the possibility of its engineering applications. PMID:25649918

  2. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite.

    Science.gov (United States)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-04-01

    Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2h) showed the properties of density of 1.92 ± 0.05 g/cm(3), weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced compared to conventional vitrification and sintering method. Chemical resistance and heavy metals leaching results of glass ceramic composites further confirmed the possibility of its engineering applications.

  3. Bed agglomeration risk related to combustion of cultivated fuels (wheat straw, red canary grass, industrial hemp) in commercial bed materials; Baeddagglomereringsrisk vid foerbraenning av odlade braenslen (hampa, roerflen, halm) i kommersiella baeddmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Erhardsson, Thomas; Oehman, Marcus; Geyter, Sigrid de; Oehrstroem, Anna

    2006-12-15

    The market of forest products is expanding and thus resulting in more expensive biomass fuels. Therefore research within the combustion industry for alternative fuels is needed, for example cultivated fuels. Combustion and gasification research on these cultivated fuels are limited. The objectives of this work was to increase the general knowledge of silicon rich cultivated fuels by study the agglomeration characteristics for wheat straw, reed canary grass and industrial hemp in combination with commercial bed materials. Controlled fluidized bed agglomeration tests was conducted in a 5 kW, bench-scale, bubbling fluidized bed reactor. The tendencies of agglomeration were determined with the three cultivated fuels in combination with various minerals present in natural sand (quarts, plagioclase and potassium feldspar) and an alternative bed material (olivine). During the experiments bed samples and formed agglomerates were collected for further analyses with a scanning electron microscope (SEM) and with X-ray microanalysis (EDS). Wheat straw had the highest agglomeration tendency of the studied fuels followed by reed canary grass and industrial hemp. No significant layer formation was found around the different bed particles. Instead, the ash forming matter were found as individual ash sticky (partial melted) particles in the bed. The bed material mineralogical composition had no influence of the agglomeration process because of the non layer formation propensities of the used silicon rich fuels.

  4. Kinetics Analysis on Mixing Calcination Process of Fly Ash and Ammonium Sulfate

    Institute of Scientific and Technical Information of China (English)

    Peng Wang; Laishi Li; Dezhou Wei

    2014-01-01

    abstract The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggrandize the research of the calcination process, the kinetics and reaction mechanism of the calcinations were studied. The result suggests that there are two stages in the calcination process, and the alumina extraction rate increases swiftly in the initial stage, but slows down increasing in the later stage. The apparent activation energy of the initial and later stages equals to 13.31 and 35.65 kJ·mol-1, respectively. In the initial stage, ammonium sulfate reacts directly with mullite in the fly ash to form ammonium aluminum sulfate, while in the later stage, alumi-num sulfate is formed by the reaction between ammonium aluminum sulfate and ammonium sulfate.

  5. Agglomeration and Deposition Behaviour of Solid Recovered Fuel

    DEFF Research Database (Denmark)

    Pedersen, Morten Nedergaard; Jensen, Peter Arendt; Hjuler, Klaus;

    2016-01-01

    formation, or accumulation of impurities. The combustion of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), wood, and SRF were studied in a rotary drum furnace. The combustion was recorded on a camera (60 frames per second), so that any agglomeration or deposition of fuel or ash...... by a careful combustion control. The ash from SRF or wood does not pose a significant risk of melting and deposits at temperatures up to 1000 °C, but the presence of glass impurities in some SRF may limit operation temperatures to 900 °C as a result of ash melting....

  6. Agglomeration Control of Ultrafine Y2 O3-ZrO2 and (MgO, Y2 O3)-ZrO2 Powders Synthesized by Coprecipitation Process

    Institute of Scientific and Technical Information of China (English)

    MA Yalu; ZHANG Yu; ZHENG Junping

    2005-01-01

    Chemical coprecipitation was used to produce ultrafine and easily sinterable Y2O3-stabilized and (Y2O3,MgO)-stabilized ZrO2 powders. Six precipitation processes for preparation of ZrO2-based ultrafine powders were designed separately, meanwhile different techniques used to control the agglomeration formation were proposed. By means of TEM, SEM, Raman spectroscopy and IR spectroscopy, the mechanisms of agglomeration control in the precipitation processes and post-precipitation and drying process were investigated. The experimental results show that adding appropriate anion surface active agents (such as PAA1460) or polymer (PEG1540 matching with PEG200) in aqueous solution systems during precipitation processes could reinforce charge effect and location effect for gel particles interface. Adding wetting agents to wet gels washing with distilled water during drying process could change interface structure of gel particles and decrease surface tension between gel particles. The agglomeration control in the precipitation, post-precipitation and drying processes had remarkable influence on the characteristics of powders. By adding various macromolecules in the processes, the agglomeration state could be controlled efficiently, and the characteristics of powders were improved.

  7. Agglomeration and Co-Agglomeration of Services Industries

    OpenAIRE

    Kolko, Jed

    2007-01-01

    Economic research on industry location and agglomeration has focused nearly exclusively on manufacturing. This paper shows that services are prominent among the most agglomerated industries, especially at the county level. Because traditional measures of knowledge spillovers, natural resource inputs, and labor pooling explain little of agglomeration in services industries, this paper takes an alternative approach and looks at co-agglomeration to assess why industries cluster together. By cons...

  8. The Structure of Agglomerates consisting of Polydisperse Particles

    OpenAIRE

    Eggersdorfer, M. L.; Pratsinis, S.E.

    2012-01-01

    Agglomeration is encountered in many natural or industrial processes, like growth of aerosol particles in the atmosphere and during material synthesis or even flocculation of suspensions, granulation, crystallization and with colloidal particle processing. These particles collide by different mechanisms and stick together forming irregular or fractal-like agglomerates. Typically, the structure of these agglomerates is characterized with the fractal dimension, Df, and pre-exponential factor, k...

  9. The influence of coal-associated trace elements on sintering and agglomeration of a model coal mineral mixture / M.V. Nel.

    OpenAIRE

    Nel, Marika Verita

    2009-01-01

    A series of experiments was conducted to investigate the potential influence of selected inorganic compounds on sintering and agglomeration of a model mineral mixture. The minerals and inorganic compounds were chosen based on the constituents found in coal. The study simulated ash formation processes in the temperature range of 500 °C to 1000 DC. The mineral mixture consisted of kaolinite, quartz, pyrite, siderite, calcite, Ti02 and magnesite in a fIxed ratio. The mixture was ...

  10. Preliminary Study on a Novel Process for Manufacturing Soda Ash from Sodium Sulfate

    Institute of Scientific and Technical Information of China (English)

    王天贵; 李佐虎

    2004-01-01

    The purpose of this work is to find a new way for utilizing the rich sodium sulfate resource to produce soda ash. A novel process is proposed which uses aqueous dichromate solution as working medium through decomposition of calcium carbonate in aqueous sodium dichromate, complex decomposition of aqueous sodium sulfate and calcium chromate, regeneration of sodium dichromate and production of sodium bicarbonate from carbonation of aqueous sodium chromate solution, processing and utilization of byproduct calcium sulfate, and production of sodium carbonate from sodium bicarbonate. The process has the features of less corrosion and pollution and low energy consumption.

  11. Mechanics and charging of nanoparticle agglomerates

    Science.gov (United States)

    Shin, Weon Gyu

    This thesis consists of two parts. The first part concerns studies on mechanics of real agglomerate particles and the second part involves studies on unipolar diffusion charging of agglomerates. Understanding mechanics of real agglomerate particles consisting of multiple primary particles is important for aerosol sizing instrumentation using electrical mobility and nanoparticle manufacturing process where coagulation and sedimentation occur. A key quantity determining transport properties of agglomerates is the friction coefficient. However, quantitative studies for the friction coefficient of agglomerates are very limited. Transmission Electron Microscopy (TEM) image analysis results of silver agglomerates provides a basis for the comparison of experimental data with estimates based on free molecular models. A new quantitative method to determine the dynamic shape factor and the two exponents, eta and Dfm, which characterize the power law dependence of friction coefficient on the number of primary spheres and the mass on the mobility diameter, was developed using Differential Mobility Analyzer (DMA)-Aerosol Particle Mass (APM) analyzer. Model predictions indicate that eta is independent of agglomerate size while Dfm is sensitive to agglomerate size. Experimentally, it appears the opposite is true. Tandem DMA (TDMA) results also show that the mass-mobility diameter scaling exponent is not dependent on mobility size range. Estimates of non-ideal effects on the agglomerate dynamics were computed as perturbations to the Chan-Dahneke agglomerate model. After the corrections, an agreement between experimental data and model predictions becomes significantly improved. Unipolar diffusion charging becomes more attractive because it has higher charging efficiency than bipolar charging as well as important applications in aerosol sizing instrumentation using electrical mobility, powder coating, and the removal of toxic particles from air stream using Electrostatic

  12. Waste Minimization Protocols for the Process of Synthesizing Zeolites from South African Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Leslie F. Petrik

    2013-04-01

    Full Text Available Production of a high value zeolite from fly ash has been shown to be an avenue for the utilization of South African fly ash which presently constitutes a huge disposal problem. The synthesis of zeolites Na-P1 and analcime on a micro-scale has been successful and preliminary investigation shows that scale-up synthesis is promising. However, the post-synthesis supernatant waste generated contains high levels of NaOH that may constitute a secondary disposal problem. A waste minimization protocol was developed to reduce the volume of waste generated with a view to enhancing the feasibility of the scale synthesis. Series of experiments were conducted in 100 mL jacketed batch reactors. Fly ash was reacted with 5 Mol NaOH on a 1:1 mass basis during the aging step, followed by hydrothermal treatment in which ultrapure water was added to the slurry. This study shows that by re-introducing the supernatant waste into the experiments in such a way that it supplies the required reagent (NaOH for the zeolite synthesis, zeolite Na-P1 and analcime can be synthesized. It also shows that the synthesis process can be altered to allow up to 100% re-use of the supernatant waste to yield high value zeolitic products. This study effectively constructed two protocols for the minimization of waste generated during the synthesis of zeolites from South African coal fly ash. This result could be used to establish a basis for legal and environmental aspects involved in the commission of a full-scale plant synthesizing zeolites NaP1 and analcime.

  13. Filtration behavior of silver nanoparticle agglomerates and effects of the agglomerate model in data analysis

    Energy Technology Data Exchange (ETDEWEB)

    Buha, Jelena, E-mail: jelena.buha@empa.ch [Empa, Analytical Chemistry (Switzerland); Fissan, Heinz [Institute of Energy and Environmental Technology e.V. (IUTA) (Germany); Wang, Jing, E-mail: jing.wang@ifu.baug.ethz.ch [Empa, Analytical Chemistry (Switzerland)

    2013-07-15

    In many data evaluation procedures for particle measuring devices and in filtration models, spherical particles are assumed. However, significant fractions of aerosol particles are agglomerates of small primary spheres. The morphology of particles in filtration processes may not be known a priori and if the filtration data are processed with wrong assumption, errors can be induced. In this work, we have quantified such errors for the case of open-structured agglomerates. Filtration efficiency tests with polydisperse silver nanoparticle agglomerates and their sintered spheres were performed. After the sintering process, particles with a compact structure with the shape close to a sphere are obtained, which are referred to as sintered spheres in the present study. The testing method involved generation of particulate forms, passing the particles through the testing section, and measurement of the particle number concentrations and size distributions before and after the filter. Measurements of the aerosols upstream and downstream of the filter were conducted using scanning mobility particle sizers (SMPS, TSI Inc.), which covered the rage from 10 to 480 nm. Particles were additionally characterized from the electron microscopic images and the average primary particle size was determined to be 16.8 nm. The number-size distribution curves were obtained and used for penetration calculation. The penetration was dependent on the particle size and morphology. Silver-sintered spheres were captured with a lower efficiency than agglomerates with the same mobility diameter because of the stronger interception effect for agglomerates. Data analysis of the number-size distribution for agglomerates was processed based on sphere assumption and using the model for open-structured agglomerates developed by Lall and Friedlander. The efficiencies based on total concentrations of number, surface and volume were affected when the agglomerate model was used. The effect was weakest for the

  14. Marketization Process, Financial Industry Agglomeration and Regional Economic Growth%金融产业集聚、市场化进程与地区经济增长

    Institute of Scientific and Technical Information of China (English)

    纪玉俊; 周素娟

    2015-01-01

    As an important industry in national economy , the financial industry agglomeration can promote regional economic growth , and the realization of the growth effect is related to regional marketization process .Empirically test about the effect of China's financial industry agglomeration on provincial economic growth shows that financial industry agglomeration has promoting effect on the regional economic growth , using data from 1992 to 2011;adding the marketization process to construct threshold regression model to analyze shows that marketization process influ -ences the extent of financial industry agglomeration's growth effect on regional economic , that is to say , a higher level of marketization can better promote the effect of financial industry agglomeration on regional economic growth .%作为国民经济中的重要产业,金融产业集聚可以促进地区经济增长,而这一增长效应的实现与地区市场化进程有关。实证检验我国1992年—2011年各省市金融产业集聚的区域经济增长效应发现,金融产业集聚对区域经济增长具有促进效应;通过加入市场化进程构建门槛回归模型进行分析得出,市场化进程影响金融产业集聚的区域经济增长效应发挥程度,较高的市场化水平可以更好的促进金融产业集聚对区域经济增长效应的发挥。

  15. Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schrodt, J.T.

    1981-02-01

    Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

  16. An environmentally-friendly vacuum reduction metallurgical process to recover germanium from coal fly ash.

    Science.gov (United States)

    Zhang, Lingen; Xu, Zhenming

    2016-07-15

    The demand for germanium in the field of semiconductor, electronics, and optical devices is growing rapidly; however, the resources of germanium are scarce worldwide. As a secondary material, coal fly ash could be further recycled to retrieve germanium. Up to now, the conventional processes to recover germanium have two problems as follows: on the one hand, it is difficult to be satisfactory for its economic and environmental effect; on the other hand, the recovery ratio of germanium is not all that could be desired. In this paper, an environmentally-friendly vacuum reduction metallurgical process (VRMP) was proposed to recover germanium from coal fly ash. The results of the laboratory scale experiments indicated that the appropriate parameters were 1173K and 10Pa with 10wt% coke addition for 40min, and recovery ratio germanium was 93.96%. On the basis of above condition, the pilot scale experiments were utilized to assess the actual effect of VRMP for recovery of germanium with parameter of 1473K, 1-10Pa and heating time 40min, the recovery ratio of germanium reached 94.64%. This process considerably enhances germanium recovery, meanwhile, eliminates much of the water usage and residue secondary pollution compared with other conventional processes. PMID:27015376

  17. Fluid bed agglomeration with a narrow droplet size distribution

    NARCIS (Netherlands)

    Schaafsma, SH; Vonk, P; Kossen, NWF

    2000-01-01

    In the fluid bed agglomeration processes liquid distribution influences the agglomerate growth. We developed a new nozzle that produces uniform droplets, which allows droplets to be easily controlled in size independently of liquid- and airflow of the nozzle. It was found that the spray rate and the

  18. WP/084 Measuring Industry Agglomeration and Identifying the Driving Forces

    DEFF Research Database (Denmark)

    Howard, Emma; Tarp, Finn; Newman, Carol

    Understanding industry agglomeration and its driving forces is critical for the formulation of industrial policy in developing countries. Crucial to this process is the definition and measurement of agglomeration. We propose a new measure and examine what it reveals about the importance of transp...

  19. Identification of odor-processing genes in the emerald ash borer, Agrilus planipennis.

    Directory of Open Access Journals (Sweden)

    Praveen Mamidala

    Full Text Available BACKGROUND: Insects rely on olfaction to locate food, mates, and suitable oviposition sites for successful completion of their life cycle. Agrilus planipennis Fairmaire (emerald ash borer is a serious invasive insect pest that has killed tens of millions of North American ash (Fraxinus spp trees and threatens the very existence of the genus Fraxinus. Adult A. planipennis are attracted to host volatiles and conspecifics; however, to date no molecular knowledge exists on olfaction in A. planipennis. Hence, we undertook an antennae-specific transcriptomic study to identify the repertoire of odor processing genes involved in A. planipennis olfaction. METHODOLOGY AND PRINCIPAL FINDINGS: We acquired 139,085 Roche/454 GS FLX transcriptomic reads that were assembled into 30,615 high quality expressed sequence tags (ESTs, including 3,249 isotigs and 27,366 non-isotigs (contigs and singletons. Intriguingly, the majority of the A. planipennis antennal transcripts (59.72% did not show similarity with sequences deposited in the non-redundant database of GenBank, potentially representing novel genes. Functional annotation and KEGG analysis revealed pathways associated with signaling and detoxification. Several odor processing genes (9 odorant binding proteins, 2 odorant receptors, 1 sensory neuron membrane protein and 134 odorant/xenobiotic degradation enzymes, including cytochrome P450s, glutathione-S-transferases; esterases, etc. putatively involved in olfaction processes were identified. Quantitative PCR of candidate genes in male and female A. planipennis in different developmental stages revealed developmental- and sex-biased expression patterns. CONCLUSIONS AND SIGNIFICANCE: The antennal ESTs derived from A. planipennis constitute a rich molecular resource for the identification of genes potentially involved in the olfaction process of A. planipennis. These findings should help in understanding the processing of antennally-active compounds (e.g. 7-epi

  20. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-03-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

  1. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; J. A. Gurtler; K. Lewandowski

    2005-09-30

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

  2. Sulfur retention by ash during coal combustion. Part II. A model of the process

    Directory of Open Access Journals (Sweden)

    BRANIMIR JOVANCICEVIC

    2003-03-01

    Full Text Available An overall model for sulfur self-retention in ash during coal particle combustion is developed in this paper. It is assumed that sulfur retention during char combustion occurs due to the reaction between SO2 and CaO in the form of uniformly distributed non-porous grains. Parametric analysis shows that the process of sulfur self-retention is limited by solid difussion through the non-porous product layer formed on the CaO grains and that the most important coal characteristics which influence sulfur self-retention are coal rank, content of sulfur forms, molar Ca/S ratio and particle radius. A comparison with the experimentally obtained values in a FB reactor showed that the model can adequately predict the kinetics of the process, the levels of the obtained values of the SSR efficiencies, as well as the influence of temperature and coal particle size.

  3. Literature review and binder and coal selection for research studies on coal agglomeration

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, S.G.; Kuby, O.A.; Girimont, J.A.; peterson, C.A.; Saller, E.

    1982-02-26

    This report discusses the results of a literature survey on coal agglomeration and the approaches that were employed in selecting binders and coals to be studied in a process development program currently being performed for the Department of Energy. The survey is the first step toward the development of a useful process for the agglomeration of coal fines for use in a fixed-bed gasifier. Literature was found and reviewed on the effects of coal composition and physical properties, on agglomeration techniques and operating variables, on binders or additives to promote agglomeration, on pretreatment techniques on agglomerate feedstocks and post-treatment techniques on formed agglomerates, and on test results obtained by researchers in the past using various additives, treatments and agglomeration techniques. Much of this information did not deal directly with agglomerates for fixed-bed gasifiers, but the reported observations and results could be extrapolated to give useful guidelines for research plans. Conclusions and plans for further work are presented.

  4. Acoustic agglomeration of fine particles based on a high intensity acoustical resonator

    Science.gov (United States)

    Zhao, Yun; Zeng, Xinwu; Tian, Zhangfu

    2015-10-01

    Acoustic agglomeration (AA) is considered to be a promising method for reducing the air pollution caused by fine aerosol particles. Removal efficiency and energy consuming are primary parameters and generally have a conflict with each other for the industry applications. It was proved that removal efficiency is increased with sound intensity and optimal frequency is presented for certain polydisperse aerosol. As a result, a high efficiency and low energy cost removal system was constructed using acoustical resonance. High intensity standing wave is generated by a tube system with abrupt section driven by four loudspeakers. Numerical model of the tube system was built base on the finite element method, and the resonance condition and SPL increase were confirmd. Extensive tests were carried out to investigate the acoustic field in the agglomeration chamber. Removal efficiency of fine particles was tested by the comparison of filter paper mass and particle size distribution at different operating conditions including sound pressure level (SPL), and frequency. The experimental study has demonstrated that agglomeration increases with sound pressure level. Sound pressure level in the agglomeration chamber is between 145 dB and 165 dB from 500 Hz to 2 kHz. The resonance frequency can be predicted with the quarter tube theory. Sound pressure level gain of more than 10 dB is gained at resonance frequency. With the help of high intensity sound waves, fine particles are reduced greatly, and the AA effect is enhanced at high SPL condition. The optimal frequency is 1.1kHz for aerosol generated by coal ash. In the resonace tube, higher resonance frequencies are not the integral multiplies of the first one. As a result, Strong nonlinearity is avoided by the dissonant characteristic and shock wave is not found in the testing results. The mechanism and testing system can be used effectively in industrial processes in the future.

  5. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-09-30

    Heap leaching is one of the methods being used to recover metal from low grade ore deposits. The main problem faced during heap leaching is the migration of fine grained particles through the heap, forming impermeable beds which result in poor solution flow. The poor solution flow leads to less contact between the leach solution and the ore, resulting in low recovery rates. Agglomeration of ore into coarse, porous masses prevents fine particles from migrating and clogging the spaces and channels between the larger ore particles. Currently, there is one facility in the United States which uses agglomeration. This operation agglomerates their ore using leach solution (raffinate), but is still experiencing undesirable metal recovery from the heaps due to agglomerate breakdown. The use of a binder, in addition to the leach solution, during agglomeration would help to produce stronger agglomerates that did not break down during processing. However, there are no known binders that will work satisfactorily in the acidic environment of a heap, at a reasonable cost. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. Increasing copper recovery in heap leaching by the use of binders and agglomeration would result in a significant decrease in the amount of energy consumed. Assuming that 70% of all the leaching heaps would convert to using agglomeration technology, as much as 1.64*10{sup 12} BTU per year would be able to be saved if a 25% increase in copper recovery was experienced, which is equivalent to saving approximately 18% of the energy currently being used in leaching heaps. For every week a leach cycle was decreased, a savings of as much as 1.23*10{sup 11} BTU per week would result. This project has identified several acid-resistant binders and agglomeration procedures. These binders and experimental procedures will be able to be used for use in improving the energy efficiency of

  6. Effect of polymers on crystallo-co-agglomeration of ibuprofen-paracetamol: Factorial design

    Directory of Open Access Journals (Sweden)

    Pawar A

    2007-01-01

    Full Text Available The purpose of this research was to study the effect of concentration of polyethylene glycol and ethyl cellulose on the properties of agglomerates of ibuprofen-paracetamol obtained by crystallo-co-agglomeration technique. The process of crystallo-co-agglomeration involved recrystallization of ibuprofen and its simultaneous agglomeration with paracetamol in presence polymers. The effect of combination of polyethylene glycol and ethylcellulose was studied by 2 2 factorial design. Ibuprofen content of the agglomerate increased with increase in ethyl cellulose while paracetamol content was decreased with increase in polyethylene glycol. Differential scanning calorimetry thermograms of agglomerates showed the unchanged endotherm for ibuprofen melting, whereas paracetamol endotherm was diffused with low enthalpy. The agglomerates were spherical but increase in polyethylene glycol caused its deformation. Agglomerates containing ethylcellulose with polyethylene glycol have higher resistance for fragmentation, modulus of elasticity but impart high tensile strength.

  7. MANIPULATION OF PHYSICAL FUNCTIONALITY OF BULK DRUG POWDER: AGGLOMERATE SIZE APPROACH

    Directory of Open Access Journals (Sweden)

    Kale Vinita

    2011-06-01

    Full Text Available Agglomeration is a size enlargement process in which primary particles stick together to form agglomerates. In past, various techniques have been developed to form agglomerates. One of the aims of this study was to form agglomerates using solvent treated method and traditional wet granulation method of a bulk drug and to study the effect of agglomeration on physical functionality of agglomerated and original bulk powders. Another objective of the study was to prepare compact of the agglomerated powders and bulk powder and to study their compactibility properties. The solvent treated agglomeration process was performed using 5% aqueous ammonia solution at different stirring speed and time. Powder flow and compactibility were considered as functionality parameters. Powder flowability was expressed in terms of – size and shape of particles, static angle of repose, Hausner ratio, Carrs index, porosity and packability. The compacts of agglomerated powders and bulk powder were prepared and tested for compressibility properties. All the powder functional properties of the solvent treated agglomerates were dramatically improved. Compacts by direct compression method could be formed successfully of solvent treated agglomerate powder that was comparable with the wet granules. The original powder of bulk drug failed to be compressed by direct compression method. Thus solvent treated agglomerates provided the requirements needed to convert wet granulated formulations to direct compression formulations, thus avoiding labor and energy intensive of wet granulation processes and is an alternative to develop cost effective formulations.

  8. Urban Agglomerations in Regional Development: Theoretical, Methodological and Applied Aspects

    Directory of Open Access Journals (Sweden)

    Andrey Vladimirovich Shmidt

    2016-09-01

    Full Text Available The article focuses on the analysis of the major process of modern socio-economic development, such as the functioning of urban agglomerations. A short background of the economic literature on this phenomenon is given. There are the traditional (the concentration of urban types of activities, the grouping of urban settlements by the intensive production and labour communications and modern (cluster theories, theories of network society conceptions. Two methodological principles of studying the agglomeration are emphasized: the principle of the unity of the spatial concentration of economic activity and the principle of compact living of the population. The positive and negative effects of agglomeration in the economic and social spheres are studied. Therefore, it is concluded that the agglomeration is helpful in the case when it brings the agglomerative economy (the positive benefits from it exceed the additional costs. A methodology for examination the urban agglomeration and its role in the regional development is offered. The approbation of this methodology on the example of Chelyabinsk and Chelyabinsk region has allowed to carry out the comparative analysis of the regional centre and the whole region by the main socio-economic indexes under static and dynamic conditions, to draw the conclusions on a position of the city and the region based on such socio-economic indexes as an average monthly nominal accrued wage, the cost of fixed assets, the investments into fixed capital, new housing supply, a retail turnover, the volume of self-produced shipped goods, the works and services performed in the region. In the study, the analysis of a launching site of the Chelyabinsk agglomeration is carried out. It has revealed the following main characteristics of the core of the agglomeration in Chelyabinsk (structure feature, population, level of centralization of the core as well as the Chelyabinsk agglomeration in general (coefficient of agglomeration

  9. Effects of kaolin-additions in combustion of wood fuels on hardening and leaching properties of ash; Paaverkan av kaolintillsats vid foerbraenning av biobraensle paa askans haerdnings- och lakningsegenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Karlfeldt, Karin (Dept. of Chemical And Biological Engineering, Chalmers Univ. of Technology, SE-412 96 Goeteborg (Sweden)). e-mail: bms@chalmers.se

    2007-06-15

    In several investigations it has been shown that kaolin works well as an anti-agglomerating and anti-ash sintering agent in combustion of bio-fuels with a potassium rich ash in fluidised bed boilers. Combustion tests have shown that the kaolin addition may result in an ash melting temperature that is a couple of hundred degrees centigrade higher than for the original ash. This way the kaolin hinders the fouling of super heater surfaces by sticky ash. Many boiler owners treat their wood fuel ash with the aim to recycle it to forest soil as a nutrient source and acid neutralising agent. Therefore it was considered important to investigate if an addition of kaolin in the boiler would have a negative influence on the ash leaching properties. Thus, the aim of the project was to investigate the hardening reactions and leaching properties of normal wood ash and wood ash produced with addition of kaolin. The ash samples were produced in the same boiler and in similar combustion conditions. It was especially interesting to study if the ash would contain soluble aluminium due to the kaolin addition since aluminium in solution may have negative effects on the eco system. The results showed that an important difference between the normal fly ash and the fly ash with kaolin was that the release of potassium i leaching was decreased due to the kaolin addition, especially at high pH levels. This is positive, since potassium normally is released very fast in the forest. In addition, the kaolin containing ash has a faster initial setting/hardening process than the normal ash. The structure of the hardened ash particles is also more durable than that of the normal ash. This is also a positive effect since it indicates that it could be possible to handle the hardened ash after a shorter storage period. However, it has not been investigated if this effect remains in large scale operation and in a longer time perspective. The acid neutralising capacity of fly ash with kaolin is

  10. Distributions, profiles and formation mechanisms of polychlorinated naphthalenes in cement kilns co-processing municipal waste incinerator fly ash.

    Science.gov (United States)

    Liu, Guorui; Zhan, Jiayu; Zhao, Yuyang; Li, Li; Jiang, Xiaoxu; Fu, Jianjie; Li, Chunping; Zheng, Minghui

    2016-07-01

    Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m(-3). The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g(-1). Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash.

  11. Distributions, profiles and formation mechanisms of polychlorinated naphthalenes in cement kilns co-processing municipal waste incinerator fly ash.

    Science.gov (United States)

    Liu, Guorui; Zhan, Jiayu; Zhao, Yuyang; Li, Li; Jiang, Xiaoxu; Fu, Jianjie; Li, Chunping; Zheng, Minghui

    2016-07-01

    Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m(-3). The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g(-1). Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash. PMID:27135696

  12. Nucleation of point defect agglomerates

    International Nuclear Information System (INIS)

    A theory of the agglomeration of point defects into dislocation loops and voids is formulated. A critical comparison between theory and experiment is made for nickel and copper irradiated in a high voltage electron microscope

  13. NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

    Energy Technology Data Exchange (ETDEWEB)

    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

    2004-04-01

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  14. Microbial effects on colloidal agglomeration

    International Nuclear Information System (INIS)

    Colloidal particles are known to enhance the transport of radioactive metals through soil and rock systems. This study was performed to determine if a soil microorganism, isolated from the surface samples collected at Yucca Mountain, NV, could affect the colloidal properties of day particles. The agglomeration of a Wyoming bentonite clay in a sterile uninoculated microbial growth medium was compared to the agglomeration in the medium inoculated with a Pseudomonas sp. In a second experiment, microorganisms were cultured in the succinate medium for 50 h and removed by centrifugation. The agglomeration of the clay in this spent was compared to sterile uninoculated medium. In both experiments, the agglomeration of the clay was greater than that of the sterile, uninoculated control. Based on these results, which indicate that this microorganism enhanced the agglomeration of the bentonite clay, it is possible to say that in the presence of microorganisms colloidal movement through a rock matrix could be reduced because of an overall increase in the size of colloidal particle agglomerates. 32 refs

  15. Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders

    NARCIS (Netherlands)

    Willemsz, Tofan A; Hooijmaijers, Ricardo; Rubingh, Carina M; Tran, Thanh N; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

    2012-01-01

    Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity.

  16. Analysis on the Spatial-Temporal Dynamics of Financial Agglomeration with Markov Chain Approach in China

    Directory of Open Access Journals (Sweden)

    Weimin Chen

    2014-01-01

    Full Text Available The standard approach to studying financial industrial agglomeration is to construct measures of the degree of agglomeration within financial industry. But such measures often fail to exploit the convergence or divergence of financial agglomeration. In this paper, we apply Markov chain approach to diagnose the convergence of financial agglomeration in China based on the location quotient coefficients across the provincial regions over 1993–2011. The estimation of Markov transition probability matrix offers more detailed insights into the mechanics of financial agglomeration evolution process in China during the research period. The results show that the spatial evolution of financial agglomeration changes faster in the period of 2003–2011 than that in the period of 1993–2002. Furthermore, there exists a very uneven financial development patterns, but there is regional convergence for financial agglomeration in China.

  17. Influence of ash composition on the sintering behavior during pressurized combustion and gasification process

    Institute of Scientific and Technical Information of China (English)

    Ni-jie JING; Qin-hui WANG; Yu-kun YANG; Le-ming CHENG; Zhong-yang LUO; Ke-fa CEN

    2012-01-01

    To determine the ash characteristics during fluidized bed combustion and gasification purposes,the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted.A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres.Meanwhile,the mineral transformations of sintered ash pellets were observed using X-ray diffractometer (XRD) analyzer to better understand the experimental results.In addition,quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer (FE-SEM/EDS) analyses of ash samples were used for clarifying the detailed ash melting mechanism.These results show that the addition of Fe2O3 can obviously reduce the sintering temperatures under gasification atmospheres,and only affect a little the sintering temperature under combustion atmosphere.This may be due to the presence of iron-bearing minerals,which will react with other ash compositions to produce low-melting-point eutectics.The FE-SEM/EDS analyses of ash samples with Fe2O3 additive show consistent results with the XRD measurements.The CaO and Na2O can reduce the sintering temperatures under both the combustion and gasification atmospheres.This can be also contributed to the formation of low-melting-point eutectics,decreasing the sintering temperature.Moreover,the fluxing minerals,such as magnetite,anhydrite,muscovite,albite and nepheline,contribute mostly to the reduction of the sintering temperature while the feldspar minerals,such as anorthite,gehlenite and sanidine,can react with other minerals to produce low-melting-point eutectics,and thereby reduce the sintering temperatures.

  18. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  19. INF 336 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    MADURA

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com INF 336 Week 1 DQ 1 Risk Management (Ash) INF 336 Week 1 DQ 2 Organizational Structure (Ash) INF 336 Week 2 DQ 1 Supply Process Improvements (Ash) INF 336 Week 2 DQ 2 Outsourcing (Ash) INF 336 Week 2 Assignment Article Review (Ash) INF 336 Week 3 DQ 1 Capital Goods (Ash) INF 336 Week 3 DQ 2 Quality (Ash) INF 336 Week 3 Assignment Need Definition (Ash) INF 336 Week 4 DQ 1 Procuring Services (Ash) ...

  20. MGT 401 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    kennith

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 401 Week 1 Individual Assignment Strategic Management Process Paper (Ash) MGT 401 Week 1 Class Activity Week 1 (Ash) MGT 401 Week 1 DQ 1 (Ash) MGT 401 Week 1 DQ 2 (Ash) MGT 401 Week 2 Learning Team Business Model Comparison Example (Ash) MGT 401 Week 2 DQ 1 (Ash) MGT 401 Week 2 DQ 2 (Ash) MGT 401 Week 2 Class Activity (Ash) MGT 401 Week 3 Individual Assignment Business Plan Evaluation (Ash) ...

  1. Agglomeration Economies in Classical Music

    DEFF Research Database (Denmark)

    Borowiecki, Karol Jan

    2015-01-01

    This study investigates agglomeration effects for classical music production in a wide range of cities for a global sample of composers born between 1750 and 1899. Theory suggests a trade-off between agglomeration economies (peer effects) and diseconomies (peer crowding). I test this hypothesis...... using historical data on composers and employ a unique instrumental variable – a measure of birth centrality, calculated as the average distance between a composer’s birthplace and the birthplace of his peers. I find a strong causal impact of peer group size on the number of important compositions...

  2. Fly ash porous material using geopolymerization process for high temperature exposure.

    Science.gov (United States)

    Abdullah, Mohd Mustafa Al Bakri; Jamaludin, Liyana; Hussin, Kamarudin; Bnhussain, Mohamed; Ghazali, Che Mohd Ruzaidi; Ahmad, Mohd Izzat

    2012-01-01

    This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash). In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash) synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure.

  3. Study of thermal-flow processes in ash cooler cooperating with CFB boiler

    Directory of Open Access Journals (Sweden)

    Paweł Regucki

    2016-03-01

    Full Text Available The article presents an example of thermal-flow analysis of the bottom ash cooler cooperating with the circulating fluidized bed boiler. There is presented a mathematical model of series-parallel hydraulic system supplying the ash cooler in cooling water. The numerical calculations indicate an influence of changes of the pipeline geometrical parameters on the cooling water flow rate in the system. Paper discusses the methodology of the studies and presents examples of the results of thermal balance calculations based on the results of measurements. The numerical results of the thermal-flow analysis in comparison with the measurements on the object indicate that the presented approach could be used as a diagnostic tool investigating the technical state of the bottom ash cooler.

  4. THE ALUMINA-SILICATES IN STABILIZATION PROCESSES IN FLUIDIZED-BED ASH

    Directory of Open Access Journals (Sweden)

    IVANA PERNA

    2011-03-01

    Full Text Available Presented study of coal fluidized-bed ash solidification was accompanied with specific studies of alumino-silicates residues in ashes. The specific technology of fluid coal burning and its relatively low temperature combustion combines coal burning and decomposition of calcium carbonate added to the fluid layer in the main endeavor to capture all sulfur oxides. The burning temperature seems be decisive to the behavior of clayed residues and calcium carbonate decomposition in connection for the future solidification of fluidized bed ash. The calcareous substances in combination with alumino-silicate residues form solid bodies where silicates play decisive role of long-term stability and insolubility of obtained solids. The position of aluminum ions in clayed residues of burned coal were studied by MAS-NMR with attention on aluminum ion coordination to oxygen and formation of roentgen amorphous phase of poly-condensed calcium alumina-silicate.

  5. Engineering Development of Advanced Physical Fine Coal Cleaning for Premium Fuel Applications: Task 9 - Selective agglomeration Module Testing and Evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Moro, N.` Jha, M.C.

    1997-09-29

    The primary goal of this project was the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and bench-scale testing of both processes on six coals to optimize the processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report summarizes the findings of all the selective agglomeration (SA) test work performed with emphasis on the results of the PDU SA Module testing. Two light hydrocarbons, heptane and pentane, were tested as agglomerants in the laboratory research program which investigated two reactor design concepts: a conventional two-stage agglomeration circuit and a unitized reactor that combined the high- and low-shear operations in one vessel. The results were used to design and build a 25 lb/hr bench-scale unit with two-stage agglomeration. The unit also included a steam stripping and condensation circuit for recovery and recycle of heptane. It was tested on six coals to determine the optimum grind and other process conditions that resulted in the recovery of about 99% of the energy while producing low ash (1-2 lb/MBtu) products. The fineness of the grind was the most important variable with the D80 (80% passing size) varying in the 12 to 68 micron range. All the clean coals could be formulated into coal-water-slurry-fuels with acceptable properties. The bench-scale results were used for the conceptual and detailed design of the PDU SA Module which was integrated with the existing grinding and dewatering circuits. The PDU was operated for about 9 months. During the first three months, the shakedown testing was performed to fine tune the operation and control of various equipment. This was followed by parametric testing, optimization/confirmatory testing, and finally a

  6. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt;

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  7. HYDROPHOBIC AGGLOMERATION OF MINERAL FINES IN AQUEOUS SUSPENSIONS AND ITS APPLICATION IN FLOTATION: A REVIEW

    OpenAIRE

    BINGQIAO YANG; SHAOXIAN SONG

    2014-01-01

    Hydrophobic agglomeration is originated from the hydrophobic attraction between particles, which is essentially different from electrolyte coagulation and polymer flocculation. It is applied to mineral processing in floc-flotation process to improve the recovery of mineral fines. In this paper, the applications of this phenomenon in mineral fines were summarized, including the origin of hydrophobic agglomeration, the main factors affect hydrophobic agglomeration (particle hydrophobicity, shea...

  8. Removal of selected heavy metals from MSW fly ash by the electrodialytic process

    DEFF Research Database (Denmark)

    Ferreira, Célia Maria Dias; Jensen, Pernille Erland; Ottosen, Lisbeth M.;

    2005-01-01

    This paper aims to assess the applicability of the electrodialytic remediation technique for the removal of zinc, lead, copper and cadmium from municipal solid waste (MSW) incinerator fly ash. A broad range of experimental conditions were studied including current densities, remediation times, us...

  9. Agglomeration and Deposition Behaviour of Solid Recovered Fuel

    DEFF Research Database (Denmark)

    Pedersen, Morten Nedergaard; Jensen, Peter Arendt; Nielsen, Mads;

    2015-01-01

    contains significant quantities of common plastics such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Fluidized bed experiments to examine the pyrolysis of polymers have shown that bed agglomeration can result from melting plastics or sticky char residues in the case...... of PET [11,12]. The main objective of this study was to characterize the combustion of SRF and especially the deposition propensity of SRF and the main constituents of SRF. This relates both to the low temperature deposits formed during plastic pyrolysis and the high temperature deposits formed by ash...... materials such as plastic and paper than mixed MSW [2]. The inhomogeneous nature of SRF [3] makes it difficult to combust and many problems may arise concerning e.g. combustion control, feeding of fuel [2,4], deposit formation [5], or accumulation of impurities [3]. Laboratory ash fusion tests typically...

  10. Crystallo-co-agglomeration: A novel particle engineering technique

    Directory of Open Access Journals (Sweden)

    Paradkar Anant

    2010-01-01

    Full Text Available Crystallo-co-agglomeration (CCA is a novel particle engineering/design technique developed by Kadam et al, to overcome the limitations of spherical crystallization (SC. Basically, it′s single step process used for size enlargement of single, two or more, small dose or large dose drugs, in combination with or without diluent. The process of CCA involves simultaneous crystallization and agglomeration of drug/s with/without excipients/s from good solvent and/or bridging liquid by addition of a non-solvent. Till date CCA has been applied for spherical agglomeration of talc, bromhexine hydrochloride-talc, ibuprofen-talc, ibuprofen-paracetamol, and naproxen-starch. The spherical agglomerates obtained by CCA can be used as intact beads (encapsulated spansules or directly compressible tablet intermediates having satisfactory micromeritic (flowability, mechanical (friability, crushing, compressional (compressibility, compactibility, and drug release properties. Modified drug release from agglomerates and compacts thereof can be achieved using suitable polymer composition in the process design. Thus, it can be concluded that, CCA is a simple and cost effective process, which can be tailor-made for particle design of all majority of drugs and combinations thereof.

  11. The soundscape dynamics of human agglomeration

    CERN Document Server

    Ribeiro, H V; Lenzi, E K; Mendes, R S; Evangelista, L R

    2011-01-01

    We report a statistical analysis about people agglomeration soundscape. Specifically, we investigate the normalized sound amplitudes and intensities that emerge from people collective meetings. Our findings support the existence of nontrivial dynamics characterized by heavy tail distributions in the sound amplitudes, long-range correlations in the sound intensity and non-exponential distributions in the return interval distributions. Additionally, motivated by the time-dependent behavior present in the volatility/variance series, we compare the observational data with those obtained from a minimalist autoregressive stochastic model, a GARCH process, finding a good agreement.

  12. Insights into methane hydrate formation, agglomeration, and dissociation in water + diesel oil dispersed system

    International Nuclear Information System (INIS)

    Highlights: • Hydrate agglomeration occurs at initial hydrate formation or under shutting down stages. • The agglomeration of hydrate is inhibited and dispersed with the action of anti-agglomerants. • The appearance of surface water may cause the agglomeration of hydrate during hydrate dissociation. • A mechanism was proposed to describe hydrate dissociation from water in oil dispersed system. - Abstract: Methane hydrate formation and dissociation in (5 vol% water + 95 vol% diesel oil) dispersed system containing a combined anti-agglomerant were experimentally studied using a high pressure autoclave installed with particle video microscope and focused beam reflectance measurement probes. The agglomeration of hydrate was found to occur at the initial hydrate formation stage. With the continuous formation of hydrate, the agglomeration of hydrate will be inhibited and hydrate was dispersed with the action of the anti-agglomerant. The agglomeration of hydrate also occurs when the hydrate containing fluid is under static state for a certain time. Larger hydrate particles attached by gas bubble with grape-like shape were found during hydrate dissociation. The dissociated surface water would contact with un-dissociated hydrate and accumulate to larger water/hydrate particles may be the reason that causes the agglomeration during initial hydrate dissociation process. A mechanism was proposed to describe hydrate dissociation from water in oil dispersed system

  13. Impact of agglomeration on the regional growth of Latin American countries

    OpenAIRE

    Rosero, Grace Carolina Guevara

    2015-01-01

    Theoretical approaches have been developed to examine the effect of agglomeration on growth. However, the understanding of the mechanisms of agglomeration in developing countries remains unaddressed. This paper aims to give empirical evidence of the role of agglomeration on the growth of Latin American regions. The study of the subcontinent is crucial because of the evidence of a rapid pace of urbanization process. Using a database with information of 162 regions of 8 Latin American countries...

  14. Commercial Demonstration of the Manufactured Aggregate Processing Technology Utilizing Spray Dryer Ash

    Energy Technology Data Exchange (ETDEWEB)

    Milton Wu; Paul Yuran

    2006-12-31

    Universal Aggregates LLC (UA) was awarded a cost sharing Co-operative Agreement from the Department of Energy (DOE) through the Power Plant Improvement Initiative Program (PPII) to design, construct and operate a lightweight aggregate manufacturing plant at the Birchwood Power Facility in King George, Virginia in October 2001. The Agreement was signed in November 2002. The installation and start-up expenses for the Birchwood Aggregate Facility are $19.5 million. The DOE share is $7.2 million (37%) and the UA share is $12.3 million (63%). The original project team consists of UA, SynAggs, LLC, CONSOL Energy Inc. and P. J. Dick, Inc. Using 115,000 ton per year of spray dryer ash (SDA), a dry FGD by-product from the power station, UA will produce 167,000 tons of manufactured lightweight aggregate for use in production of concrete masonry units (CMU). Manufacturing aggregate from FGD by-products can provide an economical high-volume use and substantially expand market for FGD by-products. Most of the FGD by-products are currently disposed of in landfills. Construction of the Birchwood Aggregate Facility was completed in March 2004. Operation startup was begun in April 2004. Plant Integration was initiated in December 2004. Integration includes mixing, extrusion, curing, crushing and screening. Lightweight aggregates with proper size gradation and bulk density were produced from the manufacturing aggregate plant and loaded on a stockpile for shipment. The shipped aggregates were used in a commercial block plant for CMU production. However, most of the production was made at low capacity factors and for a relatively short time in 2005. Several areas were identified as important factors to improve plant capacity and availability. Equipment and process control modifications and curing vessel clean up were made to improve plant operation in the first half of 2006. About 3,000 tons of crushed aggregate was produced in August 2006. UA is continuing to work to improve plant

  15. MGT 415 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    kennith archi

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 415 Week 1 DQ 1 Organizational Design (Ash) MGT 415 Week 1 DQ 2 The Research Project (Ash) MGT 415 Week 2 DQ 1 Group Development Process (Ash) MGT 415 Week 2 DQ 2 Influence of Informal Groups (Ash)  MGT 415 Week 3 DQ 1 Group Cohesion and Productivity (Ash) MGT 415 Week 3 DQ 2 Norms and Conformity (Ash) MGT 415 Week 3 Assignment Best Workplace (Ash) MGT 415 Week 4 DQ 1 Group Decisions (Ash) ...

  16. Agglomeration, Integration and Tax Harmonization

    OpenAIRE

    Richard Baldwin; Paul Krugman

    2001-01-01

    This paper considers tax competition and tax harmonization in the presence of agglomeration forces and falling trade costs. With agglomerative forces operating, industry is not indifferent to location in equilibrium, so perfectly mobile capital becomes a quasi-fixed factor. This suggests that the tax game is something subtler than a race to the bottom. Advanced 'core' nations may act like limit-pricing monopolists toward less advanced 'periphery' countries. Consequently, integration need not ...

  17. Influences of seed size and number on agglomeration in synthetic Bayer liquors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bin; ZHOU Ke-chao; CHEN Qi-yuan

    2006-01-01

    By means of Malvern laser particle size analyzer and scanning electron microscopy, the influences of seed size and number on agglomeration in Bayer process were investigated. Agglomeration is almost finished in 8 h,seeds, below 5 μm, especially below 2 μm, gather together rapidly and almost disappear in 8 h. In the same supersaturation of aluminate solution and seed size, the smaller the number of seed is, the bigger the degree of agglomeration is. With the same primary number of seed, the agglomeration of larger seed is superior to that of small seed,and the agglomeration does not happen among the coarse seeds. The agglomeration mainly happens among fine particles, and the combinations among the fine particles are unconsolidated.

  18. Ash and heavy metals in fluidized bed-combustion; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO International, Vantaa (Finland)

    1996-12-01

    Combustion ashes and submicron fly ash particles were characterized in two industrial boilers (bubbling vs. circulating fluidized bed) burning paper mill deinking sludge and bark or wood as support fuel. Bulk samples from fly ash, circulating ash and bottom ash were analyzed. Fine particles in fly ash were monitored and sampled for microscopic studies. The mass size distribution of fly ash was measured and the chemical composition according to particle size was analyzed. The results showed that ash consists of large and friable clusters formed by sintering of small mineral particles originating from paper fillers. Very few ash particles were fused and they were found only among the smallest particles. No agglomerates of fused particles were found. If the residence time in furnace is long enough sintering may proceed further and ash structure grows more dense. No indication of ash vaporization was detected. These results were similar for bubbling and circulating fluidized bed boilers. (author)

  19. ANALYSIS OF ASH FUSION IN SHELL PULVERIZED-COAL GASIFICATION PROCESS%Shell粉煤气化工艺煤灰熔融性探析

    Institute of Scientific and Technical Information of China (English)

    李亚东; 王洪进; 王可运

    2011-01-01

    The process of fly ash formation and its features in Shell pulverized-coal gasification are introduced,the ash fusion analyzed and the operation proposal for a stable running of gasifier put forward.The ash fusion is not only related to the ash composition,but also to the interaction among the components in the ash during the combustion process.The temperature of ash fusion is mainly depending on the mineral composition in the coal,the composition and ratio of its oxides and combustion atmosphere.%介绍Shell粉煤气化工艺中飞灰的形成过程及其特性,对煤灰的熔融性进行探析并提出稳定气化炉运行的操作建议。煤灰的熔融特性不仅与灰的成分有关,还与燃烧过程中灰中各成分之间的相互作用有关。灰熔融性温度主要取决于煤中的矿物组成、其氧化物的成分和配比及燃烧气氛等。

  20. Theranostic potential of gold nanoparticle-protein agglomerates

    Science.gov (United States)

    Sanpui, Pallab; Paul, Anumita; Chattopadhyay, Arun

    2015-11-01

    Owing to the ever-increasing applications, glittered with astonishing success of gold nanoparticles (Au NPs) in biomedical research as diagnostic and therapeutic agents, the study of Au NP-protein interaction seems critical for maximizing their theranostic efficiency, and thus demands comprehensive understanding. The mutual interaction of Au NPs and proteins at physiological conditions may result in the aggregation of protein, which can ultimately lead to the formation of Au NP-protein agglomerates. In the present article, we try to appreciate the plausible steps involved in the Au NP-induced aggregation of proteins and also the importance of the proteins' three-dimensional structures in the process. The Au NP-protein agglomerates can potentially be exploited for efficient loading and subsequent release of various therapeutically important molecules, including anticancer drugs, with the unique opportunity of incorporating hydrophilic as well as hydrophobic drugs in the same nanocarrier system. Moreover, the Au NP-protein agglomerates can act as `self-diagnostic' systems, allowing investigation of the conformational state of the associated protein(s) as well as the protein-protein or protein-Au NP interaction within the agglomerates. Furthermore, the potential of these Au NP-protein agglomerates as a novel platform for multifunctional theranostic application along with exciting future-possibilities is highlighted here.

  1. Electromagnetic interference shielding with Portland cement paste containing carbon materials and processed fly ash

    OpenAIRE

    Zornoza, E.; Catalá, G.; Jiménez, F.; Andión, L. Gª; Garcés, P.

    2010-01-01

    The study described in this article explored the effect of adding different types of carbon materials (graphite powder and three types of carbon fibre), fly ash (with 5.6%, 15.9% and 24.3% Fe2O3), and a mix of both on electromagnetic interference (EMI) shielding in Portland cement pastes. The parameters studied included the type and aspect ratio of the carbonic material, composite material thickness, the frequency of the incident electromagnetic r...

  2. Electromagnetic interference shielding with Portland cement paste containing carbon materials and processed fly ash

    Directory of Open Access Journals (Sweden)

    Zornoza, E.

    2010-12-01

    Full Text Available The study described in this article explored the effect of adding different types of carbon materials (graphite powder and three types of carbon fibre, fly ash (with 5.6%, 15.9% and 24.3% Fe2O3, and a mix of both on electromagnetic interference (EMI shielding in Portland cement pastes. The parameters studied included the type and aspect ratio of the carbonic material, composite material thickness, the frequency of the incident electromagnetic radiation and the percentage of the magnetic fraction in the fly ash. The findings showed that the polyacrylonitrile-based carbon fibres, which had the highest aspect ratio, provided more effective shielding than any of the other carbon materials studied. Shielding was more effective in thicker specimens and at higher radiation frequencies. Raising the magnetic fraction of the fly ash, in turn, also enhanced paste shielding performance. Finally, adding both carbon fibre and fly ash to the paste resulted in the most effective EMI shielding as a result of the synergies generated.

    En el presente trabajo se investiga la influencia de la adición de diferentes tipos de materiales carbonosos (polvo de grafito y 3 tipos de fibra de carbono, de una ceniza volante con diferentes contenidos de fase magnética (5,6%, 15,9% y 24,3% de Fe2O3 y de una mezcla de ambos, sobre la capacidad de apantallar interferencias electromagnéticas de pastas de cemento Pórtland. Entre los parámetros estudiados se encuentra: el tipo de material carbonoso, la relación de aspecto del material carbonoso, el espesor del material compuesto, la frecuencia de la radiación electromagnética incidente y el porcentaje de fracción magnética en la ceniza volante. Los resultados obtenidos indican que entre los materiales carbonosos estudiados son las fibras de carbono basadas en poliacrilonitrilo con una mayor relación de aspecto las que dan mejores resultados de apantallamiento. Al aumentar

  3. Commercial Demonstration of the Manufactured Aggregate Processing Technology Utilizing Spray Dryer Ash

    Energy Technology Data Exchange (ETDEWEB)

    Roy Scandrol

    2004-11-01

    This quarterly report covers the period from July 1st, 2004 through September 30th, 2004. It covers: technical development, permitting status, engineering status, construction status, operations summary and marketing support activities for this period. Plant startup, including equipment and system debugging, is underway. Minor adjustments to the SDA feed system, pug mill, and extruder were completed. Testing of admixtures to prevent the wetted SDA from sticking is continuing. The power plant is implementing a lime optimization program to reduce the calcium hydroxide values in the ash.

  4. AN INVESTIGATION OF THE HYDROPHOBIC AGGLOMERATION CHARACTERISTICS OF EASY DEGRADATION COAL FINES IN WATER

    Institute of Scientific and Technical Information of China (English)

    王力; 陈鹏

    1997-01-01

    The separation of ultrafine coal from three Chinese coal samples of easy degradation coal fines in water has been investigated by the application of a hydrophobic agglomeration process. In addition to yielding clean coal with high recovery, this process requires significantly less oil concentration for agglomeration (less than 0.4% in oil-water weight ratio) and produces stabler agglomerates than general oil agglomeration process, the cost of the oil would no longer be an important consideration for its commercial application. Neutral diesel oil was used to make oleophilic coal particles agglomerated with good rejection of clay minerals under little oil consumption and certain agitation speed at 2000 r/min. An important advantage of this process compared with other cleaning fine coal methods is that it can extremely reduce or eliminate the effects of coal degradation and some clay minerals on coal preparation.

  5. Agglomeration and the product mix

    OpenAIRE

    Dalvai, Wilfried

    2016-01-01

    Worldwide trade flows are dominated by high-productivity firms, that have a large range of products. Since the product range of firms reflects partly trade flows, it is a source of economic differences in space. In this paper, I analyze the effects of the product mix of firms on agglomeration. I build a theoretical model of multiproduct firms à la Mayer, Melitz, and Ottaviano (2014, AER), expand it with skilled, mobile workers and a spatial equilibrium. I show that a larger product mix of fir...

  6. Solidification/stabilization of electric arc furnace dust using coal fly ash. Analysis of the stabilization process.

    Science.gov (United States)

    Pereira, C F; Rodríguez-Piñero, M; Vale, J

    2001-03-30

    In this paper, the stabilization of electric arc furnace (EAF) dust containing hazardous metals such as Pb, Cd, Cr or Zn is described. The treatment involves a waste solidification/stabilization (S/S) process, using coal fly ash as the fundamental raw material and main binder. The article also contains a brief review of the most important recent publications related to the use of fly ash as S/S agents. The efficacy of the process has been evaluated mainly through leaching tests on the solidified products and compliance with some imposed leachate limits. The concentration of metals leaching from the S/S products was strongly leachate pH dependent; thus, the final pH of the leachate is the most important variable in reaching the limits and, therefore, in meeting the stabilization goals. In this study, the dependence relationship between the leachate pH and the concentrations of metals in the leachate are analyzed; in some cases, this allows us to estimate the speciation of contaminants in the S/S solids and to understand the mechanism responsible for reduced leachability of heavy metals from solidified wastes.

  7. Experimental determination of bed agglomeration tendencies of some common agricultural residues in fluidized bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, E.; Rao, A.N. [Anna University, Madras (India). Centre for New and Renewable Sources of Energy; Ohman, M.; Nordin, A. [Umea University (Sweden). Energy Technology Centre; Gabra, M. [Lulea University of Technology (Sweden). Div. of Energy Engineering; Liliedahl, T. [Royal Institute of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    1998-12-31

    Ever increasing energy demand and the polluting nature of existing fossil fuel energy sources demonstrate the need for other non-polluting and renewable sources of energy. The agricultural residues available in abundance in many countries can be used for power generation. The fluidized bed technology seems to be suitable for converting a wide range of agricultural residues into energy, due to its inherent advantages of fuel flexibility, low operating temperature and isothermal operating condition. The major ash-related problem encountered in fluidized beds is agglomeration which, in the worst case, may result in total defluidization and unscheduled downtime. The initial agglomeration temperature for some common tropical agricultural residues were experimentally determined by using a newly developed method based on the controlled fluidized bed agglomeration test. The agricultural residues chosen for the study were rice husk, bagasse, cane trash and olive flesh. The results showed that the initial agglomeration temperatures were less than the initial deformation temperature predicted by the ASTM standard ash fusion tests for all fuels considered. The initial agglomeration temperatures of rice husk and bagasse were more than 1000{sup o}C. The agglomeration of cane trash and olive flesh was encountered at relatively low temperatures and their initial agglomeration temperatures in gasification were lower than those in combustion with both bed materials. The use of lime as bed material instead of quartz improved the agglomeration temperature of cane trash and olive flesh in combustion and decreased the same in gasification. The results indicate that rice husk and bagasse can be used in the fluidized bed for energy generation since their agglomeration temperatures are sufficiently high. (author)

  8. Powder agglomeration in a microgravity environment

    Science.gov (United States)

    Cawley, James D.

    1994-01-01

    This is the final report for NASA Grant NAG3-755 entitled 'Powder Agglomeration in a Microgravity Environment.' The research program included both two types of numerical models and two types of experiments. The numerical modeling included the use of Monte Carlo type simulations of agglomerate growth including hydrodynamic screening and molecular dynamics type simulations of the rearrangement of particles within an agglomerate under a gravitational field. Experiments included direct observation of the agglomeration of submicron alumina and indirect observation, using small angle light scattering, of the agglomeration of colloidal silica and aluminum monohydroxide. In the former class of experiments, the powders were constrained to move on a two-dimensional surface oriented to minimize the effect of gravity. In the latter, some experiments involved mixture of suspensions containing particles of opposite charge which resulted in agglomeration on a very short time scale relative to settling under gravity.

  9. Mercury and toxic metals in ash from combustion and incineration processes; Mercurio y metales toxicos en cenizas provenientes de procesos de combustion e incineracion

    Energy Technology Data Exchange (ETDEWEB)

    Mugica, V.; Amador, M.A.; Torres, M.; Figueroa, J. de J. [Universidad Autonomo-Metropolitana-Azcapotzalco, Reynosa (Mexico)

    2003-07-01

    In Mexico, most of the ashes from combustion and incineration process were not appropriately disposed, they are either left on industrial yards and cliffs or thrown away in open spaces and then carried by the wind to places where they can harm population, affect aquatic environment or soils. For prevention and control, the knowledge on the concentration of trace elements in waste ashes is necessary. In this study, several oxidation methods for digestion of ashes followed by inductively coupled plasma emission spectrometry were evaluated. Hg, Cd, Cr, Cu, Ni, Pb and V were determined in ashes from coal and fuel oil combustion, as well as in ashes from the incineration of municipal, water treatment sludge, and medical wastes. Results showed important concentrations of different trace elements in the ashes. This suggests that adequate disposal of these wastes should be mandatory. On the other hand, concentration of trace elements in the leachates indicated that these wastes are not toxic and they could be disposed in sanitary landfill. 23 refs.

  10. Investigation of the possibility of binding fly ash particles by elemental sulphur

    Directory of Open Access Journals (Sweden)

    Vidojković V.

    2006-01-01

    Full Text Available Thermal power plants in Serbia use lignite for electrical power production The secondary product of coal combustion is fly ash in the amount of 17%. Fly ash causes the pollution of air, water and soil, and also cause many human, especially lung diseases. Secondary sulphur is a product of crude oil refining. The aim of this study was to investigate the use of sulphur as a bonding material in ultra fine particle agglomeration (smaller than 63 μm in fly ash. The agglomeration should make the ash particles larger and heavy enough to fall without flying fractions. The experiments showed that during the homogenization of the ashes and sulphur from 150 to 170 °C in a reactor with intensive mixing, an amount of 15% sulphur was sufficient to bond particles and cause agglomeration without visible flying fractions.

  11. Industrial Scope of Agglomeration Economies in Brazil

    OpenAIRE

    Ana Maria Bonomi Barufi; Eduardo A. Haddad, Peter Nijkamp

    2015-01-01

    The tendency towards urbanization in the emerging world accompanied by the constant pursuit for higher productivity prompts an urge for studies aiming at understanding agglomeration economies. In the context of Brazil, a country with extremely high regional disparities, exploring this issue is important not only for private stakeholders, but also for public policy practitioners. In the framework of static agglomeration effects, we investigate the industrial scope of agglomeration economies in...

  12. Human Capital, Talent, Agglomeration and Regional Growth

    OpenAIRE

    Karlsson, Charlie; Johansson, Börje; Stough, Roger R.

    2009-01-01

    This paper is an introductory overview highlighting some of the current knowledge as regards three critical questions related to the emerging knowledge economy: i) Why does human capital and talent tend to agglomerate in large urban regions?, ii) How does this agglomeration affect the location of different types of economic activities?, and iii) How does this agglomeration affect regional growth? There are different underlying agglomerative forces creating spatially concentrated increasing re...

  13. ENG 328 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     ENG 328 Week 1 DQ 1 What is Technical Writing (Ash) ENG 328 Week 1 DQ 2 Target Audience (Ash) ENG 328 Week 2 DQ 1 Collaborative Writing Process (Ash) ENG 328 Week 2 DQ 2 Design and Graphics (Ash) ENG 328 Week 3 DQ 1 Web Design and Readability (Ash) ENG 328 Week 3 DQ 2 Online Technical Documents (Ash) ENG 328 Week 4 DQ 1 Writing Instructions (Ash) ENG 328 Week 4 DQ 2 Writing Proposa...

  14. Simulation research on monomer agglomeration of nonmetallic inclusions in steel with a diffusion limited aggregation model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The monomer agglomeration of nonmetallic inclusions was simulated with a diffusion limited aggregation (DLA) model of the fractal theory.The simulation study with a random two-dimensional diffusion was carried out.The results indicate that the DLA model can be used for the simulation of agglomeration behavior of the cluster-type inclusions.The morphology of clusters was observed with SEM and compared with the simulated agglomerates.The modelling procedure of the DLA model is applicable for the agglomeration process.The uncertainty of agglomeration process and the persuasive average agglomerative ratio was analyzed.The factors about the agglomerative ratio with the collision path distance and the size of particles or seed were discussed.The adherence of the nonmetallic inclusions on the dam, the weir and the walls of a tundish, and the absorption of inclusions by stopper or nozzle were also discussed.

  15. Development of clean coal and clean soil technologies using advanced agglomeration technologies

    International Nuclear Information System (INIS)

    The specific objectives of the bituminous coal program were to explore and evaluate the application of advanced agglomeration technology for: (1)desulphurization of bituminous coals to sulphur content acceptable within the current EPA SO2 emission guidelines; (2) deashing of bituminous coals to ash content of less than 10 percent; and (3)increasing the calorific value of bituminous coals to above 13,000 Btu/lb. (VC)

  16. Eco-spatial Structure of Urban Agglomeration

    Institute of Scientific and Technical Information of China (English)

    GUO Rongchao; MIAO Changhong; LI Xuexin; CHEN Deguang

    2007-01-01

    In terms of ecological theory, this paper makes a comprehensive analysis of the mutualism and coevolutionary mechanism between the eco-spatial structure and socio-economic development ofthe urban agglomeration,and maps out optimized modes of the eco-spatial structure of the urban agglomeration. The analysis is a case study of the urban agglomeration on different levels of global, national, provincial and local scales, on the basis of those conclusions are drawn: 1) Within the scope of the urban agglomeration, the cities should be reasonably sized and appropriately densified; the spatial combination of the urban agglomeration ought to be orderly, and its eco-spatial structure ought to be optimized and efficient; the relationship between the economic society and eco-spatial environment ought to be that of mutual benefit and co-evolution. 2) "The mode of corridor group network" is a certain trend evoked from the spatial structure of urban agglomeration. 3) The eco-spatial structure of urban agglomeration under "the mode of corridor group network" can further increase the environmental capacity of urban agglomeration, and is in favor of the harmonious relationship between man and nature.

  17. Wood ash amendment to biogas reactors as an alternative to landfilling? A preliminary study on changes in process chemistry and biology.

    Science.gov (United States)

    Podmirseg, Sabine M; Seewald, Martin S A; Knapp, Brigitte A; Bouzid, Ourdia; Biderre-Petit, Corinne; Peyret, Pierre; Insam, Heribert

    2013-08-01

    Wood ash addition to biogas plants represents an alternative to commonly used landfilling by improving the reactor performance, raising the pH and alleviating potential limits of trace elements. This study is the first on the effects of wood ash on reactor conditions and microbial communities in cattle slurry-based biogas reactors. General process parameters [temperature, pH, electrical conductivity, ammonia, volatile fatty acids, carbon/nitrogen (C/N), total solids (TS), volatile solids, and gas quantity and quality] were monitored along with molecular analyses of methanogens by polymerase chain reaction- denaturing gradient gel electrophoresis and modern microarrays (archaea and bacteria). A prompt pH rise was observed, as was an increase in C/N ratio and volatile fatty acids. Biogas production was inhibited, but recovered to even higher production rates and methane concentration after single amendment. High sulphur levels in the wood ash generated hydrogen sulphide and potentially hampered methanogenesis. Methanosarcina was the most dominant methanogen in all reactors; however, diversity was higher in ash-amended reactors. Bacterial groups like Firmicutes, Proteobacteria and Acidobacteria were favoured, which could improve the hydrolytic efficiency of the reactors. We recommend constant monitoring of the chemical composition of the used wood ash and suggest that ash amendment is adequate if added to the substrate at a rate low enough to allow adaptation of the microbiota (e.g. 0.25 g g(-1) TS). It could further help to enrich digestate with important nutrients, for example phosphorus, calcium and magnesium, but further experiments are required for the evaluation of wood ash concentrations that are tolerable for anaerobic digestion.

  18. Wood ash amendment to biogas reactors as an alternative to landfilling? A preliminary study on changes in process chemistry and biology.

    Science.gov (United States)

    Podmirseg, Sabine M; Seewald, Martin S A; Knapp, Brigitte A; Bouzid, Ourdia; Biderre-Petit, Corinne; Peyret, Pierre; Insam, Heribert

    2013-08-01

    Wood ash addition to biogas plants represents an alternative to commonly used landfilling by improving the reactor performance, raising the pH and alleviating potential limits of trace elements. This study is the first on the effects of wood ash on reactor conditions and microbial communities in cattle slurry-based biogas reactors. General process parameters [temperature, pH, electrical conductivity, ammonia, volatile fatty acids, carbon/nitrogen (C/N), total solids (TS), volatile solids, and gas quantity and quality] were monitored along with molecular analyses of methanogens by polymerase chain reaction- denaturing gradient gel electrophoresis and modern microarrays (archaea and bacteria). A prompt pH rise was observed, as was an increase in C/N ratio and volatile fatty acids. Biogas production was inhibited, but recovered to even higher production rates and methane concentration after single amendment. High sulphur levels in the wood ash generated hydrogen sulphide and potentially hampered methanogenesis. Methanosarcina was the most dominant methanogen in all reactors; however, diversity was higher in ash-amended reactors. Bacterial groups like Firmicutes, Proteobacteria and Acidobacteria were favoured, which could improve the hydrolytic efficiency of the reactors. We recommend constant monitoring of the chemical composition of the used wood ash and suggest that ash amendment is adequate if added to the substrate at a rate low enough to allow adaptation of the microbiota (e.g. 0.25 g g(-1) TS). It could further help to enrich digestate with important nutrients, for example phosphorus, calcium and magnesium, but further experiments are required for the evaluation of wood ash concentrations that are tolerable for anaerobic digestion. PMID:23831776

  19. Leaching of valuable elements from thermal power plant bottom ash using a thermo-hydrometallurgical process.

    Science.gov (United States)

    Bojinova, Darinka; Teodosieva, Ralitsa

    2016-06-01

    The solid industrial wastes generated from thermal power plants (TPPs) can be considered as renewable secondary sources for recovery of valuable metals. This study presents the results from investigations that integrated a thermo-hydro-metallurgical method for treatment of bottom ash obtained from the Enel Maritsa East 3 TPP in Bulgaria. Leaching was performed with 20, 30 and 40 wt% sulphuric acid, respectively, in an autoclave at 100(o)C, 120(o)C and 140(o)C for 120, 240, 360 and 480 min, at a constant value of the liquid/solid ratio. After autoclaving, the samples (suspensions) were diluted with a constant value of water and stirring at 50(o)C for 60 min. On the basis of the experimental data the leaching efficiency (α) of the elements in the liquid phase after filtration was estimated. The leaching of aluminium increases significantly with increasing of the temperature, reaching the maximum value of 70 wt%. The highest leaching efficiency values for the other elements are as follows: Fe (86.4%), Ca (86.6%), Na (86.6%), Ni (83.3%) and Zn (83.3%). The maximum value of leaching for Mg, K, Mn, Cu and Cr is in the interval of 46-70%. PMID:26951342

  20. The hydrometallurgy, the agglomeration and the absorption like alternative of cleaner production in the processes of gold benefit in the northeast antioqueno

    International Nuclear Information System (INIS)

    In Colombia the small mining of precious metals, commonly uses traditional technologies with a low technological profile as consequence of the limitations in the capital of available work for the mining operation in our country, those which slowly they have specialized according to the origin of the mineral observing a tendency toward the gravimetric concentration in the alluvial mining, while in the underground mining more complex processes are used that include the triturating, mill, amalgamation and cyanidation. Independently of the tendency, in each one of the carried out processes they are presented lost of materials for the inefficiency and the not well state of the equipment, generating different levels of environmental impacts and that for their importance in most of the cases invite to the search of alternative economically viable that allow the progressive decrease of the effects on the natural resources and the communities in general. It is as well as Corantioquia has come developing some successful experiences in the search of the sustainability of the mining sector, contributing alternative that allow the decrease of the row material for reuse and of the effusions of highly toxic materials as they are the mercury and the cyanide. For the emissions control of mercury to the atmosphere, the use of the retorts was fomented by means of the technical exploration of all and each one of the available systems commercially in the market, reaching superior yields to 80% in the recovery of the mercury in the burns process of the amalgam, but its use has always been surrounded of an aureole of distrust on the part of the small miner that has not allowed the massification of the system and especially in the sales and purchases of gold; factor that impelled the development of the denominated cubicle of mercury like a contribution of the corporation, in which allows the miner and the observers to see the burn of the amalgam in permanent form through the walls in

  1. Engineering development of selective agglomeration. Site closeout report

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    The Selective Agglomeration POC facility consisted of a coal crushing and grinding circuit, followed by an agglomeration circuit and product dewatering. (A plot plan of the facility is shown in Figure 1-2.) The coal crushing and grinding system consisted of a hammermill coal crusher, weigh-belt feeder, two ball mills (primary and secondary), and necessary hoppers, pumps, and conveyors. The mills were capable of providing coal over a range of grinds from a d{sub 50} of 125 to 25 microns. Slurry discharged from the ball mills was pumped to the agglomeration circuit. The agglomeration circuit began with a high-shear mixer, where diesel was added to the slurry to begin the formation of microagglomerates. The high-shear mixer was followed by two stages of conventional flotation cells for microagglomerate recovery. The second-stage-flotation-cell product was pumped to either a rotary-drum vacuum filter or a high-G centrifuge for dewatering. The dewatered product was then convoyed to the product pad from which dump trucks were used to transfer it to the utility plant located next to the facility. Plant tailings were pumped to the water clarifier for thickening and then dewatered in plate-and-frame filter presses. These dewatered tailings were also removed to the utility via dump truck. Clarified water (thickener overflow) was recycled to the process via a head tank.

  2. Investigation of the possibility of binding fly ash particles by elemental sulphur

    OpenAIRE

    Vidojković V.; Đorđević N.; Boljanac T.; Vlahović M.; Martinović S.

    2006-01-01

    Thermal power plants in Serbia use lignite for electrical power production The secondary product of coal combustion is fly ash in the amount of 17%. Fly ash causes the pollution of air, water and soil, and also cause many human, especially lung diseases. Secondary sulphur is a product of crude oil refining. The aim of this study was to investigate the use of sulphur as a bonding material in ultra fine particle agglomeration (smaller than 63 μm) in fly ash. The agglomeration should make the as...

  3. Metals accumulations during thermal processing of sewage sludge - characterization of bottom ash and air pollution control (APC) residues

    Science.gov (United States)

    Kasina, Monika; Kowalski, Piotr R.; Michalik, Marek

    2016-04-01

    Due to increasing mass of sewage sludge, problems in its management have appeared. Over years sewage sludge was landfilled, however due to EU directives concerning environmental issues this option is no longer possible. This type of material is considered hazardous due to highly concentrated metals and harmful elements, toxic organic substances and biological components (e.g. parasites, microbes). Currently in Europe, incineration is considered to be the most reasonable method for sewage sludge treatment. As a result of sludge incineration significant amount of energy is recovered due to high calorific value of sewage sludge but bottom ash and APC residues are being produced. In this study we show the preliminary results of chemical and mineral analyses of both bottom ash and APC residues produced in fluidized bed boiler in sewage sludge incineration plant in Poland, with a special emphasis on metals which, as a part of incombustible fraction can accumulate in the residual materials after thermal processing. The bottom ash was a SiO2-P2O5-Fe2O3-CaO-Al2O3 dominated material. Main mineral phases identified in X-ray diffraction patterns were: quartz, feldspar, hematite, and phosphates (apatite and scholzite). The bottom ash was characterized by high content of Zn - 4472 mg kg‑1, Cu - 665.5 mg kg‑1, Pb - 138 mg kg‑1, Ni - 119.5 mg kg‑1, and interestingly high content of Au - 0.858 mg kg‑1 The APC residues composition was dominated by soluble phases which represent more than 90% of the material. The XRD patterns indicated thenardite, halite, anhydrite, calcite and apatite as main mineral phases. The removal of soluble phases by dissolution in deionised water caused a significant mass reduction (ca. 3% of material remained on the filters). Calcite, apatite and quartz were main identified phases. The content of metals in insoluble material is relatively high: Zn - 6326 mg kg‑1, Pb - 514.3 mg kg‑1, Cu - 476.6 mg kg‑1, Ni - 43.3 mg kg‑1. The content of Cd

  4. Magnetic agglomeration method for size control in the synthesis of magnetic nanoparticles

    Science.gov (United States)

    Huber, Dale L.

    2011-07-05

    A method for controlling the size of chemically synthesized magnetic nanoparticles that employs magnetic interaction between particles to control particle size and does not rely on conventional kinetic control of the reaction to control particle size. The particles are caused to reversibly agglomerate and precipitate from solution; the size at which this occurs can be well controlled to provide a very narrow particle size distribution. The size of particles is controllable by the size of the surfactant employed in the process; controlling the size of the surfactant allows magnetic control of the agglomeration and precipitation processes. Agglomeration is used to effectively stop particle growth to provide a very narrow range of particle sizes.

  5. Ash Management Review—Applications of Biomass Bottom Ash

    Directory of Open Access Journals (Sweden)

    Harpuneet S. Ghuman

    2012-10-01

    Full Text Available In industrialized countries, it is expected that the future generation of bioenergy will be from the direct combustion of residues and wastes obtained from biomass. Bioenergy production using woody biomass is a fast developing application since this fuel source is considered to be carbon neutral. The harnessing of bioenergy from these sources produces residue in the form of ash. As the demand for bioenergy production increases, ash and residue volumes will increase. Major challenges will arise relating to the efficient management of these byproducts. The primary concerns for ash are its storage, disposal, use and the presence of unburned carbon. The continual increase in ash volume will result in decreased ash storage facilities (in cases of limited room for landfill expansion, as well as increased handling, transporting and spreading costs. The utilization of ash has been the focus of many studies, hence this review investigates the likely environmental and technological challenges that increased ash generation may cause. The presence of alkali metals, alkaline earth metals, chlorine, sulphur and silicon influences the reactivity and leaching to the inorganic phases which may have significant impacts on soils and the recycling of soil nutrient. Discussed are some of the existing technologies for the processing of ash. Unburned carbon present in ash allows for the exploration of using ash as a fuel. The paper proposes sieve fractionation as a suitable method for the separation of unburnt carbon present in bottom ash obtained from a fixed-bed combustion system, followed by the application of the gasification technology to particle sizes of energy importance. It is hoped that this process will significantly reduce the volume of ash disposed at landfills.

  6. Melting Behavior of Volcanic Ash relevant to Aviation Ash Hazard

    Science.gov (United States)

    Song, W.; Hess, K.; Lavallee, Y.; Cimarelli, C.; Dingwell, D. B.

    2013-12-01

    Volcanic ash is one of the major hazards caused by volcanic eruptions. In particular, the threat to aviation from airborne volcanic ash has been widely recognized and documented. In the past 12 years, more than 60 modern jet airplanes, mostly jumbo jets, have been damaged by drifting clouds of volcanic ash that have contaminated air routes and airport facilities. Seven of these encounters are known to have caused in-flight loss of engine power to jumbo jets carrying a total of more than 2000 passengers. The primary cause of engine thrust loss is that the glass in volcanic ash particles is generated at temperatures far lower than the temperatures in the combustion chamber of a jet engine ( i.e. > 1600 oC) and when the molten volcanic ash particles leave this hottest section of the engine, the resolidified molten volcanic ash particles will be accumulated on the turbine nozzle guide vanes, which reduced the effective flow of air through the engine ultimately causing failure. Thus, it is essential to investigate the melting process and subsequent deposition behavior of volcanic ash under gas turbine conditions. Although few research studies that investigated the deposition behavior of volcanic ash at the high temperature are to be found in public domain, to the best our knowledge, no work addresses the formation of molten volcanic ash. In this work, volcanic ash produced by Santiaguito volcano in Guatemala in November 8, 2012 was selected for study because of their recent activity and potential hazard to aircraft safety. We used the method of accessing the behavior of deposit-forming impurities in high temperature boiler plants on the basis of observations of the change in shape and size of a cylindrical coal ash to study the sintering and fusion phenomena as well as determine the volcanic ash melting behavior by using characteristic temperatures by means of hot stage microscope (HSM), different thermal analysis (DTA) and Thermal Gravimetric Analysis (TGA) to

  7. Ash chemistry and sintering, verification of the mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Skrifvars, B.J.; Backman, R.; Lauren, T.; Uusikartano, T.; Malm, H.; Stenstroem, P.; Vesterkvist, M. [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

    1997-10-01

    In this project four sintering mechanisms have been studied, i.e., partial melting with a viscous liquid, partial melting with a non-viscous liquid, chemical reaction sintering and solid state sintering. The work has aimed at improving the understanding of ash sintering mechanisms and quantifying their role in combustion and gasification. The work has been oriented in particular on the understanding of biomass ash behavior. The work has not directly focused on any specific technical application. However, results can also be applied on other fuels such as brown coal, petroleum coke, black liquor and different types of wastes (PDF, RDF, MSW). During 1996 the work has focused on identifying bed agglomeration mechanisms and analysing bed agglomerates in both full scale and lab scale FB reactors, as well as comparing how well the compression strength based sintering test can predict bed agglomeration in an FB furnace. (orig.)

  8. Use of Incineration MSW Ash: A Review

    OpenAIRE

    Charles H. K. Lam; Alvin W. M. Ip; John Patrick Barford; Gordon McKay

    2010-01-01

    This study reviews the characteristics of municipal solid waste incineration (MSWI) ashes, with a main focus on the chemical properties of the ashes. Furthermore, the possible treatment methods for the utilization of ash, namely, separation processes, solidification/stabilization and thermal processes, are also discussed. Seven types of MSWI ash utilization are reviewed, namely, cement and concrete production, road pavement, glasses and ceramics, agriculture, stabilizing agent, adsorbents and...

  9. The effects of the mechanical-chemical stabilization process for municipal solid waste incinerator fly ash on the chemical reactions in cement paste.

    Science.gov (United States)

    Chen, Cheng-Gang; Sun, Chang-Jung; Gau, Sue-Huai; Wu, Ching-Wei; Chen, Yu-Lun

    2013-04-01

    A water extraction process can remove the soluble salts present in municipal solid waste incinerator (MSWI) fly ash, which will help to increase the stability of the synthetic materials produced from the MSWI fly ash. A milling process can be used to stabilize the heavy metals found in the extracted MSWI fly ash (EA) leading to the formation of a non-hazardous material. This milled extracted MSWI fly ash (MEA) was added to an ordinary Portland cement (OPC) paste to induce pozzolanic reactions. The experimental parameters included the milling time (96h), water to binder ratios (0.38, 0.45, and 0.55), and curing time (1, 3, 7 and 28 days). The analysis procedures included inductively coupled plasma atomic emission spectroscopy (ICP/AES), BET, mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) imaging. The results of the analyses indicate that the milling process helped to stabilize the heavy metals in the MEA, with an increase in the specific surface area of about 50times over that of OPC. The addition of the MEA to the OPC paste decreased the amount of Ca(OH)2 and led to the generation of calcium-silicate-hydrates (C-S-H) which in turned increased the amount of gel pores and middle sized pores in the cement. Furthermore, a comparison shows an increase in the early and later strength over that of OPC paste without the addition of the milled extracted ash. In other words, the milling process could stabilize the heavy metals in the MEA and had an activating effect on the MEA, allowing it to partly substitute OPC in OPC paste. PMID:23375995

  10. Preliminary results on the ash behavior of peach stones during fluidized bed gasification: evaluation of fractionation and leaching as pre-treatments

    Energy Technology Data Exchange (ETDEWEB)

    Arvelakis, S.; Koukios, E.G. [National Technical Univ., Athens (Greece). Dept. of Chemical Engineering; Gehrmann, H. [Clausthaler Umwelttechnik Institut GmbH, Claushal Zellerfeld (Germany); Beckmann, M. [Bauhaus Universitat Dept. of Process Engineering and Environment, Weimar (Germany)

    2005-03-01

    Peach stones comprise a valuable agroindustrial by-product that is available in many countries of the World and especially in the Mediterranean region. A number of important advantages such as its high energy value, the low ash content in combination with the absence of transportation costs due to the fact that is produced in agro-industries, make peach stones an ideal fuel for energy production via gasification. Gasification tests were performed in a lab-scale fluidized bed gasifier in order to study the behavior of peach stones and especially its ash during the gasification process. Apart from the tests with the initial peach stone samples, gasification tests were performed using peach stones that had been pre-treated using two different methods fractionation and leaching. Pre-treatments used in order to study their effect on the beneficiation of the materials ash and on the avoidance of ash-related problems such as deposition, agglomeration and corrosion during the gasification process. A water-cooled steel tube placed vertical to the flow of the gasification gases was used in order to collect samples of ash deposits that were analyzed using SEM-EDX analysis techniques in order to assess the effect of the pre-treatment techniques on the peach stones ash behavior. The produced results showed that peach stones can be used as gasification feedstock without significant ash problems. Fractionation resulted in a deterioration of the ash behavior of the material, increasing the amounts of alkali metals and chlorine included in its ash, while leaching showed a positive effect but to a moderate extent. (author)

  11. Preparation and characterization of carbon-enriched coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, B.; Izquierdo, M.T.; Mayoral, M.C.; Bona, M.T.; Martinez-Tarazona, R.M. [CSIC, Zaragoza (Spain)

    2008-09-15

    Carbon-enriched fractions have been obtained from two coal fly ash (FA) samples. The FA came from two pulverized-coal fired power stations (Lada and Escucha, Spain) and were collected from baghouse filters. Sieving was used to obtain carbon-enriched fractions, which were further subjected to two beneficiation processes: acid demineralization using HCl and HF, and oil agglomeration using soya oil-water. Yield in weight after sieving, unburned carbon content, and several physicochemical characteristics, of the obtained fractions were used to compare the performance of the beneficiation methods. Low carbon concentration was obtained by sieving. particularly in the case of Escucha FA. However, after acid demineralization or oil agglomeration, fractions containing unburned carbon in a range of 63% to 68% were obtained. These fractions showed differences in mineral phase composition and distribution depending on the FA and oil the beneficiation method used. The textural properties of the obtained fractions varied as a function of their carbon content and the beneficiation method used. However, no significant differences in morphology of the carbonaceous particles were found

  12. Spectral-element agglomerate coarsening in AMGe

    Energy Technology Data Exchange (ETDEWEB)

    Vassilevski, P S

    2000-12-06

    In this talk the authors present a highly accurate coarsening algorithm for constructing coarse finite element spaces to be used in algebraic multigrid methods designed for finite element problems on generally unstructured meshes. The new algorithm relies on removing certain percentage of the high oscillating components from the spectrum of local stiffness matrices corresponding to element agglomerations. By doing so, one is guaranteed that the hierarchical complement finite element subspace gives rise to a well conditioned matrix. The coarsening consists of an agglomeration step and of computing a few minimal eigenvectors of the corresponding assembled agglomerate stiffness matrix. The method requires access to the individual element matrices. Based on the topological agglomeration algorithms they employed one is able to define coarse elements and coarse element matrices thus allowing for recursive use of the same algorithm. Some numerical illustration for elliptic problems is also given.

  13. Agglomeration of Charged Nanopowders in Suspensions

    OpenAIRE

    Werth, J. H.; Linsenbuehler, M.; Dammer, S. M.; Farkas, Z.; Hinrichsen, H.; Wirth, K. -E.; Wolf, D. E.

    2002-01-01

    The aim of this work is to understand agglomeration of charged powders suspended in nonpolar fluids. The concerted influence of electromagnetic, hydrodynamic and van der Waals forces as well as Brownian motion leads to a complex agglomeration behaviour which depends on several parameters, e.g., the ratios of electric charges, particle sizes, temperature and concentrations of the particles. Both experimental and theoretical considerations are presented.

  14. Study on process parameters for activating fly ash with alkali by calcination%加碱煅烧活化粉煤灰工艺参数研究

    Institute of Scientific and Technical Information of China (English)

    吴勇勇; 周勇敏; 张苏伊

    2012-01-01

    The calcination process for activating fly ash with Na2CO3 as accessory ingredient was investigated.The concenta-tions of Si and A1 in the fly ash activated under different calcination conditions (calcination temperature and calcination time), that dissolved in the sodium hydroxide solution were measured by titering process.The phase composition of fly ash obtained under different calcination conditions (mass ratio of fly ash and sodium carbonate ) was characterized by XRD.The best process parameters were obtained as follows: calcination temperature was 875 X. .holding time was 1.5 h,and mass ratio of fly ash and sodium carbonate was 1:0.87.The products after calcination were mainly made up of soluble NaAlSiO4 and Na2SiO3,and the quartz and mullitein in the raw fly ash both almost disappeared.Therefore, the fly ash was activated adequately.%研究了以碳酸钠为助剂活化粉煤灰的煅烧工艺.采用滴定法测定不同煅烧条件(煅烧温度和煅烧时间)所得活化粉煤灰溶解在氢氧化钠溶液中的硅、铝浓度,并采用X射线衍射(XRD)表征不同煅烧条件(灰碱质量比)所得活化粉煤灰的物相组成,得出粉煤灰较佳煅烧工艺参数:煅烧温度为875℃,保温时间为1.5 h,粉煤灰与碳酸钠的质量比为1∶0.87.煅烧后的产物主要以可溶性的硅铝酸钠(NaAlSiO4)和硅酸钠(Na2SiO3)为主,原粉煤灰中的石英、莫来石基本消失,粉煤灰得到充分活化.

  15. Radiation-induced silver agglomeration in molecular sieves: a comparison between A and X zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Sadlo, J.; Wasowicz, T.; Michalik, J. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1995-06-01

    The stabilization conditions of silver atoms and clusters in hydrated and dehydrated AgNa-A and AgNa-X zeolites {gamma}-irradiated at 77 K have been studied by ESR. It was found that silver agglomeration mechanisms in hydrated A and X zeolites are very similar and are controlled by the migration of silver atoms into the {alpha}-cages. In dehydrated zeolites agglomeration leads to completely different silver clusters in A and X zeolites. Small cationic clusters are stabilized in A zeolites and metallic clusters in X zeolites. Various factors affecting the agglomeration process in A and X zeolites are discussed. (author).

  16. Coke yield and heat transfer in reaction of liquid-solid agglomerates of Athabasca vacuum residue

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M.; Courtney, M.; Boddez, L.; Gray, M. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2010-02-15

    Delayed coking and fluid-bed coking are the most common commercial processes used by the petroleum industry for the thermal conversion of vacuum residues into petroleum distillate products. This paper presented the results of an experimental study of coke yield at long reaction times from agglomerates of coke particles and Athabasca vacuum residue (AVR). The ultimate coke yield was determined for a range of agglomerate thicknesses, liquid concentrations and reaction temperatures. The agglomerates were heated on Curie-point alloy strips in an induction furnace at 503 and 530 degrees C until all toluene-soluble material was converted. A simple heat transfer model was used to describe the temperature profile within the agglomerates. Coke yield results from agglomerates were compared to the coke yield results from reacting thin films of vacuum residue. The average coke yield from the agglomerates was 23 per cent, while the coke yield from thin films of 20 {mu}m thickness was 11 per cent, which supports the role of mass transfer in coke formation reactions. The ultimate coke yield was insensitive to vacuum residue concentration, agglomerate size, and reaction temperature. According to control experiments on thin films of liquid at different heating rates, the temperature-time history has little effect on the ultimata coke yield. 13 refs., 2 tabs., 10 figs.

  17. Nanoparticle agglomeration in an evaporating levitated droplet for different acoustic amplitudes

    Science.gov (United States)

    Tijerino, Erick; Basu, Saptarshi; Kumar, Ranganathan

    2013-01-01

    Radiatively heated levitated functional droplets with nanosilica suspensions exhibit three distinct stages namely pure evaporation, agglomeration, and finally structure formation. The temporal history of the droplet surface temperature shows two inflection points. One inflection point corresponds to a local maximum and demarcates the end of transient heating of the droplet and domination of vaporization. The second inflection point is a local minimum and indicates slowing down of the evaporation rate due to surface accumulation of nanoparticles. Morphology and final precipitation structures of levitated droplets are due to competing mechanisms of particle agglomeration, evaporation, and shape deformation. In this work, we provide a detailed analysis for each process and propose two important timescales for evaporation and agglomeration that determine the final diameter of the structure formed. It is seen that both agglomeration and evaporation timescales are similar functions of acoustic amplitude (sound pressure level), droplet size, viscosity, and density. However, we show that while the agglomeration timescale decreases with initial particle concentration, the evaporation timescale shows the opposite trend. The final normalized diameter can be shown to be dependent solely on the ratio of agglomeration to evaporation timescales for all concentrations and acoustic amplitudes. The structures also exhibit various aspect ratios (bowls, rings, spheroids) which depend on the ratio of the deformation timescale (tdef) and the agglomeration timescale (tg). For tdef

  18. APPLICATION OF SPHERICAL AGGLOMERATION TECHNIQUE TO IMPROVE MICROMERITIC PROPERTIES AND DISSOLUTION CHARACTERISTICS OF NABUMETONE

    Directory of Open Access Journals (Sweden)

    Pradnya Patil

    2012-01-01

    Full Text Available The present work is aimed to enhance the solubility and dissolution rate of Nabumetone, 4-(6-methoxy-2-naphalenyl-2-butanone water insoluble anti-inflammatory drug by spherical agglomeration technique using a solvent change method consisting of acetone, water and dichloromethane as solvent, non solvent and bridging liquid respectively. The hydrophilic polymers like poly vinyl pyrrolidone K-30 (PVP and sodium alginate were used in the agglomeration process. Infrared (I.R spectroscopic studies, Differential scanning calorimetery (DSC and Scanning electron microscopy (SEM were used for characterization of pure drug and its agglomerates. The I.R spectroscopy revealed that there is no chemical interaction between drug and polymers, also indicated that no chemical changes in the crystallized agglomerates .The agglomerates exhibited significantly improved solubility, dissolution rate and micromeritic properties (angle of repose, Carr’s index, bulk density, tapped density. Hausner’s ratio compared with pure drug Nabumetone. The aqueous solubility and dissolution rate of the drug from spherical agglomerates was significantly (p < 0.05 increased (nearly two times. SEM studies revealed that the agglomerates possess a good spherical shape. The study revealed that Micromeritic Properties, Solubility and Invitro drug release rate is increased with increase in PVP concentration from 0.25% to 1% as compared to sodium alginate.

  19. Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region

    Energy Technology Data Exchange (ETDEWEB)

    Smolka-Danielowska, D. [University of Silesia, Sosnowiec (Poland). Faculty of Earth Science

    2010-11-15

    The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations of Th-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: {sup 226}Ra - 85.4 Bq kg{sup -1}, {sup 40}K-689 Bq kg{sup -1}, {sup 232}Th - 100.8 Bq kg{sup -1}, {sup 235}U - 13.5 Bq kg{sup -1}, {sup 238}U - 50 Bq kg{sup -1} and {sup 228}Ac - 82.4 Bq kg{sup -1}.

  20. Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region.

    Science.gov (United States)

    Smolka-Danielowska, Danuta

    2010-11-01

    The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations ofTh-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: 226Ra - 85.4 Bq kg(-1), 40 K-689 Bq kg(-1), 232Th - 100.8 Bq kg(-1), 235U-13.5 Bq kg(-1), 238U-50 Bq kg(-1) and 228Ac - 82.4 Bq kg(-1).

  1. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  2. ENG 328 ASH Course Tutorial / eng328dotcom

    OpenAIRE

    anil3

    2015-01-01

    ENG 328 Entire Course (Ash) For more course tutorials visit www.eng328.com ENG 328 Week 1 DQ 1 What is Technical Writing (Ash) ENG 328 Week 1 DQ 2 Target Audience (Ash) ENG 328 Week 2 DQ 1 Collaborative Writing Process (Ash) ENG 328 Week 2 DQ 2 Design and Graphics (Ash) ENG 328 Week 3 DQ 1 Web Design and Readability (Ash) ENG 328 Week 3 DQ 2 Online Technical Documents (Ash) ENG 328 Week 4 DQ 1 Writing Instructions (Ash) ENG 328 Week 4 DQ 2 Writing Propo...

  3. ENG 328 ASH Material-eng328dotcom

    OpenAIRE

    Sandywilliam

    2015-01-01

    ENG 328 Entire Course (Ash) For more course tutorials visit www.eng328.com ENG 328 Week 1 DQ 1 What is Technical Writing (Ash) ENG 328 Week 1 DQ 2 Target Audience (Ash) ENG 328 Week 2 DQ 1 Collaborative Writing Process (Ash) ENG 328 Week 2 DQ 2 Design and Graphics (Ash) ENG 328 Week 3 DQ 1 Web Design and Readability (Ash) ENG 328 Week 3 DQ 2 Online Technical Documents (Ash) ENG 328 Week 4 DQ 1 Writing Instructions (Ash) ENG 328 Week 4 DQ 2 Writing Propo...

  4. Light-Induced Agglomeration and Diffusion of Different Particles with Optical Tweezers

    Institute of Scientific and Technical Information of China (English)

    LI Xue-Cong; SUN Xiu-Dong; LIU Hong-Peng; ZHANG Jian-Long

    2010-01-01

    @@ The dynamic process of light-induced agglomeration of carbon nanotubes(CNTs),C60 and Escherichia coli(E.coli)in aqueous solutions is demonstrated using an optical tweezers system.Based on the results,the diameter of the agglomerated region and the agglomeration rate increase with the increasing laser power.After the saturation-stable period,CNTs diffuse completely,C60 dusters only diffuse partially,and E.coli never diffuses in the agglomeration region.Theoretical analyses show that the molecular polarization and thermal diffusion of particles play crucial roles in the diffusion process.The results indicate the possibility of using light to aggregate and sort nanoparticles.

  5. AGGLOMERATION AND RADIATION EFFECT OF THE PULL OF URBANIZATION

    Institute of Scientific and Technical Information of China (English)

    QI Jin-li

    2003-01-01

    In order to explore the train of thought for China's urbanizing development and coordinated rural eco-nomic development, and to find good ways of solving rural problems through urbanization, this paper absorbs the push-and-pull forces theory and the systematic dynamic theory in the traditional population migration theories, views urbanization as a dynamic system, makes research on the push-and-pull mechanism of urbanization. The pull ingpower of urbanization is analyzed according to two aspects, the agglomeration effect and the radiation effect of cities. The agglomeration effect provides continuous propelling force for urbanization, and the radiation effect furtheraccelerates the urbanization process by pushing forward the development of rural economy. Of course, the slow de-velopment of urbanization can result in the hindrance to rural economic development.

  6. Engineering development of selective agglomeration: Trace element removal study

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    Southern Company Services, Inc., (SCS) was contracted in 1989 by the US Department of Energy (DOE) to develop a commercially acceptable selective agglomeration technology to enhance the use of high-sulfur coals by 1993. The project scope involved development of a bench-scale process and components, as well as the design, testing, and evaluation of a proof-of-concept (POC) facility. To that end, a two-ton-per-hour facility was constructed and tested near Wilsonville, Alabama. Although it was not the primary focus of the test program, SCS also measured the ability of selective agglomeration to remove trace elements from coal. This document describes the results of that program.

  7. Public Action and Innovationsupport Institutions in New Technological Agglomerations

    DEFF Research Database (Denmark)

    Borras, Susana; Bacaria, Jordi; Fernandez-Ribas, Andrea

    2002-01-01

    In all industrial and technological agglomerations several types of public and semi-public actors coexist. The same happens with the levels of government. Consequently, the daily reality of agglomerations is characterized by a wide diversity of innovation-support institutions more or less actively....... The first is that policy strategies should not try to be hegemonic. Instead, they should be elaborated seeking complementarity and coexistence. A second normative conclusion is the necessity of fostering the learning processes within and across institutions, by mobilizing collectively the assets of the area...... into an open explicit option for the economic performance of the territory. The conclusions include a final plea for further research about the industrial dynamics and knowledge flows in the Vallès Occidental County, an important growth pole of Catalonia....

  8. Can ash clog soil pores?

    Science.gov (United States)

    Stoof, Cathelijne; Stoof, Cathelijne; Gevaert, Anouk; Gevaert, Anouk; Baver, Christine; Baver, Christine; Hassanpour, Bahareh; Hassanpour, Bahareh; Morales, Veronica; Morales, Veronica; Zhang, Wei; Zhang, Wei; Martin, Deborah; Martin, Deborah; Steenhuis, Tammo; Steenhuis, Tammo

    2015-04-01

    Wildfire can greatly increase a landscape's vulnerability to flooding and erosion events, and ash is thought to play a large role in controlling runoff and erosion processes after wildfire. Although ash can store rainfall and thereby reduce runoff and erosion for a limited period after wildfires, it has also been hypothesized to clog soil pores and reduce infiltration. Several researchers have attributed the commonly observed increase in runoff and erosion after fire to the potential pore-clogging effect of ash. Evidence is however incomplete, as to date, research has solely focused on identifying the presence of ash in the soil, with the actual flow processes associated with the infiltration and pore-clogging of ash remaining a major unknown. In several laboratory experiments, we tested the hypothesis that ash causes pore clogging to the point that infiltration is hampered and ponding occurs. We first visualized and quantified pore-scale infiltration of water and ash in sand of a range of textures and at various infiltration rates, using a digital bright field microscope capturing both photo and video. While these visualization experiments confirm field and lab observation of ash washing into soil pores, we did not observe any clogging of pores, and have not been able to create conditions for which this does occur. Additional electrochemical analysis and measurement of saturated hydraulic conductivity indicate that pore clogging by ash is not plausible. Electrochemical analysis showed that ash and sand are both negatively charged, showing that attachment of ash to sand and any resulting clogging is unlikely. Ash also had quite high saturated conductivity, and systems where ash was mixed in or lying on top of sand had similarly high hydraulic conductivity. Based on these various experiments, we cannot confirm the hypothesis that pore clogging by ash contributes to the frequently observed increase in post-fire runoff, at least for the medium to coarse sands

  9. The effects of the mechanical–chemical stabilization process for municipal solid waste incinerator fly ash on the chemical reactions in cement paste

    International Nuclear Information System (INIS)

    Highlights: ► Milling extracted MSWI fly ash. ► Increasing specific surface area, destruction of the crystalline texture, and increasing the amount of amorphous materials. ► Increasing heavy metal stability. ► Inducing pozzolanic reactions and increasing the early and later strength of the cement paste. - Abstract: A water extraction process can remove the soluble salts present in municipal solid waste incinerator (MSWI) fly ash, which will help to increase the stability of the synthetic materials produced from the MSWI fly ash. A milling process can be used to stabilize the heavy metals found in the extracted MSWI fly ash (EA) leading to the formation of a non-hazardous material. This milled extracted MSWI fly ash (MEA) was added to an ordinary Portland cement (OPC) paste to induce pozzolanic reactions. The experimental parameters included the milling time (96 h), water to binder ratios (0.38, 0.45, and 0.55), and curing time (1, 3, 7 and 28 days). The analysis procedures included inductively coupled plasma atomic emission spectroscopy (ICP/AES), BET, mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) imaging. The results of the analyses indicate that the milling process helped to stabilize the heavy metals in the MEA, with an increase in the specific surface area of about 50 times over that of OPC. The addition of the MEA to the OPC paste decreased the amount of Ca(OH)2 and led to the generation of calcium–silicate–hydrates (C–S–H) which in turned increased the amount of gel pores and middle sized pores in the cement. Furthermore, a comparison shows an increase in the early and later strength over that of OPC paste without the addition of the milled extracted ash. In other words, the milling process could stabilize the heavy metals in the MEA and had an activating effect on the MEA, allowing it to partly substitute OPC in OPC paste

  10. Centrifugal air-assisted melt agglomeration for fast-release "granulet" design.

    Science.gov (United States)

    Wong, Tin Wui; Musa, Nafisah

    2012-07-01

    Conventional melt pelletization and granulation processes produce round and dense, and irregularly shaped but porous agglomerates respectively. This study aimed to design centrifugal air-assisted melt agglomeration technology for manufacture of spherical and yet porous "granulets" for ease of downstream manufacturing and enhancing drug release. A bladeless agglomerator, which utilized shear-free air stream to mass the powder mixture of lactose filler, polyethylene glycol binder and poorly water-soluble tolbutamide drug into "granulets", was developed. The inclination angle and number of vane, air-impermeable surface area of air guide, processing temperature, binder content and molecular weight were investigated with reference to "granulet" size, shape, texture and drug release properties. Unlike fluid-bed melt agglomeration with vertical processing air flow, the air stream in the present technology moved centrifugally to roll the processing mass into spherical but porous "granulets" with a drug release propensity higher than physical powder mixture, unprocessed drug and dense pellets prepared using high shear mixer. The fast-release attribute of "granulets" was ascribed to porous matrix formed with a high level of polyethylene glycol as solubilizer. The agglomeration and drug release outcomes of centrifugal air-assisted technology are unmet by the existing high shear and fluid-bed melt agglomeration techniques. PMID:22531845

  11. Agglomeration in counter-current spray drying towers. Part B: Interaction between multiple spraying levels

    OpenAIRE

    Francia, V; Martín, L; Bayly, AE; Simmons, MJH

    2016-01-01

    A new experimental method is developed here to investigate agglomeration in spray drying towers operating with multiple nozzles. It allows studying independently the contribution of each spray to the product and obtaining a valuable insight into the agglomeration processes. The paper studies a two level swirl counter-current dryer of detergent in a full-scale production system. It shows that operation with two nozzle levels increases the energy efficiency compared to the use of single sprays,...

  12. Distribution Characteristics and Compressibility of Agglomerates as a Reflection of Granulation Parameters

    OpenAIRE

    Macho Oliver; Peciar Peter; Peciar Marián; Svěrák Tomáš

    2015-01-01

    Selective adjustment of the properties of particular material agglomeration has its inherent place in the chemical, food, but especially in the pharmaceutical, industry. The requirement to produce an agglomerate with desired particle size at a given strength is often formulated. To create the targeted product, it is necessary to know the process parameters affecting the preparation of its features. This paper deals with survey distribution characteristics and compressibility changes of an agg...

  13. Reducing carbon-in-ash

    Energy Technology Data Exchange (ETDEWEB)

    Nigel S. Dong [IEA Clean Coal Centre, London (United Kingdom)

    2010-05-15

    High levels of carbon-in-ash lead to reduced power plant efficiency and higher fuel costs, degrade the performance of electrostatic precipitators and increase emissions of particulates. Increased carbon levels in the fly ash can lead to problems with ash use in cement/concrete production. This report reviews current measures and technologies that can be used to prevent excessive carbon-in-ash in pulverised coal combustion (PCC) power plants. These include coal cleaning, coal fineness improvement, reduction of distribution imbalance of coal among burners, increasing coal-air mixing rates at both burner and OFA levels and optimising excess air ratios. A plasma-assisted combustion enhancement technology can help achieve better ignition and more stable flame for coals that are normally difficult to burn. Computer-based combustion optimisation using expert systems, neural network systems and coal combustion simulation is becoming an invaluable means to tackle the carbon-in-ash issue. This report also reviews the regulations in nine major coal-consuming countries, which stipulate the maximum unburnt carbon levels permitted for fly ash for use in concrete/cement production. The Loss on Ignition (LOI) parameter is used in all national standards, although it is considered inadequate and may exclude some usable fly ash from being utilised. Performance-based regulations are more appropriate and have been adopted by Canada and USA. The EU and Canada now permit the use of fly ash produced from co-combustion of coal and biomass. China and Russia allow very high LOI levels for certain fly ash but the other countries require similar LOI limits for fly ash for use in concrete. Finally, this report discusses measures and technologies for reduction of carbon-in-ash, including classification, froth flotation, triboelectrostatic separators, thermal processes and carbon surface modification. 146 refs., 19 figs., 15 tabs.

  14. Use of Incineration MSW Ash: A Review

    Directory of Open Access Journals (Sweden)

    Charles H. K. Lam

    2010-07-01

    Full Text Available This study reviews the characteristics of municipal solid waste incineration (MSWI ashes, with a main focus on the chemical properties of the ashes. Furthermore, the possible treatment methods for the utilization of ash, namely, separation processes, solidification/stabilization and thermal processes, are also discussed. Seven types of MSWI ash utilization are reviewed, namely, cement and concrete production, road pavement, glasses and ceramics, agriculture, stabilizing agent, adsorbents and zeolite production. The practical use of MSWI ash shows a great contribution to waste minimization as well as resources conservation.

  15. Degradation processes in Al/SiC{sub p}/MgAl{sub 2}O{sub 4} composites prepared from recycled aluminum with fly ash and rice hull ash

    Energy Technology Data Exchange (ETDEWEB)

    Pech-Canul, M.I.; Escalera-Lozano, R.; Rendon-Angeles, J.C.; Lopez-Cuevas, J. [Cinvestav Saltillo, Carr. Saltillo-Mty. Km. 13, Saltillo, Coah, Mexico 25900 (Mexico); Pech-Canul, M.A. [Cinvestav Merida, Km. 6 Antigua Carr. a Progreso Apdo. Postal 73, Cordemex. Merida, Yuc., Mexico 97310 (Mexico)

    2007-11-15

    The degradation characteristics of Al/SiC{sub p}/spinel composites prepared with fly ash (FA) and rice hull ash (RHA) under environmental conditions were investigated. Composite specimens were prepared with recycled aluminum via reactive infiltration in the temperature range 1050-1150 C for 50-70 min and, in argon atmosphere at a pressure slightly above that of the atmospheric pressure. Results reveal that although both FA and RHA help in preventing SiC{sub p} dissolution and the subsequent chemical degradation of the composites, due to the interaction of native carbon in FA with liquid aluminum, FA-composites are susceptible to corrosion via Al{sub 4}C{sub 3}. Moreover, this phase accelerates the degradation process and increases the damage severity. The primary corrosion mechanism in both types of composites is attributed to microgalvanic coupling between the intermetallic Mg{sub 2}Si and the matrix. Accordingly, an appropriate control of the Si/(Si + Mg) molar ratio in the aluminum alloy hinders the Mg{sub 2}Si corrosion mechanism in both types of composites and a proper FA calcination prevents chemical degradation in FA composites. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  16. Zirconia nanoceramic via redispersion of highly agglomerated nanopowder and spark plasma sintering.

    Science.gov (United States)

    Suárez, Gustavo; Borodianska, Hanna; Sakka, Yoshio; Aglietti, Esteban F; Vasylkiv, Oleg

    2010-10-01

    A 2.7 mol% yttria stabilizing tetragonal zirconia (2.7Y-TZP) nanopowder was synthesized and stored for five years. Humidity and unsatisfactory storage conditions gradually caused heavy agglomeration. Within a few months, 2.7Y-TZP nanopowder became useless for any technological application. A bead-milling deagglomeration technique was applied to recover the heavily agglomerated yttria-stabilized zirconia nanopowder. Low-temperature sintering and spark plasma sintering (SPS) were performed, resulting in fully dense nanostructured ceramics. Compacts formed with heavily agglomerated powder present low sinterability and poor mechanical properties. Bead-milling suspension formed compacts exhibit mechanical properties in the range of the values reported for nanostructured zirconia. This observation confirms the effectiveness of bead-milling in the deagglomeration of highly agglomerated nanopowders. The high value of Vickers hardness of 13.6 GPa demonstrates the success of the processing technique for recovering long-time-stored oxide nanopowders. PMID:21137774

  17. Agglomeration Evolution of Nano-Particles Aluminium in Normal Incident Shock Wave

    Institute of Scientific and Technical Information of China (English)

    YAN Zheng-Xin; WU Jing-He; HU Dong; YANG Xiang-Dong

    2006-01-01

    Agglomeration behaviour of nano-particle aluminium (nano-Al) in normal incident shock waves is investigated by our devised shock tube technology. The morphology, particle size, agglomeration process of nano-Al studied in normal incident shock waves are comprehensible evaluated by x-ray diffraction, transmission electron microscopy and scanning electron microscopy. The above-mentioned techniques show that the high strength and temperature of incident shock wave give a chance for activity of nano-Al in the reactions and decrease the agglomeration, and the morphology of agglomeration is affected by the temperature of nano-Al reaction region. The dynamic temperature of reaction region determined by the intensity ratio of two AlO bands is 2602K, which is closer to nano-Al actual reacted temperature than the determined temperature of ordinary methods (i.e. six channel instantaneous optical pyrometer; plank black body radiation law, etc.)

  18. Study on Agglomeration and Densification Behaviors of Gadolinium-Doped Ceria Ceramics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped ceria (GDC) with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders were dispersed with the terpineol as the dispersant through different methods such as ball milling and high-shear dispersing. Coagulation factor (CF) was used to mark the degree of agglomeration on the nano-scale GDC in this work. The effect of agglomeration on the densification behavior at different sintering temperatures was investigated. The studies indicated that agglomeration retarded the densification at the sintering stage. The powders with better dispersion exhibited a higher sintered density at the same temperature. After effective dispersion treatment, GDC could be fully densified at the sintering temperature of 1300 ℃. The densification temperature was significantly lower than those reported previously. The high sintering kinetics of the ceramics was obtained based on the agglomeration control.

  19. Compression Behaviour of Porous Dust Agglomerates

    CERN Document Server

    Seizinger, Alexander; Kley, Wilhelm

    2012-01-01

    The early planetesimal growth proceeds through a sequence of sticking collisions of dust agglomerates. Very uncertain is still the relative velocity regime in which growth rather than destruction can take place. The outcome of a collision depends on the bulk properties of the porous dust agglomerates. Continuum models of dust agglomerates require a set of material parameters that are often difficult to obtain from laboratory experiments. Here, we aim at determining those parameters from ab-initio molecular dynamics simulations. Our goal is to improveon the existing model that describe the interaction of individual monomers. We use a molecular dynamics approach featuring a detailed micro-physical model of the interaction of spherical grains. The model includes normal forces, rolling, twisting and sliding between the dust grains. We present a new treatment of wall-particle interaction that allows us to perform customized simulations that directly correspond to laboratory experiments. We find that the existing i...

  20. EDU 626 ASH

    OpenAIRE

    NARESH 40 course tutorial/tutorialoutlet

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     Product Description EDU 626 Week 1 Research Topic (Ash) EDU 626 Week 2 Annotated Bibliography (Ash) EDU 626 Week 2 Critical Thinking Questions (Ash) EDU 626 Week 3 Procedures or Methods (Ash) EDU 626 Week 4 Critical Thinking Questions (Ash) EDU 626 Week 5 Critical Thinking Questions (Ash) EDU 626 Week 6 Final Paper (Ash)  

  1. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  2. Preliminary Study on a Novel Process for Manufacturing Soda Ash from Sodium Sulfate%一种新的芒硝制碱法实验室研究

    Institute of Scientific and Technical Information of China (English)

    王天贵; 李佐虎

    2004-01-01

    The purpose of this work is to find a new way for utilizing the rich sodium sulfate resource to produce soda ash.A novel process is proposed which uses aqueous dichromate solution as working medium through decomposition of calcium carbonate in aqueous sodium dichromate,complex decomposition of aqueous sodium sulfate and calcium chromate,regeneration of sodium dichromate and production of sodium bicarbonate from carbonation of aqueous sodium chromate solution,processing and utilization of byproduct calcium sulfate,and production of sodium carbonate from sodium bicarbonate.The process has the features of less corrosion and pollution and low energy consumption.

  3. Surface-coated fly ash used as filler in biodegradable poly(vinyl alcohol) composite films: Part 1-The modification process

    International Nuclear Information System (INIS)

    The surfaces of fly ash (FA) particles were modified by surfactant, sodium lauryl sulphate (SLS) and used in fabrication of composite films with polyvinyl alcohol (PVA). Both unmodified fly ash (FA) and modified fly ash (SLS-FA) samples were examined using a range of analytical tools including X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The distribution patterns of SLS-FA particles were shifted to the higher regions compared to FA by adding 1.2-4.2 μm in the ranges between 2 and 25 μm, whereas the modification process reduced the size of the particles over 25 μm due to grinding during the activation process. The increased 1.2-4.2 μm in average can be considered the thickness of the surfactant on the SLS-FA surface. On the oxides based chemical analysis by XRF, the compositions were almost unchanged. SEM and TEM were visualised the irregular sizes morphology mostly spherical of the particles, although it is impossible to capture the images of exactly same particles in modified and unmodified forms. The composite films reinforced with SLS-FA showed 33% higher strength than those of FA filled films. The enhancement of tensile strength attributed from the level of physical bonding between SLS-FA and PVA surfaces.

  4. Fluidized-Bed Coating with Sodium Sulfate and PVA-TiO2, 1. Review and Agglomeration Regime Maps

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, Poul; Jensen, Anker Degn

    2009-01-01

    salt and polymer film coating is provided, along with a presentation of the equipment and materials being used in this and the following papers. Results from agglomeration studies over a broad range of process conditions are presented, showing that the tendency toward agglomeration is always less...... for the salt coating process than for the polymer coating process, under similar process conditions. Based on the experimental results, an agglomeration regime map is suggested for each of the two types of coating solutions, based on values of the drying force and the coating solution spray rate....

  5. Measuring Agglomeration Forces in a Financial Center

    OpenAIRE

    Bourgain, Arnaud; Pieretti, Patrice

    2006-01-01

    Basing on Scitovsky's (1954) definition of external economies and applying the method of Caballero and Lyons (1990) to macro data of Luxembourg services industry, we find significant agglomeration forces between financial intermediaries (downstream industry) on the one hand and business services and computer industry (upstream industries) on the other.

  6. Industrial Agglomeration and Use of the Internet

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); Y-C. Wu (Yu-Chieh)

    2015-01-01

    textabstractTaiwan has been hailed as a world leader in the development of global innovation and industrial clusters for the past decade. This paper investigates the effects of industrial agglomeration on the use of the internet and internet intensity for Taiwan manufacturing firms, and analyses whe

  7. Laser-induced agglomeration of gold nanoparticles dispersed in a liquid

    International Nuclear Information System (INIS)

    Highlights: • Pulsed laser irradiation of dense gold nanoparticles colloidal solution can result in their agglomeration. • Gas bubbles in-phase pulsation induced by laser radiation accounts for nanoparticles agglomeration. • Time evolution of the size distribution function proceeds in activation mode. • The electrostatic-like model of nanoparticles agglomeration is in good correspondence with the experimental data. - Abstract: Dynamics of gold nanoparticles (NPs) ensemble in dense aqueous solution under exposure to picosecond laser radiation is studied both experimentally and theoretically. Properties of NPs are examined by means of transmission electron microscopy, optical spectroscopy, and size-measuring disk centrifuge. Theoretical investigation of NPs ensemble behavior is based on the analytical model taking into account collisions and agglomeration of particles. It is shown that in case of dense NPs colloidal solutions (above 1014 particles per milliliter) the process of laser fragmentation typical for nanosecond laser exposure turns into laser-induced agglomeration which leads to formation of the particles with larger sizes. It is shown that there is a critical concentration of NPs: at higher concentrations agglomeration rate increases tremendously. The results of mathematical simulation are in compliance with experimental data

  8. Laser-induced agglomeration of gold nanoparticles dispersed in a liquid

    Energy Technology Data Exchange (ETDEWEB)

    Serkov, A.A.; Shcherbina, M.E. [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov Street, 119991 Moscow (Russian Federation); The Federal State Educational Institution of Higher Professional Education, Moscow Institute of Physics and Technology (State University), Moscow (Russian Federation); Kuzmin, P.G., E-mail: qzzzma@gmail.com [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov Street, 119991 Moscow (Russian Federation); Kirichenko, N.A. [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov Street, 119991 Moscow (Russian Federation); The Federal State Educational Institution of Higher Professional Education, Moscow Institute of Physics and Technology (State University), Moscow (Russian Federation)

    2015-05-01

    Highlights: • Pulsed laser irradiation of dense gold nanoparticles colloidal solution can result in their agglomeration. • Gas bubbles in-phase pulsation induced by laser radiation accounts for nanoparticles agglomeration. • Time evolution of the size distribution function proceeds in activation mode. • The electrostatic-like model of nanoparticles agglomeration is in good correspondence with the experimental data. - Abstract: Dynamics of gold nanoparticles (NPs) ensemble in dense aqueous solution under exposure to picosecond laser radiation is studied both experimentally and theoretically. Properties of NPs are examined by means of transmission electron microscopy, optical spectroscopy, and size-measuring disk centrifuge. Theoretical investigation of NPs ensemble behavior is based on the analytical model taking into account collisions and agglomeration of particles. It is shown that in case of dense NPs colloidal solutions (above 10{sup 14} particles per milliliter) the process of laser fragmentation typical for nanosecond laser exposure turns into laser-induced agglomeration which leads to formation of the particles with larger sizes. It is shown that there is a critical concentration of NPs: at higher concentrations agglomeration rate increases tremendously. The results of mathematical simulation are in compliance with experimental data.

  9. Bipolar charged aerosol agglomeration and collection by a two zone agglomerator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In older to collect fine particles more efficiently, a new-type electrostatic agglomerator with two sones was developed. The distinguishing feature of this electrostatic agglomerator is that the particles are bipolarly charged and coagulated in the same alternating electric field simultaneously. The silica flour with 2 μm mass median diameter and the smoke from burning wood powder were used as test aerosol. The comparison experimental results have shown that when the mean electric field is 4 kV/cm the collection efficiency of the new electrostatic agglomerator was 98.2% for silica flour and 67.4% for wood powder smoke. Under the same experimental condition, the collection efficiency of the electrostatic agglomerator with three zones was 97.4% for collecting silica flour and the collection efficiency of the electrostatic precipitator was 56.3% for wood powder smoke.

  10. Structure and Properties of BaFe12O19 Coated Fly Ash Cenospheres by Sol-Gel Process

    Institute of Scientific and Technical Information of China (English)

    ZENG Aixiang; XIONG Weihao; WANG Caifang; ZHOU Qionghua

    2006-01-01

    Thin films of barium hexaferrite were prepared on fly ash cenosphere particles by the sol-gel method using Fe(NO3)3·9H2O,Ba(NO3)2 and citric acid as raw materials. The prepared films were characterized by differential thermal and thermogravimetric analysis (DTA-TG), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry. The magnetic and structural properties of barium hexaferrite coated cenosphere particles were also studied. The experimental results show that even and continual barium hexaferrite coatings were prepared on fly ash cenospheres, and the magnetic conductivity was imparted to these non-conducting oxide ceramic particles. The low density barium hexaferrite coated cenosphere particles may be utilized for manufacturing microwave absorbing materials.

  11. Fibre agglomerate transport in a horizontal flow

    International Nuclear Information System (INIS)

    Loss of coolant accidents in the primary circuit of pressure and boiling water reactors can cause the damage of adjacent insulation materials. These materials may then find their way to the containment sump where water is drawn into the ECCS (emergency core cooling system). Strainers in the containment sump may become fully or partially blocked by the insulation materials. The consequences of such blockages are an increased pressure drop acting on the operating ECCS pumps. If the strainers are partially blocked smaller particles can also penetrate the strainers. These smaller particles can therefore enter the reactor coolant system and then accumulate in the reactor pressure vessel. An experimental and theoretical study that concentrates on mineral wool fibre transport in the containment sump and the ECCS is being performed. The study entails the generation of fibre agglomerates and the assessment of their transport in single and multi-effect experiments. The experiments include measurement of the terminal settling velocity, the strainer pressure drop, fibre sedimentation and resuspension in a channel flow, jet flow in a rectangular tank and the importance of chemical effects on any filter cake formed on the strainer. An integrated test facility is also operated to assess the compounded effects. Each experimental facility is used to provide data for the validation of equivalent computational fluid dynamic models. The channel flow facility allows the determination of the steady state distribution of the fibres at different flow velocities. The channel has a racetrack configuration with nine straight sections (1 m by 1 m by 0.1 m) and two 90 deg. bends with a radius of 0.5 m to the channel midpoint. The height of the bends is also 1 m and the channel width is 0.1 m. An elliptical section located upstream of one of the bends is used to house the impellers, which drives the flow into the next bend. Laser Doppler anemometry, particle image velocimetry, ultrasound

  12. Water migration mechanisms in amorphous powder material and related agglomeration

    NARCIS (Netherlands)

    Renzetti, S.; Voogt, J.A.; Oliver, L.; Meinders, M.B.J.

    2012-01-01

    The agglomeration phenomenon of amorphous particulate material is a major problem in the food industry. Currently, the glass transition temperature (Tg) is used as a fundamental parameter to describe and control agglomeration. Models are available that describe the kinetics of the agglomeration proc

  13. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  14. Agglomeration techniques for the production of spheres for packed beds

    International Nuclear Information System (INIS)

    One attractive fusion-breeder-blanket design features a lithium bearing ceramic in the form of spheres packed into a random array. The spheres have diameters of 3 mm and 0.3 mm. This report surveys techniques used to produce ceramic spheres on an industrial scale. The methods examined include tumbling and mixing granulation, extrusion, briquetting and pelletizing. It is concluded that the required quantities of 0.3 mm diameter spheres can be produced by the tumbling agglomeration of a feed powder. The 3 mm diameter spheres will be made using a process of extrusion, chopping and rolling

  15. Investigation of coalescence kinetics of microcristalline cellulose in fluidised bed spray agglomeration: experimental studies and modelling approach

    Directory of Open Access Journals (Sweden)

    M. Peglow

    2005-06-01

    Full Text Available In this paper a model for fluidized bed spray agglomeration is presented. To describe the processes of heat and mass transfer, a physical based model is derived. The model takes evaporation process from the wetted particles as well as the effects of transfer phenomena between suspension gas and bypass gas into account. The change of particle size distribution during agglomeration, modeled by population balances, is linked to the heat and mass transfer model. A new technique is derived to extract agglomeration and nucleation rates from experimental data. Comparisons of experiments and simulations are presented.

  16. Research on Fly Combustion Process of Self-reaction Quenching Agglomerate Powders Based on High-speed Camera%基于高速摄影的自反应淬熄团聚粉飞行燃烧行为研究

    Institute of Scientific and Technical Information of China (English)

    王建江; 娄鸿飞; 蔡旭东; 温晋华

    2012-01-01

    Hollow multiphase ceramic microspheres including ferrite is a new kind of lightweight absorbert. Take AI-TiO2-Fe-Fe2O3-MnO2-sucrose-epoxy resin as reaction system, agglomerate powders are prepared in the size between 50 and 90μm by bailing, drying, and carbonation, grinding and sieving process. Hollow multiphase ceramic microspheres including ferrite was obtained through spraying and melting agglomerate powders by self-reactive quenching technology. Flying combustion process of agglomerate powders is analyzed by high-speed camera method, and surface morphology is characterized by SEM. The results show that three phases compose the fly combustion of agglomerate powders: heat storage, heat releasing and after combustion, then hollow ceramic beads are formed. Hollow ceramic microspheres are formed by solidification in high supercooling.%含铁氧体成分的空心复相陶瓷微珠是一种新型轻质吸波材料。本文以Al-TiO2-Fe-Fe2O3-MnO2-蔗糖-环氧树脂为反应体系,经球磨、烘干、碳化、粉碎、筛分制成粒径为50-90μ的团聚粉,利用自反应淬熄技术熔射团聚粉获得了含铁氧体成分的空心复相陶瓷微珠。用SEM表征了淬熄前后团聚粉的形貌变化,通过高速摄影技术研究分析了团聚粉粒子在熔射过程中的飞行燃烧行为。试验结果表明,团聚粉粒子在飞行燃烧过程中经历受热蓄能、热释放与后燃烧三个阶段形成空心陶瓷熔滴,该熔滴在大过冷条件下凝固结晶最终形成空心陶瓷微珠。

  17. Distribution Characteristics and Compressibility of Agglomerates as a Reflection of Granulation Parameters

    Directory of Open Access Journals (Sweden)

    Macho Oliver

    2015-12-01

    Full Text Available Selective adjustment of the properties of particular material agglomeration has its inherent place in the chemical, food, but especially in the pharmaceutical, industry. The requirement to produce an agglomerate with desired particle size at a given strength is often formulated. To create the targeted product, it is necessary to know the process parameters affecting the preparation of its features. This paper deals with survey distribution characteristics and compressibility changes of an agglomerate in dependence on the duration of the granulation process through the usage of the most modern devices working with particulate materials. The investigated product will be prepared for coating granulating disc designed at the Institute of Process Engineering, Faculty of Mechanical Engineering, Slovak University of Technology in Bratislava.

  18. Industry-specific firm growth and agglomeration

    OpenAIRE

    Duschl, Matthias; Scholl, Tobias; Brenner, Thomas; Luxen, Dennis; Raschke, Falk

    2013-01-01

    This paper studies the industry-specific relationship between industrial clustering and firm growth. The literature usually considers industrial clusters as positive for the general economic development of regions. In particular, their relationship with the formation rate of new firms and the survival rate of existing firms is well documented. However, the impact of agglomeration effects on growth prospects of firms is less clear. Because of the heterogeneity of industries, different agglomer...

  19. Specialization and Agglomeration Patterns in Eastern Europe

    Directory of Open Access Journals (Sweden)

    Chapman, Sheila A.

    2013-04-01

    Full Text Available The paper investigates specialization and agglomeration trends in EU-27 NUTS2 regions over 1991-2011 by means of two versions of the relative Theil indicator that use employment data. The paper’s main focus is on Central and Eastern European Countries (CEECs regions. As a legacy of central planning, in the early ‘Nineties these regions presented significantly above-average specialization and agglomeration. The paper shows that over 1991-2011 these features change very little; moreover, while disproportions fall in the other EU members, they rise in CEECs, implying growing divergence among the two groups in real terms, notwithstanding EU emphasis on real convergence. Indicators disaggregated by sectors show that for CEECs specialization/agglomeration change most in agriculture, market services and manufacturing. The paper focuses on the last two sectors. It argues that performance in the service sector is largely due to capital regions catching up on previous underdevelopment in the sector, therefore getting closer to Western regions. Non-capital regions instead lag behind, moving away from the EU sectoral average. As far as manufacturing is concerned, CEECs regions continue to specialize in the more traditional lines of production, for which also agglomeration remains extremely high. Consideration of the changes over time gives a partially different picture and shows that the higher specialization in overall manufacturing results from the development of a small but dynamic medium-high technology sub-sector that is significantly disseminated across regions, thus appearing to result from successful industrial restructuring and reconversion.

  20. Remedial processing of oil shale fly ash (OSFA) and its value-added conversion into glass-ceramics.

    Science.gov (United States)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-12-01

    Recently, various solid wastes such as sewage sludge, coal fly ash and slag have been recycled into various products such as sintered bricks, ceramics and cement concrete. Application of these recycling approaches is much better and greener than conventional landfills since it can solve the problems of storage of industrial wastes and reduce exploration of natural resources for construction materials to protect the environment. Therefore, in this study, an attempt was made to recycle oil shale fly ash (OSFA), a by-product obtained from the extracting of shale oil in the oil shale industry, into a value-added glass-ceramic material via melting and sintering method. The influence of basicity (CaO/SiO2 ratio) by adding calcium oxide on the performance of glass-ceramics was studied in terms of phase transformation, mechanical properties, chemical resistances and heavy metals leaching tests. Crystallization kinetics results showed that the increase of basicity reduced the activation energies of crystallization but did not change the crystallization mechanism. When increasing the basicity from 0.2 to 0.5, the densification of sintering body was enhanced due to the promotion of viscous flow of glass powders, and therefore the compression strength and bending strength of glass-ceramics were increased. Heavy metals leaching results indicated that the produced OSFA-based glass-ceramics could be taken as non-hazardous materials. The maximum mechanical properties of compression strength of 186 ± 3 MPa, bending strength of 78 ± 6 MPa, good chemical resistances and low heavy metals leaching concentrations showed that it could be used as a substitute material for construction applications. The proposed approach will be one of the potential sustainable solutions in reducing the storage of oil shale fly ash as well as converting it into a value-added product. PMID:26387050

  1. Remedial processing of oil shale fly ash (OSFA) and its value-added conversion into glass-ceramics.

    Science.gov (United States)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-12-01

    Recently, various solid wastes such as sewage sludge, coal fly ash and slag have been recycled into various products such as sintered bricks, ceramics and cement concrete. Application of these recycling approaches is much better and greener than conventional landfills since it can solve the problems of storage of industrial wastes and reduce exploration of natural resources for construction materials to protect the environment. Therefore, in this study, an attempt was made to recycle oil shale fly ash (OSFA), a by-product obtained from the extracting of shale oil in the oil shale industry, into a value-added glass-ceramic material via melting and sintering method. The influence of basicity (CaO/SiO2 ratio) by adding calcium oxide on the performance of glass-ceramics was studied in terms of phase transformation, mechanical properties, chemical resistances and heavy metals leaching tests. Crystallization kinetics results showed that the increase of basicity reduced the activation energies of crystallization but did not change the crystallization mechanism. When increasing the basicity from 0.2 to 0.5, the densification of sintering body was enhanced due to the promotion of viscous flow of glass powders, and therefore the compression strength and bending strength of glass-ceramics were increased. Heavy metals leaching results indicated that the produced OSFA-based glass-ceramics could be taken as non-hazardous materials. The maximum mechanical properties of compression strength of 186 ± 3 MPa, bending strength of 78 ± 6 MPa, good chemical resistances and low heavy metals leaching concentrations showed that it could be used as a substitute material for construction applications. The proposed approach will be one of the potential sustainable solutions in reducing the storage of oil shale fly ash as well as converting it into a value-added product.

  2. Control methods for mitigating biomass ash-related problems in fluidized beds.

    Science.gov (United States)

    Vamvuka, D; Zografos, D; Alevizos, G

    2008-06-01

    Embodiment of biomass combustion technologies in the Cretan energy system will play an important role and will contribute to the local development. The main biomass fuels of Crete are the agricultural residues olive kernel and olive tree wood. Future applications of these biofuels may create, among others, operational problems related to ash effects. In this regard, the thermal behavior of the ashes during lab-scale fluidized bed combustion tests was examined, in terms of slagging/fouling and agglomeration of bed material. Control methodologies for mitigating ash problems were applied, such as leaching the raw fuels with water and using different mineral additives during combustion. The ashes and the bed material were characterized in terms of mineralogical, chemical and morphological analyses and the slagging/fouling and agglomeration propensities were determined. The results showed that fly ashes were rich in Ca, Si and Fe minerals and contained substantial amounts of alkali, falling within the range of "certain or probable slagging/fouling". Leaching of the raw fuels with water resulted in a significant reduction of the problematic elements K, Na, Cl and S in the fly ashes. The use of fuel additives decreased the concentrations of alkali and iron minerals in the fly ashes. With clay additives calcium compounds were enriched in the bottom ash, while with carbonate additives they were enriched in the fly ash. Fuel additives or water leaching reduced the slagging/fouling potential due to alkali. Under the conditions of the combustion tests, no signs of ash deposition or bed agglomeration were noticed. PMID:17826986

  3. On the Mechanism of Ultrasound-Driven Deagglomeration of Nanoparticle Agglomerates in Aluminum Melt

    Science.gov (United States)

    Kudryashova, Olga; Vorozhtsov, Sergey

    2016-05-01

    One of the promising directions in the technology of composite alloys with improved mechanical properties is reinforcement of the metallic matrix with nanopowders introduced in the liquid metal. Ultrasonic processing is known to significantly improve the introduction of submicrone particles to the metallic melt. This study focuses on the mechanisms of deagglomeration and wettability of such particles by the melt under the action of ultrasound. The suggested mechanism involves the penetration of the liquid metal into the pores and cracks of the agglomerates under the excess pressure created by imploding cavitation bubbles and further destruction of the agglomerate by the sound wave. The main dependences connecting the acoustic parameters and processing time with the physical and chemical properties of particles and the melt are obtained through analytical modeling. The mathematical description of the ultrasonic deagglomeration in liquid metal is presented; a dependence of the threshold intensity of ultrasound for the break-up of agglomerates on their size is reported.

  4. Effect of agglomeration during coprecipitation: Delayed spinellization of magnesium aluminate hydrate

    Indian Academy of Sciences (India)

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal

    2010-08-01

    Precipitation of magnesium aluminate hydrate with faster addition of ammonia at desired pH causes agglomeration. Agglomerated powder, without any further treatment, on calcination forms intermediate compounds at low temperatures (≤ 900°C). The intermediate compounds on further heat treatment (≥ 1000°C) decompose into MgO, MgAl2O4 and -Al2O3. Effect of agglomeration and absorption of foreign ions such as Cl–, SO$^{2-}_{4}$, and NH$^{+}_{4}$ in complex compounds probably cause loss of Al3+ and Mg2+ ions during heat treatment, and stoichiometry changes. Powders prepared by continuous method with better control of process parameters than batch process yields better spinellization.

  5. Experimental studies on pulp and paper mill sludge ash behavior in fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Latva-Somppi, J. [VTT Chemical Technology, Espoo (Finland). Process Technology

    1998-11-01

    Ash formation during the fluidized bed combustion (FBC) of pulp and paper mill sludges has been experimentally studied on an industrial and bench scale. The methods included aerosol measurements, chemical and crystalline composition analyses, thermogravimetry and electron microscopy. Fly ash mass and number size distributions and elemental enrichment in submicron particles and bottom ash were measured. Fly ash, bottom ash and ash deposits were characterized and their formation mechanisms are discussed. During combustion the fine paper-making additives in sludge, clay minerals and calcite, sintered fanning porous agglomerates. The fly ash mass mean size was 7.5 - 15 lam and the supermicron particles included 93.6 - 97.3 % of the fly ash. Condensation of the volatilized inorganic species formed spherical submicron particles in the fly ash. Their mass concentration was almost negligible when co-firing paper mill sludges and wood. This suggests that the fraction of the volatilized inorganic species in the paper mill sludges was low. Results from pulp mill sludge and bark co-firing were different. A clear mass mode below 0.3 pm, presenting 2.2 - 5.0 weight-% of the fly ash was detected. The condensed species included K, Na, S and Cl. Their mass fraction was higher in the pulp mill sludge than in the paper mill sludge. Evidently this resulted in increased volatilization and formation of condensed particles. The following trace elements were enriched in the submicron ash during pulp mill sludge and wood co-firing: As, Cd, Rb and Pb. The main part of the volatile species was, however, captured in the bulk ash. Presumably, this was due to the high surface area concentration in the bulk ash. Sludge moisture was observed to reduce the inorganic species volatilization. Probably steam vaporization from the wet sludge through the burning layer decreased combustion temperatures on char surface and less char was produced. Hence, the volatilization of ash forming species was

  6. Rheology of fly ashes from coal and biomass co-combustion

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Frandsen, Flemming

    2010-01-01

    The presence of large amounts of alkali metals, chlorine and sulphur in most biomass fuels - compared to coal - can create serious ash-related problems such as deposition, agglomeration and/or corrosion. This paper discusses the viscosity characteristics of fly ash from the co-combustion of vario...... viscosity leading to higher stickiness of the ash particles. Wood co-firing has only minor effects, due to the composition of wood ash and the low percentage of wood in the coal/biomass blend.......The presence of large amounts of alkali metals, chlorine and sulphur in most biomass fuels - compared to coal - can create serious ash-related problems such as deposition, agglomeration and/or corrosion. This paper discusses the viscosity characteristics of fly ash from the co-combustion of various...... coal/biomass blends in a pilot scale pf-boiler. The produced data provide information on the melting of the ash and its flow characteristics, as a function of temperature, which may be used to modify the temperature profile of the boiler in order to avoid slagging. Straw co-firing lowers the ash...

  7. Development of standards and a cost model for coal agglomeration and related studies

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, S.G.; Kuby, O.A.; Korosi, F.A.; Paulin, M.O.

    1982-02-26

    Several topics concerning coal agglomeration and fixed-bed coal gasification, as they relate to an agglomeration-process development program presently being performed for the Department of Energy, are discussed in this report. Specific topics include an examination of the performance of coals in fixed-bed gasifiers, the development of properties' standards by which agglomerates produced in the program may be compared, the development of a cost model to judge the economic feasibility of coal agglomeration for potential users and the maximum binder levels to be considered in the program, the definition of a suitable briquette size for coal gasification, and a study of upgrading methods at the mines to improve agglomeration. Extensive property data and the results of a number of special tests on six coals (Pittsburgh No. 8 bituminous coal, Illinois No. 6 bituminous coal, Wyoming Bighorn subbituminous coal, Montana Rosebud No. 14 subbituminous coal, North Dakota Indian Head lignite and Pennsylvania Nanoth anthracite coal) and on FMC formcoke and Simplex briquettes are reported.

  8. Scale-Up and Demonstration of Fly Ash Ozonation Technology

    Energy Technology Data Exchange (ETDEWEB)

    Rui Afonso; R. Hurt; I. Kulaots

    2006-03-01

    The disposal of fly ash from the combustion of coal has become increasingly important. When the fly ash does not meet the required specification for the product or market intended, it is necessary to beneficiate it to achieve the desired quality. This project, conducted at PPL's Montour SES, is the first near full-scale ({approx}10 ton/day), demonstration of ash ozonation technology. Bituminous and sub bituminous ashes, including two ash samples that contained activated carbon, were treated during the project. Results from the tests were very promising. The ashes were successfully treated with ozone, yielding concrete-suitable ash quality. Preliminary process cost estimates indicate that capital and operating costs to treat unburned carbon are competitive with other commercial ash beneficiation technologies at a fraction of the cost of lost sales and/or ash disposal costs. This is the final technical report under DOE Cooperative Agreement No.: DE-FC26-03NT41730.

  9. Separation Process of Municipal Solid Waste Incineration Bottom Ash%生活垃圾焚烧炉渣分选处理工艺研究

    Institute of Scientific and Technical Information of China (English)

    黄炳辉

    2013-01-01

      通过一个实例,分析介绍了生活垃圾焚烧炉渣分选处理的一种工艺。实践证明:综合利用破碎、筛分、磁力分选、跳汰分选、摇床分选等固废处理技术,对炉渣进行分选预处理,可有效回收利用Fe、Cu、Al等废旧金属,有效分离收集未燃尽的剩余垃圾,并妥善处理,从而使炉渣的性质满足资源化利用的技术要求,变废为宝。%This article takes an example to introduce a separation process of municipal solid waste incineration bottom ash .It has proven that sScrap metal like iron ,copper and aluminum can be recycled and fully used by using the combination technology such as crushing ,screening ,Magnetic ,jigging ,oscillating ,etc .This method is also very efficient for unburnt residual waste's separation and treatment ,so as to make sure that bottom ash can be utilized completely .

  10. Research on Desilicating Process from High Aluminium Fly Ash%高铝粉煤灰脱硅反应的研究

    Institute of Scientific and Technical Information of China (English)

    宋说讲; 孔德顺

    2013-01-01

      Desilicating process of soluble sinlicon from high aluminium fly ash in certain concentration sodium hydroxide was re-searched with investagation of concentration of sodium hydroxide, temperature, time and solid content. The result showed that the optimization conditions were:concentration of sodium hydroxide 150g/L, temperature 120℃, time 30min and solid content 350g/L. Alumina silica ratio of desiliconized fly ash increased to more than 1.80.%  采用一定浓度的氢氧化钠溶液与高铝粉煤灰中可溶性二氧化硅进行反应,考察苛碱浓度、反应温度、反应时间、浆液固含条件对脱硅反应的影响。结果表明,脱硅反应的优化条件为苛碱浓度150g·L-1,温度120℃,反应时间30min,固含量350g·L-1,脱硅粉煤灰铝硅比由1.20提高到1.80以上。

  11. Process development for the removal and recovery of hazardous dye erythrosine from wastewater by waste materials-Bottom Ash and De-Oiled Soya as adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Alok [Department of Applied Chemistry, Maulana Azad National Institute of Technology, Bhopal 462007 (India)]. E-mail: aljymittal@yahoo.co.in; Mittal, Jyoti [Department of Applied Chemistry, Maulana Azad National Institute of Technology, Bhopal 462007 (India); Kurup, Lisha [Department of Applied Chemistry, Maulana Azad National Institute of Technology, Bhopal 462007 (India); Singh, A.K. [Department of Applied Chemistry, University Institute of Technology, RGPV, Bhopal 462036 (India)

    2006-11-02

    Erythrosine is a water-soluble xanthene class of dye. It is widely used as colorant in foods, textiles, drugs and cosmetics. It is highly toxic, causes various types of allergies, thyroid activities, carcinogenicity, DNA damage behaviour, neurotoxicity and xenoestrogen nature in the humans and animals. The photochemical and biochemical degradation of the erythrosine is not recommended due to formation of toxic by-products. The present paper is an attempt to remove erythrosine from wastewater using adsorption over Bottom Ash-a power plant waste and De-Oiled Soya-an agricultural waste. Under the batch studies, effect of concentration of dye, temperature, pH of the solution, dosage of adsorbents, sieve size of adsorbents, etc., have been studied for the uptake of the dye over both adsorbents. The adsorption process verifies Langmuir and Freundlich adsorption isotherms in both the cases and based on the data different thermodynamic parameters have been evaluated. Batch studies also include kinetic measurements, rate constant study, mass transfer behaviour and establishment of mechanistic pathway for both the cases. For the bulk removal of the dye column operations have been carried out and breakthrough capacities of the Bottom Ash and De-Oiled Soya columns have been calculated. Attempts have also been made for the recovery of the adsorbed dye from exhausted columns by eluting dilute NaOH and more than 90% of the dye was recovered.

  12. Process development for the removal and recovery of hazardous dye erythrosine from wastewater by waste materials-Bottom Ash and De-Oiled Soya as adsorbents

    International Nuclear Information System (INIS)

    Erythrosine is a water-soluble xanthene class of dye. It is widely used as colorant in foods, textiles, drugs and cosmetics. It is highly toxic, causes various types of allergies, thyroid activities, carcinogenicity, DNA damage behaviour, neurotoxicity and xenoestrogen nature in the humans and animals. The photochemical and biochemical degradation of the erythrosine is not recommended due to formation of toxic by-products. The present paper is an attempt to remove erythrosine from wastewater using adsorption over Bottom Ash-a power plant waste and De-Oiled Soya-an agricultural waste. Under the batch studies, effect of concentration of dye, temperature, pH of the solution, dosage of adsorbents, sieve size of adsorbents, etc., have been studied for the uptake of the dye over both adsorbents. The adsorption process verifies Langmuir and Freundlich adsorption isotherms in both the cases and based on the data different thermodynamic parameters have been evaluated. Batch studies also include kinetic measurements, rate constant study, mass transfer behaviour and establishment of mechanistic pathway for both the cases. For the bulk removal of the dye column operations have been carried out and breakthrough capacities of the Bottom Ash and De-Oiled Soya columns have been calculated. Attempts have also been made for the recovery of the adsorbed dye from exhausted columns by eluting dilute NaOH and more than 90% of the dye was recovered

  13. Measurement of temperature conditions in grate zone of a 1 MW wood-pellets boiler fired with high ash content wood-pellets

    OpenAIRE

    Skotland, Christer Heen

    2009-01-01

    The combustion of biomass could in some cases lead to ash problems induced by high temperatures such as ash sintering, agglomeration and melting. The degrees of these problems depend on the fuel feedstock and are highly dependent on the amount of potassium, sodium and chlorine in the biomass. Straw, grass, bark, branches and wood residues are typical examples of biomass fuels that are connected to the mentioned ash problems.Addition of additives in the problematic fuels is a possible measure ...

  14. Models of agglomeration and glass transition

    CERN Document Server

    Kerner, Richard

    2007-01-01

    This book is for any physicist interested in new vistas in the domain of non-crystalline condensed matter, aperiodic and quasi-crystalline networks and especially glass physics and chemistry. Students with an elementary background in thermodynamics and statistical physics will find the book accessible. The physics of glasses is extensively covered, focusing on their thermal and mechanical properties, as well as various models leading to the formation of the glassy states of matter from overcooled liquids. The models of agglomeration and growth are also applied to describe the formation of quasicrystals, fullerenes and, in biology, to describe virus assembly pathways.

  15. Internal migration, regional labor markets and the role of agglomeration economies

    DEFF Research Database (Denmark)

    Mitze, Timo Friedel; Schmidt, Torben Dall

    2015-01-01

    by “new” migration theories related to regional growth models and the new economic geography. The work contributes to the field in the following way: we extend the scarce literature on the different channels through which agglomeration economies act as an attractor for mobile labor. Moreover, we account...... for the role of space–time dynamic adjustment processes and simultaneity among migration and labor market variables and finally test for heterogeneity in the migration response to regional labor market disparities among low- and high-skilled migrants. Our results support the view that agglomeration economies...... are indeed key drivers of internal migration flows in Denmark. That is, while we obtain mixed evidence with regard to the role of traditional labor and housing market variables, most of the included proxies for agglomeration economies such as the region’s population density, patent intensity, endowment...

  16. FORMATION MECHANISM AND SPATIAL PATTERN OF URBAN AGGLOMERATION IN CENTRAL JILIN OF CHINA

    Institute of Scientific and Technical Information of China (English)

    QIN Gan; ZHANG Ping-yu; JIAO Bin

    2006-01-01

    Urban agglomeration is made up of cities with different sizes to be linked by traffic network in a given area, and it is an inevitable result when urbanization reaches a certain level. Taking urban agglomerationin central Jilin(UACJ) as an example, this article analyzes the formation mechanism and spatial pattern of urban agglomeration in the less-developed area. First, the dynamics of UACJ has been analyzed from the aspects of geographical condition, economic foundation, policy background, and traffic condition. Then the development process is divided into three stages-single city, city group and city cluster. Secondly, the central cities are identified from the aspects of city centrality, and the development axes are classified based on economic communication capacity. Finally, the urban agglomeration is divided into five urban economic regions in order to establish the reasonable distribution of industries.

  17. The Morphology of Urban Agglomerations for Developing Countries: A Case Study with China

    CERN Document Server

    Gangopadhyay, Kausik

    2010-01-01

    In this article, the relationship between two well-accepted empirical propositions regarding the distribution of population in cities, namely, Gibrat's law and Zipf's law, are rigorously examined using the Chinese census data. Our findings are quite in contrast with the most of the previous studies performed exclusively for developed countries. This motivates us to build a general environment to explain the morphology of urban agglomerations both in developed and developing countries. A dynamic process of job creation generates a particular distribution for the urban agglomerations and introduction of Special Economic Zones (SEZ) in this abstract environment shows that the empirical observations are in good agreement with the proposed model.

  18. Study on Leaching Process of Germanium Fly Ash with Sulfuric Acid%含锗烟尘的硫酸浸出工艺研究

    Institute of Scientific and Technical Information of China (English)

    郑东升; 肖松; 梁杰

    2012-01-01

    为简化含锗烟尘浸出过程,提出一段硫酸浸出工艺。浸出工艺条件为:浸出温度90℃,初始硫酸质量浓度120g/L,液固比8mL/g,浸出时间2.5h,搅拌转速120r/min。在该条件下,锌、锗浸出率分别为99.1%和87.61%左右,最终硫酸质量浓度约34.80g/L。去除不溶性锗后,锗浸出率可达到97.21%。%To simplify the leaching process of germanium fly ash, the one stage sulfuric acid leaching process was studied. The result shows the leaching processing as following: leaching temperature 90℃ initial sulfuric acid concentration 120 g/L, ratio of hquid to solid 5 mL/g, leaching time 2 h, and mixing speed 120 r/min. Under these conditions, the leaching rates of Zn and Ge were about 99.1% and 87.61%, and the concentration of end acid is about 34.80 g/L, and by removal of insoluble germanium, the leaching rate of Germanium could be about 97.21%. Zinc and Germanium can be effectively leached from Germanium fly ash in the leaching process, and the leaching technique is effective and stable.

  19. Plutonium dissolution from Rocky Flats Plant incinerator ash

    International Nuclear Information System (INIS)

    Rockwell Hanford Operations (Rockwell) soon will commence recovery of plutonium from Rocky Flats Plant incinerator ash. In preparation for this processing, Rockwell undertook literature and laboratory studies to identify, select and optimize plutonium dissolution methods for treating the ash. Ash reburning, followed by dissolution in nitric acid containing calcium fluoride, was selected as the processing method for the ash. Recommended values of process parameters were identified. Using the selected process, 99.5% plutonium recovery was achieved, leaving about 12.7 wt % heel residue for an equal weight composite of the three ashes tested. 15 refs., 26 figs

  20. Reduced ash-related operational problems by co-combustion peat and agricultural fuels; Minskade askrelaterade driftsproblem genom inblandning av torv i aakerbraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Marcus; Bostroem, Dan; Skoglund, Nils; Grimm, Alejandro; Boman, Christoffer; Kofod-Hansen, Marie

    2010-06-15

    controlled combustion experiments in bench scale (grate/fluidized bed). Good agreement between the theoretical and practical results on critical ash-chemical sub-processes was observed. Combustion tests were carried out during approximately 2 days in a 4 MW grate fired boiler, using; - briquetted reed canary grass (RCG) fuel with high ash content (totally 25 ton DS). - a RCG with low ash content, co-briquetted with peat (85/15 % on DS basis, totally 25 tons). - Salix chips (approx. 40 tons). - Salix chips admixed with peat (15% on DS basis, totally approx. 40 tons). The overall conclusions of the model calculations concerning the ash content of a 'good peat' was that high ash content, high Si content, high S content and high Ca/Si ratio were favourable. Therefore the peat that mostly corresponded to these requirements was chosen for the demonstration tests. Combustion tests were also performed in a 20 kW underfed pellets burner attached to a pellets boiler. Pelletized straw (50 kg) and straw co-pelletized with peat (60/40% on DS basis, totally 50 kg), were used as fuel. The results shows that admixing a typical carex based peat into Salix and Reed canary grass with low ash content gives positive effects concerning both bed agglomeration and deposit formation (corrosion) in the convection parts of the boiler, already at low levels (15 weight% on DS basis). A carex based peat with a relative high Ca/Si ratio is recommended for co-firing with Salix in grate fired boilers, to avoid slagging. The same type of peat should also be utilized in co-firing Reed canary grass with low ash content (relative low admixing levels is sufficient) and wheat straw (high levels are required) to reduce the risk of slagging. In the choice of peat, a general recommendation can be made that peat with high ash content (carex based peat), preferably with high S content and a high Ca/Si ratio (a wt-ratio around 1 is desirable). Reed canary grass with high ash content is not expected to cause

  1. Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

  2. Dispersion of TiO2 Nanoparticle Agglomerates by Pseudomonas aeruginosa▿ †

    OpenAIRE

    Horst, Allison M.; Neal, Andrea C.; Mielke, Randall E.; Sislian, Patrick R.; Suh, Won Hyuk; Mädler, Lutz; Stucky, Galen D.; Holden, Patricia A.

    2010-01-01

    Engineered nanoparticles are increasingly incorporated into consumer products and are emerging as potential environmental contaminants. Upon environmental release, nanoparticles could inhibit bacterial processes, as evidenced by laboratory studies. Less is known regarding bacterial alteration of nanoparticles, including whether bacteria affect physical agglomeration states controlling nanoparticle settling and bioavailability. Here, the effects of an environmental strain of Pseudomonas aerugi...

  3. Evidence that pentosans and xylanase affect the re-agglomeration of the gluten network

    NARCIS (Netherlands)

    Wang, M.; Vliet, van T.; Hamer, R.J.

    2004-01-01

    In the gluten-starch separation process gluten is formed first as a result of breakdown of the gliadin-glutelin structures during mixing followed by their re-agglomeration. To date the effect of pentosans and enzymes have not been studied separately. A simple modification of TNO Glutomatic system en

  4. A Comprehensive Quantitative Evaluation of New Sustainable Urbanization Level in 20 Chinese Urban Agglomerations

    Directory of Open Access Journals (Sweden)

    Cong Xu

    2016-01-01

    Full Text Available On 16 March 2014, the State Council of China launched its first urbanization planning initiative dubbed “National New Urbanization Planning (2014–2020” (NNUP. NNUP put forward 20 urban agglomerations and a sustainable development approach aiming to transform traditional Chinese urbanization to sustainable new urbanization. This study quantitatively evaluates the level of sustainability of the present new urbanization process in 20 Chinese urban agglomerations and provides some positive suggestions for the achievement of sustainable new urbanization. A three-level index system which is based on six fundamental elements in a city and a Full Permutation Polygon Synthetic Indicator evaluation method are adopted. The results show that China is undergoing a new urbanization process with a low level of sustainability and there are many problems remaining from traditional urbanization processes. There exists a polarized phenomenon in the urbanization of 20 urban agglomerations. Based on their own development patterns, the 20 urban agglomerations can be divided into seven categories. Every category has its own development characteristics. The analyses also show that waste of water resources, abuse of land resources, and air pollution are three big problems that are closely linked to traditional Chinese urbanization processes. To achieve sustainable new urbanization in China, four relevant suggestions and comments have been provided.

  5. [Ash Meadows Purchase Proposal

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A proposal sent to the Richard King Mellon Foundation for a loan to fund the purchase of Ash Meadows by the Nature Conservancy. Ash Meadows, set outside of Las...

  6. Study on urban agglomeration: Progress and prospects%城市群研究进展与展望

    Institute of Scientific and Technical Information of China (English)

    顾朝林

    2011-01-01

    Urban agglomeration is a complex with the central city as the core surrounded by two or more cities. It is the objective reflection of the economic growth and social development as well as industrial layout in a region. It has also become a main form of urbanization in developed countries. In fact, the "urban agglomeration" concept in China is the characteristics of a noun, no equivalence in foreign countries. In Western literature, the"urban agglomeration" means "urban cluster", that is, a big city and its surrounding satellite towns in remote sensing image formed the connected irregularities each other, and the spatial range includes "urbanization area (UA)" and "metropolitan area (MA)". Sometimes, some of metropolisesconnected each other are also called as urban agglomeration.United Nations gave a definition of urban agglomeration as follows: "Comprises a city or town proper and also the suburban fringe or thickly settled territory lying outside, but adjacent to, its boundaries. A single large urban agglomeration may comprise several cities or towns and their suburban fringes." Therefore, urban agglomeration in the Western concept includes the cities, towns and urban--region outlying areas. "Urban agglomeration" in China refers to geographical concepts of a group of major cities which are similar and interactions among administrative, transportation, economic, and social fields. In the 21st century, thanks to China's entry into the World Trade Organization, a national coastal urban agglomeration has become the main region for the national trade economy, export and the "world manufacturing bases". Urban agglomeration as an important urban spatial pattern was a unique choice to promote the process of urbanization in China. This article reviewed some progress in studies of urban agglomeration, such as the concept of urban agglomeration, overseas research of urban agglomeration, early researches of Chinese urban agglomeration and studies on Chinese urban

  7. Investigations into the control of agglomeration and defluidisation during fluidised-bed combustion of low-rank coals

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Linjewile, T.M.; Zhang, D.; Manzoori, A.R. [University of Adelaide, Adelaide, SA (Australia). Dept. of Chemical Engineering

    1999-03-01

    A laboratory scale spouted bed combustor was used to study the effectiveness of various control methodologies in alleviating ash-related problems such as particle agglomeration and bed defluidisation during bed combustion of low-rank coals. The three control techniques investigated are: (1) the use of mineral additives; (2) alternative bed materials; and (3) pretreatment of coal. Mineral additives including dolomite, two clays and gibbsite, were injected into the spouted bed combustor while burning a South Australian low-rank coal at 800{degree}C. Samples of the same coal treated with Al, water washing and acid washing were also tested in the spouted bed combustor. In addition, experiments were also conducted with alternative bed materials including bauxite and calcined sillimanite. Experiments showed that the three techniques reported in this paper are effective to different extents in reducing particle agglomeration and defluidisation. Among the mineral additives tested, gibbsite and a clay additive rich in kaolinite and sillimanite were found to be most effective. The use of calcined sillimanite and bauxite as alterative bed materials extended the combustion time before defluidisation occurred by 7 and 10 times, respectively, compared to silica sand. While A1 pretreatment and water-washing were found effective for control of agglomeration and defluidisation, acid-washing did not improve the operation of the bed burning this particular coal. Al enrichment in ash coating of bed particles which suppress the formation of Na and S rich eutectics was identified as the main mechanism for prevention of agglomeration and defluidisation by these control techniques. 10 refs., 4 figs., 3 tabs.

  8. Immobilization of B, F, Cr, and As in alkaline coal fly ash through an aging process with water.

    Science.gov (United States)

    Ogawa, Yasumasa; Sakakibara, Kento; Wang, Li; Suto, Koichi; Inoue, Chihiro

    2014-10-01

    Fourteen different alkaline coal fly ashes (CFAs) were used for the experiment, in which each sample was mixed with water to be 28.6% of water content (wt/wt) and aged for 1-4 weeks at 10-30 °C. This simple treatment is advantageous for decreases in water-soluble B, F, Cr, and As. Compared to non-aged CFAs, their water-soluble fractions remained 0.56-88%, 21-85%, 0.37-93% and 2.6-88%, respectively, after aging for a week at 20 °C, although the amounts of Cr and As released from some CFA samples increased. Considering the significant decrease in elution of sulfate, Ca and Al after aging, the immobilization, namely prevention of toxic element elution, could be related to formation of secondary minerals such as portlandite, gypsum and ettringite. Immobilization of B and Cr tends to proceed preferentially under colder conditions. Aging at higher temperatures enhances the leachability of Cr in some CFA samples. Contrary to the behavior of B and Cr, water-soluble F effectively decreases under warmer conditions.

  9. Coagulation of Agglomerates Consisting of Polydisperse Primary Particles.

    Science.gov (United States)

    Goudeli, E; Eggersdorfer, M L; Pratsinis, S E

    2016-09-13

    The ballistic agglomeration of polydisperse particles is investigated by an event-driven (ED) method and compared to the coagulation of spherical particles and agglomerates consisting of monodisperse primary particles (PPs). It is shown for the first time to our knowledge that increasing the width or polydispersity of the PP size distribution initially accelerates the coagulation rate of their agglomerates but delays the attainment of their asymptotic fractal-like structure and self-preserving size distribution (SPSD) without altering them, provided that sufficiently large numbers of PPs are employed. For example, the standard asymptotic mass fractal dimension, Df, of 1.91 is attained when clusters are formed containing, on average, about 15 monodisperse PPs, consistent with fractal theory and the literature. In contrast, when polydisperse PPs with a geometric standard deviation of 3 are employed, about 500 PPs are needed to attain that Df. Even though the same asymptotic Df and mass-mobility exponent, Dfm, are attained regardless of PP polydispersity, the asymptotic prefactors or lacunarities of Df and Dfm increase with PP polydispersity. For monodisperse PPs, the average agglomerate radius of gyration, rg, becomes larger than the mobility radius, rm, when agglomerates consist of more than 15 PPs. Increasing PP polydispersity increases that number of PPs similarly to the above for the attainment of the asymptotic Df or Dfm. The agglomeration kinetics are quantified by the overall collision frequency function. When the SPSD is attained, the collision frequency is independent of PP polydispersity. Accounting for the SPSD polydispersity in the overall agglomerate collision frequency is in good agreement with that frequency from detailed ED simulations once the SPSD is reached. Most importantly, the coagulation of agglomerates is described well by a monodisperse model for agglomerate and PP sizes, whereas the detailed agglomerate size distribution can be obtained by

  10. 声波团聚煤飞灰微粒强化旋风分离的试验研究%Experimental Research on Enhanced Cyclone Separation of Acoustic Agglomerated Particles

    Institute of Scientific and Technical Information of China (English)

    刘淑艳; 黄虹宾; 阎为革

    2000-01-01

    研究在试验冷态下,声场中煤飞灰微粒团聚后的坚固程度和分离效率. 对煤飞灰微粒在声场中团聚的现象进行试验研究,探索在冷态下声波增强旋风分离煤飞灰微粒的分离技术. 在声波声压级150dB的声场下,经声波辐射后的微粒强化旋风分离效率增加了3%-4%. 声波团聚微粒强化旋风分离的冷态试验,为高温下燃煤增压流化床燃烧联合循环中煤飞灰微粒分离的应用提供了技术基础.%To test the particles solidity and to verify the separating efficiency at normal atmospheric temperature, the experimental research was made on the enhanced cyclone separation of acoustic agglomerated fly-ash particles. The separating efficiency has increased by 3%-4% in a sound field with 150dB pressure level compared with that obtained without acoustic wave processing. The enhanced cyclone separation test study for acoustic agglomerated particles has provided a technical basis for pressurized fluid-bed combustion(PFBC) application.

  11. Discussion on the dispersion & agglomeration of aircraft industry

    Institute of Scientific and Technical Information of China (English)

    Bo Chu

    2009-01-01

    The aircraft industry is crucial to the economy and security of a nation. In this paper, the spatial characteristics and patterns of the aircraft industry are analyzed on different spatial scales. It is found that there is a 'Matthew effect' in the global aircraft industry and the spatial evolution of the industry is consistent with the industrialization process of the whole country. It is also revealed that the spatial evolution of the country is driven by both the centripetal forces including capital, talents, technology and agglomeration economies and the centrifugal forces including the comparative advantage, cost &risk sharing, emerging markets, development policy for less-developed regions and the military imperative. These forces have both market-stabilizing and market-disrupting effects on the spatial evolution of the aircraft industry. The study suggests that lessons drawn from the experiences in the United States and France are expected to be conducive to the rise of China's aircraft industry in the future.

  12. Selective catalytic reduction of NO by ammonia over oil shale ash and fly ash catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Changtao Yue; Shuyuan Li [University of Petroleum, Beijing (China). State Key Lab of Heavy Oil Processing

    2003-07-01

    Acid rain and urban air pollution, produced mainly by pollutants such as SOX and NOX and other volatile organic compounds, has become the most serious environmental problem. The selective catalytic reduction (SCR) of NO with NH{sub 3} in the presence of oxygen is a wellproven method to limit the NOX emissions. The work in this field has been the subject of much research in recent years. In this paper, NO reduction with NH{sub 3} over oil shale ash or fly ash catalysts was studied. Fe, Cu, V or Ni as active elements was loaded by adding aqueous solutions of the metal nitrate over the oil shale ash or fly ash support. The activities of the catalysts for NO removal were measured in a fixed-bed reactor. According to the results, oil shale ash or fly ash, after pre-treatment, can be reasonably used as the SCR catalyst support to remove NO from flue gas. Cu gave the highest catalytic activity and NO conversion for fly ash while V for oil shale ash. As the support, fly ash is more feasible than oil shale ash. Because of their low cost and high efficiency, the catalysts should be used in the SCR process. Further research on this subject is necessary in the future to understand more details of the SCR system and issue of pollution control. 9 refs., 2 figs., 2 tabs.

  13. Fluidization and mixing of nanoparticle agglomerates assisted via magnetic impaction

    Energy Technology Data Exchange (ETDEWEB)

    Scicolone, James V.; Lepek, Daniel; Louie, Lin; Dave, Rajesh N., E-mail: dave@adm.njit.edu [New Jersey Institute of Technology, Department of Chemical, Biological and Pharmaceutical Engineering (United States)

    2013-02-15

    Mixing of nanopowders in an environmentally benign magnetically assisted fluidized bed (MAFB) system was studied. Examination of fluidization behavior of agglomerate particulate fluidization (APF; silica R974 or R972) and agglomerate bubbling fluidization (ABF; alumina or titania) nano-powders in un-assisted and MAFB systems confirmed previous results on decreased minimum fluidization velocity and increased bed expansion of APF and ABF powders due to magnetic assistance. APF and ABF powder mixtures behaved like APF powders with the bed expansions in between those of individual constituents. Unlike previous MAFB studies, fluidization as a function of time was studied to examine its influence on nano-mixing. With time, the bed expansion reduced, and reduction was faster as magnet-to-powder ratio increased from 0:1 to 5:1, although fluidization was sustained, confirmed via the pressure drop measurements. Reduction in bed expansion was attributed to change in the nature of nanoagglomerates, which showed increased density as a function of processing time, ruling out electrostatics or elutriation as major factors. Mixtures of silica (APF) and alumina (ABF), processed at various magnet-to-powder ratios, were characterized via statistical analysis from energy dispersive x-ray spectroscopy using field emission scanning electron microscope to compute homogeneity of mixing (HoM). Magnetic assistance improved the HoM as a function of time, and was strongly related to the product of number of magnets and time, similar to previous results in magnetically assisted impaction mixing (MAIM). The best achievable HoM was significantly better than unassisted fluidization and comparable to previous results for rapid expansion of high-pressure suspensions and MAIM.

  14. Fluidization and mixing of nanoparticle agglomerates assisted via magnetic impaction

    International Nuclear Information System (INIS)

    Mixing of nanopowders in an environmentally benign magnetically assisted fluidized bed (MAFB) system was studied. Examination of fluidization behavior of agglomerate particulate fluidization (APF; silica R974 or R972) and agglomerate bubbling fluidization (ABF; alumina or titania) nano-powders in un-assisted and MAFB systems confirmed previous results on decreased minimum fluidization velocity and increased bed expansion of APF and ABF powders due to magnetic assistance. APF and ABF powder mixtures behaved like APF powders with the bed expansions in between those of individual constituents. Unlike previous MAFB studies, fluidization as a function of time was studied to examine its influence on nano-mixing. With time, the bed expansion reduced, and reduction was faster as magnet-to-powder ratio increased from 0:1 to 5:1, although fluidization was sustained, confirmed via the pressure drop measurements. Reduction in bed expansion was attributed to change in the nature of nanoagglomerates, which showed increased density as a function of processing time, ruling out electrostatics or elutriation as major factors. Mixtures of silica (APF) and alumina (ABF), processed at various magnet-to-powder ratios, were characterized via statistical analysis from energy dispersive x-ray spectroscopy using field emission scanning electron microscope to compute homogeneity of mixing (HoM). Magnetic assistance improved the HoM as a function of time, and was strongly related to the product of number of magnets and time, similar to previous results in magnetically assisted impaction mixing (MAIM). The best achievable HoM was significantly better than unassisted fluidization and comparable to previous results for rapid expansion of high-pressure suspensions and MAIM.

  15. Numerical study of agglomerate abrasion in a tumbling mixer

    NARCIS (Netherlands)

    Thanh Nguyen, [No Value; Willemsz, Tofan; Frijlink, Henderik; Maarschalk, Kees van der Voort

    2014-01-01

    A numerical simulation using the Discrete Element Method (DEM) was performed to investigate the phenomena concerning the abrasion and breakage of agglomerates in a diffusion powder mixer. Agglomerates were created by defining a single structure of particles with bonds of different strengths using th

  16. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  17. Geochemical modelling and identification of leaching processes in MSWI bottom ash : implications for the short-term and long-term release of contaminants

    NARCIS (Netherlands)

    Meima, J.A.

    1997-01-01

    Municipal Solid Waste Incinerator (MSWI) bottom ash is the major residue that remains after the incineration of Municipal Solid Waste. The slag-like material is produced world-wide in very large and everincreasing quantities. In the past the bottom ash was usually disposed, nowadays it is increasing

  18. Market assessment and technical feasibility study of PFBC ash use

    Energy Technology Data Exchange (ETDEWEB)

    Smith, V.E.; Bland, A.E.; Brown, T.H. [Western Research Inst., Laramie, WY (United States); Georgiou, D.N. [Jacques, Whitford and Associates Ltd., Dartmouth, NS (Canada); Wheeldon, J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1994-10-01

    The overall objectives of this study are to determine the market potential and the technical feasibility of using PFBC ash in high volume ash use applications. The information will be of direct use to the utility industry in assessing the economics of PFBC power generation in light of ash disposal avoidance through ash marketing. In addition, the research is expected to result in the generation of generic data on the use of PFBC ash that could lead to novel processing options and procedures. The specific objectives of the proposed research and demonstration effort are: Define resent and future market potential of PFBC ash for a range of applications (Phase I); assess the technical feasibility of PFBC ash use in construction, civil engineering and agricultural applications (Phase II); and demonstrate the most promising of the market and ash use options in full-scale field demonstrations (Phase III).

  19. ASH MELTING TEMPERATURE PREDICTION FROM CHEMICAL COMPOSITION OF BIOMASS ASH

    OpenAIRE

    Holubcik, Michal; Jandacka, Jozef; Malcho, Milan

    2015-01-01

    Solid fuels, including biomass, consist of combustible, ash and water. Ash in fuel is result of reaction of minerals presented in the biomass. Minerals and other different substances which form ash got into biomass during growth. Ash is solid residue resulted from the perfect laboratory combustion of fuel. It is composed of minerals that are present in the fuel. Some species of biomass ash have low ash melting temperature and can cause various problems in combustion boilers. Ash slags and sin...

  20. Ash in fire affected ecosystems

    Science.gov (United States)

    Pereira, Paulo; Jordan, Antonio; Cerda, Artemi; Martin, Deborah

    2015-04-01

    Ash in fire affected ecosystems Ash lefts an important footprint in the ecosystems and has a key role in the immediate period after the fire (Bodi et al., 2014; Pereira et al., 2015). It is an important source of nutrients for plant recover (Pereira et al., 2014a), protects soil from erosion and controls soil hydrological process as runoff, infiltration and water repellency (Cerda and Doerr, 2008; Bodi et al., 2012, Pereira et al., 2014b). Despite the recognition of ash impact and contribution to ecosystems recuperation, it is assumed that we still have little knowledge about the implications of ash in fire affected areas. Regarding this situation we wanted to improve our knowledge in this field and understand the state of the research about fire ash around world. The special issue about "The role of ash in fire affected ecosystems" currently in publication in CATENA born from the necessity of joint efforts, identify research gaps, and discuss future cooperation in this interdisciplinary field. This is the first special issue about fire ash in the international literature. In total it will be published 10 papers focused in different aspects of the impacts of ash in fire affected ecosystems from several parts of the world: • Fire reconstruction using charcoal particles (Burjachs and Espositio, in press) • Ash slurries impact on rheological properties of Runoff (Burns and Gabet, in press) • Methods to analyse ash conductivity and sorbtivity in the laboratory and in the field (Balfour et al., in press) • Termogravimetric and hydrological properties of ash (Dlapa et al. in press) • Effects of ash cover in water infiltration (Leon et al., in press) • Impact of ash in volcanic soils (Dorta Almenar et al., in press; Escuday et al., in press) • Ash PAH and Chemical extracts (Silva et al., in press) • Microbiology (Barreiro et al., in press; Lombao et al., in press) We believe that this special issue will contribute importantly to the better understanding of

  1. A discrete element and ray framework for rapid simulation of acoustical dispersion of microscale particulate agglomerations

    Science.gov (United States)

    Zohdi, T. I.

    2016-03-01

    In industry, particle-laden fluids, such as particle-functionalized inks, are constructed by adding fine-scale particles to a liquid solution, in order to achieve desired overall properties in both liquid and (cured) solid states. However, oftentimes undesirable particulate agglomerations arise due to some form of mutual-attraction stemming from near-field forces, stray electrostatic charges, process ionization and mechanical adhesion. For proper operation of industrial processes involving particle-laden fluids, it is important to carefully breakup and disperse these agglomerations. One approach is to target high-frequency acoustical pressure-pulses to breakup such agglomerations. The objective of this paper is to develop a computational model and corresponding solution algorithm to enable rapid simulation of the effect of acoustical pulses on an agglomeration composed of a collection of discrete particles. Because of the complex agglomeration microstructure, containing gaps and interfaces, this type of system is extremely difficult to mesh and simulate using continuum-based methods, such as the finite difference time domain or the finite element method. Accordingly, a computationally-amenable discrete element/discrete ray model is developed which captures the primary physical events in this process, such as the reflection and absorption of acoustical energy, and the induced forces on the particulate microstructure. The approach utilizes a staggered, iterative solution scheme to calculate the power transfer from the acoustical pulse to the particles and the subsequent changes (breakup) of the pulse due to the particles. Three-dimensional examples are provided to illustrate the approach.

  2. Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

    Science.gov (United States)

    Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

    2011-12-01

    By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

  3. Urban agglomerations and transformations of medium-sized towns in Poland

    Directory of Open Access Journals (Sweden)

    Runge Anna

    2016-09-01

    the immediate surroundings of the main city. Such situation occurs especially in the conurbation of Gdańsk and the agglomerations of Warszawa, Kraków and Poznań. This shows that the largest cities of Poland are the main engines of economic development by stimulating their surroundings and their impact on the surrounding areas. Unfortunately, the towns located in the marginal zones of several agglomerations (the zone 25–50 km away from the main city experience certain disadvantages, such as the process of “the backwash effect”. Furthermore, the lack of developmental impulses is observed in many medium-sized towns at the distance of 50-100 km from the main city of the agglomeration.

  4. Transformations in oil shale ash at wet deposition

    International Nuclear Information System (INIS)

    Estonian oil shale ash contains chemically active compounds which would undergo different spontaneous transformations in the atmosphere of air. For explaining these processes the system ash-water-air was studied storing moisture samples of ash in laboratory in open-air as well as hermetic conditions. The samples of dry ash formed at pulverized combustion of oil shale at the Baltic Power Plant, and samples obtained from ash storing plateau from different depth of different boreholes were under investigation. Storing conditions as well as the properties of initial samples have a great influence upon the processes taking place at storing of ashes. The results obtained could be used to explain and control the processes taking place at storing of ashes under atmospheric (wet) conditions

  5. The performance of a biological aerated filter loaded with a novel non-sintered fly-ash ceramsite as pretreatment for dual membrane processes.

    Science.gov (United States)

    Li, Lihua; Hu, Chaowu; Dai, Xiulan; Jin, Wenjie; Hu, Cheng; Ma, Fang

    2015-01-01

    This work focused on wastewater reclamation of secondary treated ethylene chemical plant effluent, which contained high conductivity and high organic concentration. To reduce the cost and improve operation stability, a biological aerated filter-ultrafiltration-reverse osmosis (BAF-UF-RO) process was proposed. The feasibility and effectiveness of BAF loaded with a novel non-sintered fly-ash ceramsite (NSFC) as a pretreatment method of a dual membrane system were investigated in detail. The results showed that the CODCr, turbidity, NH3-N and the silt density index (SDI) in the effluent from the BAF were reduced to 24.2 mg/L, 12.17 NTU, 0.42 mg/L and 7.52, respectively, and most of the organic compounds were biodegraded. The BAF-UF-RO process was stable with a recovery rate of 75%, and the desalination rate was up to about 97.5%. Compared with the UF-RO process, the operating pressure and backwash frequency decreased from 1.12-1.26 Mpa and 3 times/d to 0.94-0.98 Mpa and 2 times/d, respectively. After continuous operation for four months, there appeared to be no need for chemical cleaning of the RO membrane. Moreover, the analysis results of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy proved that there was only slight membrane fouling, which was mainly colloidal blocking caused by refractory organic compound. PMID:25686627

  6. Thermal treatment of ashes[Fly Ash from Municipal Waste Incineration]; Termisk rening av askor

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, Karin; Berg, Magnus; Bjurstroem, Henrik [AaF-Energi och Miljoe AB, Stockholm (Sweden); Nordin, Anders [Umeaa Univ. (Sweden). Dept. of Applied Physics and Electronics

    2003-04-01

    In this project descriptions of different processes for thermal treatment of ashes have been compiled. A technical and economic evaluation of the processes has been done to identify possibilities and problems. The focus in the project lays on treatment of fly ash from municipal waste incineration but the processes can also be used to treat other ashes. When the ash is heated in the thermal treatment reactor, with or without additives, the material is sintered or vitrified and at the same time volatile substances (Zn, Pb, Cd, Hg etc.) are separated. In general the separation is more effective in processes with reducing conditions compared to oxidizing conditions. Oxidizing processes have both worse separation capacity and require more energy. The oxidizing processes are mainly used to stabilize the ash through vitrification and they are in some cases developed for management of municipal sewage sludge and bottom ash. However, these processes are often not as complex as for example an electric arc melting furnace with reducing conditions. The research today aim to develop more effective electrical melting systems with reducing conditions such as plasma melting furnaces, electric resistance melting furnaces and low frequency induction furnaces. A central question in the evaluation of different thermal treatment processes for ash is how the residues from the treatment can be used. It is not certain that the vitrified material is stable enough to get a high economic value, but it can probably be used as construction material. How the remaining metals in the ash are bound is very important in a long-time perspective. Further studies with leaching tests are necessary to clarify this issue. The heavy metal concentrate from the processes contains impurities, such as chlorine, which makes it unprofitable to obtain the metals. Instead the heavy metal concentrate has to be land filled. However, the amount of material for land filling will be much smaller if only the heavy

  7. Direct numerical simulations of agglomeration of circular colloidal particles in two-dimensional shear flow

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Joon, E-mail: yjchoi@uvic.ca; Djilali, Ned, E-mail: ndjilali@uvic.ca [Institute for Integrated Energy Systems and Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada)

    2016-01-15

    Colloidal agglomeration of nanoparticles in shear flow is investigated by solving the fluid-particle and particle-particle interactions in a 2D system. We use an extended finite element method in which the dynamics of the particles is solved in a fully coupled manner with the flow, allowing an accurate description of the fluid-particle interfaces without the need of boundary-fitted meshes or of empirical correlations to account for the hydrodynamic interactions between the particles. Adaptive local mesh refinement using a grid deformation method is incorporated with the fluid-structure interaction algorithm, and the particle-particle interaction at the microscopic level is modeled using the Lennard-Jones potential. Motivated by the process used in fabricating fuel cell catalysts from a colloidal ink, the model is applied to investigate agglomeration of colloidal particles under external shear flow in a sliding bi-periodic Lees-Edwards frame with varying shear rates and particle fraction ratios. Both external shear and particle fraction are found to have a crucial impact on the structure formation of colloidal particles in a suspension. Segregation intensity and graph theory are used to analyze the underlying agglomeration patterns and structures, and three agglomeration regimes are identified.

  8. Interaction between magnetic agglomerates and an extended free radicals network studied by magnetic resonance

    Science.gov (United States)

    Guskos, Niko; Zolnierkiewicz, Grzegorz; Typek, Janusz; Guskos, Aleksander; Berczynski, Pawel; Petridis, Dimitri

    2012-02-01

    Solids containing an extended network of free radicals have been prepared and studied by magnetic resonance techniques in the 4-290 K temperature range. One solid contained additionally a small amount of magnetic γ-Fe2O3 in the form of nanoparticle agglomerates. The solid without agglomerates displayed only a narrow, single resonance line centered at g eff = 2.0043. The magnetic resonance measurements of the solid with γ-Fe2O3 agglomerates gave a spectrum composed of two lines attributed to two different magnetic centers: a narrow line due to free radicals and a broad line arising from magnetic iron oxide agglomerates. In the high temperature range the integrated intensities of both lines decreased with decreasing temperature. The resonance field of the broad line shifted to lower magnetic fields upon lowering the temperature with the gradient ΔH r/ΔT = 2.3 G/K, while the narrow line shifted towards higher magnetic fields. The linewidth of the broader line increased with decreasing temperature while for the narrow lines in both samples this change was small. The magnetic iron oxide clusters produce a magnetic field which acts on the free radicals network and its strength depends essentially on the concentration of clusters. The reorientation process in the free radicals network is more intense in the sample without magnetic clusters.

  9. Operational source receptor calculations for large agglomerations

    Science.gov (United States)

    Gauss, Michael; Shamsudheen, Semeena V.; Valdebenito, Alvaro; Pommier, Matthieu; Schulz, Michael

    2016-04-01

    For Air quality policy an important question is how much of the air pollution within an urbanized region can be attributed to local sources and how much of it is imported through long-range transport. This is critical information for a correct assessment of the effectiveness of potential emission measures. The ratio between indigenous and long-range transported air pollution for a given region depends on its geographic location, the size of its area, the strength and spatial distribution of emission sources, the time of the year, but also - very strongly - on the current meteorological conditions, which change from day to day and thus make it important to provide such calculations in near-real-time to support short-term legislation. Similarly, long-term analysis over longer periods (e.g. one year), or of specific air quality episodes in the past, can help to scientifically underpin multi-regional agreements and long-term legislation. Within the European MACC projects (Monitoring Atmospheric Composition and Climate) and the transition to the operational CAMS service (Copernicus Atmosphere Monitoring Service) the computationally efficient EMEP MSC-W air quality model has been applied with detailed emission data, comprehensive calculations of chemistry and microphysics, driven by high quality meteorological forecast data (up to 96-hour forecasts), to provide source-receptor calculations on a regular basis in forecast mode. In its current state, the product allows the user to choose among different regions and regulatory pollutants (e.g. ozone and PM) to assess the effectiveness of fictive emission reductions in air pollutant emissions that are implemented immediately, either within the agglomeration or outside. The effects are visualized as bar charts, showing resulting changes in air pollution levels within the agglomeration as a function of time (hourly resolution, 0 to 4 days into the future). The bar charts not only allow assessing the effects of emission

  10. Fly ash carbon passivation

    Science.gov (United States)

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  11. Associative properties of 137Cs in biofuel ashes

    International Nuclear Information System (INIS)

    The present study aims to reveal how radiocesium is associated to the ash particles derived from biofuel combustion. A sequential extraction procedure was carried out for the characterisation of radiocesium speciation in ash generated by different fuels and burner types. The ash types considered were fly ash and bottom ash collected from Swedish district heating plants using bark wood or peat as fuel. A fraction of the radiocesium in biofuel ash can easily become solubilised and mobilised by water and also, a significant fraction of the radionuclides can be bound to the ash particles in cation-exchangeable forms. Therefore, at using the ash derived from biofuels to recycle mineral nutrients for forestry or short rotation coppicing, radiocesium solubilised and leached from the ash by rains has a potential to rather quickly enter the rooting zone of forest vegetation or energy crops. On the other hand, radiocesium strongly bound to the ash will migrate slowly into the soil column with the successive accumulation of litter and in the process act to maintain the external dose rate at an elevated level for a long time. The results of the sequential extraction procedure and activity determination of the different extracted fractions implies that the bioavailable fraction of radiocesium in ash from bark, wood or peat is in the range between 20-85% of the total ash contents. Peat ash collected from a powder burner strongly retained a large fraction (70-90%) of its radiocesium content while the peat ash from a continuos fluidized bed type burner retained nearly 100% of the radiocesium in the bottom ash and only about 15% in the fly ash

  12. Ultrasonic ash/pyrite liberation

    Energy Technology Data Exchange (ETDEWEB)

    Yungman, B.A.; Buban, K.S.; Stotts, W.F.

    1990-06-01

    The objective of this project was to develop a coal preparation concept which employed ultrasonics to precondition coal prior to conventional or advanced physical beneficiation processes such that ash and pyrite separation were enhanced with improved combustible recovery. Research activities involved a series of experiments that subjected three different test coals, Illinois No. 6, Pittsburgh No. 8, and Upper Freeport, ground to three different size fractions (28 mesh [times] 0, 200 mesh [times] 0, and 325 mesh [times] 0), to a fixed (20 kHz) frequency ultrasonic signal prior to processing by conventional and microbubble flotation. The samples were also processed by conventional and microbubble flotation without ultrasonic pretreatment to establish baseline conditions. Product ash, sulfur and combustible recovery data were determined for both beneficiation processes.

  13. Fragmentation and bond strength of airborne diesel soot agglomerates

    Directory of Open Access Journals (Sweden)

    Messerer Armin

    2008-06-01

    Full Text Available Abstract Background The potential of diesel soot aerosol particles to break up into smaller units under mechanical stress was investigated by a direct impaction technique which measures the degree of fragmentation of individual agglomerates vs. impact energy. Diesel aerosol was generated by an idling diesel engine used for passenger vehicles. Both the aerosol emitted directly and aerosol that had undergone additional growth by Brownian coagulation ("aging" was investigated. Optionally a thermo-desoption technique at 280°C was used to remove all high-volatility and the majority of low-volatility HC adsorbates from the aerosol before aging. Results It was found that the primary soot agglomerates emitted directly from the engine could not be fragmented at all. Soot agglomerates permitted to grow additionally by Brownian coagulation of the primary emitted particles could be fragmented to a maximum of 75% and 60% respectively, depending on whether adsorbates were removed from their surface prior to aging or not. At most, these aged agglomerates could be broken down to roughly the size of the agglomerates from the primary emission. The energy required for a 50% fragmentation probability of all bonds within an agglomerate was reduced by roughly a factor of 2 when aging "dry" agglomerates. Average bond energies derived from the data were 0.52*10-16 and 1.2*10-16 J, respectively. This is about 2 orders of magnitude higher than estimates for pure van-der-Waals agglomerates, but agrees quite well with other observations. Conclusion Although direct conclusions regarding the behavior of inhaled diesel aerosol in contact with body fluids cannot be drawn from such measurements, the results imply that highly agglomerated soot aerosol particles are unlikely to break up into units smaller than roughly the size distribution emitted as tail pipe soot.

  14. Mechanochemical process to recover heavy metals from industrial ash; Procedimenti meccanochimici per l'estrazione di metalli pesanti da ceneri industriali

    Energy Technology Data Exchange (ETDEWEB)

    La Barbera, A.; Bimbi, C.; De Francesco, M.; Padella, F. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione; Ranaldi, E. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1999-07-01

    An innovative mechanochemical process has been conceived to recover heavy metals from industrial ashes. The low environmental impact process is based on the transformation of heavy metals oxides into soluble salts. In particular high energy ball milling has been successfully applied on real samples from iron electrometallurgy. Heavy metals extractions higher than the ones resulting from the typical acid attack were obtained. [Italian] A partire da simulazioni termidinamiche, e' stato ideato un innovativo processo meccanochimico a basso impatto ambientale per il recupero di metalli pesanti da ceneri pericolose di origine industriale. Il processo, che prevede la conversione in fasi solubili di metalli pesanti presenti nelle ceneri sotto forma di ossidi misti insolubili, e' stato sperimentato con successo sia su campioni di laboratorio che su campioni reali. In particolare la macinazione ad alta energia e' stata applicata a campioni di cenere provenienti da elettrometallurgia del ferro, con un elevato contenuto di zinco, ottenendo risultati migliori di quelli ottenibili da un tradizionale attacco acido.

  15. Physical properties of soils in Rostov agglomeration

    Science.gov (United States)

    Gorbov, S. N.; Bezuglova, O. S.; Abrosimov, K. N.; Skvortsova, E. B.; Tagiverdiev, S. S.; Morozov, I. V.

    2016-08-01

    Physical properties of natural and anthropogenically transformed soils of Rostov agglomeration were examined. The data obtained by conventional methods and new approaches to the study of soil physical properties (in particular, tomographic study of soil monoliths) were used for comparing the soils of different functional zones of the urban area. For urban territories in the steppe zone, a comparison of humus-accumulative horizons (A, Asod, Ap, and buried [A] horizons) made it possible to trace tendencies of changes in surface soils under different anthropogenic impacts and in the buried and sealed soils. The microtomographic study demonstrated differences in the bulk density and aggregation of urban soils from different functional zones. The A horizon in the forest-park zone is characterized by good aggregation and high porosity, whereas buried humus-accumulative horizons of anthropogenically transformed soils are characterized by poor aggregation and low porosity. The traditional parameters of soil structure and texture also proved to be informative for the identification of urban pedogenesis.

  16. Externalities, Floating Population and Spatial Agglomeration

    Institute of Scientific and Technical Information of China (English)

    Du Yu; Wang Chuansheng; Fan Jie

    2007-01-01

    With the further development of socialist market economy,the mobility of factor markets in China,especially the labor market.is strengthened.Extemalities interacts with the agglomeration of productive factors.Under the framework of new economic geographg this article presents a theoretical model involving the endogenous population density affected by urban externalities.Results show that the population density is more concentrated around the center because the degree and extent of interaction between individuals intensifies when the distance from the center decreases.When there are several extemalifies resonurces,the aggregation of externalities changes the configuration of spatial factor allocation.These results fit well with the empirical facts about the decreasing density of floating population along the cities of Guangzhou,Dongguan and Shenzhen in Guangdong Province which is situat d in the eastern coast of the Pearl River Delta.We find that under the impacts of externalities released from Hong Kong into the coast,floating population Was more concentrated around Shenzhen and Dongguan,which are more adjacent to Hong Kong compared with Guangzhou City.

  17. Structural properties of silver nanoparticle agglomerates based on transmission electron microscopy: relationship to particle mobility analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Weon Gyu; Wang Jing [University of Minnesota, Department of Mechanical Engineering (United States); Mertler, Michael; Sachweh, Bernd [Fine Particle Technology and Particle Characterization, BASF SE (Germany); Fissan, Heinz [Institute of Energy and Environmental Technology e. V. (IUTA) (Germany); Pui, David Y. H., E-mail: dyhpui@umn.ed [The University of Minnesota, Department of Mechanical Engineering (United States)

    2009-01-15

    In this work, the structural properties of silver nanoparticle agglomerates generated using condensation and evaporation method in an electric tube furnace followed by a coagulation process are analyzed using Transmission Electron Microscopy (TEM). Agglomerates with mobility diameters of 80, 120, and 150 nm are sampled using the electrostatic method and then imaged by TEM. The primary particle diameter of silver agglomerates was 13.8 nm with a standard deviation of 2.5 nm. We obtained the relationship between the projected area equivalent diameter (d{sub pa}) and the mobility diameter (d{sub m}), i.e., d{sub pa} = 0.92 {+-} 0.03 d{sub m} for particles from 80 to 150 nm. We obtained fractal dimensions of silver agglomerates using three different methods: (1) D{sub f} = 1.84 {+-} 0.03, 1.75 {+-} 0.06, and 1.74 {+-} 0.03 for d{sub m} = 80, 120, and 150 nm, respectively from projected TEM images using a box counting algorithm; (2) fractal dimension (D{sub fL}) = 1.47 based on maximum projected length from projected TEM images using an empirical equation proposed by Koylu et al. (1995) Combust Flame 100:621-633; and (3) mass fractal-like dimension (D{sub fm}) = 1.71 theoretically derived from the mobility analysis proposed by Lall and Friedlander (2006) J Aerosol Sci 37:260-271. We also compared the number of primary particles in agglomerate and found that the number of primary particles obtained from the projected surface area using an empirical equation proposed by Koylu et al. (1995) Combust Flame 100:621-633 is larger than that from using the relationship, d{sub pa} = 0.92 {+-} 0.03 d{sub m} or from using the mobility analysis.

  18. A new stochastic approach for the simulation of agglomeration between colloidal particles.

    Science.gov (United States)

    Henry, Christophe; Minier, Jean-Pierre; Pozorski, Jacek; Lefèvre, Grégory

    2013-11-12

    This paper presents a stochastic approach for the simulation of particle agglomeration, which is addressed as a two-step process: first, particles are transported by the flow toward each other (collision step) and, second, short-ranged particle-particle interactions lead either to the formation of an agglomerate or prevent it (adhesion step). Particle collisions are treated in the framework of Lagrangian approaches where the motions of a large number of particles are explicitly tracked. The key idea to detect collisions is to account for the whole continuous relative trajectory of particle pairs within each time step and not only the initial and final relative distances between two possible colliding partners at the beginning and at the end of the time steps. The present paper is thus the continuation of a previous work (Mohaupt M., Minier, J.-P., Tanière, A. A new approach for the detection of particle interactions for large-inertia and colloidal particles in a turbulent flow, Int. J. Multiphase Flow, 2011, 37, 746-755) and is devoted to an extension of the approach to the treatment of particle agglomeration. For that purpose, the attachment step is modeled using the DLVO theory (Derjaguin and Landau, Verwey and Overbeek) which describes particle-particle interactions as the sum of van der Waals and electrostatic forces. The attachment step is coupled with the collision step using a common energy balance approach, where particles are assumed to agglomerate only if their relative kinetic energy is high enough to overcome the maximum repulsive interaction energy between particles. Numerical results obtained with this model are shown to compare well with available experimental data on agglomeration. These promising results assert the applicability of the present modeling approach over a whole range of particle sizes (even nanoscopic) and solution conditions (both attractive and repulsive cases). PMID:24111685

  19. Characterisation of the de-agglomeration effects of bovine serum albumin on nanoparticles in aqueous suspension.

    Science.gov (United States)

    Tantra, Ratna; Tompkins, Jordan; Quincey, Paul

    2010-01-01

    This paper describes the use of nanoparticle characterisation tools to evaluate the interaction between bovine serum albumin (BSA) and dispersed nanoparticles in aqueous media. Dynamic light scattering, zeta-potential measurements and scanning electron microscopy were used to probe the state of zinc oxide (ZnO) and titanium dioxide (TiO(2)) nanoparticles in the presence of various concentrations of BSA, throughout a three-day period. BSA was shown to adhere to ZnO but not to TiO(2). The adsorption of BSA led to subsequent de-agglomeration of the sub-micron ZnO clusters into smaller fragments, even breaking them up into individual isolated nanoparticles. We propose that certain factors, such as adsorption kinetics of BSA on to the surface of ZnO, as well as the initial agglomerated state of the ZnO, prior to BSA addition, are responsible for promoting the de-agglomeration process. Hence, in the case of TiO(2) we see no de-agglomeration because: (a) the nanoparticles are more highly agglomerated to begin with and (b) BSA does not adsorb effectively on the surface of the nanoparticles. The zeta-potential results show that, for either ZnO or TiO(2), the presence of BSA resulted in enhanced stability. In the case of ZnO, the enhanced stability is limited to BSA concentrations below 0.5 wt.%. Steric and electrostatic repulsion are thought to be responsible for improved stability of the dispersion. PMID:19775871

  20. An Empirical Analysis of Industrial Agglomeration in the Western Ethnic Region

    Institute of Scientific and Technical Information of China (English)

    HE Xionglang; ZHANG Huiyin

    2014-01-01

    Industrial agglomeration refers to a high concentration of the same industry or related industries in a particular geographic area , and a process of gradual concentration of industrial cap-ital elements within a space .The new economic geography considers that industrial agglomeration is caused by circulating cumulative cause and effect . Accidental disturbance destroys the original bal-ance of the symmetrical area , which in turn brings about the expansion of the market in a concentrated industrial area , which then causes the effect of market expansion.This, accordingly, induces the factors of production to begin to concentrate in the area.The concentration of elements and industries brings about the “regional price index effect”.The concentration of manufacturers in the region is helpful in reducing both transportation costs and living costs of the labor .Accordingly , the elements become further concentrated , which causes the ex-pansion of market scale and the concentration of el-ements.Finally, a kind of industrial agglomeration forms.Industrial agglomeration is not only a kind of group concentration of similar enterprises in a specific region , but most importantly it is a kind of common growth among the enterprises .Therefore, the degree of concentration of an industry reflects the competiveness of an industry , which in turn re-flects the economic strength of a region or a coun-try.The concept that industrial concentration could promote the relative competiveness of the industries in the region has already been accepted by most e-conomists .Hence , it has an important meaning re-garding the study of industrial agglomeration in the western ethnic region . There are two ways to measure industrial ag-glomeration.One is the Gini Coefficient index and the other is the Industrial Agglomeration Index of location quotient .The author thinks that the degree of regional industrial agglomeration could either be examined with a static stock index , or a dynamic

  1. Evolution of Zipf's Law for Indian Urban Agglomerations vis-\\`{a}-vis Chinese Urban Agglomerations

    CERN Document Server

    Gangopadhyay, Kausik

    2012-01-01

    We investigate into the rank-size distributions of urban agglomerations for India between 1981 to 2011. The incidence of a power law tail is prominent. A relevant question persists regarding the evolution of the power tail coefficient. We have developed a methodology to meaningfully track the power law coefficient over time, when a country experience population growth. A relevant dynamic law, Gibrat's law, is empirically tested in this connection. We argue that these empirical findings for India goes in contrast with the findings in case of China, another country with population growth but monolithic political system.

  2. In-Situ Agglomeration and De-agglomeration by Milling of Nano-Engineered Lubricant Particulate Composites for Cold Spray Deposition

    Science.gov (United States)

    Neshastehriz, M.; Smid, I.; Segall, A. E.

    2014-10-01

    Nano-engineered self-lubricating particles comprised of hexagonal-boron-nitride powder (hBN) encapsulated in nickel have been developed for cold spray coating of aluminum components. The nickel encapsulant consists of several nano-sized layers, which are deposited on the hBN particles by electroless plating. In the cold spray deposition, the nickel becomes the matrix in which hBN acts as the lubricant. The coating demonstrated a very promising performance by reducing the coefficient of friction by almost 50% and increasing the wear resistance more than tenfold. The coatings also exhibited higher bond strength, which was directly related to the hardenability of the particles. During the encapsulation process, the hBN particles agglomerate and form large clusters. De-agglomeration has been studied through low- and high-energy ball milling to create more uniform and consistent particle sizes and to improve the cold spray deposition efficiency. The unmilled and milled particles were characterized with Scanning Electron Microscopy, Energy-Dispersive X-Ray Spectroscopy, BET, and hardness tests. It was found that in low-energy ball milling, the clusters were compacted to a noticeable extent. However, the high-energy ball milling resulted in breakup of agglomerations and destroyed the nickel encapsulant.

  3. Aluminum recovery from coal fly ash by high temperature chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Wijatno, H.

    1977-10-01

    A study of aluminum recovery from power plant fly ash by high temperature chlorination was undertaken to demonstrate that fly ash could be a potential source of aluminum, iron and possibly silicon. Magnetic separation of the iron oxide served as a first step to alleviate the iron contamination problem. However, the agglomeration of some iron oxide with alumina and silica made it difficult to completely separate the iron from the fly ash. Further iron separation was achieved by chlorinating the nonmagnetic ash fraction at 550/sup 0/C for 30 minutes. This reduced the iron oxide content to less than 4 percent by weight. Chlorine flow rates affected the reaction rate much more drastically than temperatures. This suggested that diffusion was the major rate-controlling step. Besides Fe/sub 2/O/sub 3/, Al/sub 2/O/sub 3/ and SiO/sub 2/, other oxides such as CaO, K/sub 2/O, Na/sub 2/O and MgO might have complicated the alumina recovery by forming individual chlorides or complexes. Investigating methods for separating more Fe/sub 2/O/sub 3/, and possibly CaO, K/sub 2/O, Na/sub 2/O and MgO from the nonmagnetic ash fraction before chlorinating it is highly recommended.

  4. Effect of bed temperature and bed composition on agglomeration during gasification of high-sodium, high-sulphur lignite in a spouted fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    D.P. McCullough; P.J. Mullinger; P.J. Ashman [University of Adelaide, Adelaide, SA (Australia). Cooperative Research Centre for Clean Power from Lignite, School of Chemical Engineering

    2003-07-01

    Fluidised bed gasification (FBG) is an alternative process for coal utilisation that delivers improved efficiencies and lower temperature operation compared to conventional technology. Agglomeration and defluidisation are phenomena that have the potential to occur within fluidised bed reactors, which can interrupt stable process operation. While extensive work has been carried out investigating fluidised bed combustion of lignite, relatively little work has been carried out for lignite under fluidised bed gasification conditions. Gasification of high sodium, high sulphur content lignite in a spouted bed gasifier (SBG) indicates that agglomeration and defluidisation is only an issue when maximum bed temperature exceeds approximately 850{degree}C and air/fuel ratios of 2.5 outside of these conditions, defluidisation is not detected. It is also demonstrated that defluidisation occurs before agglomeration, rather than as a result of agglomeration as previously thought. The Rosin-Rammler method of describing particle size distribution is found to yield appropriate variables for quantification of the extent of agglomeration taking place in cases where defluidisation is a factor. However, it has been shown by this method that while initial results indicated that agglomeration extent varies directly with maximum bed temperature, further results have shown that other variables, such as superficial velocity, have a significant impact on the extent of agglomeration. Investigations are currently continuing. 9 refs., 8 figs., 9 tabs.

  5. Effect of temperature on the hydration process and strength development in blends of Portland cement and activated coal gangue or fly ash

    Institute of Scientific and Technical Information of China (English)

    Pei-ming WANG; Xian-ping LIU

    2011-01-01

    This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 ℃ on the hydration process,pore structure variation,and compressive strength development of activated coal gangue-cement blend (ACGC).Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method,thermal analysis,mercury intrusion porosimetry,and mechanical testing.To evaluate the specific effect of activated coal gangue (ACG) as a supplementary cementing material (SCM),a fly ash-cement blend (FAC) was used as a control.Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs,increasing the degree of hydration of the cement blends,and hence increasing the rate of improvement in strength.The effect of curing temperature on FAC is greater than that on ACGC.The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 ℃,but when the curing temperature reaches 60 ℃,the changing nature of the pore structure leads to a decrease in strength.The correlation between compressive strength and the degree of hydration and porosity is linear in nature.

  6. Research on the Agglomeration Collision and Fragmentation Process in a Fluidized Bed of ZnO and CuO Composite Nanoparticles Added with FCC Coarse Particles%ZnO和CuO混合纳米颗粒在添加FCC粗颗粒的流态化及聚团碰撞与破碎过程研究

    Institute of Scientific and Technical Information of China (English)

    徐宝; 周涛; 罗传宝; 张金霞; 范百林

    2016-01-01

    研究混合纳米ZnO和CuO颗粒添加3种不同粒径FCC粗颗粒(催化裂化催化剂)的流化行为,用高速摄像机观察流化现象并对聚团碰撞与破碎过程、聚团成分进行分析。结果表明,添加FCC粗颗粒可显著改善纳米颗粒的流化性能,FCC3对纳米颗粒流化性能的改善效果比FCC1或FCC2更明显;且随着FCC粗颗粒添加量的增加,纳米颗粒流化行为的改善效果越好,体系的混合均匀程度是影响混合纳米ZnO和CuO流化性能的重要因素。%A research has been conducted on the fluidization behaviors of ZnO and CuO composite nanoparticles, added with FCC coarse particles of three different particle sizes (catalytic cracking catalysts). An observation of the whole fluidization process, with the aid of a high-speed camera, has been made for a detailed analysis of the agglomeration collision and fragmentation, and agglomeration components as well. The results show that the fluidization performance of the composite nanoparticles can be improved significantly with the addition of FCC coarse particles. Moreover, compared with the other two kinds of coarse particles FCC2 or FCC1, a more significant effect can be achieved with the addition of FCC3 in the process. With the increase of the addition amount of FCC coarse particles, the improvement of the fluidization performance of the composite nanoparticles becomes more obvious. Thus, it can be concluded that the mixing uniformity of nanoparticles is an important factor that influence the fluidization performance of ZnO and CuO composite nanoparticles.

  7. Asymmetric Ashes

    Science.gov (United States)

    2006-11-01

    Astronomers are reporting remarkable new findings that shed light on a decade-long debate about one kind of supernovae, the explosions that mark a star's final demise: does the star die in a slow burn or with a fast bang? From their observations, the scientists find that the matter ejected by the explosion shows significant peripheral asymmetry but a nearly spherical interior, most likely implying that the explosion finally propagates at supersonic speed. These results are reported today in Science Express, the online version of the research journal Science, by Lifan Wang, Texas A&M University (USA), and colleagues Dietrich Baade and Ferdinando Patat from ESO. "Our results strongly suggest a two-stage explosion process in this type of supernova," comments Wang. "This is an important finding with potential implications in cosmology." ESO PR Photo 44/06 ESO PR Photo 44/06 Clumpy Explosion (Artist's Impression) Using observations of 17 supernovae made over more than 10 years with ESO's Very Large Telescope and the McDonald Observatory's Otto Struve Telescope, astronomers inferred the shape and structure of the debris cloud thrown out from Type Ia supernovae. Such supernovae are thought to be the result of the explosion of a small and dense star - a white dwarf - inside a binary system. As its companion continuously spills matter onto the white dwarf, the white dwarf reaches a critical mass, leading to a fatal instability and the supernova. But what sparks the initial explosion, and how the blast travels through the star have long been thorny issues. The supernovae Wang and his colleagues observed occurred in distant galaxies, and because of the vast cosmic distances could not be studied in detail using conventional imaging techniques, including interferometry. Instead, the team determined the shape of the exploding cocoons by recording the polarisation of the light from the dying stars. Polarimetry relies on the fact that light is composed of electromagnetic waves

  8. Characterization of the geometrical properties of agglomerated aerosol particles

    International Nuclear Information System (INIS)

    A method for the absolute mass determination of agglomerated aerosol particles is presented. Based on this method it is possible to determine simultaneously and in situ mass, exposed surface and mobility diameter. From these measurements the fractal dimension of aerosol particles can be derived. For silver agglomerates produced by spark discharge it was found that they are bifractal. The fractal dimension was 3 in the free molecular regime and 1.9 in the transition regime. By variation of the gas mean free path it was shown that the region where the agglomerate structure changes from close-packed particle to low density agglomerates depends on the Knudsen number. In the free molecular regime the fractal dimension was not at all affected by any change of the generation conditions. Only sintering caused an increase in the density which was attributed to mass transport within the agglomerate. In the transition regime the fractal dimension remained constant with increasing monomer concentration and with increasing flow rate, but it increased with increasing pressure, increasing Ar:He ratio and with increasing sintering temperature. For sintering this effect was explained by the minimization of the surface free energy. It was found that the structure changing rate is proportional to the product of sintering temperature and residence time in the sintering oven. By carefully adjusting the temperature it is possible to produce agglomerates of a well defined structure. In desorption experiments of 136I from silver and carbon agglomerates it could be shown that the desorption behavior is different. It was found that the desorption enthalpy of iodine from graphite and silver particles were -142 kJ/mol and -184 kJ/mol, respectively. Moreover, it was demonstrated that the 136I attachment to particles is different for silver agglomerates with the same mobility, but different structures. (author) 41 figs., refs

  9. Using Raster Based Solutions to Identify Spatial Economic Agglomerations

    Directory of Open Access Journals (Sweden)

    Marian DARDALA

    2013-01-01

    Full Text Available The efficient economic activities incline to be concentrated in space, and therefore there is an increased attention over the forces of spatial economic agglomerations and the role of location in economic development. This paper proposes some solutions to automate the identification of spatial agglomerations and their intensities, function on the spatial distribution of items in the geographical areas. The software components developed to accomplish this task are Geographic Information Systems specific tools.

  10. Agglomeration economies and global activities: impact on firm survival

    OpenAIRE

    FERRAGINA, Anna Maria; Mazzotta, Fernanda

    2014-01-01

    The focus of our contribution is to shed light on the importance of firm agglomerations and FDI as drivers of firm survival in Italy. We focus upon different types of agglomeration economies related to the geographical context checking how these economies impact differently on heterogeneous firms survival and whether effects are robust to different estimators (Probit, Cox hazard models, Probit Heckman) and to different assumptions about inter-and intra-regional spillovers. The novelty our pap...

  11. Does firm agglomeration drive product innovation and renewal?.

    OpenAIRE

    De Beule, Filip; Van Beveren, Ilke

    2010-01-01

    This paper uses data from the Community Innovation Survey for Belgium to evaluate to what extent regional concentration (clusters) of firms, also known as agglomeration economies, may be enhancing for innovation. These agglomeration economies are positive externalities that benefit firms in various ways. For innovative performance, especially externalities related to knowledge spillovers matter. Knowledge spillovers or learning externalities typically emerge between firms that belong to the s...

  12. Defect agglomeration in ferroelectric ceramics under cyclic electric field

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The agglomeration of point defects in ferroelectric ceramics could be driven by repeated domain switching under cyclic electric field. The evolution equation of pore concentration under cyclic electric field is derived, with the help of a relation between the pore concentration and the extent of pore agglomeration. The results of the simulation agree quantitatively with the experimental data. An integrated framework about the mechanisms of electrically induced fatigue is proposed, which links the mechanisms at different scales.

  13. Marshallian Agglomeration Economies and Entrepreneurship: The Spanish Case

    OpenAIRE

    Fernandez, Roberto Dopeso

    2011-01-01

    This paper analyzes to what extent marshallian agglomeration economies affect the creation of new entrepreneurial ventures at the metropolitan level. The measuring of agglomeration economies is based on the construction of indexes using the methodology of Glaeser and Kerr (2009). The indexes attempt to capture the effects of resource sharing, labor matching and knowledge spillovers according to the taxonomy proposed by Marshall (1920). Also an index to measure the influence of small suppliers...

  14. Chemical composition in relation with biomass ash structure

    Science.gov (United States)

    Holubcik, Michal; Jandacka, Jozef

    2014-08-01

    Biomass combustion can be more complicated like combustion of fossil fuels because it is necessary to solve problems with lower ash melting temperature. It can cause a lot of problems during combustion process. Chemical composition of biomass ash has great impact on sinters and slags creation in ash because it affects structure of heated ash. In this paper was solved relation between chemical composition and structure of heated ash from three types of biomass (spruce wood, miscanthus giganteus and wheat straw). Amount of SiO2, CaO, MgO, Al2O3 and K2O was determined. Structure of heated ash was optically determined after heating to 1000 °C or 1200 °C. Results demonstrated that chemical composition has strong effect on structure and color of heated ash.

  15. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2003-01-01

    related to the combustion of MSW and the formation of fly ash, especially in what concerns heavy metals. Treatment of the flue gas in air pollution control equipment plays an important role and the basic processes to accomplish this are explained. Fly ash from a semi-dry flue gas treatment system......Incineration is a common solution for dealing with the increasing amount of municipal solid waste (MSW). During the process, the heavy metals initially present in the waste go through several transformations, ending up in combustion products, such as fly ash. This article deals with some issues...... is characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2 g...

  16. Remediation of oil-contaminated sand by coal agglomeration using ball milling.

    Science.gov (United States)

    Shin, Yu-Jen; Shen, Yun-Hwei

    2011-10-01

    The mechanical shear force provided by a less energy intensive device (usually operating at 20-200 rpm), a ball mill, was used toperform coal agglomeration and its effects on remediation of a model fuel oil-contaminated sand were evaluated. Important process parameters such as the amount of coal added, milling time, milling speed and the size of milling elements are discussed. The results suggested that highly hydrophobic oil-coal agglomerates, formed by adding suitable amounts of coal into the oil-contaminated sand, could be mechanically liberated from cleaned sand during ball milling and recovered as a surface coating on the steel balls. Over 90% removal of oil from oil-contaminated sand was achieved with 6 wt% of coal addition and an optimum ball milling time of 20 min and speed of 200 rpm. This novel process has considerable potential for cleaning oil-contaminated sands.

  17. XRD and DTA Analysis of Developed Agglomerated Fluxes for Submerged Arc Welding

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2013-01-01

    Full Text Available A unique study of structural and chemical analysis of crystalline phases in developed agglomerated fluxes was carried out. Thirty-two fluxes were developed by using a mixture of oxides, halides, carbonates, silicates, and ferroalloys for submerged arc welding. The present paper focuses on only ten (out of thirty-two fluxes which were analyzed by X-ray diffraction (XRD to know the different types of oxides formed and changed in oxidation number of metallic centers after sintering process at around 850∘C. To know the effect of temperature over phase transformation and melting of different compounds, differential thermal analysis (DTA was carried out from 1000 to 1400∘C. This study aims to know the quantity of ions present (percentage and melting behavior of developed agglomerated fluxes for submerged arc welding process.

  18. An integrated modeling method for prediction of sulfur content in agglomerate

    Institute of Scientific and Technical Information of China (English)

    陈晓方; 桂卫华; 王雅琳; 吴敏

    2003-01-01

    Based on the idea of fusing modeling, an integrated prediction model for sintering process was proposed.A framework for sulfur content prediction was established, which integrated multi modeling ways together, including mathematical model combined with neural network(NN), rule model based on empirical knowledge and modelchoosing coordinator. Via metallurgic mechanism analysis and material balance computation, a mathematical model calculated the sulfur content in agglomerate by the material balance equation with some parameters predicted by NN method. In the other model, the relationship between sulfur content and key factors was described in the form of expert rules. The model-choosing coordinator based on fuzzy logic was introduced to decide the weight of result of each model according to process conditions. The model was tested by industrial application data and produced a relatively satisfactory prediction error. The model also preferably reflected the varying tendency of sulfur content in agglomerate as the evidence of its prediction performance.

  19. Steric stabilization of nonaqueous silicon slips. I - Control of particle agglomeration and packing. II - Pressure casting of powder compacts

    Science.gov (United States)

    Kerkar, Awdhoot V.; Henderson, Robert J. M.; Feke, Donald L.

    1990-01-01

    The application of steric stabilization to control particle agglomeration and packing of silicon powder in benzene and trichloroethylene is reported. The results provide useful guidelines for controlling unfavorable particle-particle interactions during nonaqueous processing of silicon-based ceramic materials. The application of steric stabilization to the control and improvement of green processing of nonaqueous silicon slips in pressure consolidation is also demonstrated.

  20. Recovering germanium from coal ash by chlorination with ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new process of enriching germanium from coal ash was developed. The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH4Cl/coal ash is 0.15, roasting temperature 400℃ and roasting time 90 min.

  1. Industrial Regions, Agglomerations and Industrialisation: The Iron and Steel Industry in Central Sweden 1805-1910

    OpenAIRE

    Olsson, Fredrik

    2006-01-01

    This paper focuses on regional and sectoral aspects of the Swedish industrialisation process. The aim is to discern geographical patterns of industrial agglomerations in the iron industry in Central Sweden during the period 1805-1910. Geographical patterns for the benchmark years 1805, 1855 and 1910 are based on employment statistics, which is analysed with the statistical Cluster Analysis. All parishes’ employment structure are compared at each benchmark year. The results are visualized in m...

  2. Radioisotope studies on the paradox in dispersion and agglomeration of sewage greases discharged from ocean outfalls

    International Nuclear Information System (INIS)

    Experiments have been undertaken in the ocean off Sydney, Australia to monitor the movement and the dispersion of sewage solids. These solids were labelled with a radioisotope, gold-198 prior to ocean discharge. The labelled material was followed at sea using submersible scintillation detectors. Lateral and vertical dispersion coefficients were determined. The experiments showed that under some conditions the labelled sewage grease dispersed and under others the grease agglomerated. This variation is explained in terms of non-conservative processes

  3. The role of specialisation and diversity externalities in the agglomeration of innovative activities

    OpenAIRE

    Paci, Raffaele; Usai, Stefano

    1999-01-01

    This paper contributes to the analysis of the process of spatial agglomeration of innovative activities by investigating directly its determinants. Our main purpose is to identify the extent to which the degree of industrial specialisation (Marshall externalities) or diversity (Jacobs externalities) in the region may affect the innovative output in a particular local industry. Moreover, we test if any relevant difference arises with respect to the role of diversity in metropolitan areas and i...

  4. Kinetic modelling of methane hydrate formation and agglomeration with and without anti-agglomerants from emulsion in pipelines

    OpenAIRE

    Pham, Trung-Kien; Melchuna, Aline; Cameirao, Ana; Herri, Jean-Michel; Duchet-Suchaux, Pierre; Glenat, Philippe

    2015-01-01

    Offshore systems mainly containing crude oil, natural gas and water operate at low temperature and high pressure which favour conditions for gas hydrate formation and agglomeration. Gas hydrate is a serious issue in flow assurance; it may cause many troubles, especially, plugging in oil and gas pipeline. This work is to intend to develop a kinetic model to predict gas hydrate formation, agglomeration and plugging in flowlines based on the experimental data obtained from Archimede Flowloop fro...

  5. Expansion control for cementation of incinerated ash

    International Nuclear Information System (INIS)

    A method, in which incinerated ash is solidified with a cement material, has been developed to dispose of radioactive incinerated ash waste. A small amount of metallic Al, which was not oxidized in the incineration, existed in the ash. When such ash was mixed with a cement material and water, alkaline components in the ash and the cement were dissolved in the mixing water and then metallic Al reaction with the alkaline compounds resulted in generation of H2. Because the H2 generation began immediately just after the mixing, H2 bubbles pushed up the mixed grout material and an expanded solidified form was obtained. The expansion leads to lowering the strength of the solidified form and making harmful void. In this study, we tried to control H2 generation from the reaction of metallic Al in the cementation by means of following two methods, one was a method to let metallic Al react prior to the cementation and the other was a method to add an expansion inhibitor that made an oxide film on the surface of metallic Al. In the pre-treatment, the ash was soaked in water in order to let metallic Al react with it, and then the ash with the immersion solution was dried at 105 Celsius degrees. The pre-treated ash was mixed with an ordinary portland cement and water. The inhibitor of lithium nitrite, sodium nitrite, phosphoric acid, or potassium dihydrogen phosphate was added at the mixing process. The solidified forms prepared using the pre-treated ash and lithium nitrite were not expanded. Phosphoric acid and sodium nitrite were effective for expansion control, but potassium dihydrogen phosphate did not work. (authors)

  6. MEROS: an improved dry-type gas-cleaning process for the treatment of sinter offgas; MEROS, un procede perfectionne d'epuration de fumees d'agglomeration

    Energy Technology Data Exchange (ETDEWEB)

    Fleischanderl, A. [Siemens AG Industrial Solutions and Services, VAI Environmental Technologies, Erlangen (Germany)

    2006-11-15

    VAI has developed the MEROS process (Maximized Emission Reduction Of Sintering) in which dust and harmful metallic and organic components present in sinter offgas are removed in a series of treatment steps to levels previously un-attained with conventional gas-treatment techniques. In a number of test campaigns, the technical and economical advantages of this innovative sinter offgas-cleaning process were verified. Voestalpine Stahl subsequently placed an order with VAI for the installation of an industrial MEROS facility to be started-up in August 2007. (author)

  7. Combined treatment of SO2 and high resistivity fly ash using a pulse energized electron reactor

    International Nuclear Information System (INIS)

    The combined removal of SO2 and high resistivity fly ash has been demonstrated in a pulse energized electron reactor (PEER). The PEER system which was originally developed for the removal of SO2 utilizes a positive pulse streamer corona discharge in a non-uniform field geometry. In performance tests on SO2, more than 90% was removed with an advantageously small power requirement. Combined treatment performance was demonstrated by introducing high resistivity fly ash into the test gas and the PEER is significantly more efficient than a conventional electrostatic precipitator operated with a dc voltage. Observations show that the PEER agglomerates the fly ash and further that the SO2 removal efficiency is improved by the presence of fly ash. The electrode configuration and performance results make retrofit consideration attractive

  8. Adsorption of Superplasticizers in Fly Ash Blended Cement Pastes and Its Rheological Effects

    Institute of Scientific and Technical Information of China (English)

    CHEN Wei; SHEN Peiliang; SHUI Zhonghe; FAN Jianfeng

    2012-01-01

    The adsorption of superplasticizers in fly ash blended cement paste and its rheological effects were investigated.It is shown that the absorption of superplasticizer on portland cement particles is very different from that on fly ash particles.The fly ash particles have smooth surfaces and are negatively charged,so its adsorption capacity is weaker than the portland cement particles.The amount of adsorbed SP in the fly ash blended cement paste depends highly on the replacement proportion of portland cement with fly ash,and to a much less extent on the nature of the fly ash.However,the amount of adsorbed superplasticizer does not correspond well the ζ-potential of the solid particles,due the strong adsorbing capacities of the Portland cement particles.When fly ash replaces portland cement in the paste,the rheological behavior is radically changed,which is closely related to the fineness and density of the ash.The packing and agglomeration of the solid particles are the controlling factors on the rheological parameters of the fresh paste,instead of the amount and type of adsorbed superplasticizer.

  9. Characterizing the Hydrological Properties of Wildfire Ash

    Science.gov (United States)

    Woods, S.; Balfour, V.

    2010-12-01

    Wildfires are extreme disturbance events that can increase runoff and erosion rates by 2-3 orders of magnitude. Fire related sediment presents a significant geomorphic hazard in terms of debris flows and other catastrophic erosion events, but ultimately plays a key role in landscape evolution in fire prone regions. The hyper-dessicated ash and soil layers making up the near surface profile in recently burned areas respond very differently to rainfall than the litter and unburned soil that existed prior to the fire. Limited knowledge regarding the hydrological properties of the ash-soil profile, and the ash layer in particular, currently limits efforts to model the infiltration process in burned areas and hence predict the location and magnitude of post fire runoff and erosion events. In our ongoing research we are investigating and quantifying the hydrologic properties of wildfire ash. Wherever possible we use conventional laboratory techniques from soil hydrology but in some cases we have had to adapt these techniques to account for the distinct physical and chemical properties of ash, such as the variability in particle density and the partial solubility of many of the mineral components. Some of the hydrologic properties of ash, such as the hydraulic conductivity, are similar to those of a mineral soil with a comparable particle size distribution. For example, ash from Spain with a silty loam texture had a hydraulic conductivity of 7 x 10-4 cm s-1, which is within the range reported for mineral soils with the same texture. However, other properties such as the porosity are considerably different; an undisturbed ash sample with a sandy loam texture had a porosity of 93 percent compared to the typical range of 30 to 50 percent for mineral soils with this texture. Scanning electron microscopy analysis indicates that the contrasting hydrologic properties of ash and soil are due to differences in the particle shape, particle packing and pore structure. Using examples

  10. Sorption of aqueous phosphorus onto bituminous and lignitous coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Yan Jinying; Kirk, Donald W. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada); Jia, Charles Q. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada)], E-mail: cqjia@chem-eng.toronto.edu; Liu Xinan [College of Chemical Engineering, Chongqing University, Chongqing (China)

    2007-09-05

    Aiming at the development of a phosphorus removal technology for waste water, phosphate (PO{sub 4}{sup 3-}) retention behavior of bituminous and lignitous coal ashes was investigated using a batch reactor. Ash samples, including fresh and weathered fly and bottom ashes, were studied for their sorption isotherms and reversibility. Fly ashes had a much higher phosphate retention capacity (4000-30,000 mg P/kg) than bottom ashes (15-600 mg P/kg). Lignitous coal ashes were more capable of retaining phosphate than bituminous coal ashes. The retention process was largely irreversible, and the irreversibility increased with the increase in the retention capacity. Weathering enlarged the retention capacity of the bituminous bottom ash, but substantially lowered that of the fly ash, likely due to the difference in the weather-induced changes between the fly and bottom ashes. Sorption isotherms of fly ashes were found to be adequately represented by the Langmuir model while those of bottom ashes fitted better to the Freundlich model. Concentrations of Ca{sup 2+} and PO{sub 4}{sup 3-} in the aqueous phase were measured at the end of sorption and desorption experiments, and were compared with solubilities of three calcium phosphate minerals. The aqueous solutions were saturated or super-saturated with respect to tricalcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}) and hydroxyapatite (Ca{sub 5}(PO{sub 4}){sub 3}OH), and slightly under-saturated with respect to amorphous calcium phosphate. It is concluded that precipitation of calcium phosphate is the predominant mechanism for phosphate retention by coal ash under the conditions studied. There is a strong and positive correlation between alkalinity and phosphate sorption capacity. Consequently, acid neutralization capacity (ANC) can be used as an indicator of phosphate sorption capacity of coal ashes.

  11. The optimization of the quantity of coke and agglomerate in lead production in “Water-Jacket” furnace

    Directory of Open Access Journals (Sweden)

    E. Haxhiaj

    2012-01-01

    Full Text Available The dependence of technical lead production on the composition of the agglomerate has been analyzed on “Water-Jacket” furnace in Trepça. Additionally, the theoretical and real raport of coke consumption per ton of technical lead was studied. The goal of this study was to optimize the parameters of the process with respect to the amount of technical lead produced, the amounts of lead in the agglomerate and the air in the furnace. Special attention was also placed on minimization of energy consumption and environmental pollution.

  12. Utilization Of Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    S. D. Nagrale

    2012-07-01

    Full Text Available India is a major rice producing country, and the husk generated during milling is mostly used as a fuel in the boilers for processing paddy, producing energy through direct combustion and / or by gasification. About 20 million tones of Rice Husk Ash (RHA is produced annually. This RHA is a great environment threat causing damage to the land and the surrounding area in which it is dumped. Lots of ways are being thought of for disposing them by making commercial use of this RHA. RHA can be used as a replacement for concrete (15 to 25%.This paper evaluates how different contents of Rice Husk Ash added to concrete may influence its physical and mechanical properties. Sample Cubes were tested with different percentage of RHA and different w/c ratio, replacing in mass the cement. Properties like Compressive strength, Water absorption and Slump retention were evaluated.

  13. ACC 305 ASH

    OpenAIRE

    admn

    2015-01-01

    ACC 305 ASH Check this A+ tutorial guideline at   http://www.assignmentcloud.com/ACC-305-ASH/ACC-305-ASH-Complete-Class ACC 305 Week 1 Assignments E 3-18, E 3-20, J Case 3-5 ACC 305 Week 1 DQ 1 FASB and Ethics ACC 305 Week 1 DQ 2 Cash versus Accrual & Financial Disclosures ACC 305 Week 2 DQ 1 Earnings Management Case 4-3 ACC 305 Week 2 DQ 2 Revenue Recognition Case 5-2 ACC 305 Week 2 Problem E4-16 Bluebonnet Bakers ACC 305 Week 2 Problem E4-19 ...

  14. HIS 204 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    JOHN

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HIS 204 Week 1 DQ 1 (Ash) HIS 204 Week 1 DQ 2 (Ash) HIS 204 Week 1 Quiz (Ash) HIS 204 Week 2 DQ 1 (Ash) HIS 204 Week 2 DQ 2 (Ash) HIS 204 Week 2 Quiz (Ash) HIS 204 Week 3 Assignment Women Right, Sacrifices & Independence (Ash) HIS 204 Week 3 DQ 1 (Ash) HIS 204 Week 3 DQ 2 (Ash) HIS 204 Week 4 DQ 1 (Ash) HIS 204 Week 4 DQ 2 (Ash) HIS 204 Week 4 Quiz (Ash) HIS 204 Week 5 DQ 1 (Ash) ...

  15. Study on the factors influencing the ash changes in starch sugar production process%淀粉糖生产过程相关因素影响灰分变化的研究

    Institute of Scientific and Technical Information of China (English)

    郭峰; 李茹; 罗思; 黄立新

    2016-01-01

    测定了果葡糖浆和葡萄糖浆生产过程中原料、中间物料和产品的灰分、电导率、pH、钠离子浓度等指标。结果表明,果葡糖浆和葡萄糖浆生产过程中,灰分的变化与电导率、pH、钠离子浓度的变化具有相关性,为进一步研究淀粉糖生产在线监控灰分含量提供了基础数据和技术参考。%Ash content,conductivity,pH,sodium ion concentration of raw starch,intermediate materials and products were measured in the high fructose corn syrup and glucose syrup production process. The results indicated that the changes had dependent interaction between the ash content and its conductivity,pH and sodium ion concentration of high fructose corn syrup and glucose syrup. This study might provide more references for the further study of on–line analysis of ash content in the starch sugar production process.

  16. AMG by element agglomeration and constrained energy minimization interpolation

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, T V; Vassilevski, P S

    2006-02-17

    This paper studies AMG (algebraic multigrid) methods that utilize energy minimization construction of the interpolation matrices locally, in the setting of element agglomeration AMG. The coarsening in element agglomeration AMG is done by agglomerating fine-grid elements, with coarse element matrices defined by a local Galerkin procedure applied to the matrix assembled from the individual fine-grid element matrices. This local Galerkin procedure involves only the coarse basis restricted to the agglomerated element. To construct the coarse basis, one exploits previously proposed constraint energy minimization procedures now applied to the local matrix. The constraints are that a given set of vectors should be interpolated exactly, not only globally, but also locally on every agglomerated element. The paper provides algorithmic details, as well as a convergence result based on a ''local-to-global'' energy bound of the resulting multiple-vector fitting AMG interpolation mappings. A particular implementation of the method is illustrated with a set of numerical experiments.

  17. Corrosion of Modified Concrete with Sugar Cane Bagasse Ash

    OpenAIRE

    Núñez-Jaquez, R. E.; J. E. Buelna-Rodríguez; C. P. Barrios-Durstewitz; Gaona-Tiburcio, C.; Almeraya-Calderón, F.

    2012-01-01

    Concrete is a porous material and the ingress of water, oxygen, and aggressive ions, such as chlorides, can cause the passive layer on reinforced steel to break down. Additives, such as fly ash, microsilica, rice husk ash, and cane sugar bagasse ash, have a size breakdown that allows the reduction of concrete pore size and, consequently, may reduce the corrosion process. The objective of this work is to determine the corrosion rate of steel in reinforced concrete by the addition of 20% sugar ...

  18. Control methods for remediation of ash-related problems in fluidized-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.

    1999-07-01

    The paper reports on investigations into control methodologies for mitigating ash-related problems such as particle agglomeration and bed defluidization during fluidized-bed combustion of low-rank coals. A laboratory scale spouted bed combustor is used to study the effectiveness of control methodologies. In the present work, two control methods are investigated viz., the use of alternative bed materials and pretreatment of coal. Bauxite and calcined sillimanite are used as alternative bed materials in the spouted bed combustor while burning South Australian low-rank coal. Samples of the same coal subjected to Al pretreatment, water washing and acid washing are also tested in the spouted bed combustor. Experiments showed that both methods are effective to different extents in reducing ash-related problems. Tests with calcined sillimanite and bauxite (as the bed material) showed trouble free operation for longer periods (7--12 hr at 800 C and 3--5 hr at 850 C) than with sand runs at the same bed temperatures. Al pretreatment and water-washing were also found to be effective and resulted in extended combustion operation. Al enrichment in ash coating of bed particles has been identified as the main mechanism for prevention of agglomeration and defluidization by these control methodologies. For water-washing, the principal reason behind agglomeration and defluidization control is the reduction in sodium levels.

  19. Reconstruction of Industrial Location in View of Industrial Agglomeration

    Institute of Scientific and Technical Information of China (English)

    ZHU Huayou; DING Sibao

    2006-01-01

    The Industrial Agglomeration Theory has been evolving all the time. The study on the industrial location has become the focus of the massive theoretical location problems about agglomeration since the 1970s. The authors here analyze the evolution and the characteristics of the Industrial Agglomeration Theory and study its effect on the reconstruction of industrial location. The study suggests that the new idea of reconstruction of industrial location is to cultivate regional innovative system. On this basis, the authors analyze two cases of old industrial bases on their construction-Tiexi Industrial District in Shenyang City and Changchun Industrial Economic Development Zone. Finally, the authors put forward some suggestions that should be regarded, which include: 1) to combine industrial location reconstruction and enterprises' inner reform; 2) to speed up adjustment of resources and opening to the world; 3) to combine government mechanism with the market mechanism properly.

  20. 还原挥发氧化锌烟尘中有价金属分离工艺研究%Research on process of separating valuable metals from zinc oxide fly ash

    Institute of Scientific and Technical Information of China (English)

    范兴祥; 汪云华; 吴跃东; 赵家春; 董海刚

    2011-01-01

    On the basis of zinc oxide fly ash bearing multiple valuable metals, a whole hydrometallurgical technique for separation valuable metals from zinc oxide fly ash has been put forward. First, zinc oxide fly ash was leached by adding hydrogen peroxide and sulfuric acid, leaching liquor bearing zinc sulfate and indium sulfate and leaching residue bearing Pb and Bi were obtained by filtration and washing,and realized the separation of Zn and In from Pb and Bi. Leaching liquor realized the separation of Zn from In by P204 extraction. Lead sulfate in leaching residue was converted into lead carbonate by adding ammonium bicarbonate,and then lead carbonate reacted with added nitric acid, which realized the separation of Pb from Bi. On the one hand,the process realized the separation valuable metals from zinc oxide fly ash,on the other hand,zinc sulfate,indium sulfate,lead nitrate, and rich bismuth residue during the separation were used for producing the other chemical products. This process has supplied a new process for making comprehensive use of zinc oxide fly ash.%针对含多种有价金属的还原挥发氧化锌烟尘,提出一条全湿法分离烟尘中有价金属的工艺路线.首先采用加双氧水氧化稀硫酸浸出,经过滤和洗涤,分别获得含硫酸锌、硫酸钢浸出液和含铅、铋浸出渣,实现锌、铟与铅、铋分离;对含硫酸锌和硫酸铟浸出液采用P204萃取,实现锌与铟的分离;对含铅、铋浸出渣采用碳酸氧铵转化生成碳酸铅,加硝酸溶解,实现铅与铋的分离.该工艺不仅可有效分离烟尘中的有价金属,而且获得的硫酸锌、硫酸钢、硝酸铅、富铋渣可用于生产其他化工产品,为氧化锌烟尘高效综合利用提供了一条新的途径.

  1. Application of synchrotron radiation X-ray computed tomography to investigate the agglomerating behavior of TiB{sub 2} particles in aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei; Mao, Feng; Chen, Zongning; Han, Jingyu; Yan, Guangyuan [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Tongmin, E-mail: tmwang@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Cao, Zhiqiang, E-mail: caozq@dlut.edu.cn [Laboratory of Special Processing of Raw Materials, Dalian University of Technology, Dalian 116024 (China)

    2015-02-15

    Highlights: • SR-CT was a powerful tool to investigate the TiB{sub 2} distribution in Al-TiB{sub 2} in situ composites. • Three kinds of agglomerations frequently present in the composites. • Agglomerations formed via the diffused atoms reacting with intermediate products. • The composites containing agglomerations show a much reduced ductility. - Abstract: Agglomeration of reinforcing particles has a number of deleterious effects on the properties of in situ metal matrix composites (MMCs). In order to better understand this phenomenon, the agglomerating behavior of TiB{sub 2} particles in aluminum based in situ MMCs was investigated using synchrotron radiation X-ray computed tomography (SR-CT) and field emission scanning electron microscope (FESEM). SR-CT was shown to be a powerful tool for visualizing and quantifying the three-dimensional (3D) features within the composites. Based on the SR-CT and FESEM results, a formation mechanism of the flaky agglomerates, flocculent agglomerates and clusters of coarse TiB{sub 2} particles, which are most frequently presented in the in situ Al/TiB{sub 2} composite, has been proposed. The mechanism shows that the formation of these three kinds of agglomerates can be attributed to three parallel processes, i.e. diffusing titanium atoms reacting with AlB{sub 2}, aluminum melt directly reacting with emulsified salt, diffusing boron atoms reacting with TiAl{sub 3}, respectively. Moreover, the mechanism may shed some light on how to design better processing techniques for obtaining homogenous particle distribution in in situ Al/TiB{sub 2} composites in the future.

  2. Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Peter Y. [National Energy Technology Lab. (NETL), Albany, OR (United States); Kwong, Kyei-Sing [National Energy Technology Lab. (NETL), Albany, OR (United States); Bennett, James [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2015-09-27

    Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. Here, we measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometer and their ash fusion temperatures through optical image analysis. We made all measurements in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. Finally, an understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.

  3. Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes*

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Peter

    2015-07-02

    Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. We measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometer and their ash fusion temperatures through optical image analysis. All measurements were made in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. An understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.

  4. 垃圾焚烧飞灰水洗-酸浸稳定化技术研究%Effects of a water-washing process on heavy metal speciation and leaching efficiency in MSWI fly ash during acid extraction

    Institute of Scientific and Technical Information of China (English)

    于昕; 薛军

    2011-01-01

    垃圾焚烧飞灰中富集了浓度较高的重金属,对环境存在潜在威胁,但同时具有一定的回收价值.对水洗-酸浸稳定化技术处理城市垃圾焚烧飞灰的效果进行了实验室研究,分析了垃圾焚烧飞灰的主要化学组成,考察了水洗过程对于飞灰中主要元素和重金属去除的影响、水洗过程中的化学组成变化和飞灰重金属酸浸的效果,评价了水洗飞灰酸浸残渣的稳定性.结果表明:L/S =20时,水洗过程可以浸出60%以上的Cl,47%以上的Na、K、Ca,18%以上的Pb.水洗后,重金属Zn、Pb、Cu含量分别增加76.37%、21.91%和46.16%.与原灰相比,水洗飞灰酸浸过程中的Zn浸出量也有很大提高,而Pb浸出量的增加很小.当HCl 浓度<1M时, Pb和Zn的浸出量随着HCl浓度增加迅速增大,这主要是因为重金属的可交换态和碳酸盐结合态对溶液中离子强度和pH变化敏感.对水洗飞灰酸浸残渣进行的连续提取实验表明,重金属以残留态存在为主,其稳定性显著提高.本文的结果表明,水洗-酸浸工艺能够通过增加飞灰的稳定性和减少重金属的浸出性来提高飞灰的环境安全.%Fly ash from municipal waste incinerators form a major environmental problem as they are polluted with heavy metals. But the metal value can be partly removed and recovered by extracting with acid solution. Experiments have been performed to investigate the effect of water washingacid extraction process (WWAF process) for treatment of MSWI fly ash. The chemical composition of fly ash has been analyzed. The effects of waterwashing process on the removal of the major elements and on heavy metals, their speci ation in the washing process, the effects of acid extraction have been elucidated and heavy metals stability in the extracted washed ash residuals have been evaluated. The results indicate that more than 60% of the C1, and more than 47% of the major elements of Na, K, and Ca, as well as more than 18

  5. Leaching of nutrient salts from fly ash from biomass combustion

    DEFF Research Database (Denmark)

    Thomsen, Kaj; Vu, Duc Thuong; Stenby, Mette;

    2005-01-01

    Methods to selectively leach nutrient salts from fly ash, while leaving cadmium un-dissolved were studied. Temperature, pH, water to fly ash ratio are all expected to influence the kinetics and the equilibrium boundaries for this process. Three different leaching methods were investigated. The...... moving bed process with agitation/centrifugation. It was found that a satisfactory leaching of the nutrient salts could be achieved with the third method using only two or three stages, depending on the water to fly ash ratio. It is an advantage to perform the process at temperatures above 50°C as the...... first method was a counter current moving bed process in four stages. The ash was kept in filter bags and leached with water that was introduced into the bags at 40-50°C. In the second method, fly ash and water was brought into contact in a partially fluidized bed. The third method was a counter current...

  6. Fusion characterization of biomass ash

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang;

    2016-01-01

    The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two...... stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, Tm, is proposed to represent the severe melting temperature of biomass ash. The fusion...... characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates....

  7. Pre-study - Straw ash in a nutrient loop; Foerstudie - Halmaska i ett kretslopp

    Energy Technology Data Exchange (ETDEWEB)

    Ottosson, Peter; Bjurstroem, Henrik; Johansson, Christina; Svensson, Sven-Erik; Mattsson, Jan Erik

    2009-03-15

    straw from soils with higher cadmium content. To avoid that a farm with a low cadmium concentration in the straw receives ash with a high content, one could combust area-wise and recycle area-wise, or choose not to fetch straw from farms with high cadmium contents in soils, or spread only bottom ash. However, if fly ash is not utilised, a large part of the potassium is lost. The conclusion is that recycling of straw ash to fields is feasible and development work should continue after this pre-study. The pre-study need to be developed in the following areas: Means to spread a small quantity of ash to fields, with as small a negative effect as possible. Machines for spreading straw ash have been studied in some Swedish investigations, and before proceeding further one should gather additional information, a.o. on foreign machinery for spreading straw ash Test lime spreading techniques, pipe model, for agglomerated ash (wet, cured, crushed and sieved straw ash) As ash is a fertiliser, a method to calculate doses should be developed. This implies a.o. an analysis of potassium and phosphorus available to plants The availability of cadmium to plants should be studied in order to determine in which phase of a crop rotation ash should be returned in order to minimize the risk that plants take up cadmium If one chooses to recycle only bottom ash, one should continue to investigate means to extract potassium from fly ash, as ca 50 % of the potassium content is in the fly ash

  8. Agglomeration and size distribution of debris in DEFOR-A experiments with Bi{sub 2}O{sub 3}–WO{sub 3} corium simulant melt

    Energy Technology Data Exchange (ETDEWEB)

    Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se; Karbojian, Aram, E-mail: aram@safety.sci.kth.se; Tran, Chi-Thanh, E-mail: thanh@safety.sci.kth.se; Villanueva, Walter, E-mail: walter@safety.sci.kth.se

    2013-10-15

    Highlights: • Debris agglomeration in case of melt pouring into a coolant is experimentally investigated. • The effects of jet diameter, melt superheat and water subcooling are addressed. • Most influential factor which can significantly increase fraction of agglomerates is melt superheat. • Rapid decrease of the fraction of agglomerates as a function of water depth is obtained in all cases. • Provided data is valuable for model development and code validation. -- Abstract: Flooding of lower drywell has been adopted as a cornerstone of severe accident management strategy in Nordic type Boiling Water Reactors (BWR). It is assumed that the melt ejected into a deep pool of water will fragment, quench and form a porous debris bed coolable by natural circulation. If debris bed is not coolable, then dryout and possibly re-melting of the debris can occur. Melt attack on the containment basemat can threaten containment integrity. Agglomeration of melt debris and formation of solid “cake” regions provide a negative impact on coolability of the porous debris bed. In this work we present results of experimental investigation on the fraction of agglomerated debris obtained in the process of hot binary oxidic melt pouring into a pool of water. The Debris Bed Formation and Agglomeration (DEFOR-A) experiments provide data about the effects of the pool depth and water subcooling, melt jet diameter, and initial melt superheat on the fraction of agglomerated debris. The data presents first systematic study of the debris agglomeration phenomena and facilitates understanding of underlying physics which is necessary for development and validation of computational codes to enable prediction of the debris bed coolability in different scenarios of melt release.

  9. Ash and heavy metals in fluidized-bed combustion of wood wastes; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO Power Engineering, Vantaa (Finland); Kauppinen, E.; Latva-Somppi, J.; Kurkela, J. [VTT Chemical Technology, Espoo (Finland); Partanen, J. [IVO Technology Centre, Vantaa (Finland)

    1997-10-01

    Ash formation and deposition mechanisms during co-combustion of pulp mill sludge and bark in industrial bubbling fluidized bed (BFB) combustor have been studied. Similar fuels were used in a bench-scale BFB for co-combustion of sludge and bark pellets and comparative studies with separate combustion of these fuels. Results indicated that in industrial scale unit significant fraction of ash had vaporization. About 14 mass-% of the total fly ash was found in the particle size below 0.2 {mu}m. The vaporized species consisted of potassium (K), sulfur (S), chlorine (Cl) and also of minor quantities of sodium (Na). In the benchscale similar vaporization fractions during co-combustion were measured, about 11 mass-%. During the combustion of bark this ratio, about 20 mass-%, was higher than during sludge combustion. The vaporized ash fraction was in the case of dried sludge combustion about 7 mass-%, but with wet sludge the vaporization rate was remarkably lower, about 1-2 mass-%. An increase in the bed temperature increased also ash vaporization. Test run period without combustion at elevated temperatures produced very low quantities of vaporized ash. The vaporized species in bench-scale test during bark pellet combustion were K, S and Cl, for sludge combustion also Na was clearly detected. No condensation of the vaporized species in bed area or furnace walls was observed. Bed defluidization was studied in the bench-scale unit. During bark pellet combustion the bed-agglomeration proceeded via small ash particle, below 2 {mu}m, coating on sand particle surface and consequent bonding between the ash layers. In the case of sludge combustion the accumulation of large ash particles and sintering of these porous agglomerates was observed to cause bed coarsening and defluidization. (orig.)

  10. 汽车服务业空间布局演化研究——基于潍坊市奎文区的实证分析%RESEARCH ON THE SPATIAL AGGLOMERATION PROCESSES OF AUTOMOTIVE SERVICE INDUSTRY A CASE STUDY OF KUIWEN DISTRICT, WEIFANG CITY

    Institute of Scientific and Technical Information of China (English)

    周珂慧; 甄峰; 余洋; 韩青

    2011-01-01

    By using GIS spatial analysis and statistics of the SingTel Yellow Pages, this paper analyzes the characteristics of the spatial variation of the study area's automotive service industry in the approximately past 10 years, and summarizes three models (“point-axis” model, “point-block” model and “point-axis-block” mode)of evolution of trends in automotive service industry and reasons behind these phenomena. In the end of this paper, it concludes that the spatial agglomeration process' modes of the automotive service industry are in high degree of diversification in study area, corresponding to the industry's own characteristics and stages of development;influencing factors such as policy, economy, social, and historical dynamic mechanism are interacted in the course of this evolution; automotive service industry's industrial space and urban space have strong connection and interaction. And to guide the spatial layout and optimization ,this paper gives some proposal and suggestion:Flexible plan the industrial layout pattern, regulate the market and make reasonable spatial guidance; at the same time strengthen the links between automotive service industry and related supporting industries, and orderly organization of space capabilities within the cluster, in order to promote the development of automotive service industry, and provide scientific and reasonable guidance for the further agglomeration trend of the financial services industry in China.%近年来随着我国汽车生产与消费的不断增长,汽车服务业呈现快速发展的趋势.通过GIS空间分析和电信黄贞统计模拟,对潍坊市奎文区汽车服务业近10年的空间演变趋势进行实证研究,从中提炼和归纳其产业空间演化的三种结构模式.得出结论:汽车服务业空间演化模式多元,与产业自身特征、发展情况和发展阶段对应;演化过程受政策性、经济性、社会性和历史性动力机制共同作用;产业空间与城市

  11. Quantitative characterization of nanoparticle agglomeration within biological media

    Energy Technology Data Exchange (ETDEWEB)

    Hondow, Nicole, E-mail: n.hondow@leeds.ac.uk; Brydson, Rik [University of Leeds, Institute for Materials Research (United Kingdom); Wang, Peiyi [University of Leeds, Institute of Molecular and Cellular Biology (United Kingdom); Holton, Mark D.; Brown, M. Rowan; Rees, Paul; Summers, Huw D. [Swansea University, Centre for Nanohealth, College of Engineering (United Kingdom); Brown, Andy [University of Leeds, Institute for Materials Research (United Kingdom)

    2012-07-15

    Quantitative analysis of nanoparticle dispersion state within biological media is essential to understanding cellular uptake and the roles of diffusion, sedimentation, and endocytosis in determining nanoparticle dose. The dispersion of polymer-coated CdTe/ZnS quantum dots in water and cell growth medium with and without fetal bovine serum was analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. Characterization by TEM of samples prepared by plunge freezing the blotted solutions into liquid ethane was sensitive to the dispersion state of the quantum dots and enabled measurement of agglomerate size distributions even in the presence of serum proteins where DLS failed. In addition, TEM showed a reduced packing fraction of quantum dots per agglomerate when dispersed in biological media and serum compared to just water, highlighting the effect of interactions between the media, serum proteins, and the quantum dots. The identification of a heterogeneous distribution of quantum dots and quantum dot agglomerates in cell growth medium and serum by TEM will enable correlation with the previously reported optical metrology of in vitro cellular uptake of this quantum dot dispersion. In this paper, we present a comparative study of TEM and DLS and show that plunge-freeze TEM provides a robust assessment of nanoparticle agglomeration state.

  12. MEASUREMENT OF AGGLOMERATION ECONOMIES AT COUNTY LEVEL IN JIANGSU PROVINCE

    Institute of Scientific and Technical Information of China (English)

    GE Ying; PU Ying-xia; YAO Shi-mou

    2005-01-01

    Agglomeration economies are the important factors for the regional development. However, the common indicators to measure them, such as Gini Coefficients neglect the spatial ingredient of data, leading to a-spatial estimates. In order to assess spatial neighbor effects of agglomeration economies, this study makes the new attempts by applying a series of techniques of spatial autocorrelation analysis, specifically, measuring the economies of urbanization and localization at the county level in the secondary and tertiary industries of Jiangsu Province in 1999 and 2002. The conclusions in this study reveal that on the whole, the localization effects on the economies of the secondary industry might be stronger than urbanization effects for that period, and highly agglomerative economies were limited within the southern Jiangsu and parts of middle along the Changjiang (Yangtze) River. Moreover, the tertiary industry has been strong urbanization rather than localization economies in the whole Jiangsu. Unlike the secondary industry, the tertiary industry held the high levels of agglomeration economies can be also found in the poor northern Jiangsu, and then the spatial clusters of trade and services might be basically seen in each of urban districts in 13 cities. All in all, spatial autocorrelation analysis is a better method to test agglomeration economies.

  13. Current Trends in wastewater treatment in small agglomerations; Tendencias actuales en las tecnologias de tratamiento de las aguas residuales generadas en las pequenas aglomeraciones urbanas

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer Medina, Y.; Ortega de Miguel, E.; Salas Rodriguez, J. J.

    2012-07-01

    Spain has a great number of small agglomerations. In fact from the 8.111 existing municipalities, 72% have less than 2.000 inhabitants and 47% of them (3.800) have less than 500 inhabitants. Concerning wastewater treatment in small agglomerations three periods can be distinguished. Before the 80{sup t}h, wastewater treatment plants were merely small reproductions of those applied in bigger agglomerations, and Extended Aeration was basically the only process. Due to their high energy and technical requirements, many of these small plants were left out of service. Extensive technologies appeared in Spain during the 80{sup t}h. Results were not as good as expected mainly due to design and construction failures. Nowadays, we are just starting to be aware that wastewater treatment in small agglomerations, need a new approach, more demanding concerning technical and management issues, to give an owner's to the origin of previous mistakes. This new approach offers a wide range of possible technologies (extensive, and mixed) each of them could be a good option depending on the specific characteristics of the agglomeration, and the discharge requirements. These paper reviews current trends concerning urban wastewater treatment is mall agglomerations, including consolidated technologies, emerging technologies and technologies which are still in development or in an experimental phase. (Author)

  14. Sulphation characteristics of paper sludge ash

    Energy Technology Data Exchange (ETDEWEB)

    Roh, S.A. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of); Kim, S.D. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of). Dept. of Chemical and Biomolecular Engineering

    2007-04-15

    Landfills are no longer a viable solution for the disposal of sludge produced from waste water treatment plants because of the decrease in available space, rising fees and growing environmental concerns. However, thermal utilization of this waste may be an economic and sustainable disposal solution. Co-combustion of low heating value sludge with fossil fuels has a positive effect for sulfur dioxide (SO{sub 2}) emissions due to the low sulphur content of biomass fuels and increased sulphur retention in the ash. The sulphur retention is attributed to the formation of sulphates, such as CaSO{sub 4}, K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4}. The amount of fuel-ash-related sulphur sorption increases during co-combustion. Therefore, sorbents for sulphur reduction may not be required if proper control of the biomass feed is maintained. This paper presented a study in which the sulphation characteristics of calcium-rich paper sludge ash were determined for the use of co-combustion of biomass and coal. The calcium in the paper sludge ash came from the limestone filler used in the manufacturing process to increase the density and whiteness of the paper at 2 paper mills in Korea. A thermobalance reactor along with XRD and SEM-EDX were used for the analysis of sulphated ash to determine the effects of sulphation temperature, particle size and SO{sub 2} concentration on sulphation conversion. The activation energy and pre-exponential factor of sulphation reaction of sludge ash were determined based on the uniform-reaction model. X-ray diffraction analysis revealed that most of the sulphation compounds were CaSO{sub 4}. The sulphation occurred uniformly throughout the ash and the CaSO{sub 4} did not block the outer pore of the sludge ash. The uniform distributions of CaO and other inert minerals in the ash resulted in uniform sulphation with good penetration of SO{sub 2} into pores of the sludge ash without pore blocking during sulphation of CaO. 13 refs., 1 tab., 9 figs.

  15. The behavior of ash species in suspension fired biomass boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt

    formation in suspension fired boilers. The presentation provides an overview of the knowledge obtained with respect to ash species behavior insuspension fired biomass boilers. A mechanistic understanding of the fly ash formation process in biomass fired PF boilers isobtained today. A high fraction of alkali...... salt species are released to the gas phase during the initial fuel combustion process. The salt species are present in gas phase in the boil chamberand upon cooling in the convective pass aerosols are formed. Recent studies indicates that a large fraction of the residual condensed phase ash fragments...... to generate ash particles typically in the size range of 50 to 200 μm on biomass suspension fired power plant boilers. A fragmentation rate of fuel particles of 3 have been used to describe both the residual ash formation process in laboratory entrained flow reactors and in full scale boilers.A range...

  16. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Task 6 -- Selective agglomeration laboratory research and engineering development for premium fuels

    Energy Technology Data Exchange (ETDEWEB)

    Moro, N.; Jha, M.C.

    1997-06-27

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and benchscale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report represents the findings of Subtask 6.5 Selective Agglomeration Bench-Scale Testing and Process Scale-up. During this work, six project coals, namely Winifrede, Elkhorn No. 3, Sunnyside, Taggart, Indiana VII, and Hiawatha were processed in a 25 lb/hr continuous selective agglomeration bench-scale test unit.

  17. Formation of the economic efficiency of industrial Dnipropetrovsk and Dniprodzerzhynsk agglomeration. O. V. Gladkyj

    OpenAIRE

    Gladkyj O.V.

    2009-01-01

    The features are opened of the formation of polycentric economic efficiency of industrial agglomerations. An assessment of the effectiveness of industrial Dnipropetrovsk Dneprodzerzhinskoy agglomeration and recommendations on optimization of its functional structure.

  18. Formation of the economic efficiency of industrial Dnipropetrovsk and Dniprodzerzhynsk agglomeration. O. V. Gladkyj

    Directory of Open Access Journals (Sweden)

    Gladkyj O.V.

    2009-08-01

    Full Text Available The features are opened of the formation of polycentric economic efficiency of industrial agglomerations. An assessment of the effectiveness of industrial Dnipropetrovsk Dneprodzerzhinskoy agglomeration and recommendations on optimization of its functional structure.

  19. Experimental Study on Volume for Fly Ash of Building Block

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2013-04-01

    Full Text Available Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, adding aggregate with reasonable ratio and additives with reasonable dosage and do the experimental research on manufacture products for properties, production technology and selection about technology parameter of production equipment. Index of strength grade and freezing-thawing resisting etc and the high doping fly ash brick building which we are working on can achieve the national standard on building materials industry. Based on the tests, this achievement of research has a very wide practical prospect in using fly ash, industrial waste residue, environmental protection and reducing the cost of enterprises. The efficient reuse of fly ash from coal boiler and power plants has very vital significance of protecting the environment, benefiting descendants and developing of circular economy.

  20. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    KAUST Repository

    Lima, A.T.

    2010-12-17

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. © 2010 Elsevier Ltd.

  1. MAT 126 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    stylia

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 126 Week 1 DQ 1 (Ash) MAT 126 Week 1 Quiz (Ash) MAT 126 Week 1 Written Assignment (Arithmetic and geometric sequence) (Ash) MAT 126 Week 2 DQ 1 (Ash) MAT 126 Week 2 DQ 2 (Ash) MAT 126 Week 2 Assignment Is It Fat Free (Ash) MAT 126 Week 2 Quiz (Ash) MAT 126 Week 3 DQ 1 (Ash) MAT 126 Week 3 DQ 2 (Ash) MAT 126 Week 3 Assignment Quadratic Equations (Ash) MAT 126 Week 3 Quiz (Ash) MAT 126...

  2. Sintering of MSWI fly ash by microwave energy.

    Science.gov (United States)

    Chou, Sun-Yu; Lo, Shang-Lien; Hsieh, Ching-Hong; Chen, Ching-Lung

    2009-04-15

    This study presents the sintering of municipal solid waste incineration (MSWI) fly ash assisted by microwave energy. The composition of fly ash was investigated by chemical sequential extraction and modified microwave digestion method. Effects of process time, container materials, aging time and salt contents were also discussed. The major elements of fly ash are Ca, Cl, Na, Si, K, Al, Mg, and Zn, and the metal species, Zn, Cr, Pb, Ca, and Cu, are mainly in the oxide phase. Under microwave processing, the fly ash was sintered into a glass-ceramics and the leaching concentrations of heavy metals were restrained. The stabilization efficiency increased with an increase in processing time in most of the cases. Better stabilization efficiency of fly ash was discovered by using the SiO(2) or Al(2)O(3) container than by using the graphite plate/SiC plate. The presence of salt in the fly ash could enhance the sintering and stabilization of fly ash. During the aging time of 0-30 days, negligible Pb in the sintered fly ash was leached out, and the leaching concentration was lower than the criterion. PMID:18692957

  3. Aerosol influence domain of Beijing and peripheral city agglomeration and its climatic effect

    Institute of Scientific and Technical Information of China (English)

    XU Xiangde; SHI Xiaohui; ZHANG Shengjun; DING Guoan; MIAO Qiuju; ZHOU Li

    2006-01-01

    the main body of the high correlation area prolongating southwards, forming an aerosol influence domain of "eccentric ellipse" shape,that is to say, there was an aerosol influence domain of some "radius" in Beijing City and its peripheral areas, within and outside which sunshine duration,low cloud cover, and fog days showed a remarkable difference in interannual variation trend. At the downstream of the city agglomeration there was a significant interdecadal increment area of fog or low cloud cover, which might be associated with the local climatic feature of the regional flow convergent field in the diffusion process of city agglomeration pollutants in the aerosol influence domain, and such a local dynamical convergence feature might lead to the regional exacerbation of aerosol impact downstream of the city agglomeration. The research result reveals that the significant area of interdecadal change rate of low cloud cover within the aerosol influence domain is correlated with the regional strengthening effect of aerosol impact of the local wind structure in the "downstream plume area" of the city.

  4. Agglomeration in fluidized beds: detection and counteraction

    NARCIS (Netherlands)

    Bartels. M.

    2008-01-01

    Fluidized beds comprise a quantity of solid particles that is suspended by an upward flowing gas. They are used for a variety of processes in the chemical industry, such as catalytic reactions, drying, coating and energy conversion. A major problem in industrial practice is the occurrence of unwante

  5. A Novel Plasma-Sprayed Nanostructured Coating with Agglomerated-Unsintered Feedstock

    Science.gov (United States)

    Gao, Yang; Zhao, Yan; Yang, Deming; Gao, Jianyi

    2016-01-01

    In this article, an unusual agglomerated powder of Y2O3-stabilized ZrO2 (YSZ) that did not undergo calcination was introduced as a feedstock for thermal spray deposition using internal injection atmospheric plasma spray (APS) and the very-low-pressure plasma spray (VLPPS) methods at an ambient pressure of 100-150 Pa. The results show that the microstructure of the coating is influenced not only by the spray parameters (such as arc gas composition, ambient pressure, and arc current) but also by the manufacture process of the agglomerates particularly the sintering process. The microstructure of the coating exhibited a bimodal structure if the APS method was used; in this case, the microstructure resembles that of other nanostructured coatings using regular agglomerated-sintered feedstock. A coating having a novel fully nano-equiaxed structure with a microporosity of 10-15% was first successfully deposited using VLPPS with 20Ar-30He SLPM plasma gas flows at a current of 500 A. The experimental results suggest that the nano-scale equiaxed structure in the coating is directly formed from original nanoparticles that had undergone melting, while inside the nozzle they were subsequently solidified on the substrate. The VLPPS method, which offers some unique advantages over the conventional plasma spray process, is generic in nature and can potentially be used to deposit a wide variety of ceramic coatings for diverse applications. The thermal conductivity values of the fully nanostructured and bimodal structured coatings were measured, and the microstructures of the coating both in the as-sprayed state and after heat treatment for 10 h at 1300 °C were investigated.

  6. Cleanup Verification Package for the 126-F-1, 184-F Powerhouse Ash Pit

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Clark and H. M Sulloway

    2007-10-31

    This cleanup verification package documents completion of remedial action for the 126-F-1, 184-F Powerhouse Ash Pit. This waste site received coal ash from the 100-F Area coal-fired steam plant. Leakage of process effluent from the 116-F-14 , 107-F Retention Basins flowed south into the ash pit, contaminating the northern portion.

  7. Cleanup Verification Package for the 126-F-1, 184-F Powerhouse Ash Pit

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Clark and H. M. Sulloway

    2007-09-26

    This cleanup verification package documents completion of remedial action for the 126-F-1, 184-F Powerhouse Ash Pit. This waste site received coal ash from the 100-F Area coal-fired steam plant. Leakage of process effluent from the 116-F-14 , 107-F Retention Basins flowed south into the ash pit, contaminating the northern portion.

  8. Water migration mechanisms in amorphous powder material and related agglomeration propensity

    NARCIS (Netherlands)

    Renzetti, S.; Voogt, J.A.; Oliver, L.; Meinders, M.B.J.

    2012-01-01

    The agglomeration phenomenon of amorphous particulate material is a major problem in the food industry. Currently, the glass transition temperature (Tg) is used as a fundamental parameter to describe and control agglomeration. Models are available that describe the kinetics of the agglomeration proc

  9. Vectorized image segmentation via trixel agglomeration

    Science.gov (United States)

    Prasad, Lakshman; Skourikhine, Alexei N.

    2006-10-24

    A computer implemented method transforms an image comprised of pixels into a vectorized image specified by a plurality of polygons that can be subsequently used to aid in image processing and understanding. The pixelated image is processed to extract edge pixels that separate different colors and a constrained Delaunay triangulation of the edge pixels forms a plurality of triangles having edges that cover the pixelated image. A color for each one of the plurality of triangles is determined from the color pixels within each triangle. A filter is formed with a set of grouping rules related to features of the pixelated image and applied to the plurality of triangle edges to merge adjacent triangles consistent with the filter into polygons having a plurality of vertices. The pixelated image may be then reformed into an array of the polygons, that can be represented collectively and efficiently by standard vector image.

  10. Electrodialytic treatment of fly ash

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Pedersen, Anne Juul; Kirkelund, Gunvor Marie;

    Heavy metals are removed from the fly ashes by an electrodialytic treatment with the aim of up-grading the ashes for reuse in stead of disposal in landfill.A great potential for upgrading of bio- and waste incineration ashes by electrodialytic treatment exists. In the future, the applicability...

  11. Optimization of extraction process of the melanin from prickly ash seed%花椒籽中黑色素提取工艺的优化研究

    Institute of Scientific and Technical Information of China (English)

    徐文秀; 王晓燕; 王鹏

    2013-01-01

    In order to improve the economy value of prickly ash seed and fully use of its by-products, the melanin was extracted from prickly ash seed by solvents.Effects of different factors,such as extraction solvent,extraction solvent concentration,extraction temperature,extraction time,ratio of solid to liquid and extraction times on melanin yield of prickly ash seed were studied by single factor test.Absorbance was selected as a substitute of melanin content.Based on single factor test,response surface analysis methodology was used to determine the optimal extraction conditions of melanin.Response surface analysis indicated that:optimal extraction conditions were 66℃, 4.5h,1:33(g/mL).The absorbance value of the melanin obtained was 0.305.The order of three factors affecting melanin yield from prickly ash seed was:temperature > ratio of solid to liquor Mime.%为了提高花椒的经济价值,充分利用花椒下脚料,以山西运域花椒籽为原料,采用溶剂法对花椒籽中的黑色素进行提取.通过单因素实验对影响花椒籽黑色素得率的因素:提取溶剂、提取溶剂浓度、提取温度、提取时间、料液比、提取次数进行探讨,用花椒籽黑色素提取液的吸光值来代替黑色素含量.在单因素实验的基础上,应用Box-Behnken 中心组合设计建立数学模型,以花椒籽黑色素提取液的吸光值作为响应值,进行响应面法分析(RSM),得出黑色素提取最佳工艺条件参数结果表明,最优工艺参数为:最佳提取温度为66℃,最佳提取时间4.5h,料液比1∶33 (g/mL).此条件下,黑色素吸光值为0.305.三个因素对花椒籽黑色素得率影响依次为:温度>料液比>时间.

  12. Laser-induced agglomeration of gold and silver nanoparticles dispersed in liquid

    Science.gov (United States)

    Serkov, A. A.; Kuzmin, P. G.; Shafeev, G. A.

    2016-03-01

    Evolution of size distribution function, morphology, and extinction spectra of Ag nanoparticles and Au-Ag nanoparticles mixture dispersed in liquids under picosecond laser exposure are experimentally studied. It is shown that picosecond laser exposure of dense aqueous solutions of NPs (above 1014 particles per ml) leads to formation of elongated agglomerates. Time dependence of the size distribution function is monitored during irradiation process and compared to optical spectra and Transmission Electron Microscope images. Exposure of Au-Ag nanoparticles mixture is shown to result in formation of NPs chains consisting of Au and Ag, or Au-Ag alloy NPs.

  13. Study of agglomeration behavior of combustion-synthesized nano-crystalline ceria using new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Srirupa T.; Bedekar, Vinila [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Patra, A.; Sastry, P.U. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India)], E-mail: aktyagi@barc.gov.in

    2008-10-20

    Ceria powders were prepared by gel combustion process using cerium nitrate and hitherto unexplored amino acid fuels such as aspartic acid, glutamic acid, arginine, tryptophan, phenyl alanine, valine, etc. These powders were characterized by X-ray diffraction, surface area analysis, sinterability, dynamic light scattering, scanning electron microscopy (SEM) and small angle X-ray scattering (SAXS). The combustion-synthesized powders were agglomerates of nano-crystallites. SAXS profiles of the powders prepared using tryptophan, phenyl alanine and dimethyl urea exhibited fractal behavior.

  14. Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

    International Nuclear Information System (INIS)

    Highlights: ► Separation of Pb and Zn from Fe and Cu in ash-melting of municipal solid waste. ► Molar ratio of Cl to Na and K in fly ash affected the metal-separation efficiency. ► The low molar ratio and a non-oxidative atmosphere were better for the separation. - Abstract: In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of the ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu

  15. 某电厂贮灰坝失稳过程及破坏机制研究%Study of instability process and failure mechanism of ash storage dam in a power plant

    Institute of Scientific and Technical Information of China (English)

    陈善雄; 冯美果; 许锡昌; 陈守义

    2009-01-01

    Based on unsaturated soil mechanics theory, the instability process of ash storage dam in a power plant is analyzed and failure mechanism of that is revealed. With the increase of lasting time of retaining water by the 1st sub dam, some phenomena will occur, such as water infiltrates into the dam body gradually, the phreatic surface rises constantly, the unsaturated region reduces corresponsively, the pore water pressure increases and the shear strength decreases continuously in the site which is influenced by water infiltration. When the process develops to a certain degree, the damage and slide of this ash storage will happen. The analysis in this paper explains clearly the reason why the stability of this ash storage dam suffers great threat if the dry beach disappears for a long period. This study may provide a reference for stability evaluation and forecast of those ash storage dams and tailings dams with the similar working condition.%运用非饱和土土力学理论分析了某电厂贮灰坝失稳过程,揭示了该贮灰坝的失稳和破坏机制.分析表明,随着子坝挡水历时的增加,积水不断下渗,浸润线逐渐抬高,非饱和区域相应减少,坝体中受此影响的部位的孔隙水压力也随之不断增高,抗剪强度不断降低.此过程发展到一定程度,则导致贮灰坝产生破坏和滑动.上述分析清楚地诠释了干滩长期消失会使贮灰坝的稳定性遭受巨大威胁的原因.其研究结果可为贮灰坝、尾矿坝在类似工况下的稳定性评价和预测预报提供借鉴.

  16. Reverse micelle synthesis of oxide nanopowders: mechanisms of precipitate formation and agglomeration effects.

    Science.gov (United States)

    Graeve, Olivia A; Fathi, Hoorshad; Kelly, James P; Saterlie, Michael S; Sinha, Kaustav; Rojas-George, Gabriel; Kanakala, Raghunath; Brown, David R; Lopez, Enrique A

    2013-10-01

    We present an analysis of reverse micelle stability in four model systems. The first two systems, composed of unstable microemulsions of isooctane, water, and Na-AOT with additions of either iron sulfate or yttrium nitrate, were used for the synthesis of iron oxide or yttrium oxide powders. These oxide powders were of nanocrystalline character, but with some level of agglomeration that was dependent on calcination temperature and cleaning procedures. Results show that even though the reverse micellar solutions were unstable, nanocrystalline powders with very low levels of agglomeration could be obtained. This effect can be attributed to the protective action of the surfactant on the surfaces of the powders that prevents neck formation until after all the surfactant has volatilized. A striking feature of the IR spectra collected on the iron oxide powders is the absence of peaks in the ~1715 cm(-1) to 1750 cm(-1) region, where absorption due to the symmetric C=O (carbonyl) stretching occurs. The lack of such peaks strongly suggests the carbonyl group is no longer free, but is actively participating in the surfactant-precipitate interaction. The final two microemulsion systems, containing CTAB as the surfactant, showed that loss of control of the reverse micelle synthesis process can easily occur when the amount of salt in the water domains exceeds a critical concentration. Both model systems eventually resulted in agglomerated powders of broad size distributions or particles that were large compared to the sizes of the reverse micelles, consistent with the notion that the microemulsions were not stable and the powders were precipitated in an uncontrolled fashion. This has implications for the synthesis of nanopowders by reverse micelle synthesis and provides a benchmark for process control if powders of the highest quality are desired. PMID:23906861

  17. Electrochemical removal of cadmium from bio-ash; Elektrokemisk fjernelse af cadmium fra bioasker

    Energy Technology Data Exchange (ETDEWEB)

    Juul Pedersen, Anne; Ottosen, Lisbeth M.; Simonsen, Peter; Christensen, Terkel C.

    2004-07-01

    The potential of using the method electrodialytic remediation for removal of cadmium from bioashes has been investigated. Five different types of fly ash from biomass combustion were included in the study: 1) A straw combustion fly ash from grate-firing at Avedoere power plant. 2) A fly ash from co-firing of wood and fuel oil at Avedoere power plant. 3) A suspended, grain size fractionated straw fly ash, obtained from PSO project FU 2201, fine and coarse size fraction. The ash was originally produced at Avedoere power plant. 4) A straw pellet fly ash from dust-firing at Amager power plant. Thr five ashes were characterised, and a series of preliminary elekctrodialytic remediation experiments were conducted on each ash. In spite a significant differences between the five ashes with respect to parameters such as pH and content of cadmium, all ashes showed promising remediation potential. For all ashes cadmium concentrations below the regulatory limits for recycling were reached in one or more of the preliminary remediation experiements. The best results were obtained with the suspended straw ash from PSO FU 2201, whereas the results with the wood chips ash, due to a high initial pH value, were less sucessful, meaning that the remediation process was progressing more slowly. (BA)

  18. Improved dissolution and micromeritic properties of naproxen from spherical agglomerates: preparation, in vitro and in vivo characterization

    Directory of Open Access Journals (Sweden)

    Damineni Saritha

    2012-12-01

    Full Text Available Naproxen, an anti-inflammatory drug, exhibits poor aqueous solubility, which limits the pharmacological effects. The present work was carried out to study the effect of agglomeration on micromeritic properties and dissolution. Naproxen agglomerates were prepared by using a three solvents system composed of acetone (good solvent, water (non-solvent and dichloromethane (bridging liquid. Differential Scanning Calorimetry (DSC results showed no change in the drug after crystallization process. X-Ray Powder Diffraction (XRPD studies showed the sharp peaks are present in the diffractograms of spherical agglomerates with minor reduction in height of the peaks. The residual solvents are largely below the tolerated limits in the agglomerates. Scanning Electronic Microscopy (SEM studies showed that agglomerates were spherical in structure and formed by cluster of small crystals. The agglomerates exhibited improved solubility, dissolution rate and micromeritic properties compared to pure drug. Anti-inflammatory studies were conducted in Wistar strain male albino rats and naproxen agglomerates showed more significant activity than the pure drug.Naproxeno, fármaco anti-inflamatório, apresenta baixa solubilidade em água, o que limita os efeitos farmacológicos. O presente trabalho foi realizado para estudar o efeito da aglomeração nas propriedades micromeríticas e na dissolução. Aglomerados de naproxeno foram preparados por meio da utilização de sistema de três solventes composto de acetona (bom solvente, água (não-solvente e diclorometano (líquido de ligação. A DSC não resulta mostrou nenhuma mudança na droga depois de processo de cristalização. Estudos de difração de Raios X do Pó (XRPD mostraram picos agudos nos difratogramas de aglomerados esféricos, com redução mínima dea altura dos picos. Os solventes residuais estão amplamente abaixo dos limites tolerados nos aglomerados. Os estudos de Microscopia Eletrônica de Varredura

  19. ASH and NASH.

    Science.gov (United States)

    Scaglioni, F; Ciccia, S; Marino, M; Bedogni, G; Bellentani, S

    2011-01-01

    Non-alcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) have a similar pathogenesis and histopathology but a different etiology and epidemiology. NASH and ASH are advanced stages of non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD). NAFLD is characterized by excessive fat accumulation in the liver (steatosis), without any other evident causes of chronic liver diseases (viral, autoimmune, genetic, etc.), and with an alcohol consumption ≤20-30 g/day. On the contrary, AFLD is defined as the presence of steatosis and alcohol consumption >20-30 g/day. The most common phenotypic manifestations of primary NAFLD/NASH are overweight/obesity, visceral adiposity, type 2 diabetes, hypertriglyceridemia and hypertension. The prevalence of NAFLD in the general population in Western countries is estimated to be 25-30%. The prevalence and incidence of NASH and ASH are not known because of the impossibility of performing liver biopsy in the general population. Up to 90% of alcoholics have fatty liver, and 5-15% of these subjects will develop cirrhosis over 20 years. The risk of cirrhosis increases to 30-40% in those who continue to drink alcohol. About 10-35% of alcoholics exhibit changes on liver biopsy consistent with alcoholic hepatitis. Natural histories of NASH and ASH are not completely defined, even if patients with NASH have a reduced life expectancy due to liver-related death and cardiovascular diseases. The best treatment of AFLD/ASH is to stop drinking, and the most effective first-line therapeutic option for NAFLD/NASH is non-pharmacologic lifestyle interventions through a multidisciplinary approach including weight loss, dietary changes, physical exercise, and cognitive-behavior therapy. PMID:21734385

  20. Bifurcation theory for hexagonal agglomeration in economic geography

    CERN Document Server

    Ikeda, Kiyohiro

    2014-01-01

    This book contributes to an understanding of how bifurcation theory adapts to the analysis of economic geography. It is easily accessible not only to mathematicians and economists, but also to upper-level undergraduate and graduate students who are interested in nonlinear mathematics. The self-organization of hexagonal agglomeration patterns of industrial regions was first predicted by the central place theory in economic geography based on investigations of southern Germany. The emergence of hexagonal agglomeration in economic geography models was envisaged by Krugman. In this book, after a brief introduction of central place theory and new economic geography, the missing link between them is discovered by elucidating the mechanism of the evolution of bifurcating hexagonal patterns. Pattern formation by such bifurcation is a well-studied topic in nonlinear mathematics, and group-theoretic bifurcation analysis is a well-developed theoretical tool. A finite hexagonal lattice is used to express uniformly distri...

  1. Experimental study of fluidized bed agglomeration of acerola powder

    Directory of Open Access Journals (Sweden)

    G. C. Dacanal

    2008-03-01

    Full Text Available The aim of this work was to study the main effects of acerola powder on fluidized bed agglomeration. A 2(4-1 fractional factoring design was used to evaluate the main operating conditions (fluidizing air temperature, fluidizing air velocity, atomizing air flow and height of nozzle in the bed. The mechanical and physicochemical product changes were determined by analysis of particle diameter, moisture content, wetting time and bed porosity. The particle enlargement by agglomeration occurred when the relative humidity in the bed increased and, thus, the moisture of the product increased. However, the excessive increase in relative humidity resulted in a decrease in yield, caused by caking and product incrustation. The consolidation of small granules resulted in an increase in the instant properties, decreasing the wetting time and increasing the solubility in a short period of agitation.

  2. Study on the Flow of Particle Agglomerates in Desulfurization Tower

    Directory of Open Access Journals (Sweden)

    Zheng Jian-Xiang

    2014-01-01

    Full Text Available In order to study the flow feature of particle agglomerates in a desulfurization tower, a three-dimensional numerical simulation of the gas-solid two phase flow in the tower is carried out by use of the LES model and the cohesive particles kinetics theory. Based on the experimental model of the internal circulation multistage spray desulfurization tower, the simulation successfully captures the key flow features in a desulfurization tower, find that: agglomerates forming a stable fluidization and stable internal circulation in the tower, present a typical ring-nuclear flow distribution trend. And the effects of the inlet gas velocity and inlet mass flux to the internal circulation are also analyzed.

  3. MGT 330 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    alfoniz

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 330 Week 1 Individual Assignment Functions of Management Paper (Ash) MGT 330 Week 1 DQ 1 (Ash) MGT 330 Week 1 DQ 2 (Ash) MGT 330 Week 1 DQ 3 (Ash) MGT 330 Week 1 Summary (Ash) MGT 330 Week 2 Team Assignment External Internal Factors Paper (Ash) MGT 330 Week 2 Individual Assignment Delegation (Ash) MGT 330 Week 2 Summary (Ash) MGT 330 Week 2 DQ 1 (Ash) MGT 330 Week 2 DQ 2 (Ash) MGT 330 W...

  4. Industry Relatedness, Agglomeration Externalities and Firm Survival in China

    OpenAIRE

    Canfei He; Qi Guo; David Rigby

    2015-01-01

    The importance of agglomeration externalities for economic activities is widely recognized. Recent developments highlight the importance of industry relatedness to the performance of firms, industries and regions. This study explores the determinants of firm survival in China and tests the significance of industry relatedness using firm-level data over the period 1999-2007. Industry relatedness is developed from the co-occurrence analysis of paired industries. Results based on Cox regression ...

  5. Acquisition of skills, education subsidies, and agglomeration of firms

    OpenAIRE

    Toulemonde, Eric

    2003-01-01

    An analytically solvable model of new economic geography is developed. Acquisition of skills is costly for workers but it allows them to earn wages that are larger than those of the unskilled. Moreover, skills acquisition can be subsidized by a regional government. For large transport costs, firms spread more or less evenly between regions, their precise location being determined by the level of education subsidies. For low transport costs, firms agglomerate in one region. We also identify eq...

  6. Spatial costs in a monocentric city (and implications for agglomeration)

    OpenAIRE

    Hugh B. Wenban-Smith

    2009-01-01

    Using water supply as a model for a wider range of infrastructure services, the effect of a negative exponential density gradient on distribution costs is investigated for four monocentric urban development scenarios: (a) Densification; (b) Dispersion; (c) Suburbanisation; and (d) Constant density. It is shown that economies of scale in production can be outweighed by diseconomies in distribution in cases (b) and (c), suggesting that the agglomeration benefits of infrastructure cannot be take...

  7. Reynolds number effects on particle agglomeration in turbulent channel flow

    OpenAIRE

    M Afkhami; A. Hassanpour; Fairweather, M.; Njobuenwu, DO

    2014-01-01

    The work described in this paper employs large eddy simulation and a discrete element method to study particle-laden flows, including particle dispersion and agglomeration, in a horizontal channel. The particle-particle interaction model is based on the Hertz- Mindlin approach with Johnson-Kendall-Roberts cohesion to allow the simulation of Van der Waals forces in a dry air flow. The influence of different flow Reynolds numbers, and therefore the impact of turbulence, on particle agglomeratio...

  8. Gas generation in incinerator ash; Gasbildning i aska

    Energy Technology Data Exchange (ETDEWEB)

    Arm, Maria; Lindeberg, Johanna; Rodin, Aasa; Oehrstroem, Anna; Backman, Rainer; Oehman, Marcus; Bostroem, Dan

    2006-02-15

    In recent years, explosions have occurred in certain phases of ash handling in Sweden. Investigations have revealed that hydrogen may have been present in all cases. The hydrogen is believed to be generated by chemical reactions of aluminium and other metals within the ash in the presence of water. The purpose with this study is to increase the knowledge of gas generation of incinerator ash. Thereby, guides for appropriate ash management can be introduced and the risk for further explosions prevented. The study has comprised analyses of the ash properties, such as chemical and physical composition and the pH, of ash from 14 incineration plants (mostly waste incineration plants). Different fractions of ash materials representing different parts of the process in each plant have been analysed. Furthermore, the fuel and the technical differences between the plants have been analysed. A tool for measuring the gas generation in the laboratory has been developed and the gas generation of the different ash materials at natural and increased pH was measured. Gas analyses and thermodynamic calculations have also been performed. The results showed that: bottom ash from fluidised bed boilers generated small amounts of gas at increased pH, much smaller amounts than the idle pass, cyclone and filter ash did, bottom ash from grate fired boilers generated more gas at increased pH than their cyclone ash and filter ash, with exception of the Linkoeping plant, all bio waste incineration plants generated ash with low gas generation potential, all fly ash materials with a gas generation potential of more than 10 l/kg originated from municipal waste incineration plants, filter ash that had been stored in oxygen rich environment generated significant less gas than fresh filter ash of the same origin, hardly any other gases were generated apart from hydrogen (very small amounts of acetone, furane, benzene and most likely methane were detected in some of the ash materials), there were no

  9. One-step aerosol synthesis of nanoparticle agglomerate films: simulation of film porosity and thickness

    Energy Technology Data Exchange (ETDEWEB)

    Maedler, Lutz; Lall, Anshuman A; Friedlander, Sheldon K [Nanoparticle Technology and Air Quality Laboratory, Department of Chemical and Biomolecular Engineering, University of California, Los Angeles (UCLA), 5531-G Boelter Hall, Los Angeles, CA 90095 (United States)

    2006-10-14

    A method is described for designing nanoparticle agglomerate films with desired film porosity and film thickness. Nanoparticle agglomerates generated in aerosol reactors can be directly deposited on substrates to form uniform porous films in one step, a significant advance over existing technologies. The effect of agglomerate morphology and deposition mechanism on film porosity and thickness are discussed. Film porosity was calculated for a given number and size of primary particles that compose the agglomerates, and fractal dimension. Agglomerate transport was described by the Langevin equation of motion. Deposition enhancing forces such as thermophoresis are incorporated in the model. The method was validated for single spherical particles using previous theoretical studies. An S-shape film porosity dependence on the particle Peclet number typical for spherical particles was also observed for agglomerates, but films formed from agglomerates had much higher porosities than films from spherical particles. Predicted film porosities compared well with measurements reported in the literature. Film porosities increased with the number of primary particles that compose an agglomerate and higher fractal dimension agglomerates resulted in denser films. Film thickness as a function of agglomerate deposition time was calculated from the agglomerate deposition flux in the presence of thermophoresis. The calculated film thickness was in good agreement with measured literature values. Thermophoresis can be used to reduce deposition time without affecting the film porosity.

  10. Pretreatment and utilization of waste incineration bottom ashes

    DEFF Research Database (Denmark)

    Astrup, Thomas

    2007-01-01

    Within recent years, researchers and authorities have had increasing focus on leaching properties from waste incineration bottom ashes. Researchers have investigated processes such as those related to carbonation, weathering, metal complexation, and leaching control. Most of these investigations......, however, have had a strong emphasis on lab experiments with little focus on full scale bottom ash upgrading methods. The introduction of regulatory limit values restricting leaching from utilized bottom ashes, has created a need for a better understanding of how lab scale experiences can be utilized...... in full scale bottom ash upgrading facilities, and the possibilities for complying with the regulatory limit values. A range of Danish research and development projects have within 1997-2005 investigated important techniques for bottom ash upgrading. The primary focus has been placed on curing...

  11. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Eric Suuberg; John Veranth; Xu Chen

    2003-05-20

    The overall objective of the present project is to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific research issues to be addressed include: (1) the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; (2) the effect of various low-NOx firing modes on ash properties and adsorptivity; and (3) the kinetics and mechanism of ash ozonation. This data will provide scientific and engineering support of the ongoing process development activities. During this fourth project period we completed the characterization of ozone-treated carbon surfaces and wrote a comprehensive report on the mechanism through which ozone suppresses the adsorption of concrete surfactants.

  12. Phenolic acids as bioindicators of fly ash deposit revegetation

    Energy Technology Data Exchange (ETDEWEB)

    L. Djurdjevic; M. Mitrovic; P. Pavlovic; G. Gajic; O. Kostic [Institute for Biological Research ' Sinisa Stankovic,' Belgrade (Serbia and Montenegro). Department of Ecology

    2006-05-15

    The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the 'Nikola Tesla-A' thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges. Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

  13. Fly ash: Perspective resource for geo-polymer materials production

    Science.gov (United States)

    Kargin, Aleksey; Baev, Vladimir; Mashkin, Nikolay; Uglyanica, Andrey

    2016-01-01

    The present paper presents the information about the chemical and mineralogical composition of the ash and slag and their amounts at the dumps of the thermoelectric plants located in the city of Kemerovo. It is known that about 85% of ash and slag from the thermoelectric plants in Russia are removed by means of the hydraulic sluicing systems and only about 15% - by the systems of pneumatic ash handling. Currently, however, the transition from the "wet" ash removal systems to the "dry" ones is outlined. This process is quite logical since the fly ash has the higher reactivity compared with the hydraulic sluicing ash and therefore it is of the great interest for recycling and use. On the other hand, the recent trend is the increased use of fly ash in the production of geo-polymers due to their availability, workability and the increased life of the final product. The analysis is carried out to check the possibility of using the fly ash from various Kemerovo thermoelectric plants as a raw material for the production of the alkali-activated binder.

  14. Washing of granulated solidification fly ash containing radioactive contaminants

    International Nuclear Information System (INIS)

    Incineration fly ash produced from city garbage, water-and-sewage sludge, and wastes generated by radioactive decontamination activities tends to have a high concentration of radioactive materials, and radioactive cesium in fly ash has high solubility in water. In order to advance the safe processing of incineration fly ash, it is necessary to have a technology for reducing the cesium in the fly ash. Washing the fly ash with water is an effective way of reducing the amount of radioactive cesium. Then, this study developed a new method for washing fly ash after granulated solidification. Laboratory tests showed that 70% or more of the radioactive cesium was removed by washing of the granulated solidification fly ash adjusted into 1-9.5 mm diameter particles under the following conditions: flow rate (SV) ≦ 10h-1 and flow volume ≧ 10 times of fly ash volume. Demonstration tests also confirmed the effectiveness of washing and the reduction of the volume of radioactive wastes. (author)

  15. Stabilization of Fly Ash Deposits through Selected Cereal Crops

    Directory of Open Access Journals (Sweden)

    Florica Morariu

    2012-10-01

    Full Text Available Fly ash, a waste product from burning coal in power plants, occupies important spaces and is a major harm forenvironment: water, air, soil and associated ecosystems. New deposits do not have available nutrients for plantgrowth. The study presents a process of stimulating growth of oats in deposits of fly ash, which eliminates listed.Phytostabilization of new deposit is fast after fertilization with sewage sludge-based compost in the presence/absence of native or modified volcanic tuff with grain species, Avena sativa L., and variety Lovrin 1. Experimentalstudies have shown the species adaptability to climatic conditions and a growth rate until the maturity correlated withtype of treatment of upper layers of fly ash deposit. Fly ash with sewage sludge compost treatment 50 t/hadetermined the growth with 75% of the amount of grains vs. the amount of grains harvested from untreated fly ash.Fly ash with sewage sludge compost mixed with modified indigenous volcanic tuff 2.5 t/ha treatment determined thegrowth with 80% vs. the amount of grains harvested from untreated fly ash. If oat straw harvested from fertilizedvariant without modified indigenous volcanic tuff increases in weight are 30% and for fertilized variant in thepresence of tuff increases in weight are 39.8% vs. quantities harvested from untreated fly ash.

  16. Investigation of the chemical composition of ash generated from Kosovo lignite and the possibility for biological land reclamation on ash dumps

    Energy Technology Data Exchange (ETDEWEB)

    Urosevic, D.; Filipovic, R. [Mining Institute Belgrade, Belgrade (Yugoslavia)

    1997-07-01

    This paper presents the results of investigation of the chemical composition and other properties of ash generated in the coal combustion process in the coal-fired power plants Kosovo, in order to determine the possibilities for biological land reclamation on ash dumps and other degraded soil surfaces. It was established that a certain chemical composition of ash has a beneficial effect on biological land reclamation of ash dumps, thus protecting the environment (i.e. the area surrounding the ash dumps), against pollution. It was concluded that, because of the high percentage of calcium and other earth-alkaline and toxic elements, the ash should not be used as substitution for agricultural production. Ash dumps in Kosovo are not so susceptible to erosion since CaO{sub 3} acts as a binding component. 22 refs., 7 tabs.

  17. MAT 221 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    mirat

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 221 Week 1 Assignment 1 Simplifying Expressions (Ash) MAT 221 Week 1 DQ 1 Evaluating Algebraic Expressions (Ash) MAT 221 Week 2 Assignment 2 Inequalities (Ash) MAT 221 Week 2 DQ 1 Formulas (Ash) MAT 221 Week 3 Assignment 3 Two-Variable Inequality (Ash) MAT 221 Week 3 DQ 1 Parallel and Perpendicular (Ash) MAT 221 Week 4 Assignment 4 Financial Polynomials (Ash) MAT 221 Week 4 DQ 1 Initial Investme...

  18. Potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment.

    Science.gov (United States)

    Havukainen, Jouni; Nguyen, Mai Thanh; Hermann, Ludwig; Horttanainen, Mika; Mikkilä, Mirja; Deviatkin, Ivan; Linnanen, Lassi

    2016-03-01

    All life forms require phosphorus (P), which has no substitute in food production. The risk of phosphorus loss from soil and limited P rock reserves has led to the development of recycling P from industrial residues. This study investigates the potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment (ASH DEC) in Finland. An ASH DEC plant could receive 46-76 kt/a of sewage sludge ash to produce 51-85 kt/a of a P-rich product with a P2O5 content of 13-18%, while 320-750 kt/a of manure ash could be supplied to produce 350-830 kt/a of a P-rich product with a P content of 4-5%. The P2O5 potential in the total P-rich product from the ASH DEC process using sewage sludge and manure ash is estimated to be 25-47 kt/a, which is significantly more than the P fertilizer demand in Finland's agricultural industries. The energy efficiency of integrated incineration and the ASH DEC process is more dependent on the total solid content and the subsequent need for mechanical dewatering and thermal drying than on the energy required by the ASH DEC process. According to the results of this study, the treated sewage sludge and manure ash using the ASH DEC process represent significant potential phosphorus sources for P fertilizer production. PMID:26810030

  19. Fluidized-Bed Coating with Sodium Sulfate and PVA-TiO2, 2. Influence of Coating Solution Viscosity, Stickiness, pH, and Droplet Diameter on Agglomeration

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, Poul; Jensen, Anker Degn

    2009-01-01

    the PVA-TiO2 coating formulation and process to achieve a low tendency of agglomeration, similar to that of the salt coating process. The best results for the PVA-TiO2 solution are obtained by substituting the PVA-TiO2 in equal amounts with Neodol 23-6.5 and further reducing the pH value in the coating......In the first part of this study [Hede, P. D.; Bach, P.; Jensen, A. D. Ind. Eng. Chem. Res. 2009, 49, 1914], agglomeration regime maps were developed for two types of coatings: sodium sulfate and PVA-TiO2. It was observed here how the agglomeration tendency is always lower for the salt coating...

  20. Remediation of a heavy metal-contaminated soil by means of agglomeration.

    Science.gov (United States)

    Polettini, Alessandra; Pomi, Raffaella; Valente, Mattia

    2004-01-01

    The feasibility of treating a heavy metal-contaminated soil by means of a solidification/stabilization treatment consisting of a granulation process is discussed in the present article. The aim of the study was to attain contaminant immobilization within the agglomerated solid matrix. The soil under concern was characterized by varying levels of heavy metal contamination, ranging from 50 to 500 mg kg(-1) dry soil for chromium. from 300 to 2000 mg kg(-1) dry soil for lead and from 270 to 5000 mg kg(-1) dry soil for copper. An artificially contaminated soil with contaminant concentrations corresponding to the upper level of the mentioned ranges was prepared from a sample of uncontaminated soil by means of spiking experiments. Pure soluble species of chromium, copper and lead. namely CrCl3.6H2O, CuCl2.2H2O and Pb(NO3)2, were selected for the spiking experiments, which were arranged according to a 2(3) full factorial design. The solidification/stabilization treatment was based on an agglomeration process making use of hydraulic binders including Portland cement, hydrated lime and sodium methasilicate, which were selected on the basis of preliminary test runs. It was found that after 7 days of curing the applied treatment was able to efficiently immobilize the investigated heavy metals within the hydrated matrix. Good acid neutralization behavior was also observed, indicating improved matrix resistance to acid attack and decreased potential for metal leaching. PMID:15137715

  1. Experimental and theoretical studies of agglomeration effects in multi-walled carbon nanotube-polycarbonate melts

    Directory of Open Access Journals (Sweden)

    2009-12-01

    Full Text Available In this study we report on morphological and rheological characterization of multi-walled carbon nanotube (MWNT-polycarbonate composites produced by injection molding. The main focus is to carry out nonlinear viscoelastic experiments that allow following the structural rearrangements of carbon nanotubes in the polycarbonate melt. Small angle X-ray scattering reveals only a slight orientation of MWNTs in the as-received samples, i.e. after application of extremely high shear rates. Thus, the main structural effect observed during the stress growth experiment is the breakage of MWNT agglomerates. To study this effect in detail a flocculation experiment, in which the sample undergoes oscillatory deformation first at a small strain amplitude in the linear regime succeeded by higher amplitudes in the nonlinear regime, has been carried out. The agglomeration process manifests itself in an increase of the storage and loss moduli in the linear regime, whereas the deagglomeration process does vice versa. The corresponding effects can be described in the frame of a superposition approach that takes into account the stress contribution of the polycarbonate matrix, the hydrodynamic reinforcement due to embedded nanotubes and the viscoelastic stress due to the presence of a MWNT-network.

  2. Volcanic ash melting under conditions relevant to ash turbine interactions

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B.

    2016-03-01

    The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines.

  3. Fly ash effects. II. The active effect of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Aiqin Wang; Chengzhi Zhang; Wei Suna [Southeast University, Nanjing (China). Department of Materials Science and Engineering

    2004-11-01

    This paper examines the method for determining the hydration degree of cement clinker and the pozzolanic reaction degree of fly ash in the system of cement and fly ash. In the base, the active effect of fly ash is studied. The studied results show that the active effect includes two aspects: (1) Fly ash has stronger pozzolanic activity and can react with Ca(OH)2, and (2) it can promote the hydration of cement. When the content of fly ash is less, its pozzolanic activity can exert well, but its promoting role to the hydration of cement is weaker. When the content of fly ash is more, it is less than its pozzolanic activity can be used, but its promoting role to the hydration of cement is stronger.

  4. Volcanic ash melting under conditions relevant to ash turbine interactions.

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B

    2016-03-02

    The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines.

  5. Volcanic ash melting under conditions relevant to ash turbine interactions.

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B

    2016-01-01

    The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines. PMID:26931824

  6. Ashes for organic farming

    OpenAIRE

    Kousa, T.; Heinonen, M; Suoniitty, T.; Peltonen, K

    2013-01-01

    Nowadays only eight percent of the cultivated field area is used for organic farming. The Ministry of Agriculture and Forestry has published the guidelines for the program of organic farming to diversify the supply and the consumption of organic food. The aim is to increase organically arable land to 20% by the year 2020.The demand of organic fertilizer products is strongly increasing. Interest in forestry by-products (ash, bark, zero fiber, etc.) for use in organic production has recently be...

  7. INF 325 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    SINDHU

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com INF 325 Week 1 DQ 1 Network Management (Ash) INF 325 Week 1 DQ 2 Ethernet Network (Ash) INF 325 Week 1 Commercial Internet Expansion (Ash) INF 325 Week 2 DQ 1 UTP Cord Problem (Ash) INF 325 Week 2 DQ 2 Managed Switches (Ash) INF 325 Week 2 Leased Lines (Ash) INF 325 Week 3 DQ 1 WPA (Ash) INF 325 Week 3 DQ 2 Remote Access Management (Ash) INF 325 Week 3 Mobile Service (Ash) INF 325 Week 4 DQ 1 Ro...

  8. INF 410 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    MADHURA

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     INF 410 Week 1 DQ 1 Project Life Cycle (Ash) INF 410 Week 1 DQ 2 The Importance of Project Management (Ash) INF 410 Week 1 Quiz (Ash) INF 410 Week 2 DQ 1 Project Charter (Ash) INF 410 Week 2 DQ 2 Project Management Plan (Ash) INF 410 Week 2 Quiz (Ash) INF 410 Week 3 DQ 1 Risk Identification (Ash) INF 410 Week 3 DQ 2 Triple Constraint (Ash) INF 410 Week 3 Quiz (Ash) INF 410 Week 4 DQ...

  9. Treating waste waters in small agglomerations. The current situation, commitments and alternatives; Depuracion de las aguas residuales en pequenos nuclear. Situacion actual, compromisos y alternativas

    Energy Technology Data Exchange (ETDEWEB)

    Collado Lara, R. [Universidad de Cantabria. (Spain)

    2003-07-01

    In 1991, the European Economic Community issued a directive on urban waste water treatment: (91/27/EEC). This directive laid down that such treatment had to be in place ny the period 2000-2005, depending on the application of different requirements according to the size of the agglomeration and the discharge area. A large number of sewage plants are being built in Spain at the present time, especially in medium-size and large agglomeration (pop>10.000 inhabitants). However, in the smaller agglomeration, over 50% of the waste waters have still to be treated. In agglomerations of less than 10.000 inhabitants, which make up 95% of the municipalities in Spain, it is possible to apply a greater diversity of treatments not all of them conventional that comply with the directive in question. Natural systems and biofilm processes are low-cost solutions that are well adapted to the natural environment. However, conventional technologies are virtually essential in medium-size and large agglomerations, as the lack of space and the exacting demands render them irreplaceable (Collado, 2002). This article describes the distribution of the municipalities in Spain according to the number of inhabitants, the current state os sewage treatment,the commitments made by the European Economic Community and the viable alternatives. Some comments have been added regarding the running of such systems and the need for them to be managed by associations of local councils or regional bodies. (Author)

  10. Supplying Fe from molten coal ash to revive kelp community

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, K.; Yamamoto, M.; Sadakata, M. [University of Tokyo, Tokyo (Japan)

    2006-02-15

    The phenomenon of a kelp-dominated community changing to a crust-dominated community, which is called 'barren-ground', is progressing in the world, and causing serious social problems in coastal areas. Among several suggested causes of 'barren-ground', we focused on the lack of Fe in seawater. Kelp needs more than 200 nM of Fe to keep its community. However there are the areas where the concentration of Fe is less than 1 nM, and the lack of Fe leads to the 'barren-ground.' Coal ash is one of the appropriate materials to compensate the lack of Fe for the kelp growth, because the coal ash is a waste from the coal combustion process and contains more than 5 wt% of Fe. The rate of Fe elution from coal fly ash to water can be increased by 20 times after melting in Ar atmosphere, because 39 wt% of the Fe(III) of coal fly ash was reduced to Fe(II). Additionally molten ash from the IGCC (integrated coal gasification combined cycle) furnace in a reducing atmosphere and one from a melting furnace pilot plant in an oxidizing atmosphere were examined. Each molten ash was classified into two groups; cooled rapidly with water and cooled slowly without water. The flux of Fe elution from rapidly cooled IGCC molten ash was the highest; 9.4 x 10{sup -6} g m{sup -2} d{sup -1}. It was noted that the coal ash melted in a reducing atmosphere could elute Fe effectively, and the dissolution of the molten ash itself controlled the rate of Fe elution in the case of rapidly cooled molten ash.

  11. Ash in the Soil System

    Science.gov (United States)

    Pereira, P.

    2012-04-01

    Ash is the organic and inorganic residue produced by combustion, under laboratory and field conditions. This definition is far away to be accepted. Some researchers consider ash only as the inorganic part, others include also the material not completely combusted as charcoal or biochar. There is a need to have a convergence about this question and define clear "what means ash". After the fire and after spread ash onto soil surface, soil properties can be substantially changed depending on ash properties, that can be different according to the burned residue (e.g wood, coal, solid waste, peppermill, animal residues), material treatment before burning, time of exposition and storage conditions. Ash produced in boilers is different from the produced in fires because of the material diferent propertie and burning conditions. In addition, the ash produced in boilers is frequently treated (e.g pelletization, granulation, self curing) previously to application, to reduce the negative effects on soil (e.g rapid increase of pH, mycorrhiza, fine roots of trees and microfauna). These treatments normally reduce the rate of nutrients dissolution. In fires this does not happen. Thus the implications on soil properties are logically different. Depending on the combustion temperature and/or severity, ash could have different physical (e.g texture, wettability) and chemical properties (e.g amount and type of total and leached nutrients) and this will have implications on soil. Ash can increase and decrease soil aggregation, wettablity and water retention, bulk density, runoff and water infiltration. Normally, ash increases soil pH, Electrical Conductivity, and the amount of some basic nutrients as calcium, magnesium, sodium and potassium. However it is also a potential source of heavy metals, especially if ash pH is low. However the effect of ash on soil in space and time depends especially of the ash amount and characteristics, fire temperature, severity, topography, aspect

  12. Intensity of Spherical Agglomerated Boron Particles%球形团聚硼颗粒的强度研究

    Institute of Scientific and Technical Information of China (English)

    庞维强; 樊学忠; 胥会祥; 李勇宏

    2009-01-01

    The amorphous boron powders were agglomerated to high-intensity spherical particles by means of mechanical mixing with hydroxyl terminated polybutadiene as raw materials and with acetic ether as solvent. The factors affecting the intensity of particles during the agglomerated process were analyzed. The optimal process conditions were obtained: the rotation speed is 90 r · min~(-1); the agglomerated process temperature is 30 ℃ ; the mass ratio of binder and amorphous boron powder is 10/90 and the mass content of solidification catalyst is 0. 02% ; the morphological structure of agglomerated boron particles prepared by the method is preferable and the intensity of particles is higher.%以端羟基聚丁二烯(HTPB)为原材料,乙酸乙酯为溶剂,采用机械搅拌方法对无定形硼粉进行团聚改性处理,对球形团聚硼颗粒制备过程中不同工艺条件下的颗粒强度的影响因素进行了研究,获得了强度较高的球形团聚硼颗粒,最佳工艺条件为: 搅拌速度为90 r·min~(-1),团聚工艺温度为30 ℃,黏结剂与硼粉的质量配比为10/90,固化催化剂的质量含量为0.02%,在此工艺条件下制备出的团聚硼颗粒形貌较好,颗粒强度较高.

  13. Experimental study on size-dependency of effective permittivity of particle-gas mixture with agglomeration

    Institute of Scientific and Technical Information of China (English)

    Li Xiaomin; Xu Lijun; Li Songyun

    2007-01-01

    The effective medium approximation (EMA) theory is the basis of a capacitance sensor used for concentration measurement of a particulate solid flow, its measurement result is independent on particle size. In existence of particle agglomeration or aggradation, however, it is found that the effective permittivity of a gas/solid mixture is dependent on particle size. In this paper, a parallel plate, differential capacitance sensor is utilized to investigate the influence of particle size on the effective permittivity of the mixture in such a case. Static experiments using three materials including glass, limestone and quartz particles were carried out in an off-line manner. The volume fraction of particles being tested ranged from 20×10-6 to 600×10-6, while the particle size was between 3 and 100 μm. Experimental results show that the effective permittivity of a particle-gas mixture with particle agglomeration is larger than that predicted by EMA and the smaller the particle size, the larger the effective permittivity. The experiment process and analysis results are discussed in detail in the paper.

  14. Study of thermal environment in Jingjintang urban agglomeration based on WRF model and Landsat data

    International Nuclear Information System (INIS)

    In recent decades, unprecedented urban expansion has taken place in developing countries resulting in the emergence of megacities or urban agglomeration. It has been highly concerned by many countries about a variety of urban environmental issues such as greenhouse gas emissions and urban heat island phenomenon associated with urbanization. Generally, thermal environment is monitored by remote sensing satellite data. This method is usually limited by weather and repeated cycle. Another approach is relied on numerical simulation based on models. In the study, these two means are combined to study the thermal environment of Jingjintang urban agglomeration. The high temperature processes of the study area in 2009 and 1990s are simulated by using WRF (the Weather Research and Forecasting Model) coupled with UCM (Urban Canopy Model) and the urban impervious surface estimated from Landsat-5 TM data using support vector machine. Results show that the trend of simulated air temperature (2 meter) is in accord with observed air temperature. Moreover, it indicates the differences of air temperature and Land Surface Temperature caused by the urbanization efficiently. The UHI effect at night is stronger than that in the day. The maximum difference of LST reaches to 8–10°C for new build-up area at night. The method provided in this research can be used to analyze impacts on urban thermal environment caused by urbanization and it also provides means on thermal environment monitoring and prediction which will benefit the coping capacity of extreme event

  15. CO2 capture using fly ash from coal fired power plant and applications of CO2-captured fly ash as a mineral admixture for concrete.

    Science.gov (United States)

    Siriruang, Chaichan; Toochinda, Pisanu; Julnipitawong, Parnthep; Tangtermsirikul, Somnuk

    2016-04-01

    The utilization of fly ash as a solid sorbent material for CO2 capture via surface adsorption and carbonation reaction was evaluated as an economically feasible CO2 reduction technique. The results show that fly ash from a coal fired power plant can capture CO2 up to 304.7 μmol/g fly ash, consisting of 2.9 and 301.8 μmol/g fly ash via adsorption and carbonation, respectively. The CO2 adsorption conditions (temperature, pressure, and moisture) can affect CO2 capture performance of fly ash. The carbonation of CO2 with free CaO in fly ashes was evaluated and the results indicated that the reaction consumed most of free CaO in fly ash. The fly ashes after CO2 capture were further used for application as a mineral admixture for concrete. Properties such as water requirement, compressive strength, autoclave expansion, and carbonation depth of mortar and paste specimens using fly ash before and after CO2 capture were tested and compared with material standards. The results show that the expansion of mortar specimens using fly ash after CO2 capture was greatly reduced due to the reduction of free CaO content in the fly ash compared to the expansion of specimens using fresh fly ash. There were no significant differences in the water requirement and compressive strength of specimens using fly ash, before and after CO2 capture process. The results from this study can lead to an alternative CO2 capture technique with doubtless utilization of fly ash after CO2 capture as a mineral admixture for concrete. PMID:26803257

  16. CO2 capture using fly ash from coal fired power plant and applications of CO2-captured fly ash as a mineral admixture for concrete.

    Science.gov (United States)

    Siriruang, Chaichan; Toochinda, Pisanu; Julnipitawong, Parnthep; Tangtermsirikul, Somnuk

    2016-04-01

    The utilization of fly ash as a solid sorbent material for CO2 capture via surface adsorption and carbonation reaction was evaluated as an economically feasible CO2 reduction technique. The results show that fly ash from a coal fired power plant can capture CO2 up to 304.7 μmol/g fly ash, consisting of 2.9 and 301.8 μmol/g fly ash via adsorption and carbonation, respectively. The CO2 adsorption conditions (temperature, pressure, and moisture) can affect CO2 capture performance of fly ash. The carbonation of CO2 with free CaO in fly ashes was evaluated and the results indicated that the reaction consumed most of free CaO in fly ash. The fly ashes after CO2 capture were further used for application as a mineral admixture for concrete. Properties such as water requirement, compressive strength, autoclave expansion, and carbonation depth of mortar and paste specimens using fly ash before and after CO2 capture were tested and compared with material standards. The results show that the expansion of mortar specimens using fly ash after CO2 capture was greatly reduced due to the reduction of free CaO content in the fly ash compared to the expansion of specimens using fresh fly ash. There were no significant differences in the water requirement and compressive strength of specimens using fly ash, before and after CO2 capture process. The results from this study can lead to an alternative CO2 capture technique with doubtless utilization of fly ash after CO2 capture as a mineral admixture for concrete.

  17. Field observations of artificial sand and oil agglomerates

    Science.gov (United States)

    Dalyander, Patricia (Soupy); Long, Joseph W.; Plant, Nathaniel G.; McLaughlin, Molly R.; Mickey, Rangley C.

    2015-01-01

    Oil that comes into the surf zone following spills, such as occurred during the 2010 Deepwater Horizon (DWH) blowout, can mix with local sediment to form heavier-than-water sand and oil agglomerates (SOAs), at times in the form of mats a few centimeters thick and tens of meters long. Smaller agglomerates that form in situ or pieces that break off of larger mats, sometimes referred to as surface residual balls (SRBs), range in size from sand-sized grains to patty-shaped pieces several centimeters (cm) in diameter. These mobile SOAs can cause beach oiling for extended periods following the spill, on the scale of years as in the case of DWH. Limited research, including a prior effort by the U.S. Geological Survey (USGS) investigating SOA mobility, alongshore transport, and seafloor interaction using numerical model output, focused on the physical dynamics of SOAs. To address this data gap, we constructed artificial sand and oil agglomerates (aSOAs) with sand and paraffin wax to mimic the size and density of genuine SOAs. These aSOAs were deployed in the nearshore off the coast of St. Petersburg, Florida, during a field experiment to investigate their movement and seafloor interaction. This report presents the methodology for constructing aSOAs and describes the field experiment. Data acquired during the field campaign, including videos and images of aSOA movement in the nearshore (1.5-meter and 0.5-meter water depth) and in the swash zone, are also presented in this report.

  18. 公路粉煤灰水泥水化过程的研究%Studies on Hydrated Process of High Road Fly Ash Cement

    Institute of Scientific and Technical Information of China (English)

    付兴华; 孙景旭; 董友军; 文福民

    2001-01-01

    The hydrated products and pore size distribution of high road fly ash cements were studied by means of XRD,DTA,Mercury porosimeter,etc.,The experiment results showed that C-S-H gel,AFt were the main hydrated products in high road fly ash cement,but the contents of Ca(OH)2 were lower.The exothermic peaks of the formation of AFt and AFm appeared in hydrated exotermic curves of this cements,while the peaks of C-H-S gel and Ca(OH)2 were not.Although the total porosity of this cement stone were higher,the volume porosity of large pores which sizes were more than 1000A。 were lower after 7 days,the micropores and gel pores which size were little than 500A。 were higher.Thus,the cement stone was fine and close in texture,properties were also higher in late ages.%采用X-射线衍射、差热分析、微量热计及压汞测孔仪对公路粉煤灰水泥的水化产物、水化放热曲线、孔尺寸分布进行了研究。实验结果表明,公路粉煤灰水泥的主要水化产物是C-S-H凝胶、AFt及少量的Ca(OH)2。在该水泥的1天水化放热曲线上仅出现了AFt及AFm的形成放热峰,未出现C-S-H凝胶及Ca(OH)2的快速形成放热峰。尽管该水泥的空隙率较高,但水化7天以后大于1000A。的连通大孔体积率较低,而小于500A。的微孔及凝胶孔体积率较高,因此水泥石的结构致密,后期性能较好。

  19. Dielectric properties of fly ash

    Indian Academy of Sciences (India)

    S C Raghavendra; R L Raibagkar; A B Kulkarni

    2002-02-01

    This paper reports the dielectric properties of fly ash. The dielectric measurements were performed as a function of frequency and temperature. The sample of fly ash shows almost similar behaviour in the frequency and temperature range studied. The large value of dielectric constant in the typical frequency range is because of orientation polarization and tight binding force between the ions or atoms in the fly ash. The sample of fly ash is of great scientific and technological interest because of its high value of dielectric constant (104).

  20. Diamond-like-carbon nanoparticle production and agglomeration following UV multi-photon excitation of static naphthalene/helium gas mixtures

    Science.gov (United States)

    Walsh, A. J.; Tielens, A. G. G. M.; Ruth, A. A.

    2016-07-01

    We report the formation of nanoparticles with significant diamond character after UV multi-photon laser excitation of gaseous naphthalene, buffered in static helium gas, at room temperature. The nanoparticles are identified in situ by their absorption and scattering spectra between 400 and 850 nm, which are modeled using Mie theory. Comparisons of the particles' spectroscopic and optical properties with those of carbonaceous materials indicate a sp3/sp2 hybridization ratio of 8:1 of the particles formed. The particle extinction in the closed static (unstirred) gas-phase system exhibits a complex and quasi-oscillatory time dependence for the duration of up to several hours with periods ranging from seconds to many minutes. The extinction dynamics of the system is based on a combination of transport features and particle interaction, predominantly agglomeration. The relatively long period of agglomeration allows for a unique analysis of the agglomeration process of diamond-like carbon nanoparticles in situ.

  1. Magmatic and fragmentation controls on volcanic ash surface chemistry

    Science.gov (United States)

    Ayris, Paul M.; Diplas, Spyros; Damby, David E.; Hornby, Adrian J.; Cimarelli, Corrado; Delmelle, Pierre; Scheu, Bettina; Dingwell, Donald B.

    2016-04-01

    The chemical effects of silicate ash ejected by explosive volcanic eruptions on environmental systems are fundamentally mediated by ash particle surfaces. Ash surfaces are a composite product of magmatic properties and fragmentation mechanisms, as well as in-plume and atmospheric alteration processes acting upon those surfaces during and after the eruption. Recent attention has focused on the capacity of alteration processes to shape ash surfaces; most notably, several studies have utilised X-ray photoelectron spectroscopy (XPS), a technique probing the elemental composition and coordination state of atoms within the top 10 nm of ash surfaces, to identify patterns of elemental depletions and enrichments relative to bulk ash chemical composition. Under the presumption of surface and bulk equivalence, any disparities have been previously attributed to surface alteration processes, but the ubiquity of some depletions (e.g., Ca, Fe) across multiple ash studies, irrespective of eruptive origin, could suggest these to be features of the surface produced at the instant of magma fragmentation. To investigate this possibility further, we conducted rapid decompression experiments at different pressure conditions and at ambient and magmatic temperature on porous andesitic rocks. These experiments produced fragmented ash material untouched by secondary alteration, which were compared to particles produced by crushing of large clasts from the same experiments. We investigated a restricted size fraction (63-90 μm) from both fragmented and crushed materials, determining bulk chemistry and mineralogy via XRF, SEM-BSE and EPMA, and investigated the chemical composition of the ash surface by XPS. Analyses suggest that fragmentation under experimental conditions partitioned a greater fraction of plagioclase-rich particles into the selected size fraction, relative to particles produced by crushing. Trends in surface chemical composition in fragmented and crushed particles mirror that

  2. Carbonatation Influence on Fly Ash and Portland Cement Mortars

    OpenAIRE

    P.L. Valdez–Tamez; A. Durán–Herrera; G. Fajardo–San Miguel; C.A. Juárez–Alvarado

    2009-01-01

    The influence of carbonation on mortars containing 25% of fly ash instead of the cementitious materials was studied. Mortar cylinder specimens were fabricated for 4 different W/C ratios: 0.35, 0.45, 0.55 and 0.65. Mortars with and without fly ash were subjected to an accelerated carbonation process. Volumetric weight, water absorption, compressive strength, water permeability, pH and mercury intrusion porosimetry of the mortar specimens were determined. Due to the fly ash pozzolanic potential...

  3. [Study on mercury re-emissions during fly ash utilization].

    Science.gov (United States)

    Meng, Yang; Wang, Shu-Xiao

    2012-09-01

    The amount of fly ash produced during coal combustion is around 400 million tons per year in China. About 65%-68% of fly ash is used in building material production, road construction, architecture and agriculture. Some of these utilization processes include high temperature procedures, which may lead to mercury re-emissions. In this study, experiments were designed to simulate the key process in cement production and steam-cured brick production. A temperature programmed desorption (TPD) method was used to study the mercury transformation in the major utilization processes. Mercury re-emission during the fly ash utilization in China was estimated based on the experimental results. It was found that mercury existed as HgCl2 (Hg2 Cl2), HgS and HgO in the fly ash. During the cement production process, more than 98% of the mercury in fly ash was re-emitted. In the steam-curing brick manufacturing process, the average mercury re-emission percentage was about 28%, which was dominated by the percentage of HgCl2 (Hg2 Cl2). It is estimated that the mercury re-emission during the fly ash utilization have increased from 4.07 t in 2002 to 9.18 t in 2008, of which cement industry contributes about 96.6%. PMID:23243850

  4. Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products

    Directory of Open Access Journals (Sweden)

    Philip Van den Heede

    2015-12-01

    Full Text Available Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25 could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete’s water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction.

  5. 氨—碳铵法浸出含锌烟灰%Leaching of Zinc-bearing Ash with Ammonia-ammonium Bicarbonate Process

    Institute of Scientific and Technical Information of China (English)

    陈启元; 王树宾; 胡慧萍; 王为振

    2012-01-01

    研究氨—碳铵体系中pH、总氨浓度、液固比(L/S)、反应温度、反应时间等因素对三种含锌烟灰中锌和主要杂质元素浸出行为的影响.结果表明,较佳的工艺条件是:浸出剂总氨浓度9 mol/L、pH=10.00、L/S=5、反应温度50℃、反应时间60 min.此时锌浸出率大于80%.%The effects of pH, total ammonia concentration of ammonia-ammonium bicarbonate system, ratio of solid to liquid (L/S) , temperature and leaching time on the leaching behavior of zinc and main impurities in three kinds of zinc-bearing ash were investigated. The results show that the zinc leaching rate is over 80% under the optimum conditions including total ammonia concentration of 9 mol/L and pH of 10.00, L/S of 5, temperature of 50 ℃ , and the leaching time of 60 min.

  6. Influence of Bed Ash and Fly Ash Replacement in Mortars

    Directory of Open Access Journals (Sweden)

    S. L. Summoogum-Utchanah

    2015-03-01

    Full Text Available The study evaluates the influence of fly ash and bottom ash as partial cement substitutes in mortars by studying the particle size distribution, consistency, flow, fresh density, air content, compressive strength and flexural strength characteristics. The results revealed that fly ash and cement had relatively the same particle size distribution unlike bottom ash. In the fresh state, as the amount of pozzolans increased in the mixtures, the mortars showed an enhancement in workability, were susceptible to water loss by bleeding, and exhibited a decline in fresh density. The early strength gains of the fly ash samples were low but reached higher than the control after 28 days of curing. The flexural strength increased as the fly ash content rose to reach a maximum at 20 % replacement. However, the 2-day compressive strength of bottom ash samples was higher than the control but decreased after 28 days of curing while the flexural strength declined with addition of bottom ash except at 5 % substitution.

  7. Study of Commercial Wheat Flour Milling Process:Relation of Flour Yield,Ash and Protein Contents of Flour Mill and Characteristics of Wheat Blend%Study of Commercial Wheat Flour Milling Process: Relation of Flour Yield, Ash and Protein Contents of Flour Mill and Characteristics of Wheat Blend

    Institute of Scientific and Technical Information of China (English)

    Y S Kim; C W Deyoe; O K Chung; E Haque

    2006-01-01

    The profit margin in the flour milling industry is quite narrow, so high-quality raw materials and efficiency of milling operations are crucial for every company. Many flour mills, especially those which import wheat from other countries and have limited storage space for the different varieties or classes of wheat, can not afford to buy low quality wheat. Consequently, a mathematical model which can test the impact and interactions of raw materials, in technical point of view, would be a useful decision-making tool for the milling industry. A flour miller tests wheat for physical and chemical characteristics, cleanness and soundness. The miller also performs experimental milling, if available, to have some idea how the given wheat will behave during commercial milling. Based on these test results, the miller can only guess the commercial milling results such as flour yields and flour ash and protein contents. Thus, the objective of this study was to develop empirical equations to estimate commercial milling results, using the physical, chemical and experimental milling data of the given wheat blend and also, additionally, flour ash and protein specifications of the end-user. This was done by using the actual commercial milling procedures and their wheat physical, chemical, experimental milling data, and other vital data. Data were collected from a commercial mill located in East Asia that had four production lines and used wheat blend combinations from five different wheat classes, i.e. Hard Red Winter (HRW),Dark Northern Spring (DNS), Soft White (SW), Australian Soft (AS), and Australian Standard White (ASW) wheat to produce over 40 different products. The wheat physical and chemical characteristics included test weight, thousand kernel weight, ash and protein contents. The experimental milling data were straight-grade and patent flour yields, along with patent flour ash and protein contents from a Buhler experimental mill. The commercial milling results included

  8. Large Agglomerations and Economic Growth in Urban India: An Application of Panel Data Model

    OpenAIRE

    Tripathi, Sabyasachi

    2012-01-01

    This paper investigates the impact of urban agglomeration on urban economic growth, using static and dynamic panel data approach, based on data of 52 large cities in India for the period 2000 to 2009. The results shows that agglomeration has a strong positive effect on urban economic growth and support the “Williamson hypothesis” that agglomeration increases economic growth only up to certain level of economic development. The critical level per-capita city income is estimated about Rs. 37049...

  9. Mathematical modeling of pigment dispersion taking into account the full agglomerate particle size distribution

    DEFF Research Database (Denmark)

    Kiil, Søren

    2016-01-01

    The purpose of this work is to develop a mathematical model that can quantify the dispersion of pigments, with a focus on the mechanical breakage of pigment agglomerates. The underlying physical mechanism was assumed to be surface erosion of spherical pigment agglomerates. The full agglomerate pa.......g., in the development of novel dispersion principles and for analysis of dispersion failures. The general applicability of the model, beyond the three pigments considered, needs to be confirmed....

  10. The adsorption of HCl on volcanic ash

    Science.gov (United States)

    Gutiérrez, Xochilt; Schiavi, Federica; Keppler, Hans

    2016-03-01

    Understanding the interaction between volcanic gases and ash is important to derive gas compositions from ash leachates and to constrain the environmental impact of eruptions. Volcanic HCl could potentially damage the ozone layer, but it is unclear what fraction of HCl actually reaches the stratosphere. The adsorption of HCl on volcanic ash was therefore studied from -76 to +150 °C to simulate the behavior of HCl in the dilute parts of a volcanic plume. Finely ground synthetic glasses of andesitic, dacitic, and rhyolitic composition as well as a natural obsidian from Vulcano (Italy) served as proxies for fresh natural ash. HCl adsorption is an irreversible process and appears to increase with the total alkali content of the glass. Adsorption kinetics follow a first order law with rate constants of 2.13 ṡ10-6 s-1 to 1.80 ṡ10-4 s-1 in the temperature range investigated. For dacitic composition, the temperature and pressure dependence of adsorption can be described by the equation ln ⁡ c = 1.26 + 0.27 ln ⁡ p - 715.3 / T, where c is the surface concentration of adsorbed HCl in mg/m2, T is temperature in Kelvin, and p is the partial pressure of HCl in mbar. A comparison of this model with a large data set for the composition of volcanic ash suggests that adsorption of HCl from the gas phase at relatively low temperatures can quantitatively account for the majority of the observed Cl concentrations. The model implies that adsorption of HCl on ash increases with temperature, probably because of the increasing number of accessible adsorption sites. This temperature dependence is opposite to that observed for SO2, so that HCl and SO2 are fractionated by the adsorption process and the fractionation factor changes by four orders of magnitude over a temperature range of 250 K. The assumption of equal adsorption of different species is therefore not appropriate for deriving volcanic gas compositions from analyses of adsorbates on ash. However, with the experimental

  11. Utilization of washed MSWI fly ash as partial cement substitute with the addition of dithiocarbamic chelate.

    Science.gov (United States)

    Gao, Xingbao; Wang, Wei; Ye, Tunmin; Wang, Feng; Lan, Yuxin

    2008-07-01

    The management of the big amount of fly ash as hazardous waste from the municipal solid waste incinerator (MSWI) has encountered many problems in China. In this study, a feasibility research on MSWI fly ash utilization as partial cement substitute in cement mortars was therefore carried out. MSWI fly ash was subjected to washing process to reduce its chlorine content (from 10.16% to 1.28%). Consequently, it was used in cement mortars. Ten percent and 20% replacement of cement by washed ash showed acceptable strength properties. In TCLP and 180-day monolithic tests, the mortars with washed ash presented a little stronger heavy metal leachability, but this fell to the blank level (mortar without washed ash) with the addition of 0.25% chelate. Therefore, this method is proposed as an environment-friendly technology to achieve a satisfactory solution for MSWI fly ash management.

  12. Analysis of the fly ash from the processing of wood chips in a pilot-scale downdraft gasifier: Comparison of inorganic constituents determined by PIXE and ICP-AES

    International Nuclear Information System (INIS)

    Gasification of biomass ultimately generates at least one solid byproduct in which the inorganic constituents of the biomass are concentrated. Given the potential for utilization, or issues with disposal, facile methods are needed for determining the compositions of the fly ashes from recently-available gasifier-based bioenergy systems. Proton induced x-ray emission spectroscopy (PIXE) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) were used to characterize the fly ash recovered from a pilot-scale (25 kW) modular bioenergy system operated with wood chips as the feedstock. The composition of the fly ash from the downdraft gasifier showed some similarities to compositions reported for boiler wood ashes, apart from one half of the material being unburned carbon. Although ICP-AES showed greater sensitivity for the analysis of the fly ash, especially for small amounts of heavy metal contaminants, PIXE proved to be a powerful analytical tool for screening of elements from sodium to uranium. Such broad spectrum screenings could prevent the inadvertent land application of unsuspected pollutant elements. Fly ashes from biomass gasification appear to be suitable for use as ash-based fertilizers for forest lands; however, combustion to remove unburned carbon may be advisable. -- Highlights: ► Fly ash composition data for commercial modular bioenergy systems are now reported. ► PIXE analysis better suited for analysis of fly ashes rich in silicates. Fly ashes generated by biomass gasification may be suitable for land application. ► Combustion of biomass-derived fly ashes is recommended before use as soil amendments

  13. BUS 611 Ash course tutorial / uophelp

    OpenAIRE

    uophelp

    2015-01-01

    For more course tutorials visit www.uophelp.com   BUS 611 Week 1 Assignment Article Review (Ash Course) BUS 611 Week 2 Assignment Project Risk (Ash Course) BUS 611 Week 3 Assignment WBS (Ash Course) BUS 611 Week 4 Assignment Integrated Project Management Tools (Ash Course) BUS 611 Week 5 Assignment Monthly Status Reports (Ash Course) BUS 611 Week 6 Final Research Paper (Ash Course)  

  14. Measurement of natural activity in peat ashes

    International Nuclear Information System (INIS)

    High proportions of radioactive materials in peat ashes may involve radiation hazards during handling and deposition of these waste materials. Measurements have been performed to determine the content of radioactive materials in ashes from peat burning. The activities in fly ash and ''solid'' ash in seven peat-fired power plants in Sweden are presented. The methods of analysing and measuring peat ashes for activity from different radionuclides are described. The activity levels in ash samples are given

  15. PURIFICATION AND ENRICHMENT OF BIOGAS IN ASH-WATER MIXTURE

    Directory of Open Access Journals (Sweden)

    Andrzej Brudniak

    2014-10-01

    Full Text Available Biogas, produced in an aerobic digestion process, is a mixture of gases, and that is why its inexpensive and effective valorisation is essential. Research on this process is necessary in order to use biogas as a renewable energy source. The aim of this thesis is to present methods of biogas purification and enrichment in the fly ash - water mixture, that is generated on the base of fly ash produced during burning coal in power industry. Experience presented that the fly ash absorbs CO2 and H2S, even in conventional conditions. The absorption efficiency depends not only on the chemical composition of the ash but also on its physical properties. There was also a strong neutralization of alkaline waste combustion.

  16. Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash

    Directory of Open Access Journals (Sweden)

    Martin Ernesto Kalaw

    2016-07-01

    Full Text Available Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC, which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1 their technical properties are comparable if not better; (2 they can be produced from industrial wastes; and (3 within reasonable constraints, their production requires less energy and emits significantly less CO2. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA and coal bottom ash (CBA, and rice hull ash (RHA. The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF for elemental and X-ray diffraction (XRD for mineralogical composition. The raw materials’ thermal stability and loss on ignition (LOI were determined using thermogravimetric analysis (TGA and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR

  17. Prevention of Bed Agglomeration Problems in a Fluidized Bed Boiler by Finding the Trigging Value of Sewage Sludge Dosage Added to Combustion of Biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Kajsa; Gervind, Pernilla

    2009-07-01

    Agglomeration of bed sand is a common problem during combustion of biofuels with high ash content in fluidized bed boilers. Former studies have shown that co-combustion of biofuels with sewage sludge increases the agglomeration temperature. Sewage sludge has a low heating value and high ash content. It would therefore be better to use sludge as an additive to the combustion than as a co-combusted biofuel. In this study the trigging value of sludge addition to the combustion of some biofuel was investigated. The effect of adding sludge with different precipitation chemicals, iron sulphate and aluminium sulphate, was investigated. The biofuels used for the experiments were bark, refused derived fuel (RDF) and a mixture of wood and straw, 75/25 % on energy basis. All experiments were carried out in a laboratory scale fluidized bed reactor. Analyses of chemical composition of bed sand and SEM/EDX analyses were performed after the combustion. Eventually agglomeration tests were performed in order to find the agglomeration temperature of the samples. Some of the samples sintered during the combustion and were not tested for the agglomeration temperature. SEM/EDX showed that all samples of bed sand contained sand particles with more or less coatings. In some cases the coatings seemed to consist of one dense inner layer and one more porous outer layer. From SEM/EDX and chemical composition analyses it was found that the total amount of phosphorous in the bed sand samples was increased with an increased addition of sludge in all experiments. The concentration of phosphorous was especially higher in the outer layers/coatings. It was also found that elements from the sludge seem to get caught by a sticky layer at the bed sand surface and form a non-sticky or less sticky layer that prevents agglomeration. The total amount of aluminium was increased with an increased addition of sludge for the wood/straw samples, while it increased with an increased amount of combusted fuel for

  18. Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions.

    Science.gov (United States)

    Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

    2016-12-01

    We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

  19. Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions

    Science.gov (United States)

    Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

    2016-08-01

    We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

  20. Carbonatation Influence on Fly Ash and Portland Cement Mortars

    Directory of Open Access Journals (Sweden)

    P.L. Valdez–Tamez

    2009-01-01

    Full Text Available The influence of carbonation on mortars containing 25% of fly ash instead of the cementitious materials was studied. Mortar cylinder specimens were fabricated for 4 different W/C ratios: 0.35, 0.45, 0.55 and 0.65. Mortars with and without fly ash were subjected to an accelerated carbonation process. Volumetric weight, water absorption, compressive strength, water permeability, pH and mercury intrusion porosimetry of the mortar specimens were determined. Due to the fly ash pozzolanic potential, for all W/C ratios, results of the compressive strength tests at 28 days of the mortars with and without fly ash were similar. Mortars with fly ash presented similar water permeability as mortars without fly ash. PH results showed that alkalinity reduction is lower in mortars with fly ash compared to those containing cement only. In all the mortars, the porosimetric analysis indicated that porosity is reduced due to carbonation. Further more, it is showed the predominance of the macro and mesopores.

  1. Effects of temperature and initial molar ratio of Na2O to Al2O3 on agglomeration of fine AI(OH)3 seed in synthetic Bayer solution

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fine AI(OH)3 crystals were aggregated from supersaturated aluminate solution in the batch reaction tanks.By means of laser particle size analyzer and scanning electron microscopy,the influences of temperature and initial molar ratio of Na2O to A12O3 (αK) on agglomeration of fine seed in Bayer process were investigated.The results show that agglomeration is almost finished in 8 h,and seeds with size less than 2 μm are easily aggregated together,and almost disappear in 8 h under the optimal process conditions.In the aluminate solution with the same moderate initial αK,when the reaction temperature reaches 75 ℃,the secondary nucleation does not occur,and the effect of agglomeration is better.And at the same reaction temperature,when the initial αK is 1.62,the initial supersaturation of aluminate solution is moderate,the binders on the surfaces of the seed are enough to maintain the agglomeration process,and the agglomeration degree is better.From SEM images,agglomeration mainly occurs in the fine particles,the combinations among the fine particles are loose and the new formed coarse crystal shapes are irregular.

  2. Numerical derivation of forces on particles and agglomerates in a resonant acoustic field

    Science.gov (United States)

    Knoop, Claas; Fritsching, Udo

    2013-10-01

    Particles and agglomerates are investigated in gaseous acoustic flow fields. Acoustic fields exert forces on solid objects, which can influence the shape of the exposed bodies, even to the point of breakage of the structures. Motivated by experimentally observed breakage of agglomerates in an acoustic levitator (f = 20 kHz), a numerical study is presented that derives the acoustic forces on a complex model agglomerate from the pressure and velocity fields of a resonant standing ultrasound wave, calculated by computational fluid dynamics (CFD). It is distinguished between the drag and lift/lateral forces on the overall agglomerate and on the different primary particles of the model.

  3. ECO 316(ASH) course tutorial/tutorialoutlet

    OpenAIRE

    naresh 1

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   ECO 316 Week 1 DQ 1 Should You Invest Short Term (Ash) ECO 316 Week 1 DQ 2 Treasury Inflation Protection Bonds (Ash) ECO 316 Week 1 Quiz (Chapter 1-6) (Ash) ECO 316 Week 2 DQ 1 New Product, Will I Be Rich (Ash) ECO 316 Week 2 DQ 2 Mutual Fund Regulation (Ash) ECO 316 Week 2 Quiz (Chapter 7-12) (Ash) ECO 316 Week 3 DQ 1 Exchange Rate Risk (Ash) ECO 316 Week 3 DQ 2 Should I Expect a Bail Out (Ash) ...

  4. CRJ 303 ASH course tutorial/tutorialoutlet

    OpenAIRE

    naresh 1

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   Product Description CRJ 303 Week 1 DQ 1 Goals of Sentencing (Ash) CRJ 303 Week 1 DQ 2 Sentencing Techniques (Ash) CRJ 303 Week 2 DQ 1 Punishment (Ash) CRJ 303 Week 2 DQ 2 Privatizing Prisons (Ash) CRJ 303 Week 2 Assignment Jails vs. Prisons (Ash) CRJ 303 Wee 3 DQ 1 Probation and Parole (Ash) CRJ 303 Week 3 DQ 2 Civil Commitments (Ash) CRJ 303 Week 3 Assignment Juvenile Detainees (Ash) CRJ 303...

  5. PSY 496 ASH Tutorial Course / Uoptutorial

    OpenAIRE

    John Allen

    2015-01-01

    PSY 496 Week 1 Assignment Foundations for the Final Paper (Ash) PSY 496 Week 2 Assignment Finalized Resources and Revisions for the Final Paper (Ash) PSY 496 Week 1 DQ 1 Approaches to Research (Ash) PSY 496 Week 1 DQ 2 Measuring Change (Ash) PSY 496 Week 2 DQ 1 Protecting Participants from Harm (Ash) PSY 496 Week 2 DQ 2 Areas of Competence (Ash) PSY 496 Week 2 Journal Ethics in Research and Practice (Ash) PSY 496 Week 3 Assignment Final Paper Draft (Ash) PSY 49...

  6. HIS 103 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HIS 103 Week 1 DQ 1 (Transition to Agriculture) (Ash) HIS 103 Week 1 DQ 2 (Early Complex Societies) (Ash) HIS 103 Week 1 Quiz (Ash) HIS 103 Week 1 Assignment (Ash) HIS 103 Week 2 Assignment Greco Roman Influence Paper (Ash) HIS 103 Week 2 DQ 1 Chinese Social and Political Order Systems (Ash) HIS 103 Week 2 DQ 2 Caste System (Ash) HIS 103 Week 2 Quiz (Ash) HIS 103 Week 3 Assignment Black Death Dra...

  7. MAT 222 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    mirat

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 222 Week 1 Solving Proportions (Ash) MAT 222 Week 1 DQ 1 Can't Cancel Terms (Ash) MAT 222 Week 2 DQ 1 One-Variable Compound Inequalities (Ash) MAT 222 Week 2 Two-Variable Inequalities (Ash) MAT 222 Week 3 DQ 1 Simplifying Radicals (Ash) MAT 222 Week 3 Real World Radical Formulas (Ash) MAT 222 Week 4 DQ 1 Solving Quadratic Equations (Ash) MAT 222 Week 4 Real World Quadratic Functions (Ash) ...

  8. BUS 642 Ash course tutorial / uophelp

    OpenAIRE

    uophelp

    2015-01-01

    www.uophelp.com     BUS 642 Week 1 DQ 1 Scientific Thinking (Ash Course) BUS 642 Week 1 DQ 2 Making Research Decisions (Ash Course) BUS 642 Week 1 Exercises (Ash Course) BUS 642 Week 2 DQ 1 Ethics in Business Research (Ash Course) BUS 642 Week 2 DQ 2 Design of Research (Ash Course) BUS 642 Week 2 Exercises (Ash Course) BUS 642 Week 3 DQ 1 Measurement Scales (Ash Course) BUS 642 Week 3 DQ 2 Clarifying the Research Questions (Ash Course) BUS...

  9. Volcanic ash - Terrestrial versus extraterrestrial

    Science.gov (United States)

    Okeefe, J. A.

    1976-01-01

    A principal difference between terrestrial and extraterrestrial lavas may consist in the greater ability of terrestrial lavas to form thin films (like those of soap bubbles) and hence foams. It would follow that, in place of the pumice and spiny shards found in terrestrial volcanic ash, an extraterrestrial ash should contain minute spherules. This hypothesis may help to explain lunar microspherules.

  10. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2014-01-01

    in water. The content of the selected heavy metals (i.e. Cr, Ni, Pb and Cd) complied with the Danish Statutory Order on the use of bio-ash for agricultural purposes; however, critical releases of Cr were detected in the leachate extracts, especially in the fly ash. High alkaline pHs were measured in all...

  11. Melting and Sintering of Ashes

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug

    1997-01-01

    in the ashes lead to increased melt fractions in the temperature range 600-750°C.b) Bottom ashes from straw combustion consist purely of silicates, with varying ratios of the quite refractory Al-silicates and quartz to the less refractory K- and Ca-silicates. Bottom ashes melt in the temperature range 800......-1300°C, and a trend of higher fusion temperatures with increasing contents of Al-silicates and quartz was found.c) Fly ashes, bottom ashes and deposits from coal/straw co-firing were all found to consist mainly of metal-alumina and alumina-silicates. These ashes all melt in the temperature range 1000......The thesis contains an experimental study of the fusion and sintering of ashes collected during straw and coal/straw co-firing.A laboratory technique for quantitative determination of ash fusion has been developed based on Simultaneous Thermal Analysis (STA). By means of this method the fraction...

  12. Ash Properties of Alternative Biomass

    DEFF Research Database (Denmark)

    Capablo, Joaquin; Jensen, Peter Arendt; Pedersen, Kim Hougaard;

    2009-01-01

    The ash behavior during suspension firing of 12 alternative solid biofuels, such as pectin waste, mash from a beer brewery, or waste from cigarette production have been studied and compared to wood and straw ash behavior. Laboratory suspension firing tests were performed on an entrained flow...

  13. Ash partitioning during the oxy-fuel combustion of lignite and its dependence on the recirculation of flue gas impurities (H{sub 2}O, HCl and SO{sub 2})

    Energy Technology Data Exchange (ETDEWEB)

    Facun Jiao; Juan Chen; Lian Zhang; Yajuan Wei; Yoshihiko Ninomiya; Sankar Bhattacharya; Hong Yao [Monash University, Clayton, Vic. (Australia). Department of Chemical Engineering

    2011-06-15

    Oxy-fuel combustion of a brown coal (i.e. lignite) has been carried out at 1000{sup o}C to experimentally examine the vaporisation of organically bound metals and the agglomeration of ash particles as a function of the concentration of gaseous impurities including H{sub 2}O, HCl and SO{sub 2} in about 27% O{sub 2} balanced with CO{sub 2}. The properties of bulk ash and individual metals were investigated intensively. Particularly, attention was paid to Na which is notorious for fouling and to organically bound Al which has been less studied. The results indicate that, the organically bound metals, although possessing a very low content in the raw coal, are vital for the agglomeration of ash particles, which are also highly sensitive to the loading of gas impurities in flue gas. HCl recirculation is the most crucial factor promoting the vaporisation of metals via chlorination. Apart from alkali metals, the organically bound Al and Ti were also vaporised noticeably. Recirculation of SO{sub 2} promoted the sulfation of Na to condense into liquid droplet which increased fine ash yield. Co-existence of bulk HCl and SO{sub 2} played a synergetic role in the sulfation of Na via an initial chlorination of the char-bound Na. In contrast, co-existence of steam with HCl and SO{sub 2} favored the formation of Na alumino-silicates, which are favorable for ash agglomeration. 34 refs., 15 figs., 3 tabs.

  14. Phenolic acids as bioindicators of fly ash deposit revegetation.

    Science.gov (United States)

    Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

    2006-05-01

    The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits. PMID:16418890

  15. Phenolic acids as bioindicators of fly ash deposit revegetation.

    Science.gov (United States)

    Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

    2006-05-01

    The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

  16. To fractionate municipal solid waste incineration bottom ash: Key for utilisation?

    Science.gov (United States)

    Sormunen, Laura Annika; Rantsi, Riina

    2015-11-01

    For the past decade, the Finnish waste sector has increasingly moved from the landfilling of municipal solid waste towards waste incineration. New challenges are faced with the growing amounts of municipal solid waste incineration bottom ash, which are mainly landfilled at the moment. Since this is not a sustainable or a profitable solution, finding different utilisation applications for the municipal solid waste incineration bottom ash is crucial. This study reports a comprehensive analysis of bottom ash properties from one waste incineration plant in Finland, which was first treated with a Dutch bottom ash recovery technique called advanced dry recovery. This novel process separates non-ferrous and ferrous metals from bottom ash, generating mineral fractions of different grain sizes (0-2 mm, 2-5 mm, 5-12 mm and 12-50 mm). The main aim of the study was to assess, whether the advanced bottom ash treatment technique, producing mineral fractions of different grain sizes and therefore properties, facilitates the utilisation of municipal solid waste incineration bottom ash in Finland. The results were encouraging; the bottom ash mineral fractions have favourable behaviour against the frost action, which is especially useful in the Finnish conditions. In addition, the leaching of most hazardous substances did not restrict the utilisation of bottom ash, especially for the larger fractions (>5 mm). Overall, this study has shown that the advanced bottom ash recovering technique can be one solution to increase the utilisation of bottom ash and furthermore decrease its landfilling in Finland.

  17. To fractionate municipal solid waste incineration bottom ash: Key for utilisation?

    Science.gov (United States)

    Sormunen, Laura Annika; Rantsi, Riina

    2015-11-01

    For the past decade, the Finnish waste sector has increasingly moved from the landfilling of municipal solid waste towards waste incineration. New challenges are faced with the growing amounts of municipal solid waste incineration bottom ash, which are mainly landfilled at the moment. Since this is not a sustainable or a profitable solution, finding different utilisation applications for the municipal solid waste incineration bottom ash is crucial. This study reports a comprehensive analysis of bottom ash properties from one waste incineration plant in Finland, which was first treated with a Dutch bottom ash recovery technique called advanced dry recovery. This novel process separates non-ferrous and ferrous metals from bottom ash, generating mineral fractions of different grain sizes (0-2 mm, 2-5 mm, 5-12 mm and 12-50 mm). The main aim of the study was to assess, whether the advanced bottom ash treatment technique, producing mineral fractions of different grain sizes and therefore properties, facilitates the utilisation of municipal solid waste incineration bottom ash in Finland. The results were encouraging; the bottom ash mineral fractions have favourable behaviour against the frost action, which is especially useful in the Finnish conditions. In addition, the leaching of most hazardous substances did not restrict the utilisation of bottom ash, especially for the larger fractions (>5 mm). Overall, this study has shown that the advanced bottom ash recovering technique can be one solution to increase the utilisation of bottom ash and furthermore decrease its landfilling in Finland. PMID:26330401

  18. Using fly ash for construction

    Energy Technology Data Exchange (ETDEWEB)

    Valenti, M.

    1995-05-01

    Each year electrical utilities generate 80 million tons of fly ash, primarily from coal combustion. Typically, utilities dispose of fly ash by hauling it to landfills, but that is changing because of the increasing cost of landfilling, as well as environmental regulations. Now, the Electric Power Research Institute (EPRI), in Palo Alto, Calif., its member utilities, and manufacturers of building materials are finding ways of turning this energy byproduct into the building blocks of roads and structures by converting fly ash into construction materials. Some of these materials include concrete and autoclaved cellular concrete (ACC, also known as aerated concrete), flowable fill, and light-weight aggregate. EPRI is also exploring uses for fly ash other than in construction materials. One of the more high-end uses for the material is in metal matrix composites. In this application, fly ash is mixed with softer metals, such as aluminum and magnesium, to strengthen them, while retaining their lighter weight.

  19. Can pore-clogging by ash explain post-fire runoff?

    Science.gov (United States)

    Stoof, Cathelijne R.; Gevaert, Anouk I.; Baver, Christine; Hassanpour, Bahareh; Morales, Veronica L.; Zhang, Wei; Martin, Deborah; Giri, Shree K.; Steenhuis, Tammo S.

    2016-01-01

    Ash plays an important role in controlling runoff and erosion processes after wildfire and has frequently been hypothesised to clog soil pores and reduce infiltration. Yet evidence for clogging is incomplete, as research has focussed on identifying the presence of ash in soil; the actual flow processes remain unknown. We conducted laboratory infiltration experiments coupled with microscope observations in pure sands, saturated hydraulic conductivity analysis, and interaction energy calculations, to test whether ash can clog pores (i.e. block pores such that infiltration is hampered and ponding occurs). Although results confirmed previous observations of ash washing into pores, clogging was not observed in the pure sands tested, nor were conditions found for which this does occur. Clogging by means of strong attachment of ash to sand was deemed unlikely given the negative surface charge of the two materials. Ponding due to washing in of ash was also considered improbable given the high saturated conductivity of pure ash and ash–sand mixtures. This first mechanistic step towards analysing ash transport and attachment processes in field soils therefore suggests that pore clogging by ash is unlikely to occur in sands. Discussion is provided on other mechanisms by which ash can affect post-fire hydrology.

  20. Research on super-low-ash anthracite preparation

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-ling; ZHAO Yue-min; YANG Jian-guo

    2008-01-01

    The fundamental question of super-low-ash coal preparation is how to furthest depress high ash component pollution. A jigging process was used to remove high ash refuse and middling, then a high precision heavy medium cyclone was used to further separate near gravity light material. A two-stage heavy medium cylindrical cyclone with the same separation density was used to increase the precision of separation. The feed was de-slimed and fine-grind coal was added with media to improve the stability of the suspension. The pump frequency conversion timing and an air spring were used to steady the cyclone inlet pressure. Based on a series of study and pilot tests, a 1.00 Mt/a (output) commercial separation system with Ep value under 0.015 was built up. Super low ash (Ad_<2.00%) Taixi Anthracite has been put into commercial production.

  1. Reuse of alkali from bio fly ash; Alkaligenanvendelse fra bioflyveaske

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, Kaj; Jensen, Joergen Peter; Simonsen, Peter; Sander, B.

    2006-03-15

    Experiments to leach potassium salts from fly ash from straw combustion were performed. The fly ash was produced in the bio mass boiler at the Avedoere power plant in south western Copenhagen, Denmark. The fly ash contained approximately 90 mass percent water soluble material. When the fly ash was dissolved at low pH, a slightly higher solubility was found. 100 gram fly ash consisted typically of 9 gram insoluble material, 9 gram calcium phosphate, 29 gram potassium sulfate and 53 gram of potassium chloride. In addition, 100 gram of fly ash contained approximately 1 mg of cadmium, corresponding to a concentration of cadmium of 10 ppm in the fly ash. Fly ash from the bio mass boiler at the Avedoere power plant apparently has a significantly larger content of potassium salts than fly ash from other boilers. The Extended UNIQUAC thermodynamic model was used for calculating relevant phase diagrams and calculations of the necessary amount of water required for dissolving all the KCl and all KCl + K{sub 2}SO{sub 4} of the fly ash. This theoretical minimum amount of water was calculated at a range of temperatures between 10 and 100 deg. C. The amount of water required at 100 deg. C was less than half of that required at 10 deg. C. Experiments were performed in order to find a feasible method for separating the potassium salts of the fly ash from the ash residue and especially from the soluble cadmium salts found in the fly ash. Experiments with counter current leaching of fly ash in a fluid bed gave unsatisfactory results. Apparently there was a lack of contact between the wash water and the ash. In addition, sedimentation was very slow resulting in an incomplete separation of wash water and ash residue. Experiments with ion exchange by adding CaCl{sub 2} to the wash water and successive precipitation of gypsum or anhydrite gave unsatisfactory results. Process simulation had shown that by this method the necessary amount of washing water could be decreased. This is due to

  2. Controls on the surface chemical reactivity of volcanic ash investigated with probe gases

    Science.gov (United States)

    Maters, Elena C.; Delmelle, Pierre; Rossi, Michel J.; Ayris, Paul M.; Bernard, Alain

    2016-09-01

    Increasing recognition that volcanic ash emissions can have significant impacts on the natural and human environment calls for a better understanding of ash chemical reactivity as mediated by its surface characteristics. However, previous studies of ash surface properties have relied on techniques that lack the sensitivity required to adequately investigate them. Here we characterise at the molecular monolayer scale the surfaces of ash erupted from Eyjafjallajökull, Tungurahua, Pinatubo and Chaitén volcanoes. Interrogation of the ash with four probe gases, trimethylamine (TMA; N(CH3)3), trifluoroacetic acid (TFA; CF3COOH), hydroxylamine (HA; NH2OH) and ozone (O3), reveals the abundances of acid-base and redox sites on ash surfaces. Measurements on aluminosilicate glass powders, as compositional proxies for the primary constituent of volcanic ash, are also conducted. We attribute the greater proportion of acidic and oxidised sites on ash relative to glass surfaces, evidenced by comparison of TMA/TFA and HA/O3 uptake ratios, in part to ash interaction with volcanic gases and condensates (e.g., H2O, SO2, H2SO4, HCl, HF) during the eruption. The strong influence of ash surface processing in the eruption plume and/or cloud is further supported by particular abundances of oxidised and reduced sites on the ash samples resulting from specific characteristics of their eruptions of origin. Intense interaction with water vapour may result in a higher fraction of oxidised sites on ash produced by phreatomagmatic than by magmatic activity. This study constitutes the first quantification of ash chemical properties at the molecular monolayer scale, and is an important step towards better understanding the factors that govern the role of ash as a chemical agent within atmospheric, terrestrial, aquatic or biotic systems.

  3. Síntesis de una matriz cuasiceramica destinada a la obtención de fundentes aglomerados para proceso SAW y evaluación cinético-termodinámica de su proceso de humectación Synthesis of a cuasiceramic matrix destined to the obtaining of agglomerated fuxes for the SAW process and kinetic and thermodynamic evaluations of its humectation process

    Directory of Open Access Journals (Sweden)

    Rafael Quintana-Puchol

    2010-06-01

    Full Text Available En el presente trabajo se expone una concepción de la síntesis por sinterización, a relativa baja temperatura, de una matriz cuasicerámica amorfa destinada a la confección de fundentes aglomerados para el proceso SAW. Para diseñar la matriz cuasicerámica se hace una valoración de la composición química de los concentrados minerales de feldespato, zeolita y calcita, así como de la relación SiO2/Al2O3 de los alumosilicatos. También, como herramientas estratégicas para la síntesis, se usa el diagrama de fase SiO2-Al2O3-CaO, los índices de basicidad y de actividad química y la temperatura Temman. Mediante valoración del espectro de DRX de la matriz y un novedoso criterio sobre el grado de sinterización se selecciona la variante de síntesis más adecuada. También se hace una valoración cinética y termodinámica del proceso de absorción isotérmica de la humectación por los granos de la matriz. El modelo de las isotermas de Langmuir se ajusta aceptablemente para describir el proceso de absorción de humedad por los granos de la matriz. La determinación de los valores de las constantes de las isotermas de Langmuir a diferentes humedades relativas y temperaturas permitió calcular los valores de entalpía, entropía y energía libre de Gibbs del proceso de adsorción.In the this paper is presented a conception of the synthesis by sinterización at relative low temperature, of an amorphous cuasiceramic matrix to be used in agglomerated flux in the SAW process. In the design of the cuasiceramic it was made a valuation of the chemical composition of the diferent mineral concentrates (feldspar, zeolite and calcite, as well as of the relationship SiO2/Al2O3 of the alumosilicates. Also, as strategic tools for synthesis were used the phase diagram SiO2-Al2O3-CaO, the basicity and chemical activity indexes and the Temman temperature. It was selected the more appropriate synthesis variant by a valuation of the DRX spectrum of the matrix

  4. Idaho Nuclear Technology and Engineering Center (INTEC) (formerly ICPP) ash reutilization study

    International Nuclear Information System (INIS)

    Since 1984, the coal-fired plant at the Idaho Nuclear Technology and Engineering Center (INTEC, formerly Idaho Chemical Processing Plant) has been generating fly ash at a rate of approximately 1,000 tons per year. This ash is hydrated and placed in an ash bury pit near the coal-fired plant. The existing ash bury pit will be full in less than 1 year at its present rate of use. A conceptual design to build a new ash bury pit was completed, and the new pit is estimated to cost $1.7 million. This report evaluates ash reutilization alternatives that propose to eliminate this waste stream and save the $1.7 million required to build a new pit. The alternatives include using ash for landfill day cover, concrete admixture, flowable fill, soil stabilization, waste remediation, and carbon recovery technology. Both physical and chemical testing, under the guidance of the American Society for Testing and Materials, have been performed on ash from the existing pit and from different steps within the facility's processes. The test results have been evaluated, compared to commercial ash, and are discussed as they relate to reutilization alternatives. This study recommends that the ash be used in flowable fill concrete for Deactivation and Demolition work at the Idaho National Engineering and Environmental Laboratory

  5. Constructing Political Region Agglomerations for Effective Science Communcation

    Science.gov (United States)

    Rising, J. A.

    2015-12-01

    Often political regions form a better scale for modeling than regulargrids, since they are used for collecting socioeconomic data and aremore relevant to stakeholders and policy-makers. However, differentpolitical regions can enclose very different areas, populations,ranges of climatic variability, and for many countries there are anundesireable number of regions available at any administrative level.We provide a solution to this problem, by providing a general systemfor agglomerating regions to a larger scale, to approximately optimizearbitrary objectives. These regions provide an intermediate scale formodeling and greater comparability than unagglomerated regions. Wefirst apply the approach to the US, producing region agglomerationsthat normalize region size, population, income, and climaticvariability. We then apply the technique globally, generating acononical collection of regions for studying the impacts of climatechange.

  6. Fly ash reinforced thermoplastic vulcanizates obtained from waste tire powder.

    Science.gov (United States)

    Sridhar, V; Xiu, Zhang Zhen; Xu, Deng; Lee, Sung Hyo; Kim, Jin Kuk; Kang, Dong Jin; Bang, Dae-Suk

    2009-03-01

    Novel thermoplastic composites made from two major industrial and consumer wastes, fly ash and waste tire powder, have been developed. The effect of increasing fly ash loadings on performance characteristics such as tensile strength, thermal, dynamic mechanical and magnetic properties has been investigated. The morphology of the blends shows that fly ash particles have more affinity and adhesion towards the rubbery phase when compared to the plastic phase. The fracture surface of the composites shows extensive debonding of fly ash particles. Thermal analysis of the composites shows a progressive increase in activation energy with increase in fly ash loadings. Additionally, morphological studies of the ash residue after 90% thermal degradation shows extensive changes occurring in both the polymer and filler phases. The processing ability of the thermoplastics has been carried out in a Monsanto processability testing machine as a function of shear rate and temperature. Shear thinning behavior, typical of particulate polymer systems, has been observed irrespective of the testing temperatures. Magnetic properties and percolation behavior of the composites have also been evaluated. PMID:18838261

  7. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Eric Suuberg; John Veranth; Xu Chen; Indrek Kulaots

    2004-02-13

    The overall objective of the present project was to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific issues addressed included: (1) the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; (2) the effect of various low-NOx firing modes on ash properties and adsorptivity based on pilot-plant studies; and (3) the kinetics and mechanism of ash ozonation. This laboratory data has provided scientific and engineering support and underpinning for parallel process development activities. The development work on the ash ozonation process has now transitioned into a scale-up and commercialization project involving a multi-industry team and scheduled to begin in 2004. This report describes and documents the laboratory and pilot-scale work in the above three areas done at Brown University and the University of Utah during this three-year project.

  8. Fly ash reinforced thermoplastic vulcanizates obtained from waste tire powder.

    Science.gov (United States)

    Sridhar, V; Xiu, Zhang Zhen; Xu, Deng; Lee, Sung Hyo; Kim, Jin Kuk; Kang, Dong Jin; Bang, Dae-Suk

    2009-03-01

    Novel thermoplastic composites made from two major industrial and consumer wastes, fly ash and waste tire powder, have been developed. The effect of increasing fly ash loadings on performance characteristics such as tensile strength, thermal, dynamic mechanical and magnetic properties has been investigated. The morphology of the blends shows that fly ash particles have more affinity and adhesion towards the rubbery phase when compared to the plastic phase. The fracture surface of the composites shows extensive debonding of fly ash particles. Thermal analysis of the composites shows a progressive increase in activation energy with increase in fly ash loadings. Additionally, morphological studies of the ash residue after 90% thermal degradation shows extensive changes occurring in both the polymer and filler phases. The processing ability of the thermoplastics has been carried out in a Monsanto processability testing machine as a function of shear rate and temperature. Shear thinning behavior, typical of particulate polymer systems, has been observed irrespective of the testing temperatures. Magnetic properties and percolation behavior of the composites have also been evaluated.

  9. Ash Reduction of Corn Stover by Mild Hydrothermal Preprocessing

    Energy Technology Data Exchange (ETDEWEB)

    M. Toufiq Reza; Rachel Emerson; M. Helal Uddin; Garold Gresham; Charles J. Coronella

    2014-04-22

    Lignocellulosic biomass such as corn stover can contain high ash content, which may act as an inhibitor in downstream conversion processes. Most of the structural ash in biomass is located in the cross-linked structure of lignin, which is mildly reactive in basic solutions. Four organic acids (formic, oxalic, tartaric, and citric) were evaluated for effectiveness in ash reduction, with limited success. Because of sodium citrate’s chelating and basic characteristics, it is effective in ash removal. More than 75 % of structural and 85 % of whole ash was removed from the biomass by treatment with 0.1 g of sodium citrate per gram of biomass at 130 °C and 2.7 bar. FTIR, fiber analysis, and chemical analyses show that cellulose and hemicellulose were unaffected by the treatment. ICP–AES showed that all inorganics measured were reduced within the biomass feedstock, except sodium due to the addition of Na through the treatment. Sodium citrate addition to the preconversion process of corn stover is an effective way to reduced physiological ash content of the feedstock without negatively impacting carbohydrate and lignin content.

  10. Humid storage conditions increase the dissolution rate of diazepam from solid dispersions prepared by melt agglomeration

    DEFF Research Database (Denmark)

    Jørgensen, Anna Cecilia; Torstenson, Anette Seo

    2008-01-01

    The purpose of this study is to investigate the effect of cooling mode and storage conditions on the dissolution rate of a solid dispersion prepared by melt agglomeration. The aim has been to relate this effect to the solid state properties of the agglomerates. The cooling mode had an effect on t...

  11. Statistical Evaluation of Non-Agglomerating Coating for Granulated Natural Asphalt

    Directory of Open Access Journals (Sweden)

    Tjokorde Walmiki Samadhi

    2011-04-01

    Full Text Available Agglomeration of granulated Buton natural asphalt during storage is of major concern in its large-scale commercial application. This work develops a simple test method to evaluate the performance of agglomeration-resistant coating for granulated Buton asphalt, consisting of water-based polymeric primary coating and mineral-based secondary coating. The method uses a static load cell to measure the agglomerated granule count fraction under simulated storage conditions. A 24-1 fractional factorial experiment with two replications is employed to evaluate the effect of coating drying temperature, drying time, asphalt to secondary coating mass ratio, and secondary coating type on the agglomerated count fraction at ambient temperature and 60 oC. The test is able to measure a statistically significant increase in agglomeration resistance when the coating is applied, with an agglomerated fraction of 17.5% at 60 oC. The test identifies asphalt to secondary coating weight ratio as a significant factor, with an ANOVA p-value much lower than other effects. A decrease in this mass ratio from 5:1 to 5:2 increases the agglomeration, which is hypothesized to be attributed to the hydrated cementitious phase between granular external surfaces. More work is needed to identify the acceptable fraction of agglomerated granules.

  12. Gender Differences of Shoppers in the Marketing and Management of Retail Agglomerations

    OpenAIRE

    Teller, C; Thomson, A

    2012-01-01

    This paper aims to first identify gender differences in perception and evaluation of retail agglomerations, and second, discuss the implications of these differences for marketing and management. Based on a conceptual model 2151 agglomeration shoppers were surveyed using interviewer-administered questionnaires. Structural equation modelling revealed that accessibility, parking and infrastructure are perceived differently between gender groups. The attractiveness in terms of satisfaction, rete...

  13. Productive Places : The influence of technological change and relatedness on agglomeration externalities

    NARCIS (Netherlands)

    Neffke, F.M.H.

    2009-01-01

    This thesis addresses the topic of agglomeration externalities. Agglomeration externalities can roughly be defined as advantages and disadvantages local firms experience when locating close to other firms. An old debate exists over the question whether firms benefit more from being close to firms in

  14. 49 CFR 230.69 - Ash pans.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Ash pans. 230.69 Section 230.69 Transportation... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Ash Pans § 230.69 Ash pans. Ash pans shall be securely supported from mud-rings or frames with no part less than...

  15. Remediation of ash problems in fluidised-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.K. [Curtin University of Technology, Perth, WA (Australia). School of Chemical Engineering

    2001-03-01

    The paper reports the control methods for mitigating particle agglomeration and bed defluidisation during fluidised-bed combustion of low-rank coals. A laboratory scale spouted-bed combustion system is used to study the effectiveness of several control methods including the use of alternative bed materials, mineral additives, pretreatment of coal and coal blending. Sillimanite, bauxite, calcite and magnesite were used as alternative bed materials whereas mineral additives viz. clay, kaosil and bauxite were injected into the combustion system while burning South Australian low-rank coal at 800{degree}C. Samples of the same coal subjected to water-washing, Al pretreatment and Ca pretreatment are also tested in the spouted-bed combustor. In addition, experiments were conducted with several coal blends prepared at ratios of 50:50 and 90:10 from two lignites and one sub-bituminous coal. Experiments showed that all the control methods are effective to different extends in reducing ash problems and resulted in extended combustion operation. Tests with alternative bed materials and mineral additives showed trouble free-operation for longer periods (7-12 h at 800{degree}C) than with sand runs at the same bed temperature. Wet pretreatment and coal blending were also found to be effective and resulted in extended combustion operation (9-12 h at 800{degree}C). Chemical analyses indicated that formation of low temperature eutectics was suppressed by Al/Ca/Mg-rich phases in ash coating of bed particles. This was identified as the main mechanism for prevention of ash problems observed with the use of alternative bed materials, mineral additives, pretreated coals and coal blends. 23 refs., 9 figs., 7 tabs.

  16. Ash formation under pressurized pulverized coal combustion conditions

    Science.gov (United States)

    Davila Latorre, Aura Cecilia

    Coal combustion is a source of inorganic particulate matter (ash), which can deposit in boilers and also be emitted into the atmosphere becoming part of ambient fine particulate matter (PM 2.5). In order to decrease coal combustion emissions per unit of power produced, higher efficiency systems have been proposed, including systems operating at elevated pressures. These new operating conditions will affect pollutant formation mechanisms, particularly those associated with the conversion of mineral matter to ash. Ash particle formation mechanisms are particularly sensitive to changes in pressure as they are related to the structure of coal char particles at early stages of combustion. To assess the importance of pressure on ash particle formation, pyrolyzed chars and ash particles from pressurized pulverized combustion of two bituminous and one subbituminous U.S. coals at operating pressures up to 30 atm were studied. Pressure changes the distribution of char particle types, changing the spatial distribution of the minerals during the combustion process and therefore affecting particle formation mechanisms. Chars were examined by Scanning Electron Microscopy (SEM) and classified into two different types (cenospheric and solid) depending on porosity and wall thickness. A correlation for estimating the amount of these cenospheric char particles was then proposed for bituminous coals based on the operating conditions and coal maceral analysis. The ash particle size distribution of the coals combusted at different operating pressures was measured using Computer Controlled Scanning Electron Microscopy (CCSEM). The results of the char characterization and ash particle size distribution measurements were then incorporated into an ash particle formation algorithm that was proposed and implemented. The model predicts ash particle size and composition distributions at elevated pressures under conditions of complete char burnout. Ash predictions were calculated by first

  17. Multifrequency radar imaging of ash plumes: an experiment at Stromboli

    Science.gov (United States)

    Donnadieu, Franck; Freret-Lorgeril, Valentin; Delanoë, Julien; Vinson, Jean-Paul; Peyrin, Frédéric; Hervier, Claude; Caudoux, Christophe; Van Baelen, Joël; Latchimy, Thierry

    2016-04-01

    the beam, providing additional constraints on particle sizes and sedimentation process from ash clouds. Furthermore, proximal deposits were analyzed by sieving samples collected near the craters and processing data from a laser disdrometer. Ash samples constantly show a unimodal distribution ranging from 44 microns to 1 mm (more rarely 2 mm), with a mode in the range 0.1-0.3 mm. This is expected to be representative of the coarse content of the ash plumes generated by Strombolian explosions at Stromboli, i.e. mainly coarse ash, and will be used to constrain inversions of the radar signals.

  18. BUS 620 Ash course tutorial / uophelp

    OpenAIRE

    uophelp

    2015-01-01

    For more course tutorials visit www.uophelp.com   BUS 620 Week 1 DQ 1 What is Marketing (Ash Course) BUS 620 Week 1 DQ 2 Marketing Strategies (Ash Course) BUS 620 Week 1 The Future of the New York Times (Ash Course) BUS 620 Week 2 DQ 1 Buyer Behavior (Ash Course) BUS 620 Week 2 DQ 2 Customer Needs (Ash Course) BUS 620 Week 2 Industry Forecasting (Ash Course) BUS 620 Week 3 DQ 1 Braining Nordstrom (Ash Course) BUS 620 Week 3 DQ 2 Marketing Segmentat...

  19. GEN 499 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com       GEN 499 Week 1 DQ 1 Final Research Paper Topic and Plan (Ash) GEN 499 Week 1 DQ 2 Social Media (Ash) GEN 499 Week 2 DQ 1 Professional Resume and Cover Letter (Ash) GEN 499 Week 2 Assignment Critiquing Internet Sources (Ash) GEN 499 Week 3 DQ 1 Social Capital (Ash) GEN 499 Week 3 DQ 2 Federal Policy (Ash) GEN 499 Week 3 Assignment Annotated Bibliography (Ash) GEN 499 Week 4 DQ 1...

  20. BUS 372 ASH Material - bus372dotcom

    OpenAIRE

    lucky108

    2015-01-01

    For more course tutorials visit www.bus372.com       BUS 372 Week 1 DQ 1 The Role of Unionization (Ash Course) BUS 372 Week 1 DQ 2 Meeting Member Needs (Ash Course) BUS 372 Week 2 DQ 1 Profit Interest and Employee Interest (Ash Course) BUS 372 Week 2 DQ 2 Union Requirements (Ash Course) BUS 372 Week 2 Assignment Changing Landscape of Unions (Ash Course) BUS 372 Week 2 Quiz (Ash Course) BUS 372 Week 3 DQ 1 Strikes (Ash Course) BUS ...

  1. EDU 623 ASH COURSE Tutorial/UOPHELP

    OpenAIRE

    dgfvbhn

    2015-01-01

    For more course tutorials visit www.uophelp.com   EDU 623 Week 1 No Child Left Behind (Ash Course) EDU 623 Week 1 DQ 1 Skills Needed for Master of Education (Ash Course) EDU 623 Week 1 DQ 2 Effective Teachers (Ash Course) EDU 623 Week 2 Writing and Researching Skills Self-Assessment (Ash Course) EDU 623 Week 2 DQ 1 Evaluating Research (Ash Course) EDU 623 Week 2 DQ 2 Diversity in Schools (Ash Course) EDU 623 Week 3 Lesson Plan Critique (Ash Course) ...

  2. HCA 375 (ASH) course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com     HCA 375 Week 1 DQ 1 Management versus Leadership (Ash) HCA 375 Week 1 DQ 2 Implementation and Barriers (Ash) HCA 375 Week 2 DQ 1 Measurement (Ash) HCA 375 Week 2 DQ 2 Quality and Outcomes (Ash) HCA 375 Week 2 Assignment Customer Satisfaction and Quality Care (Ash) HCA 375 Week 3 DQ 1 Teamwork in Health Care (Ash) HCA 375 Week 3 DQ 2 The Impact of Nursing (Ash) HCA 375 Week 3 Ass...

  3. HCA 430(ASH) course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 34

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HCA 430 Week 1 DQ 1 Perspective (Ash) HCA 430 Week 1 DQ 2 Trends in Vulnerable Populations (Ash) HCA 430 Week 2 DQ 1 Vulnerable Populations (Ash) HCA 430 Week 2 DQ 2 Resource Availability (Ash) HCA 430 Week 2 DQ 3 Race, Ethnicity, and Healthcare (Ash) HCA 430 Week 2 Assignment Critical Thinking Paper (Ash) HCA 430 Week 3 DQ 1 Continuum of Care (Ash) HCA 430 Week 3 DQ 2 Paying for Healthcar...

  4. EDU 623 ASH COURSES TUTORIAL/UOPHELP

    OpenAIRE

    ROOSER12

    2015-01-01

    For more course tutorials visit www.uophelp.com   EDU 623 Week 1 No Child Left Behind (Ash Course) EDU 623 Week 1 DQ 1 Skills Needed for Master of Education (Ash Course) EDU 623 Week 1 DQ 2 Effective Teachers (Ash Course) EDU 623 Week 2 Writing and Researching Skills Self-Assessment (Ash Course) EDU 623 Week 2 DQ 1 Evaluating Research (Ash Course) EDU 623 Week 2 DQ 2 Diversity in Schools (Ash Course) EDU 623 Week 3 Lesson Plan Critique (Ash Course) ...

  5. The influence of fine char particles burnout on bed agglomeration during the fluidized bed combustion of a biomass fuel

    Energy Technology Data Exchange (ETDEWEB)

    Scala, Fabrizio; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, CNR, P.le V. Tecchio, 80-80125 Naples (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le V. Tecchio, 80-80125 Naples (Italy)

    2003-11-15

    The combustion of biomass char in a bubbling fluidized bed is hereby addressed, with specific reference to the influence that the combustion of fine char particles may exert on ash deposition and bed agglomeration phenomena. Experiments of steady fluidized bed combustion (FBC) of powdered biomass were carried out with the aim of mimicking the postcombustion of attrited char fines generated in the fluidized bed combustion of coarse char. Experimental results showed that the char elutriation rate is much smaller than expected on the basis of the average size of the biomass powder and of the carbon loading in the combustor. Samples of bed material collected after prolonged operation of the combustor were characterized by scanning electron microscopy (SEM)-EDX analysis and revealed the formation of relatively coarse sand-ash-carbon aggregates. The phenomenology is consistent with the establishment of a char phase attached to the bed material as a consequence of adhesion of char fines onto the sand particles. Combustion under sound-assisted fluidization conditions was also tested. As expected, enhancement of fines adhesion on bed material and further reduction of the elutriation rate were observed. Experimental results are interpreted in the light of a simple model which accounts for elutriation of free fines, adhesion of free fines onto bed material and detachment of attached fines by attrition of char-sand aggregates. Combustion of both free and attached char fines is considered. The parameters of the model are assessed on the basis of the measured carbon loadings and elutriation rates. Model computations are directed to estimate the effective size and the peak temperature of char-sand aggregates. The theoretical estimates of the effective aggregate size match fairly well those observed in the experiments.

  6. Assessing the potential of coal ash and bagasse ash as inorganic amendments during composting of municipal solid wastes.

    Science.gov (United States)

    Mohee, Romeela; Boojhawon, Anuksha; Sewhoo, Babita; Rungasamy, Selven; Somaroo, Geeta D; Mudhoo, Ackmez

    2015-08-15

    This study investigates the potential of incorporating inorganic amendments such as coal and bagasse ashes in different composting mixes. 10 different composting mixes were assessed as follows: A-20% bagasse ash (BA) with unsorted municipal solid wastes (UMSW); B-40% BA with UMSW; C-UMSW; D-20% BA with sorted municipal solid wastes (SMSW); E-40% BA with SMSW; F-SMSW; G-20% coal ash (CA) with UMSW; H-40% CA with UMSW; I-20% CA with SMSW and J-40% CA with SMSW. The composting processes were carried out in rotary drum composters. Composting mixes D, F, G and I achieved a temperature above 55 °C for at least 3 days, with the following peak temperatures: D-62 °C, F-57 °C, G-62 °C and I-58 °C. D resulted in the highest average net Volatile solids (VS) degradation of 68.6% and yielded the highest average volume reduction of 66.0%. The final compost from D, G, I, C and F were within range for electrical conductivities (EC) (794-1770 μS/cm) and pH (6.69-7.12). The ashes also helped in maintaining high average water holding capacities within the range of 183-217%. The C/N ratio of sorted wastes was improved by the addition of 20% coal ash and bagasse ash. Higher germination indices, above 0.8 were obtained for the ash-amended compost (D, G, I), indicating the feasibility and enhancement of using bagasse and coal ash as inorganic amendment in the composting process. Regarding heavy metals content, the chromium concentration for the composting mix G was found to be the highest whereas mixes D and I showed compliance with the MS (Mauritian Standards) 164 standards.

  7. Ash chemistry and fuel design focusing on combustion of phosphorus-rich biomass

    OpenAIRE

    Skoglund, Nils

    2014-01-01

    Biomass is increasingly used as a feedstock in global energy production. This may present operational challenges in energy conversion processes which are related to the inorganic content of these biomasses. As a larger variety of biomass is used the need for a basic understanding of ash transformation reactions becomes increasingly important. This is not only to reduce operational problems but also to facilitate the use of ash as a nutrient source for new biomass production. Ash transformatio...

  8. AshMeadowsNaucorid_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Naucorid (Ambrysus amargosus) occur. "Nevada, Nye County. Point of Rocks Springs and...

  9. Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

    International Nuclear Information System (INIS)

    Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

  10. KINETICS OF FLY ASH BENEFICIATION BY CARBON BURNOUT

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Joseph N.D. Dodoo; Dr. Joseph M. Okoh

    2000-11-01

    Surface area analyses performed on fly ash samples reveal that the surface area is controlled by carbon content. The higher surface areas found in large particles are due to the presence of highly porous carbonaceous particles. Adsorption-desorption isotherms and t-plots of fly ash samples indicate that fly ash is porous. BJH Adsorption/Desorption pore size analysis reveal that pore diameters are independent of sieve size. They appear to be dependent only on the nature of the material which confers porosity. Based on the results of Brown and Dykstra (41) it is reasonable to assume that calculations of reaction rates at temperatures above 550 C were confounded by weight losses from processes other than carbon oxidation and, therefore, are not useful in determination of the temperature dependence of carbon oxidation in fly ash. The results of the present study indicate that temperatures below 550 C should be used for future studies in order to satisfactorily assess the temperature dependence of carbon oxidation in fly ash. Furthermore, it is also advisable that percent carbon determinations be performed on fly ash samples after the oxidation reactions to determine whether all carbon present in fly ash is oxidized. This will ensure that reaction rates are representative of the complete oxidation of carbon. An inverse relationship was determined between reaction rates and oxygen concentration for this study. As discussed, this may be due to volatilization of volatiles from fly ash and ease of transport of products away from the reaction sites by the action of the vacuum applied to the samples. A more accurate determination of oxygen dependence of carbon oxidation can be accomplished by the use of specialty gases containing different concentrations of oxygen which could eliminate the need to apply vacuum to the samples.

  11. Corrosion of Modified Concrete with Sugar Cane Bagasse Ash

    Directory of Open Access Journals (Sweden)

    R. E. Núñez-Jaquez

    2012-01-01

    Full Text Available Concrete is a porous material and the ingress of water, oxygen, and aggressive ions, such as chlorides, can cause the passive layer on reinforced steel to break down. Additives, such as fly ash, microsilica, rice husk ash, and cane sugar bagasse ash, have a size breakdown that allows the reduction of concrete pore size and, consequently, may reduce the corrosion process. The objective of this work is to determine the corrosion rate of steel in reinforced concrete by the addition of 20% sugar cane bagasse ash by weight of cement. Six prismatic specimens (7×7×10 cm with an embedded steel rod were prepared. Three contained 20% sugar cane bagasse ash by weight of cement and the other three did not. All specimens were placed in a 3.5% NaCl solution and the corrosion rate was determined using polarization resistance. The results showed that reinforced concrete containing sugar cane bagasse ash has the lowest corrosion rates in comparison to reinforced concrete without the additive.

  12. Formation of Humic Substances in Weathered MSWI Bottom Ash

    Directory of Open Access Journals (Sweden)

    Haixia Zhang

    2013-01-01

    Full Text Available The study aimed at evaluating the humic substances (HSs content from municipal solid waste incinerator (MSWI bottom ash and its variation with time and the effect of temperature on HSs formation. The process suggested by IHSS was applied to extract HSs from two different bottom ash samples, and the extracted efficiency with NaOH and Na4P2O7 was compared. MSWI bottom ash samples were incubated at 37∘C and 50∘C for 1 year. HSs and nonhumic substances were extracted from the bottom ash sample with different incubated period by 0.1 M NaOH/Na4P2O7. Results show that the rate of humic acid formation increased originally with incubation time, reached a maximum at 12th week under 37∘C and at 18th week under 50∘C, and then decreased with time. More humic acid in MSWI bottom ash was formed under 50∘C incubated condition compared with that incubated under 37∘C. Also, the elemental compositions of HSs extracted from bottom ash are reported.

  13. Effect of interfacial properties on mechanical stability of ash deposit

    Directory of Open Access Journals (Sweden)

    A. Ontiveros-Ortega

    2016-04-01

    Full Text Available The paper presents a study on the cohesion of volcanic ash particles using surface free energy determination and zeta potential analyses. This is a subject of great interest in physical volcanology, as many researches on volcanic particle aggregation are frequently reported. In this case, special attention is paid to the role of structural or hydration forces between hydrophilic surfaces, which are a consequence of the electron-donor/electron-acceptor character of the interface. From this point of view, the results are potentially interesting as they could give valuable insights into this process. The results are presented in terms of the total energy of interaction between dispersed particles, computed from the extended DLVO theory. Contributions to the total free energy of interaction were determined from the zeta potential and surface free energy of ash, measured under different experimental conditions. Two samples of basaltic volcanic ash (black and white with silica contents of 44% and 63% respectively are studied. The surface free energy and zeta potential were analysed for ashes immersed in different electrolytes (NaCl, CaCl2, FeCl3. The presence of electrolytes changes the surface properties of the solid materials. The analysis of total interaction energy between the ash particles in aqueous medium shows that soil cohesion strongly depends on ash surface properties, chemical nature, the adsorbed cation on the surface, and pH value.

  14. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH; SEMIANNUAL

    International Nuclear Information System (INIS)

    The overall objective of the present project is to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific research issues to be addressed include: the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; the effect of various low-NOx firing modes on ash properties and adsorptivity; and the kinetics and mechanism of ash ozonation. This data will provide scientific and engineering support of the ongoing process development activities. This first project period, experiments were carried out to better understand the fundamental nature of the ozonation effect on ash. Carbon surfaces were characterized by surfactant adsorption, and by X-ray Photoelectron Spectroscopy before and after oxidation, both by air at 440 C and by ozone at room temperature. The results strongly suggest that the beneficial effect of ozonation is in large part due to chemical modification of the carbon surfaces

  15. The Mineral Transformation of Huainan Coal Ashes in Reducing Atmospheres

    Institute of Scientific and Technical Information of China (English)

    LI Han-xu; Yoshihiko Ninomiya; DONG Zhong-bing; ZHANG Ming-xu

    2006-01-01

    By using the advanced instrumentation of a Computer Controlled Scanning Electron Microscope (CCSEM),X-ray diffraction (XRD) and X-ray fluorescence (XRF), the ash composition and the mineral components of six typical Huainan coals of different origins were studied. The transformation of mineral matter at high temperatures was tracked by XRD in reducing conditions. The quartz phase decreased sharply and the anorthite content tended to increase at first and then decreased with increasing temperatures. The formed mullite phase reached a maximum at 1250 ℃ but showed a tendency of slow decline when the temperature was over 1250 ℃. The mullite formed in the heating process was the main reason of the high ash melting temperature of Huainan coals. Differences in peak intensity of mullite and anorthite reflected differences in phase concentration of the quenched slag fractions, which contributed to the differences in ash melting temperatures. The differences in the location of an amorphous hump maximum indicated differences of glass types which may affect ash melting temperatures. For Huainan coal samples with relatively high ash melting temperatures, the intensity of the diffraction lines for mullite under reducing condition is high while for the samples with relatively low ash melting temperature the intensity for anorthite is high.

  16. Suppressing Heavy Metal Leaching through Ball Milling of Fly Ash

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-07-01

    Full Text Available Ball milling is investigated as a method of reducing the leaching concentration (often termed stablilization of heavy metals in municipal solid waste incineration (MSWI fly ash. Three heavy metals (Cu, Cr, Pb loose much of their solubility in leachate by treating fly ash in a planetary ball mill, in which collisions between balls and fly ash drive various physical processes, as well as chemical reactions. The efficiency of stabilization is evaluated by analysing heavy metals in the leachable fraction from treated fly ash. Ball milling reduces the leaching concentration of Cu, Cr, and Pb, and water washing effectively promotes stabilization efficiency by removing soluble salts. Size distribution and morphology of particles were analysed by laser particle diameter analysis and scanning electron microscopy. X-ray diffraction analysis reveals significant reduction of the crystallinity of fly ash by milling. Fly ash particles can be activated through this ball milling, leading to a significant decrease in particle size, a rise in its BET-surface, and turning basic crystals therein into amorphous structures. The dissolution rate of acid buffering materials present in activated particles is enhanced, resulting in a rising pH value of the leachate, reducing the leaching out of some heavy metals.

  17. Aerodynamic characteristics of popcorn ash particles

    Energy Technology Data Exchange (ETDEWEB)

    Cherkaduvasala, V.; Murphy, D.W.; Ban, H.; Harrison, K.E.; Monroe, L.S. [University of Alabama, Birmingham, AL (United States). Dept. of Mechanical Engineering

    2007-07-01

    Popcorn ash particles are fragments of sintered coal fly ash masses that resemble popcorn in low apparent density. They can travel with the flow in the furnace and settle on key places such as catalyst surfaces. Computational fluid dynamics (CFD) models are often used in the design process to prevent the carryover and settling of these particles on catalysts. Particle size, density, and drag coefficient are the most important aerodynamic parameters needed in CFD modeling of particle flow. The objective of this study was to experimentally determine particle size, shape, apparent density, and drag characteristics for popcorn ash particles from a coal-fired power plant. Particle size and shape were characterized by digital photography in three orthogonal directions and by computer image analysis. Particle apparent density was determined by volume and mass measurements. Particle terminal velocities in three directions were measured in water and each particle was also weighed in air and in water. The experimental data were analyzed and models were developed for equivalent sphere and equivalent ellipsoid with apparent density and drag coefficient distributions. The method developed in this study can be used to characterize the aerodynamic properties of popcorn-like particles.

  18. Leachates from wood ash - effects of storage on soil; Lakvatten fraan skogsbraensleaska - markpaaverkan av lagring

    Energy Technology Data Exchange (ETDEWEB)

    Valeur, Inger; Thelin, Gunnar (EkoBalans FenixAB, Lund (Sweden))

    2012-02-15

    . Most risk assessments are done from standardized extractions methods, which are based upon addition of excess water to the ash. This process is fairly different from what happens when ash is stored in a pile and rained upon. Thus it is difficult, or not yet shown, how a figure given from an extraction with excess water should be translated to the total amount of leached elements from ash storages. Collecting leachates from landfills where ash is stored also has its problems, as it often is contaminated with elements from other wastes being stored at the landfill

  19. Products based on the mixes of fly ashes and fibre sludge (fibre-ashes) for road construction; Produkter baserade paa blandningar av flygaska och fiberslam (fiberaskor) foer vaegbyggande

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, Pentti; Maijala Aino; Macsik, Josef

    2005-03-01

    economically potential fibre-ash mixtures and recommendations for their further development with the help of field tests and test construction. The most noteworthy benefits of the fibre ashes as soil construction materials are their elasticity and resistance against permanent deformation. These properties make the fibre-ash materials significantly more frost resistant than the conventional materials. Also, the fibre-ashes are easier and simpler to use in the construction process than the fly ashes because the fibre-ashes are practically dust-tight materials. The results of the project will be background information for the further studies, and for the guidelines and commercialisation of e.g. road construction with fibre ashes.

  20. Effect of fly ash preliminary calcination on the properties of geopolymer.

    Science.gov (United States)

    Temuujin, J; van Riessen, A

    2009-05-30

    The influence of preliminary calcination of fly ashes on the geopolymerisation process has been studied. Preliminary calcination at 500 and 800 degrees C causes decarbonation of the fly ash while it also leads to a decrease of the amorphous content of the fly ashes from 60 to 57%. Geopolymer prepared using raw fly ash exhibited a compressive strength 55.7(9.2)MPa, while for 500 and 800 degrees C calcined samples it reduced to 54(5.8) and 44.4(5.4)MPa, respectively. The decrease in compressive strength of the geopolymers is discussed in terms of partial surface crystallisation of the fly ash particles. Reactivity of the fly ash also has been correlated with the shrinkage rate and presence of efflorescence on the surface of geopolymers.

  1. Relation between silico-aluminous fly ash and its coal of origin

    Institute of Scientific and Technical Information of China (English)

    Jean-Charles Benezet; Pierre Adamiec; Ali Benhassaine

    2008-01-01

    Fly ashes are typical complex solids which incorporate at the same time intrinsic properties derived from the layers (various mineralogical and dimensional spectra) and major transformations generated during prior processing. To use fly ashes in various applications, it is necessary to characterise them completely. The first research to date carried out on silico-aluminous fly ashes in order to characterise them physically,morphologically, chemically and mineralogically, resulted in the recognition that they are relatively simple materials. In the present study, a silico-aluminous fly ash coming from the power station of Albi (France) was selected. Heat treatment at 450 and 1200 ~C together with coal simulated the treatment undergone by coal in the power station in order to mimic real coal residue. In conclusion, the diversity of the particles contained in fly ash could only be explained by the relation existing between the fly ash and its coal of origin.

  2. Leaching Study in Immobilization of Cesium and Cobalt Radionuclides In Fly Ash- Zeolite Cement

    International Nuclear Information System (INIS)

    Fly ash-zeolite cement was synthesized from industrial by-product fly ash obtained from the thermal electric power station. The synthesis process is based on the hydrothermal-calcination-route of the fly ash. The microstructure of fly ash-zeolite cement was characterized by X-ray diffraction, FT infrared spectroscopy and surface area (F-N2). The efficiency of innovative matrices for immobilizing cesium and cobalt radionuclides is presented in this work. The aim of the present study is to investigate the possibility of solidifying 137Cs and 60Co radionuclides in synthetic fly ash zeolite cement. Leaching behavior of the radionuclides have been studied. The leachability index measured indicated that fly ash zeolite cement matrix can be utilized as an efficient material for immobilizing cesium and cobalt radionuclides than portland cement.

  3. Sequential electrodialytic recovery of phosphorus from low-temperature gasification ashes of chemically precipitated sewage sludge

    DEFF Research Database (Denmark)

    Parés Viader, Raimon; Erland Jensen, Pernille; Ottosen, Lisbeth M.;

    2016-01-01

    Phosphorus recycling from secondary materials like sewage sludge ashes offers an interesting alternative to imported mineral phosphates. However, a separation of P from the bulk ash is normally required, due to its low plant availability and the presence of heavy metals. More than 80% of P...... was recovered from incineration sewage sludge ashes in the past using a two-compartment electrodialytic cell. In contrast, the recovery was below 30% for ashes from low-temperature gasification using the same setup, due to the high presence of Al- and Fe(III)-P bindings. In the present study, an electrodialytic...... process combining sequentially a pair of two-compartment cells allowed a recovery of up to 70% of phosphorus from these ashes. The use of a second cell, where the ashes were treated in an alkaline pH, allowed the P solubilisation from aluminium and ferric phosphates and its separation from most metals...

  4. Measuring Water Vapor and Ash in Volcanic Eruptions with a Millimeter-Wave Radar/Imager

    CERN Document Server

    Bryan, Sean; Vanderkluysen, Loÿc; Groppi, Christopher; Paine, Scott; Bliss, Daniel W; Aberle, James; Mauskopf, Philip

    2016-01-01

    Millimeter-wave remote sensing technology can significantly improve measurements of volcanic eruptions, yielding new insights into eruption processes and improving forecasts of drifting volcanic ash for aviation safety. Radiometers can measure water vapor density and temperature inside eruption clouds, improving on existing measurements with infrared cameras that are limited to measuring the outer cloud surface. Millimeter-wave radar can measure the 3D mass flow of volcanic ash inside eruption plumes and drifting fine ash clouds, offering better sensitivity than existing weather radar measurements and the unique ability to measure ash particle size in-situ. Here we present sensitivity calculations in the context of developing the WAMS (Water and Ash Millimeter-wave Spectrometer) instrument. WAMS, a radar/radiometer system constructed with off-the-shelf components, would be able to measure water vapor and ash throughout an entire eruption cloud, a unique capability.

  5. Electroremediation of straw and co-combustion ash under acidic conditions

    DEFF Research Database (Denmark)

    Lima, Ana T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2009-01-01

    Biomass, such as wood and straw, is currently used in EU as a renewable energy source for energy production and this application is expected to rise in coming years. Combined heat and power installations produce fly ash, which is considered hazardous waste. The fly ash management issue should...... be addressed before biomass combustion is considered a truly sustainable technology. The electrodialytic process is a remediation technique able to assist the management of fly ash. For this work, straw and co-combustion of wood ash are briefly characterized and their electrodialytic treatment is carried out...... similarities with wood ash alone. However, further characterization should be carried out before any comparison regarding applicable legislation. Under acidic conditions, the electrodialytic treatment was not effective for the co-combustion wood ash. The heavy metals appeared in the least soluble fraction...

  6. Electrodialytic Separation of Phosphorus and Heavy Metals from Two Types of Sewage Sludge Ash

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Jensen, Pernille Erland; Kirkelund, Gunvor Marie

    2014-01-01

    of P and heavy metals is required. The present work is an experimental screening of a new combination of acid extraction and electrodialysis–electrodialytic separation (EDS) for simultaneous P recovery and removal of heavy metals. Experiments were conducted with two different ashes; rich in Fe or Al......During sewage sludge incineration phosphorus (P) is retained in the ash in a form not directly available to plants. As P is a sparse resource, it is important to develop techniques for recovery of P from incinerated sewage sludge ashes (ISSA). Heavy metals are concentrated in ISSA and separation....... The separation method was best suited for the Fe-rich ash, where it was possible to separate P into one processing solution, heavy metals (Cu, Zn, Ni, Pb) into another, keeping the ash suspended in a third solution (which though still contained P after 1 week of EDS). For the Al rich ash, the separation...

  7. Ash after forest fires. Effects on soil hydrology and erosion

    Science.gov (United States)

    Bodí, Merche B.

    2013-04-01

    from certain Eucaliptus and Pinus), or if clog soil pores (depending also on the soil type). If ash is wettable, it can store even 80% of its volume and then it will delay and reduce overland flow proportionally to the thickness of the ash layer. Once ash gets saturated, the flow tends to adjust to an infiltration rate similar to the soil itself, or sometimes higher due to the protection of ash that can reduce soil water repellency and soil sealing (Bodí et al. 2011, 2012). Still, many other aspects on ash remain unknown and ash present us more questions like, what it is its role on the carbon cycle? what is the extent of the ahs effects at basin scale? what is the fate of ash and how long it remains in the ecosystem? are there specific effects of ash depending on the ecosystem and so the type of ash? Acknowledgements This work was supported financially by a research fellowship (AP2007-04602) from the Spanish Ministry of Science and Innovation (M.B. Bodí) and the projects PT2009-0073 and CGL2010-21670-C02-01. References Bodí, M.B., Mataix-Solera, J., Doerr, S.H., Cerdà, A., 2011, The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma 160, 599-607. Bodí, M.B., Doerr, S.H., Cerdà, A., Mataix-Solera, J., 2012, Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soil. Geoderma 191, 14-23 Cerdà, A., 1998, Changes in overland flow and infiltration after a rangeland fire in a Mediterranean scrubland. Hydrological Processes 12, 1031-1042. Cerdà, A., Doerr, S.H., 2008, The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena 74, 256-263. Woods, S.W., Balfour, V., 2008, The effect of ash on runoff and erosion after a forest wildfire, Montana, U.S.A. International Journal of Wildland Fire 17, 535-548.

  8. 镀锌灰的热酸浸出和除铁试验研究%Research on Leaching of Zinc Using Hot Acid From Zinc Ash and Removal of Iron From Leaching Solution by Jarosite Process

    Institute of Scientific and Technical Information of China (English)

    何小凤; 李运刚; 陈金

    2014-01-01

    By single factor experiments ,leaching of zinc using hot acid from zinc ash and removal of iron from the leaching solution by jarosite process were researched .The results show that the optimum conditions for leaching zinc are determined as follow s initial acid concentration of 150 g/L ,leaching temperature of 90 ℃ ,ratio between liquid volume and solid mass of 6∶1 .At the optimum conditions , the leaching rate of zinc is more than 97% .Removal of iron is over 98% under the conditions of temperature of 90 ℃ ,reaction time of 3 h .%采用单因素试验法研究了从镀锌灰中热酸浸出锌及黄钾铁矾法除铁。试验结果表明:在硫酸初始质量浓度为150 g/L、浸出温度90℃、浸出时间3 h、液固体积质量比6∶1条件下,锌浸出率在97%以上;用黄钾铁矾法除铁,在温度90℃、反应时间3 h条件下,铁去除率在98%以上。

  9. The Future Resources for Eco-building Materials: II.Fly Ash and Coal Waste

    Institute of Scientific and Technical Information of China (English)

    LI Hui; XU Delong

    2009-01-01

    To use fly ash and coal waste effectively,the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed,such as utilizing fly ash as the component of fly ash cement and low heat cement after the processes of separation,removal of carbon remains and fine comminution,calcining coal waste into kaolin and meta-kaolin with suspension technology,and preparing clinkerless alkali-activated geopolymer materials with fly ash and meta-kaolin.

  10. MORPHOLOGICAL AND MICROSTRUCTURAL CHANGES DURING THE HEATING OF SPHERICAL CALCIUM ORTHOPHOSPHATE AGGLOMERATES PREPARED BY SPRAY PYROLYSIS

    Institute of Scientific and Technical Information of China (English)

    Kiyoshi Itatani; Mari Abe; Tomohiro Umeda; Ian J. Davies; Seiichiro Koda

    2004-01-01

    The microstructural changes taking place during heating of calcium orthophosphate (Ca3(PO4)2) agglomerates were examined in this study. The starting powder was prepared by the spray-pyrolysis of calcium phosphate (Ca/P air-liquid nozzle. The spray-pyrolyzed powder was found to be composed of dense spherical agglomerates with a mean diameter of 1.3 μm. This powder was further heat-treated at a temperature between 800 and 1400 ℃ for 10 min. When the spray-pyrolyzed powder was heated up to 900 ℃, only βCa3(PO4)2 was detected, and the mean pore size of the spherical agglomerates increased via the (i) elimination of residual water and nitrates, (ii) rearrangement of primary particles within the agglomerates, (iii) coalescence of small pores (below 0.1 μm), and (iv) coalescence of agglomerates with diameters below 1 μm into the larger agglomerates. Among the heat-treated powders, pore sizes within the spherical agglomerates were observed to be the largest (mean diameter: 1.8 μm) for the powder heat-treated at 900 ℃ for 10 min.With an increase in heat-treatment temperature up to 1000 ℃, the spherical agglomerates were composed of dense shells. Upon further heating up to 1400 ℃, the hollow spherical agglomerates collapsed as a result of sintering via the phase transformation from β- to α-Ca3(PO4)2 (1150 ℃), thus leading to the formation of a three-dimensional porous network.

  11. Characteristics of the ultrafine component of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    M.R. Jones; A. McCarthy; A.P.P.G. Booth [University of Dundee, Dundee (United Kingdom). Concrete Technology Unit, Division of Civil Engineering

    2006-11-15

    Post-production processing of fly ash (FA) is an important issue for its use in concrete. Given (i) the need for environmental protection, (ii) the measures being applied on coal-fired power stations to reduce acidic gas emissions and (iii) the effect these have had on fly ash quality, there is a need to consider efficient post-production processing to enhance fly ash characteristics. This is particularly important for fly ash used as a cement in concrete production, since the additional residual carbon content and decreased fineness significantly affect its quality. This paper details the material characteristics of an ultrafine, low-lime fly ash (UF-FA), produced, in this case, by processing a coarse FA (referred to as parent FA) from a bituminous coal-fired power station via air-cyclonic separation. The UF-FA is shown to have much improved material characteristics compared to the parent FA in terms of morphology, mineralogy and chemical composition. Further results are presented on the effect of UF-FA on the properties of cementitious systems. Improved consistence and compressive strengths of combined Portland cement (PC) and UF-FA mortars were observed, whilst enhanced PC hydration and a high degree of FA reactivity were concluded from heat of hydration measurements and calcium hydroxide contents of pastes. 20 refs., 10 figs., 1 tab.

  12. Characterization of ashes from biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.J.; Hansen, L.A. [Technical Univ. of Denmark. Dept. of Chemical Engineering (Denmark); Soerensen, H.S. [Geological Survey of Denmark and Greenland (Denmark); Hjuler, K. [dk-TEKNIK. Energy and Environment (Denmark)

    1998-02-01

    One motivation for initiating the present project was that the international standard method of estimating the deposit propensity of solid fuels, of which a number of variants exist (e.g. ISO, ASTM, SD, DIN), has shown to be unsuitable for biomass ashes. This goal was addressed by the development of two new methods for the detection of ash fusibility behaviour based on Simultaneous Thermal Analysis (STA) and High Temperature Light Microscopy (HTLM), respectively. The methods were developed specifically for ashes from biofuels, but are suitable for coal ashes as well. They have been tested using simple salt mixtures, geological standards and samples from straw CHP and coal-straw PF combustion plants. All samples were run in a nitrogen atmosphere at a heating rate of 10 deg. C/min. In comparison with the standard method, the new methods are objective and have superior repeatability and sensitivity. Furthermore, the two methods enable the melting behavior to be characterized by a continuous measurement of melt fraction versus temperature. Due to this two-dimensional resolution of the results, the STA and HTLM methods provide more information than the standard method. The study of bottom ash and fly ash as well as deposit samples from straw test firings at the Haslev and Slagelse Combined Heat and Power plants resulted in a better understanding of mineral behaviour during straw grate firing. In these tests a number of straws were fired which had been carefully selected for having different qualities with respect to sort and potassium and chlorine contents. By studying bottom ashes from Slagelse it was found that the melting behaviour correlated with the deposition rate on a probe situated at the outlet part of the combustion zone. (EG)

  13. Gravitational agglomeration of post-HCDA LMFBR nonspherical aerosols

    Science.gov (United States)

    Tuttle, R. F.

    1980-12-01

    A theoretical investigation of collisional dynamics of two particle interactions in a gravitational field is reported. This research is unique in that it is the first attempt at modeling the hydrodynamic interactions between a nonspherical particle and a spherical particle undergoing gravitational collisions in an LMFBR environment. Basic definitions and expressions are developed for nonspherical particles and related to spherical particles by means of shape factors. Using volume equivalent diameter as the defining length in the gravitational collision kernel, the aerodynamic shape factor, k, the density correction factor, alpha, and the gravitational collision shape factor, beta, are used to correct the collision kernel for the case of collisions between aerosol agglomerates. The Navier-Stokes equation in oblate spheroidal coordinates is solved to model a nonspherical particle and then the dynamic equations for two particle motions are developed. A computer program NGCEFF is constructed, the Navier-Stokes equation is solved by the finite difference method, and the dynamical equations are solved by Gear's method. It is concluded that the aerosol gravitational collision shape factor can be determined by further theoretical work based on the concepts and methods developed in this dissertation.

  14. Nearshore dynamics of artificial sand and oil agglomerates.

    Science.gov (United States)

    Dalyander, P Soupy; Plant, Nathaniel G; Long, Joseph W; McLaughlin, Molly

    2015-07-15

    Weathered oil can mix with sediment to form heavier-than-water sand and oil agglomerates (SOAs) that can cause beach re-oiling for years after a spill. Few studies have focused on the physical dynamics of SOAs. In this study, artificial SOAs (aSOAs) were created and deployed in the nearshore, and shear stress-based mobility formulations were assessed to predict SOA response. Prediction sensitivity to uncertainty in hydrodynamic conditions and shear stress parameterizations were explored. Critical stress estimates accounting for large particle exposure in a mixed bed gave the best predictions of mobility under shoaling and breaking waves. In the surf zone, the 10-cm aSOA was immobile and began to bury in the seafloor while smaller size classes dispersed alongshore. aSOAs up to 5 cm in diameter were frequently mobilized in the swash zone. The uncertainty in predicting aSOA dynamics reflects a broader uncertainty in applying mobility and transport formulations to cm-sized particles.

  15. Natural and agglomerated stone durability assessment according to technical standards

    Directory of Open Access Journals (Sweden)

    Ivana Šimková

    2010-01-01

    Full Text Available The assessment of rock behaviour and durability plays an important role in the use of rocks and similar materials for all building purposes. Durability is a complex term, therefore the paper deals with the terminology and aspects related to the evaluation and prediction possibilities of stone durability. Technical standards offer some laboratory procedures suitable for stone durability assessment. The paper presents the results of the application of some standard laboratory methods on select types of natural and agglomerated stones, from the physical properties determination and durability assessment point of view. On the basis of defined criteria of physical properties, such as the value of open porosity, uniaxial compressive strength and water absorption, was predicted the behaviour of selected stones against ageing and weathering. Results of the realised laboratory weathering tests such as the determination of resistance to frost and salt crystallisation, determination of resistance to ageing by SO2 action in the presence of humidity, and determination of resistance to thermal shock, confirmed and verified rock behaviour conditional on stone genesis, mineral composition and structural characteristics.

  16. Magnetic Agglomeration Among Nd-Fe-B Particles and Its Influence on Field Aligning

    Institute of Scientific and Technical Information of China (English)

    何叶青; 王震西; 周寿增; 张臻蓉; 韩宝善

    2004-01-01

    There exists strong magnetic agglomeration among Nd-FeB particles. Due to this effect, an applied field even up to 1350 kAm-1 still can not make the loose Nd-Fe-B powders to reach saturated magnetization. SEM images of a little amount of Nd-Fe-B powders were used to illustrate the agglomeration phenomenon. We believe that the general existence of misalignment grains in the magnetic force images of the sintered Nd-FeB magnet fabricated by die pressing with 1500 kAm-1 aligning field is a confirmation of the magnetic agglomeration.

  17. Cooperative Game Among Cities in Urban Agglomerations and Economical Sustainable Development

    Institute of Scientific and Technical Information of China (English)

    Shah Weidong

    2004-01-01

    This paper analyses redounded profits of cooperation and non-cooperation among cities in urban agglomerations based on game theory. It discusses the problems of economical development among cities with feeble cooperation, and deduces the conclusion that only cooperation of cities produces the maximum profits and realizes Pareto efficiency for cities and urban agglomerations. The paper states that cooperation is the cornerstone of economic sustainable development in urban agglomerations in profits produced by cooperation among cities.Some suggestions to accelerate cooperation among cities are proposed.

  18. Precious Metals in Municipal Solid Waste Incineration Bottom Ash

    Energy Technology Data Exchange (ETDEWEB)

    Muchova, Lenka; Bakker, Erwin; Rem, Peter [Faculty of Civil Engineering and Geosciences, Materials and Environment, TU Delft (Netherlands)], E-mail: P.C.REM@TUDELFT.NL

    2009-04-15

    Municipal solid waste incineration (MSWI) bottom ash contains economically significant levels of silver and gold. Bottom ashes from incinerators at Amsterdam and Ludwigshafen were sampled, processed, and analyzed to determine the composition, size, and mass distribution of the precious metals. In order to establish accurate statistics of the gold particles, a sample of heavy non-ferrous metals produced from 15 tons of wet processed Amsterdam ash was analyzed by a new technology called magnetic density separation (MDS). Amsterdam's bottom ash contains approximately 10 ppm of silver and 0.4 ppm of gold, which was found in particulate form in all size fractions below 20 mm. The sample from Ludwigshafen was too small to give accurate values on the gold content, but the silver content was found to be identical to the value measured for the Amsterdam ash. Precious metal value in particles smaller than 2 mm seems to derive mainly from waste of electrical and electronic equipment (WEEE), whereas larger precious metal particles are from jewelry and constitute the major part of the economic value. Economical analysis shows that separation of precious metals from the ash may be viable with the presently high prices of non-ferrous metals. In order to recover the precious metals, bottom ash must first be classified into different size fractions. Then, the heavy non-ferrous (HNF) metals should be concentrated by physical separation (eddy current separation, density separation, etc.). Finally, MDS can separate gold from the other HNF metals (copper, zinc). Gold-enriched concentrates can be sold to the precious metal smelter and the copper-zinc fraction to a brass or copper smelter.

  19. A novel recovery technology of trace precious metals from waste water by combining agglomeration and adsorption

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel and efficient technology for separating and recovering precious metals from waste water containing traces of Pd and Ag was studied by the combination of agglomeration and adsorption. The recovery process and the impacts of operating conditions such as pH value of waste water, adsorption time, additive quantity of the flocculant and adsorbent on the recovery efficiency were studied experimentally. The results show that Freundlich isothermal equation is suitable for describing the behavior of the recovery process, and the apparent first-order adsorption rate constant k at 25 ℃ is about 0.233 4 h-1 The optimum technology conditions during the recovery process are that pH value is 8-9; the volume ratio of flocculant to waste water is about 1 :(2 000-4 000); the mass ratio of adsorbent to waste water is 1 :(30-40); and processing time is 2-4 h. Finally, the field tests were done at the optimum technology conditions, which show that the total concentration of Pd and Ag in the waste water below 11 mg/L can be reduced to be less than 1 mg/L.

  20. Morphological characterization with image analysis of cocoa beverage powder agglomerated with steam

    Directory of Open Access Journals (Sweden)

    Fernanda Zaratini Vissotto

    2014-12-01

    Full Text Available In this study, the morphological characteristics of cocoa beverage powder granules under minimal, average, and maximal process conditions of a steam agglomerator were studied. a stereoscopic microscope coupled to a digital camera was used for the morphological analysis. The images were analyzed to obtain shape and size descriptors. aiming to evaluate the descriptors, 150 particles were analyzed. The results showed that there was no difference between the shape descriptors - compacity, circularity, roughness, and aspect ratio - in the operating conditions evaluated. It was observed that the cocoa beverage powder granules are elongated in shape. The size descriptors, area, perimeter, perimeter of convex bounding polygon, minimal and maximal Feret diameter, were different in the process conditions for the granules of size above 600 μm. as for the minimal process conditions, especially due to low solid feed rates, there is an increase in the size descriptor values. In addition, under the minimum process conditions, in which there is low solid feed rate (400g/min for a steam pressure of 1.0 bar, it was obtained a good granular condition with retention of 81.1% of granules on sieves with aperture size between 300 and 1190 μm.