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Sample records for fully liquid slags

  1. Gravitational segregation of liquid slag in large ladle

    Directory of Open Access Journals (Sweden)

    J. Chen

    2012-04-01

    Full Text Available The process of gravitational segregation makes liquid steel slag components occur differentiation. And it shows that the upper part slag in the slag ladle contains higher CaO; and the lower part slag contains higher SiO2. The content of MgO (5,48 % in the upper part slag is higher than that of the lower part (2,50 %, and only Al2O3 content of the upper and the lower part slag is close to each other. The difference of chemical compositions in the slag ladle shows that there is gravitational segregation during slow solidification of liquid steel slag, which will has some impact of the steel slag processing on the large slag ladle.

  2. Evaluation of Existing Viscosity Data and Models and Developments of New Viscosity Model for Fully Liquid Slag in the SiO2-Al2O3-CaO-MgO System

    Science.gov (United States)

    Han, Chen; Chen, Mao; Zhang, Weidong; Zhao, Zhixing; Evans, Tim; Zhao, Baojun

    2016-10-01

    Metallurgical properties of slag are determined to a great extent by its viscosity. High-temperature viscosity measurements are time-consuming and expensive. It is necessary to develop an accurate viscosity model for blast furnace slag in the SiO2-Al2O3-CaO-MgO system using reliable viscosity data. This paper describes a systemic evaluation procedure to determine the viscosity data to be used for model development. 1780 viscosity data from 10 to 65 wt pct SiO2, 3.5 to 40 wt pct Al2O3, 2 to 60 wt pct CaO, and 2 to 38 wt pct MgO in the SiO2-Al2O3-CaO-MgO system have been accepted for model evaluation after critical reviews. The existing 14 viscosity models in SiO2-Al2O3-CaO-MgO system is also reviewed and evaluated. Based on the structure of alumina-silicate slag and evaluated viscosity data, a new viscosity model has been proposed for the system SiO2-Al2O3-CaO-MgO. A new term "probability," based on the basic oxide and electronegativity, is introduced to calculate the integral activation energy of slag. The model has been evaluated and compared with existing viscosity models in three different composition ranges in SiO2-Al2O3-CaO-MgO system for different applications. The new model reports an outstanding agreement between predictions and experimental data. The industrial implications of the new model have also been discussed in ironmaking and steelmaking processes.

  3. Corrosion Behavior of Ceramic Cup of Blast Furnace Hearth by Liquid Iron and Slag

    Science.gov (United States)

    Li, Yanglong; Cheng, Shusen; Wang, Zhifeng

    2016-10-01

    Three kinds of sample bricks of ceramic cups for blast furnace hearth were studied by dynamic corrosion tests based on different corrosion systems, i.e., liquid iron system, liquid slag system and liquid iron-slag system. Considering the influence of temperature and sample rotational speed, the corrosion profiles and mass loss of the samples were analyzed. In addition, the microstructure of the corroded samples was observed by optical microscope (OM) and scanning electron microscope (SEM). It was found that the corrosion profiles could be divided into iron corrosion region, slag corrosion region and iron-slag corrosion region via corrosion degree after iron-slag corrosion experiment. The most serious corrosion occurred in iron-slag corrosion region. This is due to Marangoni effect, which promotes a slag film formed between liquid iron and ceramic cup and results in local corrosion. The corrosion of the samples deepened with increasing temperature of liquid iron and slag from 1,623 K to 1,823 K. The variation of slag composition had greater influence on the erosion degree than that of rotational speed in this experiment. Taking these results into account the ceramic cup composition should be close to slag composition to decrease the chemical reaction. A microporous and strong material should be applied for ceramic cup.

  4. Heating and melting mechanism of stainless steelmaking dust pellet in liquid slag

    Institute of Scientific and Technical Information of China (English)

    PENG ji; TANG Mo-tang; PENG Bing; YU Di; J.A.KOZINSKl; TANG Chao-bo

    2007-01-01

    The heating and melting mechanisms of the pellets immersed in liquid slag were investigated. and the effect of the pellet heating and the melting conditions were studied. The results show that the dust component in the pellet is melted from the surface and no metallic elements are melted before the dust component, the time for the pellet completely melted is reduced as the iron powder content increases since the metallic iron has high thermal conductivity. These are four stages of heating and melting of pellet in liquid slag, they are the growth and melt of solid slag shell, penetration of liquid slag, dissolving of dust component and melring of reduced metals.The lifetime of the solid slag shell is in the range of 7-16 s and increasing the pre-heating temperature of the pellet and the slag temperature can shorten the slag shell liretime. The time for the dust component in the pellet to be melted completely is in the range of 20-45 s and increasing the pre-heating temperature, especially in the range of 600-800 ℃.can obviously reduce the melting time. A higher slag temperature can also improvethe pellet melting and the melting time is reduced by l0-15 s when the slag temperature is increased from 1 450 to 1 550 ℃.The pellet with higher content of iron powder is beneficial to the melting by improving the heat conductivity.

  5. Reduction of molybdenum oxide from steelmaking slags by pure liquid iron

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    Gao Y.M.

    2012-01-01

    Full Text Available The effects of reaction temperature, slag basicity and FeO concentration on the reduction of molybdenum oxide from steelmaking slags by pure liquid iron were investigated experimently. The reduction kinetics of molybdenum oxide by liquid iron was analysed. The reaction models were developed based on the condition that diffusion of [Mo] in liquid iron and CaMoO4 in slag is the control steps, respectively. These reaction models were tested using data from a series of experiments. The results indicate that under the present experimental conditions, the temperature and the FeO content, other than slag basicity, have some effects on the reduction of molybdenum oxide from steelmaking slags by pure liquid iron. Both the molybdenum oxide reduction rate and final reduction ratio increase with an increase of temperature and a decrease of FeO content. The diffusion of CaMoO4 in slag which dominated overall reduction process is the only one ratecontrolling step with its apparent activation energy 294 kJ/mol. The reduction of molybdenum oxide used directly as alloy additive can be further enhanced by strong stirring in the converter practice.

  6. Applicability of mass action law to sulphur distribution between slag melts and liquid iron

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    According to the mass action law and the coexistence theory of slag structure, the calculating models of mass action concentration for CaO-MgO-FeO-Fe2O3-SiO2, CaO-MgO-MnO-FeO-Fe2O3-P2O5-SiO2 and CaO-MgO-MnO-FeO-Fe2O3-Al2O3-P2O5-SiO2 slag melts are formulated and sulphur distribution between the slag melts and liquid iron is treated. It is found that CaO, MnO and FeO promote desulphurization, while MgO is detrimental to desulphurization. In addition, the sulphur distribution coefficients between the slag melts and liquid iron are presented.

  7. Reactions Between Liquid CaO-SiO2 Slags and Graphite Substrates

    Science.gov (United States)

    White, Jesse F.; Lee, Jaewoo; Hessling, Oscar; Glaser, Bjoern

    2017-02-01

    In this study, the spreading and infiltration behavior of liquid slag in contact with different grades of graphite was investigated. The wetting and infiltration of slag into graphite were found to be highly material dependent. The reduction of silica by carbon is a characteristic of the system, and it generates gaseous products as evidenced by the observation of bubble formation. The higher the temperature and silica activity of the slag is, the greater the slag infiltration and the faster the rate of spreading. Silicon infiltrated into the graphite substrates much deeper than the oxide phases, indicating gas-phase transport of SiO(g) into the graphite pores. Fundamentally, in this system where the liquid and substrate are reacting, the driving force for spreading is the movement of the system toward a lower total Gibbs energy. Reduction of silica in the slag near the interface may eventually lead to the formation of a solid, CaO-rich layer, slowing down or stopping the reduction reaction.

  8. A thermodynamic study of silica-saturated iron silicate slags in equilibrium with liquid copper

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    Oishi, Toshio; Kamuo, Morinori; Ono, Katsutoshi; Moriyama, Joichiro

    1983-03-01

    The thermodynamic properties of silica-saturated iron silicate slags in equilibrium with liquid copper have been studied from oxygen partial pressure measurements in the temperature range from 1490 to 1580 K by means of a solid electrolyte galvanic cell. The following cells were used: Pt, Ni-NiO/O=/slag-Cu(l), Cr2O3, Pt; Pt, Fe-FeO/O=/slag-Cu(Fe sat.), Fe. A strong correlation was found between oxygen pressure and the copper content of the slag; the copper content increased from less than 1 pct near iron saturation to about 4 pct at an oxygen partial pressure of 7.2 x 10-3 Pa. A similar correlation was found between the ferric iron/total iron ratio and the oxygen pressure. The oxygen content in liquid copper decreased with increasing iron content in liquid copper and increased slightly near iron saturation. This behavior could be explained qualitatively by using the standard free energy of formation of FeO and the activities of components.

  9. Slag wool manufacturing from blast furnace slag

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Руських

    2016-11-01

    Full Text Available Slag wool is the most expensive and valuable product of blast furnace slag processing. Slag wool is in great demand nowadays. The article highlights the factors influencing the mineral wool quality: chemical composition that determines the acidity of the module, the temperature of the molten slag and the required slag jet thickness consistency. Mineral wool is produced by blowing air or steam into a jet of molten slag. As a result of it the slag crushes into droplets stretching. The resulting wool contains 5% slag and 95% air. The quality of the obtained slag wool depends on the module acidity of the slag. The blast furnace slags of «Ilyich iron and steel works of Mariupol» and «Azovstal iron & steel works» are the main (short slags – they give short fibers. To obtain high-quality long fiber wool it is necessary to add admixtures into basic blast furnace slag to reduce its basicity. As a result of the fuel and energy rising prices and the necessity to reduce the slag wool cost it is necessary to develop a new technology with fiery-liquid slag, with the removal of iron compounds and sulphur from the melts and the introduction of corrective additives to improve the quality of slag wool. Good thermal conductivity (about 0,03 kcal/m∙h∙°C and other indicators (resistance, volume weight make it possible to use the materials from slag wool (pads, rigid and semi-rigid plates as heat and sound insulating materials

  10. Interfacial Tension in the CaO-Al2O3-SiO2-(MgO) Liquid Slag-Solid Oxide Systems

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    Abdeyazdan, Hamed; Monaghan, Brian J.; Longbottom, Raymond J.; Rhamdhani, M. Akbar; Dogan, Neslihan; Chapman, Michael W.

    2017-08-01

    Interfacial phenomenon is critical in metal processing and refining. While it is known to be important, there are little data available for key oxide systems in the literature. In this study, the interfacial tension ( σ LS) of liquid slag on solid oxides (alumina, spinel, and calcium aluminate), for a range of slags in the CaO-Al2O3-SiO2-(MgO) system at 1773 K (1500 °C), has been evaluated. The results show that basic ladle-type slags exhibit lower σ LS with oxide phases examined compared to that of acid tundish-type slags. Also, within the slag types (acid and base), σ LS was observed to decrease with increasing slag basicity. A correlation between σ LS and slag structure was observed, i.e., σ LS was found to decrease linearly with increasing of slag optical basicity (Λ) and decrease logarithmically with decreasing of slag viscosity from acid to base slags. This indicated a higher σ LS as the ions in the slag become larger and more complex. Through a work of adhesion ( W) analysis, it was shown that basic ladle slags with lower σ LS result in a greater W, i.e., form a stronger bond with the solid oxide phases examined. This indicates that all other factors being equal, the efficiency of inclusion removal from steel of inclusions of similar phase to these solid oxides would be greater.

  11. Efficiency of a blast furnace slag cement for immobilizing simulated borate radioactive liquid waste.

    Science.gov (United States)

    Guerrero, A; Goñi, S

    2002-01-01

    The efficiency of a blast furnace slag cement (Spanish CEM III/B) for immobilizing simulated radioactive borate liquid waste [containing H3BO3, NaCl, Na2SO4 and Na(OH)] has been evaluated by means of a leaching attack in de-mineralized water at the temperature of 40 degrees C over 180 days. The leaching was carried out according to the ANSI/ANS-16.1-1986 test. Moreover, changes of the matrix microstructure were characterized through porosity and pore-size distribution analysis carried out by mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) and thermal analysis (TG). The results were compared with those obtained from a calcium aluminate cement matrix, previously published.

  12. Bubbling at high flow rates in inviscid and viscous liquids (slags)

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    Engh, T. Abel; Nilmani, M.

    1988-02-01

    The behavior of gas discharging into melts at high velocities but still in the bubbling regime has been investigated in a laboratory modeling study for constant flow conditions. Air or helium was injected through a vertical tuyere into water, zinc-chloride, and aqueous glycerol solutions. High speed cinematography and pressure measurements in the tuyere have been carried out simultaneously. Pressure fluctuations at the injection point were monitored and correlated to the mode of bubble formation. The effects of high gas flow rates and high liquid viscosities have been examined in particular. Flow rates were employed up to 10-3 m3/s and viscosity to 0.5 Ns/m2. In order to attain a high gas momentum, the tuyere diameter was only 3 x 10-3 m. The experimental conditions and modeling liquids were chosen with special reference to the established practice of submerged gas injection to treat nonferrous slags. Such slags can be highly viscous. Bubble volume is smaller than that calculated from existing models such as those given by Davidson and Schüler10,11 due to the effect of gas momentum elongating the bubbles. On the other hand, viscosity tends to retard the bubble rise velocity, thus increasing volumes. To take elongation into account, a mathematical model is presented that assumes a prolate ellipsoidal shape of the bubbles. The unsteady potential flow equations for the liquid are solved for this case. Viscous effects are taken into account by noting that flow deviates from irrotational motion only in a thin boundary layer along the surface of the bubble. Thus, drag on the bubble can be obtained by calculating the viscous energy dissipation for potential flow past an ellipse. The time-dependent inertia coefficient for the ellipsoid is found by equating the vertical pressure increase inside and outside the bubble. This pressure change in the bubble is obtained by assuming that gas enters as a homogeneous jet and then calculating the stagnation pressure at the apex of

  13. Investigation into the Pozzolanic Actionof the Liquid Slag%液态渣火山灰效应的研究

    Institute of Scientific and Technical Information of China (English)

    贾福根

    2001-01-01

    从微观形貌、水化产物、显微硬度等方面对液态渣的火山灰效应进行了研究,结果表明,液态渣的火山灰效应可使混凝土的界面结构致密化,从而改善了混凝土的宏观力学性能。%The Pozzolanic Action of the liquid slag has been studied in terms of micromorphology, hydrated products, microhardness. Results show that the liquid slag has an activation effect and the hydration products can densify the transition zone.

  14. Study on the Kinetics of Aluminum Removal from Liquid Silicon to Slag with Mechanical Stirring

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    Lee, Jaewoo; White, Jesse F.; Hildal, Kjetil; Sichen, Du

    2016-12-01

    The kinetics of aluminum removal from silicon melt to CaO-SiO2-Al2O3 slag was studied. A recently designed experimental setup using mechanical stirring was employed to focus the study on the chemical reaction. The slag and metal were found to reach chemical equilibrium in 300 seconds. A simple model could reproduce the experimental data satisfactorily. Both the experimental results and the model prediction further confirmed that the process was controlled by the chemical reaction, since the reaction rate constant was found to be independent of the amount of slag and the initial slag composition. The experimental data at equilibrium were compared with the model calculations. The discrepancy between the model calculations and the experimental data strongly suggests the need for careful thermodynamic measurements.

  15. Smelting reduction of MgO in molten slag by liquid ferrosilicon

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Q.; Gao, J.; Chen, X.; Wei, X.

    2016-10-01

    The smelting reduction of magnesium oxide was researched in this paper. The effect of molten slag composition and reduction temperature on percent reduction of magnesium oxide were discussed, and kinetics of smelting reduction of magnesium oxide in molten slag was studied. The results showed that the reduction extent of magnesium oxide increased by increasing either one of the following factors: the initial mass ratio of Al{sub 2}O{sub 3}/SiO{sub 2}, the addition of CaF{sub 2}, the initial molar ratio of Si/2MgO, and reaction temperature. The overall smelting reduction was controlled by mass transfer in slag with an apparent activation energy 586 kJ mol{sup -}1. (Author)

  16. Smelting reduction of MgO in molten slag by liquid ferrosilicon

    Directory of Open Access Journals (Sweden)

    Tang, Qifeng

    2016-06-01

    Full Text Available The smelting reduction of magnesium oxide was researched in this paper. The effect of molten slag composition and reduction temperature on percent reduction of magnesium oxide were discussed, and kinetics of smelting reduction of magnesium oxide in molten slag was studied. The results showed that the reduction extent of magnesium oxide increased by increasing either one of the following factors: the initial mass ratio of Al2O3/SiO2, the addition of CaF2, the initial molar ratio of Si/2MgO, and reaction temperature. The overall smelting reduction was controlled by mass transfer in slag with an apparent activation energy 586 kJ mol-1.En este trabajo se estudia la reducción de óxido de magnesio. La influencia de la composición de las escorias y de la temperatura de reducción sobre el porcentaje de reducción de óxido de magnesio han sido discutidas, y asimismo se ha estudiado la cinética de la reducción del óxido de magnesio en escorias fundidas. Los resultados muestran que la reducción se incrementa al aumentar alguno de los siguientes factores: la proporción de Al2O3/SiO2, la adición de CaF2, la proporción molar de Si/2MgO y la temperatura de reacción. En general la reducción fue controlada por la transferencia de masa en la escoria con una energía aparente de 586 kJ mol-1.

  17. Kinetics of Reduction of MnO in Molten Slag with Carbon Undersaturated Liquid Iron

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The reduction of MnO in molten slag with carbon undersaturated iron was studied. It was found that the process is affected by the carbon content of molten metal and the temperature. The higher the carbon content and the temperature, the faster both the reduction and the emerging of the hump on curve of ωFeO, the larger the difference betwe en ωFeO, max and ωFeO, e. The phenomena were explained with three-step reaction model.

  18. Thermodynamic Behavior of Manganese and Phosphorus between Liquid Iron and CaO-MgO-SiO2-Al2O3-FetO-MnO-P2O5 Slags

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The thermodynamic behavior of manganese and phosphorus betwe en liquid iron and CaO-MgO-SiO2-Al2O3-FetO-MnO-P2O5 ladle slag system was addressed by investigating the thermodynamic equilibria between li quid iron containing Mn and P and the ladle slag at 1873K. The Mn dist ribution ratio LMn increases with increasing FetO content and decreasi ng the basicity ((%CaO + %MgO)/ +%Al2O3+%P2O5)) in slag, while the P d istribution ratio LP seems to be increased as FetO content and the bas icity increases. The values of LMn and LP decrease by the addition of Al2O3 into slag. The expression of the dependence of LMn and LP on the basicity and content in slag was obtained.

  19. Effect of Slag Chemistry on the Desulfurization Kinetics in Secondary Refining Processes

    Science.gov (United States)

    Kang, Jin Gyu; Shin, Jae Hong; Chung, Yongsug; Park, Joo Hyun

    2017-03-01

    Desulfurization behavior was investigated based on a wide slag composition and working temperature range. Moreover, the rate-controlling step (RCS) for desulfurization with regard to the ladle-refining conditions and the transition of the RCS by changing the slag composition was systematically discussed. The desulfurization ratio reached an equilibrium value within approximately 15 minutes irrespective of the CaO/Al2O3 (=C/A = 1.3 to 1.9) and CaO/SiO2 (=C/S = 3.8 to 6.3) ratios. However, the desulfurization behavior of less basic slags (C/A = 1.1 or C/S = 1.9) exhibited a relatively sluggish [S]-decreasing rate as a function of time. The equilibrium S partition ratio increased with an increase in slag basicity (C/A and C/S ratio), not only due to an increase in sulfide capacity but also due to a decrease in oxygen activity in the molten steel. There was a good correlation between the calculated and measured S partition ratios at various slag compositions. However, the measured S partition ratio increased by adding 5 pct CaF2, followed by a constant value. Multiphase slag exhibited a relatively slow desulfurization rate compared to that of fully liquid slag, possibly due to a decrease in the effective liquid slag volume, interfacial reaction area, and a relatively slow slag initial melting rate due to a high melting point. The activation energy of the desulfurization process was estimated to be 58.7 kJ/mol, from which it was proposed that the desulfurization reaction of molten steel via CaO-Al2O3-SiO2-MgO-CaF2 ladle slag was generally controlled by the mass transfer of sulfur in the metal phase. However, there was a transitional period associated with the rate-controlling mechanism due to a change in the physicochemical properties of the slag. For slag with a viscosity greater than about 1.1 dPa·s and an equilibrium S partition ratio lower than about 400, the overall mass-transfer coefficient was affected by the slag properties. Hence, it was theoretically and

  20. Effect of Slag Chemistry on the Desulfurization Kinetics in Secondary Refining Processes

    Science.gov (United States)

    Kang, Jin Gyu; Shin, Jae Hong; Chung, Yongsug; Park, Joo Hyun

    2017-08-01

    Desulfurization behavior was investigated based on a wide slag composition and working temperature range. Moreover, the rate-controlling step (RCS) for desulfurization with regard to the ladle-refining conditions and the transition of the RCS by changing the slag composition was systematically discussed. The desulfurization ratio reached an equilibrium value within approximately 15 minutes irrespective of the CaO/Al2O3 (=C/A = 1.3 to 1.9) and CaO/SiO2 (=C/S = 3.8 to 6.3) ratios. However, the desulfurization behavior of less basic slags (C/A = 1.1 or C/S = 1.9) exhibited a relatively sluggish [S]-decreasing rate as a function of time. The equilibrium S partition ratio increased with an increase in slag basicity (C/A and C/S ratio), not only due to an increase in sulfide capacity but also due to a decrease in oxygen activity in the molten steel. There was a good correlation between the calculated and measured S partition ratios at various slag compositions. However, the measured S partition ratio increased by adding 5 pct CaF2, followed by a constant value. Multiphase slag exhibited a relatively slow desulfurization rate compared to that of fully liquid slag, possibly due to a decrease in the effective liquid slag volume, interfacial reaction area, and a relatively slow slag initial melting rate due to a high melting point. The activation energy of the desulfurization process was estimated to be 58.7 kJ/mol, from which it was proposed that the desulfurization reaction of molten steel via CaO-Al2O3-SiO2-MgO-CaF2 ladle slag was generally controlled by the mass transfer of sulfur in the metal phase. However, there was a transitional period associated with the rate-controlling mechanism due to a change in the physicochemical properties of the slag. For slag with a viscosity greater than about 1.1 dPa·s and an equilibrium S partition ratio lower than about 400, the overall mass-transfer coefficient was affected by the slag properties. Hence, it was theoretically and

  1. Influence of Partial Pressure of Sulfur and Oxygen on Distribution of Fe and Mn between Liquid Fe-Mn Oxysulfide and Molten Slag

    Science.gov (United States)

    Kim, Sun-Joong; Shibata, Hiroyuki; Takekawa, Jun; Kitamura, Shin-Ya; Yamaguchi, Katsunori; Kang, Youn-Bae

    2012-10-01

    The authors proposed an innovative process for recovering Mn from steelmaking slag. The process starts with the sulfurization of steelmaking slag to separate P from Mn by the formation of a liquid sulfide phase (matte). Then, the obtained matte is weakly oxidized to make a Mn-rich oxide phase without P. High-purity Fe-Mn alloys can therefore be produced by the reduction of the Mn-rich oxide phase. However, to the authors' knowledge, the sulfurization of molten slag containing P and Mn has not been sufficiently investigated. It was recently found that P was not distributed to the matte in equilibrium with the molten slag. To gain knowledge of the process's development, it is important to investigate the influence of the partial pressures of sulfur and oxygen on the equilibrium distribution of Mn and Fe between the matte and the molten slag. In the current work, a mineralogical microstructure analysis of the matte revealed that the existence of the oxysulfide and metal phases was dependent on the partial pressure of sulfur and oxygen. The Mn content of the matte increased with partial pressure of sulfur while the O content of the matte decreased. In contrast, the ratio of Mn/Fe in the matte was constant when the metal phase of the matte was observed at a log P_{{{{O}}2 }} below -11. These results also corresponded to the relationship between the activity coefficient ratio of MnS/FeS and the mole fraction of MnS/FeS in the matte. The γ MnS/ γ FeS value decreased exponentially as the mole fraction of MnS/FeS increased.

  2. Thermodynamics of O, N, and S in liquid Fe equilibrated with CaO-AI2O3-MgO slags

    Science.gov (United States)

    Inoue, Ryo; Suito, Hideaki

    1994-04-01

    Nitrogen and S distribution ratios between CaO-Al2O3-MgO slags and liquid Fe were measured at 1873 K as a function of Al (or Mg, Ca) content in metal, using CaO, MgO, and A12O3 crucibles. Based on the results for the solubility product of MgO, the equilibrium constant, K Mg , for the reaction MgO = Mg + O and the first-order interaction parameter, e {O/Mg} ( e {Mg/O}), were estimated to be log K Mg = -7.8 ± 0.2 and e {O/Mg} = -190 ± 60 ( e {Mg/O} = -290 ± 90), respectively. The activities of A12O3 at the slag compositions double-saturated with CaO/MgO, MgO/ MgO A12O3, and MgO Al2O3/CaO 2A12O3 components were obtained from the S distribution ratios between slag and metal, coupled with the reported values of sulfide capacities. Nitride capacities were also estimated from the N distribution ratios and the activities of A12O3.

  3. Effect of Coal Properties and Operation Conditions on Flow Behavior of Coal Slag in Entrained Flow Gasifiers: A Brief Review

    Energy Technology Data Exchange (ETDEWEB)

    Wang,Ping; Massoudi, Mehrdad

    2011-01-01

    Integrated gasification combined cycle (IGCC) is a potentially promising clean technology with an inherent advantage of low emissions, since the process removes contaminants before combustion instead of from flue gas after combustion, as in a conventional coal steam plant. In addition, IGCC has potential for cost-effective carbon dioxide capture. Availability and high capital costs are the main challenges to making IGCC technology more competitive and fully commercial. Experiences from demonstrated IGCC plants show that, in the gasification system, low availability is largely due to slag buildup in the gasifier and fouling in the syngas cooler downstream of the gasification system. In the entrained flow gasifiers used in IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter (as fly ash) is entrained with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. Therefore, it is preferable to minimize the quantity of fly ash and maximize slag. In addition, the hot raw syngas is cooled to convert any entrained molten fly slag to hardened solid fly ash prior to entering the syngas cooler. To improve gasification availability through better design and operation of the gasification process, better understanding of slag behavior and characteristics of the slagging process are needed. Slagging behavior is affected by char/ash properties, gas compositions in the gasifier, the gasifier wall structure, fluid dynamics, and plant operating conditions (mainly temperature and oxygen/carbon ratio). The viscosity of the slag is used to characterize the behavior of the slag flow and is the dominating factor to determine the probability that ash particles will stick. Slag viscosity strongly depends on the temperature and chemical composition of the slag. Because coal has varying ash content and

  4. Fully Automated Laser Ablation Liquid Capture Sample Analysis using NanoElectrospray Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Matthias [ORNL; Ovchinnikova, Olga S [ORNL; Van Berkel, Gary J [ORNL

    2014-01-01

    RATIONALE: Laser ablation provides for the possibility of sampling a large variety of surfaces with high spatial resolution. This type of sampling when employed in conjunction with liquid capture followed by nanoelectrospray ionization provides the opportunity for sensitive and prolonged interrogation of samples by mass spectrometry as well as the ability to analyze surfaces not amenable to direct liquid extraction. METHODS: A fully automated, reflection geometry, laser ablation liquid capture spot sampling system was achieved by incorporating appropriate laser fiber optics and a focusing lens into a commercially available, liquid extraction surface analysis (LESA ) ready Advion TriVersa NanoMate system. RESULTS: Under optimized conditions about 10% of laser ablated material could be captured in a droplet positioned vertically over the ablation region using the NanoMate robot controlled pipette. The sampling spot size area with this laser ablation liquid capture surface analysis (LA/LCSA) mode of operation (typically about 120 m x 160 m) was approximately 50 times smaller than that achievable by direct liquid extraction using LESA (ca. 1 mm diameter liquid extraction spot). The set-up was successfully applied for the analysis of ink on glass and paper as well as the endogenous components in Alstroemeria Yellow King flower petals. In a second mode of operation with a comparable sampling spot size, termed laser ablation/LESA , the laser system was used to drill through, penetrate, or otherwise expose material beneath a solvent resistant surface. Once drilled, LESA was effective in sampling soluble material exposed at that location on the surface. CONCLUSIONS: Incorporating the capability for different laser ablation liquid capture spot sampling modes of operation into a LESA ready Advion TriVersa NanoMate enhanced the spot sampling spatial resolution of this device and broadened the surface types amenable to analysis to include absorbent and solvent resistant

  5. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Tervola, K. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquidus temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) SULA 2 Research Programme; 2 refs.

  6. Rotational viscosity of a liquid crystal mixture:a fully atomistic molecular dynamics study

    Institute of Scientific and Technical Information of China (English)

    Zhang Ran; Peng Zeng-Hui; Liu Yong-Gang; Zheng Zhi-Gang; Xuan Li

    2009-01-01

    Fully atomistic molecular dynamics(MD)simulations at 293, 303 and 313 K have been performed for the four. component liquid crystal mixture, E7, using the software package Material Studio. Order parameters and orientational time correlation functions(TCFs)were calculated from MD trajectories. The rotational viscosity coefficients(RVCs)of the mixture were ca]culated using the Nemtsov-Zakharov and Fialkowski methods based on statistical-mechanical approaches. Temperature dependences of RVC and density were discussed in detall. Reasonable agreement between the simulated and experimental values was found.

  7. Fully developed laminar flow of two immiscible liquids through horizontal pipes: a variational approach

    Energy Technology Data Exchange (ETDEWEB)

    Kurban, Adib Paulo Abdalla [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas; Bannwart, Antonio Carlos [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica

    1990-12-31

    The fully developed laminar flow of two immiscible liquids with both different viscosities and densities through a horizontal round pipe is studied. The interface between the fluids as well as their flow fields are determined by the use of a variational principle: the so called viscous dissipation principle: The results foreseen by this paper are in agreement with the physical observation (e.g. Southern and Ballman) that the more viscous fluid is total or partially encapsulated by the less viscous one. (author) 8 refs., 4 figs.

  8. Fully atomistic molecular-mechanical model of liquid alkane oils: Computational validation.

    Science.gov (United States)

    Zahariev, Tsvetan K; Slavchov, Radomir I; Tadjer, Alia V; Ivanova, Anela N

    2014-04-15

    Fully atomistic molecular dynamics simulations were performed on liquid n-pentane, n-hexane, and n-heptane to derive an atomistic model for middle-chain-length alkanes. All simulations were based on existing molecular-mechanical parameters for alkanes. The computational protocol was optimized, for example, in terms of thermo- and barostat, to reproduce properly the properties of the liquids. The model was validated by comparison of thermal, structural, and dynamic properties of the normal alkane liquids to experimental data. Two different combinations of temperature and pressure coupling algorithms were tested. A simple differential approach was applied to evaluate fluctuation-related properties with sufficient accuracy. Analysis of the data reveals a satisfactory representation of the hydrophobic systems behavior. Thermodynamic parameters are close to the experimental values and exhibit correct temperature dependence. The observed intramolecular geometry corresponds to extended conformations domination, whereas the intermolecular structure demonstrates all characteristics of liquid systems. Cavity size distribution function was calculated from coordinates analysis and was applied to study the solubility of gases in hexane and heptane oils. This study provides a platform for further in-depth research on hydrophobic solutions and multicomponent systems.

  9. Fully-automated in-syringe dispersive liquid-liquid microextraction for the determination of caffeine in coffee beverages.

    Science.gov (United States)

    Frizzarin, Rejane M; Maya, Fernando; Estela, José M; Cerdà, Víctor

    2016-12-01

    A novel fully-automated magnetic stirring-assisted lab-in-syringe analytical procedure has been developed for the fast and efficient dispersive liquid-liquid microextraction (DLLME) of caffeine in coffee beverages. The procedure is based on the microextraction of caffeine with a minute amount of dichloromethane, isolating caffeine from the sample matrix with no further sample pretreatment. Selection of the relevant extraction parameters such as the dispersive solvent, proportion of aqueous/organic phase, pH and flow rates have been carefully evaluated. Caffeine quantification was linear from 2 to 75mgL(-1), with detection and quantification limits of 0.46mgL(-1) and 1.54mgL(-1), respectively. A coefficient of variation (n=8; 5mgL(-1)) of a 2.1% and a sampling rate of 16h(-1), were obtained. The procedure was satisfactorily applied to the determination of caffeine in brewed, instant and decaf coffee samples, being the results for the sample analysis validated using high-performance liquid chromatography. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Slippery liquid-infused porous surfaces in fully developed pipe flow

    Science.gov (United States)

    Sulaimon, Hafeez; Lee, Marcus; Hellström, Leo; Rosenberg, Brian; Smits, Alexander; Hultmark, Marcus

    2013-11-01

    Slippery liquid-infused porous surfaces (SLIPS) are created by locking a thin layer of viscous lubricating oil into a porous surface that is textured at the micro/nano scale, with resulting omniphobicity. The oil layer lies between the solid boundary and the surrounding flow, with the potential to create a partial-slip condition at the boundary. SLIPS therefore offers a new approach to achieve drag reduction. Here, SLIPS is applied to fully developed pipe flow for Reynolds numbers ranging from 600 to 1 . 8 ×105 . The pipe flow facility consists of two test sections, an untreated and a SLIPS treated section, both 32 diameters long. The two test sections are mounted in series, the first preceded by a 120 diameter long untreated developing section and the second preceded by a 60 diameter long SLIPS treated developing section, to ensure fully developed pipe flow. The effects of SLIPS using oils of different viscosity on the flow resistance is quantified by simultaneously measuring and comparing the pressure drop along the untreated and the SLIPS treated test sections. Supported under ONR Grants N00014-12-1-0875 and N00014-12-1-0962 (program manager Ki-Han Kim). M.L. was supported by the Lewis fund for innovation in Energy and the Environment through Princeton Andlinger Center for Energy and the Environment.

  11. Settling of copper drops in molten slags

    Science.gov (United States)

    Warczok, A.; Utigard, T. A.

    1995-02-01

    The settling of suspended metal and sulfide droplets in liquid metallurgical, slags can be affected by electric fields. The migration of droplets due to electrocapillary motion phenomena may be used to enhance the recovery of suspended matte/metal droplets and thereby to increase the recovery of pay metals. An experimental technique was developed for the purpose of measuring the effect of electric fields on the settling rate of metallic drops in liquid slags. Copper drops suspended in CaO-SiO2-Al2O3-Cu2O slags were found to migrate toward the cathode. Electric fields can increase the settling rate of 5-mm-diameter copper drops 3 times or decrease the settling until levitation by reversal of the electric field. The enhanced settling due to electric fields decreases with increasing Cu2O contents in the slag.

  12. 液态高铅渣直接还原工艺数值模拟研究%Numerical Simulation of Liquid High-Lead Slag Direct Reduction Process

    Institute of Scientific and Technical Information of China (English)

    易操; 朱荣; 李智铮; 乔保东

    2011-01-01

    Based on the relevant parameters of liquid high-lead slag direct reduction cold test, a numerical simulation was conducted on the cold test by using CFX software.The study showed that penetration velocity increased gradually with the increasing of coke size but decreased with the increase of the melting viscosity.The trend of the penetration speed by CFX numerical simulation was the same as cold test, which verified the creditability about the numerical simulation of liquid lead slag test in direct reduction.It served as a reference for the parameter optimization in liquid lead slag direct reduction process.%基于液态高铅渣直接还原冷态试验相关参数,利用CFX数值模拟软件对冷态试验进行数值模拟.研究发现:随着焦炭粒度的增加,熔体穿透速度逐渐增加;随着熔体黏度的增加,穿透速度逐渐减小.CFX数值模拟的熔体穿透速度与实测速度变化趋势基本一致,验证了数值模拟应用于液态铅渣直接还原试验的可信性.为液态铅渣直接还原工艺参数优化提供参考.

  13. Understanding Slag Freeze Linings

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2014-09-01

    Slag freeze linings, the formation of protective deposit layers on the inner walls of furnaces and reactors, are increasingly used in industrial pyrometallurgical processes to ensure that furnace integrity is maintained in these aggressive, high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat transfer considerations. These thermal models have assumed that the interface between the stationary frozen layer and the agitated molten bath at steady-state deposit thickness consists of the primary phase, which stays in contact with the bulk liquid at the liquidus temperature. Recent experimental studies, however, have clearly demonstrated that the temperature of the deposit/liquid bath interface can be lower than the liquidus temperature of the bulk liquid. A conceptual framework has been proposed to explain the observations and the factors influencing the microstructure and the temperature of the interface at steady-state conditions. The observations are consistent with a dynamic steady state that is a balance between (I) the rate of nucleation and growth of solids on detached crystals in a subliquidus layer as this fluid material moves toward the stagnant deposit interface and (II) the dissolution of these detached crystals as they are transported away from the interface by turbulent eddies. It is argued that the assumption that the interface temperature is the liquidus of the bulk material represents only a limiting condition, and that the interface temperature can be between T liquidus and T solidus depending on the process conditions and bath chemistry. These findings have implications for the modeling approach and boundary conditions required to accurately describe these systems. They also indicate the opportunity to integrate considerations of heat and mass flows with the selection of melt chemistries in the design of future high temperature industrial reactors.

  14. Effects of Design/Operating Parameters and Physical Properties on Slag Thickness and Heat Transfer during Coal Gasification

    Directory of Open Access Journals (Sweden)

    Insoo Ye

    2015-04-01

    Full Text Available The behaviors of the slag layers formed by the deposition of molten ash onto the wall are important for the operation of entrained coal gasifiers. In this study, the effects of design/operation parameters and slag properties on the slag behaviors were assessed in a commercial coal gasifier using numerical modeling. The parameters influenced the slag behaviors through mechanisms interrelated to the heat transfer, temperature, velocity, and viscosity of the slag layers. The velocity profile of the liquid slag was less sensitive to the variations in the parameters. Therefore, the change in the liquid slag thickness was typically smaller than that of the solid slag. The gas temperature was the most influential factor, because of its dominant effect on the radiative heat transfer to the slag layer. The solid slag thickness exponentially increased with higher gas temperatures. The influence of the ash deposition rate was diminished by the high-velocity region developed near the liquid slag surface. The slag viscosity significantly influenced the solid slag thickness through the corresponding changes in the critical temperature and the temperature gradient (heat flux. For the bottom cone of the gasifier, steeper angles were favorable in reducing the thickness of the slag layers.

  15. Activity and Activity Coefficient of Iron Oxides in the Liquid FeO-Fe2O3-CaO-SiO2 Slag Systems at Intermediate Oxygen Partial Pressures

    Science.gov (United States)

    Henao, Hector M.; Itagaki, Kimio

    2007-10-01

    At present, there is a scarcity of data on the activities of iron oxides in the FeO-Fe2O3-CaO-SiO2 slag system at intermediate oxygen partial pressures and temperatures relevant to sulfide smelting and nonferrous metallurgy. The present study provides relevant data at temperatures between 1573 and 1673 K and partial pressures of oxygen between 10-9 and 10-4 atm. The experiments were carried out by equilibrating the slag in a CO-CO2 gas mixture in a platinum crucible, after which the phases of all the experimental samples, including the platinum foil, were analyzed by electron probe microanalysis (EPMA). Where only liquid phase or liquid phase and tridymite (SiO2) were observed, wet chemical analysis was used to determine the ratio of (mass pct Fe2+)/(mass pct Fe3+). Activity and activity coefficients for FeO (liquid) and FeO1.33 (solid) were calculated. Tendencies of the effect of the (CaO/SiO2) ratio, temperature, and oxygen partial pressure on these thermochemical quantities are discussed in this article.

  16. A fully-coupled approach combining plastic deformation and liquid lubrication

    DEFF Research Database (Denmark)

    Üstünyagiz, Esmeray; Christiansen, Peter; Nielsen, Chris Valentin

    This paper presents a new approach based on a fully coupled procedure in which the lubricant flow and theplastic deformation of the metallic material are solved simultaneously. The approach is applied to strip reduction of asheet with surface pockets in order to investigate the escape of the lubr......This paper presents a new approach based on a fully coupled procedure in which the lubricant flow and theplastic deformation of the metallic material are solved simultaneously. The approach is applied to strip reduction of asheet with surface pockets in order to investigate the escape...... of the lubricant from the pocket by means of MicroPlasto HydroDynamic Lubrication (MPHDL) and Micro Plasto HydroStatic Lubrication (MPHSL) mechanisms....

  17. Activities of FetO in CaO-Al2O3-SiO2-FetO (<5 pct) slags saturated with liquid iron

    Science.gov (United States)

    Lee, Kwang Ro; Suito, Hideaki

    1994-12-01

    The activity coefficients of FetO in CaO-Al2O3 and CaO-Al2O3-SiO2 slags with 0.01 to 5 mass pct FetO were determined at 1873 K from the data obtained in the present and previous slag-metal experiments, using an alumina or lime crucible. It was found that the activity coefficients of FetO obeyed a dilute solution law and increased with increasing the content of SiO2. Based on the findings pertaining to the activity coefficient, the values for the activities of SiO2 and Al2O3 in CaO-Al2O3-SiO2 slags were assessed.

  18. Fully coupled simulation of the plasma liquid interface and interfacial coefficient effects

    Science.gov (United States)

    Lindsay, Alexander D.; Graves, David B.; Shannon, Steven C.

    2016-06-01

    There is a growing interest in the study of coupled plasma-liquid systems because of their applications to biomedicine, biological and chemical disinfection, agriculture, and other areas. Optimizing these applications requires a fundamental understanding of the coupling between phases. Though much progress has been made in this regard, there is still more to be done. One area that requires more research is the transport of electrons across the plasma-liquid interface. Some pioneering works (Rumbach et al 2015 Nat. Commun. 6, Rumbach et al 2015 J. Phys. D: Appl. Phys. 48 424001) have begun revealing the near-surface liquid characteristics of electrons. However, there has been little work to determine the near-surface gas phase electron characteristics. Without an understanding of the near-surface gas dynamics, modellers are left to make assumptions about the interfacial conditions. For instance it is commonly assumed that the surface loss or sticking coefficient of gas-phase electrons at the interface is equal to 1. In this work we explore the consequences of this assumption and introduce a couple of ways to think about the electron interfacial condition. In one set of simulations we impose a kinetic condition with varying surface loss coefficient on the gas phase interfacial electrons. In a second set of simulations we introduce a Henry’s law like condition at the interface in which the gas-phase electron concentration is assumed to be in thermodynamic equilibrium with the liquid-phase electron concentration. It is shown that for a range of electron Henry coefficients spanning a range of known hydrophilic specie Henry coefficients, the gas phase electron density in the anode can vary by orders of magnitude. Varying reflection of electrons by the interface also has consequences for the electron energy profile; increasing reflection may lead to increasing thermalization of electrons depending on choices about the electron energy boundary condition. This variation

  19. The hydraulic potential of high iron bearing steel slags

    Science.gov (United States)

    Ionescu, Denisa Virginia

    need to be addressed. However, the focus is on the glassy phase present in quenched steel slag and its influence on the hydration rate. B-SEM, linage Analysis, XRD techniques and a series of isothermal calorimetric experiments on synthetic as well as oxidized industrial steel slags vis-a-vis Portland cement assist in this endeavor. Temperature is a thermodynamic and kinetic factor modifying the enthalpy of hydrate formation (heat of hydration) and accelerating the hydration reaction. Hydration tests were carried out at temperatures ranging from 25 to 70°C to determine the heat release, the rate of reaction and the apparent activation energy for steel slag and Portland cement hydration. The kinetics of hydration were explored in synthetic steel slags in both amorphous and fully crystalline form. The mechanism of hydration for both amorphous and crystalline steel slag was found to be a combination of nucleation and growth and diffusion, with higher reaction rates for the glassy slags. The higher reactivity in the glassy slags was explained by a lower activation energy when compared to the crystalline parent. Also, it was confirmed that slags have higher activation energies than Portland cement. As expected, and comparably to granulated blast furnace slags, quenched steels slags exhibited a significant hydraulic potential and hydrated at longer times, thus being expected to contribute to the late (>5--180 days) strength development in slag-cements with compression strength superior to pure Portland cement.

  20. Fully developed laminar flow of non-Newtonian liquids through annuli: comparison of numerical calculations with experiments

    Energy Technology Data Exchange (ETDEWEB)

    Escudier, M.P.; Smith, S. [Department of Engineering, Mechanical Engineering, University of Liverpool, Brownlow Hill, Liverpool L69 3GH (United Kingdom); Oliveira, P.J. [Departamento de Engenharia Electromecanica, Universidade da Beira Interior, Rua Marques D' Avila e Boloma, 6200 Covilha (Portugal); Pinho, F.T. [Centro de Estudos de Fenomenos de Transporte, DEMEGI, Faculdade de Engenharia, Universidade do Porto, Rua Roberto Frias, 4200-465 Porto (Portugal)

    2002-07-01

    Experimental data are reported for fully developed laminar flow of a shear-thinning liquid through both a concentric and an 80% eccentric annulus with and without centrebody rotation. The working fluid was an aqueous solution of 0.1% xanthan gum and 0.1% carboxymethylcellulose for which the flow curve is well represented by the Cross model. Comparisons are reported between numerical calculations and the flow data, as well as with other laminar annular-flow data for a variety of shear-thinning liquids previously reported in the literature. In general, the calculations are in good quantitative agreement with the experimental data, even in situations where viscoelastic effects, neglected in the calculations, would be expected to play a role. (orig.)

  1. In situ observation of the role of alumina particles on the crystallization behavior of slags

    Energy Technology Data Exchange (ETDEWEB)

    Orrling, C.

    2000-09-01

    The confocal laser scanning microscope (CLSM) allows crystallization behavior in liquid slags to he observed in situ at high temperatures. Slags in the lime-silica-alumina-magnesia system are easily tinder cooled and it is possible to construct time temperature transformation (TTT) diagrams for this system. The presence of solid alumina particles its these liquid slags was studied to determine if these particles act as heterogeneous nucleation sites that cause she precipitation of solid material within slags. The introduction of alumina particles reduced the incubation time for the onset of crystallization and increased the temperature at which crystallization was observed in the slags to close to the liquidus temperature for the slag. Crystal growth rates are in a good agreement with Ivantsov's solution of the problem of diffusion controlled dendritic growth. Alumina appears to be a potent nucleating agent in the slag systems that were studied. (author)

  2. Fully automated high-performance liquid chromatographic assay for the analysis of free catecholamines in urine.

    Science.gov (United States)

    Said, R; Robinet, D; Barbier, C; Sartre, J; Huguet, C

    1990-08-24

    A totally automated and reliable high-performance liquid chromatographic method is described for the routine determination of free catecholamines (norepinephrine, epinephrine and dopamine) in urine. The catecholamines were isolated from urine samples using small alumina columns. A standard automated method for pH adjustment of urine before the extraction step has been developed. The extraction was performed on an ASPEC (Automatic Sample Preparation with Extraction Columns, Gilson). The eluate was collected in a separate tube and then automatically injected into the chromatographic column. The catecholamines were separated by reversed-phase ion-pair liquid chromatography and quantified by fluorescence detection. No manual intervention was required during the extraction and separation procedure. One sample may be run every 15 min, ca. 96 samples in 24 h. Analytical recoveries for all three catecholamines are 63-87%, and the detection limits are 0.01, 0.01, and 0.03 microM for norepinephrine, epinephrine and dopamine, respectively, which is highly satisfactory for urine. Day-to-day coefficients of variation were less than 10%.

  3. Fully Coupled Simulation of the Plasma Liquid Interface and Interfacial Coefficient Effects

    CERN Document Server

    Lindsay, Alexander; Shannon, Steven

    2016-01-01

    There is a growing interest in the study of coupled plasma-liquid systems because of their applications to biomedicine, biological and chemical disinfection, agriculture, and other areas. Without an understanding of the near-surface gas dynamics, modellers are left to make assumptions about the interfacial conditions. For instance it is commonly assumed that the surface loss or sticking coefficient of gas-phase electrons at the interface is equal to 1. In this work we explore the consequences of this assumption and introduce a couple of ways to think about the electron interfacial condition. In one set of simulations we impose a kinetic condition with varying surface loss coefficient on the gas phase interfacial electrons. In a second set of simulations we introduce a Henry's law like condition at the interface in which the gas-phase electron concentration is assumed to be in thermodynamic equilibrium with the liquid-phase electron concentration. It is shown that for a range of electron Henry coefficients spa...

  4. Roles of Mineralogical Phases in Aqueous Carbonation of Steelmaking Slag

    Directory of Open Access Journals (Sweden)

    Huining Zhang

    2016-05-01

    Full Text Available Mineralogical phases of steelmaking slags have significant influences on the carbonation of the slags. In this paper, the effects of temperature and reaction time on the conversion of calcium-related phases and the carbonation degree of a slag sample were studied. The experimental conditions were a liquid-to-solid ratio of 20 mL/g, a carbon dioxide flow rate of 1 L/min and a slag particle size of 38–75 μm. The results show that the optimum carbonation temperature and reaction time are 60 °C and 90 min, respectively, and calcite phase content is about 26.78% while the conversion rates of Ca3Al2O6, CaSiO3, Ca2SiO4 and free CaO are about 40%, 42.46%, 51% and 100%, respectively, and the carbon dioxide sequestration efficiency is about 170 g/kg slag.

  5. Molecular characterization of gel and liquid-crystalline structures of fully hydrated POPC and POPE bilayers.

    Science.gov (United States)

    Leekumjorn, Sukit; Sum, Amadeu K

    2007-05-31

    Molecular dynamics simulations were used for a comprehensive study of the structural properties of monounsaturated POPC and POPE bilayers in the gel and liquid-crystalline state at a number of temperatures, ranging from 250 to 330 K. Though the chemical structures of POPC and POPE are largely similar (choline versus ethanolamine headgroup), their transformation processes from a gel to a liquid-crystalline state are contrasting. In the similarities, the lipid tails for both systems are tilted below the phase transition and become more random above the phase transition temperature. The average area per lipid and bilayer thickness were found less sensitive to phase transition changes as the unsaturated tails are able to buffer reordering of the bilayer structure, as observed from hysteresis loops in annealing simulations. For POPC, changes in the structural properties such as the lipid tail order parameter, hydrocarbon trans-gauche isomerization, lipid tail tilt-angle, and level of interdigitation identified a phase transition at about 270 K. For POPE, three temperature ranges were identified, in which the lower one (270-280 K) was associated with a pre-transition state and the higher (290-300 K) with the post-transition state. In the pre-transition state, there was a significant increase in the number of gauche arrangements formed along the lipid tails. Near the main transition (280-290 K), there was a lowering of the lipid order parameters and a disappearance of the tilted lipid arrangement. In the post-transition state, the carbon atoms along the lipid tails became less hindered as their density profiles showed uniform distributions. This study also demonstrates that atomistic simulations of current lipid force fields are capable of capturing the phase transition behavior of lipid bilayers, providing a rich set of molecular and structural information at and near the main transition state.

  6. Analysis Of Separation Mechanism Of The Metallic Phase Of Slag In The Direct-To-Blister Process

    Directory of Open Access Journals (Sweden)

    Bydałek A.W.

    2015-09-01

    Full Text Available The article discusses the structure of the slag in the liquid state, the properties and interactions within the slag. The analysis of structures occurring in slag suspension were presented with regard to differences in chemical composition in micro-areas. Two different mechanisms for formation of precipitates in Cu-Fe-Pb alloys during extraction were showed.

  7. Process-integrated slag treatment; Prozessintegrierte Schlackebehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Koralewska, R.; Faulstich, M. [Technische Univ., Garching (Germany). Lehrstuhl fuer Wasserguete- und Abfallwirtschaft

    1998-09-01

    The present study compares two methods of washing waste incineration slag, one with water only, and one which uses additives during wet deslagging. The presented aggregate offers ideal conditions for process-integrated slag treatment. The paper gives a schematic description of the integrated slag washing process. The washing liquid serves to wash out the readily soluble constituents and remove the fines, while the additives are for immobilising heavy metals in the slag material. The study is based on laboratory and semi-technical trials on the wet chemical treatment of grate slag with addition of carbon dioxide and phosphoric acid. [Deutsch] Die dargestellten Untersuchungen beziehen sich auf den Vergleich zwischen einer Waesche der Muellverbrennungsschlacke mit Wasser und unter Zugabe von Additiven im Nassentschlacker. In diesem Aggregat bieten sich optimale Voraussetzungen fuer eine prozessintegrierte Schlackebehandlung. Die Durchfuehrung der integrierten Schlackewaesche wird schematisch gezeigt. Durch die Waschfluessigkeit sollen die leichtloeslichen Bestandteile ausgewaschen und die Feinanteile ausgetragen sowie durch die Additive zusaetzlich die Schwermetalle im Schlackematerial immobilisiert werden. Dazu erfolgten Labor- und halbtechnische Versuche zur nasschemischen Behandlung der Rostschlacken unter Zugabe von Kohlendioxid und Phosphorsaeure. (orig./SR)

  8. Sulfide capacity of high alumina blast furnace slags

    Science.gov (United States)

    Shankar, Amitabh; Görnerup, Märten; Seetharaman, S.; Lahiri, A. K.

    2006-12-01

    Sulfide capacities of high alumina blast furnace slags were experimentally determined using the gas-slag equilibration technique. Two different slag systems were considered for the current study, namely, CaO-SiO2-MgO-Al2O3 quaternary and CaO-SiO2-MgO-Al2O3-TiO2 quinary system. The liquid slag was equilibrated with the Ar-CO-CO2-SO2 gas mixture. Experiments were conducted in the temperature range of 1773 to 1873 K. The effects of temperature, basicity, and the MgO and TiO2 contents of slags on sulfide capacity were studied. As expected, sulfide capacity was found to increase with the increase in temperature and basicity. At the higher experimental temperature, titania decreases the sulfide capacity of slag. However, at the lower temperature, there was no significant effect of titania on the sulfide capacity of slag. Sulfide capacity increases with the increase in MgO content of slag if the MgO content is more than 5 pct.

  9. Fully liquid DTaP-IPV-Hib pediatric combination vaccine (Pediacel): a review of 18 years of clinical experience.

    Science.gov (United States)

    Reynolds, Donna L; Vidor, Emmanuel

    2014-08-01

    Safe and effective combination pediatric vaccines are necessary to simplify complex immunization schedules and to improve coverage and protection for children worldwide. We provide an overview of the 18 years of clinical and worldwide experience with DTaP-IPV-Hib (Pediacel(®)), a unique fully liquid pentavalent vaccine (diphtheria [D], tetanus [T], acellular pertussis, inactivated poliovirus [IPV], Haemophilus influenzae type b [Hib]). Pediacel has demonstrated good and lasting immunogenicity in many populations, with differing primary series and booster schedules, and with a variety of coadministered vaccines. The acellular pertussis antigens have proven efficacy and real-world effectiveness. Clinical and post-marketing studies confirm the safety of Pediacel. Pediacel can be used for primary series and toddler booster doses, as well as in mixed pediatric vaccine schedules.

  10. Preliminary study of a new, fully automated system for liquid-based cytology: the NovaPrep® processor system.

    Science.gov (United States)

    Esquivias López-Cuervo, Javier; Montalbán Beltran, Estanislao; Cuadros Lopez, Jose Luis; Alonso Castillo, Angeles; Nieto Sanchez, Teresa

    2011-01-01

    To evaluate a fully automated system for liquid-based cytology (LBC): the NovaPrep® Processor System (NPS), which is based on the new concept of double decantation, versus conventional cytology (CC), the gold standard for cytology. We performed a preliminary comparative study involving 1,129 female patients who underwent sampling for a Pap test; the sample was first smeared for CC and then, using the remaining specimen on the brush, for LBC with the NPS. The performances of CC and NPS were evaluated for accuracy and compared using the gold standard of a combination of one of the two methods of pathological cytology with screening for positive human papilloma virus, quantification of cells (normal and pathological), and improvement in the quality of samples and reading time. The results showed improvement in sensitivity (3.81% for CC vs. 4.52% for NPS) with a specificity superior to 90% for both, a markedly decreased number of unsatisfactory specimens, notably samples containing too many inflamed cells (7.4% for CC vs. 0.5% for NPS), and a shortening of the reading time, which was three times less using NPS. This preliminary study showed a gain in sensitivity, a drop in the number of unsatisfactory specimens and a reduction in reading time with NPS. The results achieved using this fully automated LBC procedure are very promising and will hopefully reduce the overall cost of cervical cancer screening in the future. Copyright © 2011 S. Karger AG, Basel.

  11. performance of steel slag performance of steel slag as fine ...

    African Journals Online (AJOL)

    eobe

    reduced from 0.62 to 0.50 as slag proportion increased from 0% to 100% at slump. 0.62 to 0.50 as slag ... Nigerian Journal of Technology (NIJOTECH). Vol. 34 No. 3, July ... scrap metals and hundreds of tonnes of steel slag are produced every ...

  12. Study of decomposing carbonyl slag

    Institute of Scientific and Technical Information of China (English)

    CHEN Ai-liang; SUN Pei-mei; ZHAO Zhong-wei; LI Hong-gui; CHEN Xing-yu

    2006-01-01

    A new technology was put forward to deal with the carbonyl slag at low acidity and low oxygen pressure in the kettle.With the orthogonal experiments for analyzing the sequence of four factors and some single factor experiments for the best conditions. The best conditions are used for extracting nickel, cobalt and copper and enriching precious metals: the cupric ion concentration is 5 g/L; and pH=6; the sulfur coefficient is 1.4; the oxygen pressure is 0.08 MPa; the time bubbling oxygen is 20 min;the ratio of liquid to solid is 8:1; the leaching time is 2 h; the heating time is 2.5 h. The leaching rates of nickel and cobalt are more than 98% and that of copper is above 97%. Nickel and cobalt can be separated efficiently from copper and precious metals from the carbonyl slag. Moreover, its leaching liquor has less copper. Nickel and cobalt can be reclaimed only once. During the whole process,the leaching rates of Au and Ag are more than 99.9%, while other precious metals are still in the residue without any loss.

  13. Reduction and foaming of FeO containing slag

    Energy Technology Data Exchange (ETDEWEB)

    Galgali, R.K.; Datta, P.; Ray, A.K.; Prasad, K.K.; Ray, H.S. [Regional Research Lab., Orissa (India)

    2001-07-01

    Smelting reduction processes being developed for producing liquid iron using coal and oxygen are attractive because they allow the use of ore fines directly and do not depend on coke. This paper presents a brief review of some aspects of smelting reduction and some results of an experimental investigation carried out on the reduction of 5-20 wt-% FeO in a synthetically prepared slag by various reductants in a plasma reactor. Some results of a simulation of the smelting reduction process by carrying out post-combustion with oxygen lancing over the slag surface are also presented. It has been possible to achieve a steady state condition, namely, 1-2 wt-% FeO in the slag with a slag height of 4-5 cm during periodic addition of a charge consisting of iron ore, coal, and flux. A kinetic analysis of FeO reduction with various reductants is presented in detail.

  14. Microscopic Study of Carbon Surfaces Interacting with High Carbon Ferromanganese Slag

    Science.gov (United States)

    Safarian, Jafar; Kolbeinsen, Leiv

    2015-02-01

    The interaction of carbon materials with molten slags occurs in many pyro-metallurgical processes. In the production of high carbon ferromanganese in submerged arc furnace, the carbothermic reduction of MnO-containing silicate slags yields the metal product. In order to study the interaction of carbon with MnO-containing slags, sessile drop wettability technique is employed in this study to reduce MnO from a molten slag drop by carbon substrates. The interfacial area on the carbon substrate before and after reaction with slag is studied by scanning electron microscope. It is indicated that no Mn metal particles are found at the interface through the reduction of the MnO slag. Moreover, the reduction of MnO occurs through the contribution of Boudouard reaction and it causes carbon consumption in particular active sites at the interface, which generate carbon degradation and open pore growth at the interface. It is shown that the slag is fragmented to many micro-droplets at the reaction interface, potentially due to the effect on the interfacial energies of a provisional liquid Mn thin film. The rapid reduction of these slag micro-droplets affects the carbon surface with making deep micro-pores. A mechanism for the formation of slag micro-droplets is proposed, which is based on the formation of provisional micro thin films of liquid Mn at the interface.

  15. A Blended Cement Containing Blast Furnace Slag and Phosphorous Slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Blended cement containing blast furnace slag(BFS) and phosphorous slag(PS) is a new kind of cement.The total content of blended materials could increase if two additives were used. Using the same admixtures, the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB.The strength of cement with 80% additives could reach the standard of 425-grade slag cement.The tests of strength, pore structure,hydration products,inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.

  16. Stabilization of Black Cotton Soil Using Micro-fine Slag

    Science.gov (United States)

    Shukla, Rajesh Prasad; Parihar, Niraj Singh

    2016-09-01

    This work presents the results of laboratory tests conducted on black cotton soil mixed with micro-fine slag. Different proportions of micro-fine slag, i.e., 3, 6, 9, 12 and 15 % were mixed with the black cotton soil to improve soil characteristics. The improvement in the characteristics of stabilized soil was assessed by evaluating the changes in the physical and strength parameters of the soil, namely, the Atterberg limits, free swell, the California Bearing Ratio (CBR), compaction parameters and Unconfined Compressive Strength (UCS). The mixing of micro-fine slag decreases the liquid limit, plasticity index and Optimum Moisture Contents (OMC) of the soil. Micro-fine slag significantly increases the plastic limit, UCS and CBR of the soil up to 6-7 % mixing, but mixing of more slag led to decrease in the UCS and CBR of the soil. The unsoaked CBR increased by a substantial amount unlike soaked CBR value. The swell potential of the soil is reduced from medium to very low. The optimum amount of micro-fine slag is found to be approximately 6-7 % by the weight of the soil.

  17. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  18. Hydraulic properties of ladle slags

    Directory of Open Access Journals (Sweden)

    J. Vlček

    2016-07-01

    Full Text Available The article presents results of examining of hydraulic properties of ladle slags formed during production of steel. The studied ladle slags were subjected to different cooling mode from the molten state. Based on the ability of the slag react with the water was assessed their hydraulic activity. The hydraulic properties are caused by the presence of minerals dicalcium silicate, tricalcium aluminate, mayenite, brownmillerite and dicalcium ferite. The emergence of required hydrating phases in the ladle slags is conditioned by a sufficient CaO content and their cooling rate. The contact the slag with water during processing and their ageing has a negative effect. The experiment has shown that the phase transformation of the mineral dicalcium silicate which occurs during cooling of the ladle slags cause their volume instability.

  19. Strength and Drying Shrinkage of Alkali-Activated Slag Paste and Mortar

    Directory of Open Access Journals (Sweden)

    Mao-chieh Chi

    2012-01-01

    Full Text Available The aim of this study is to investigate the strengths and drying shrinkage of alkali-activated slag paste and mortar. Compressive strength, tensile strength, and drying shrinkage of alkali-activated slag paste and mortar were measured with various liquid/slag ratios, sand/slag ratios, curing ages, and curing temperatures. Experimental results show that the higher compressive strength and tensile strength have been observed in the higher curing temperature. At the age of 56 days, AAS mortars show higher compressive strength than Portland cement mortars and AAS mortars with liquid/slag ratio of 0.54 have the highest tensile strength in all AAS mortars. In addition, AAS pastes of the drying shrinkage are higher than AAS mortars. Meanwhile, higher drying shrinkage was observed in AAS mortars than that observed comparable Portland cement mortars.

  20. Refractories Utilizability for Slagging Gasifiers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Slagging coal gasification process became a highlight of coal chemical industry in China during the last decade. Refractory lining's life of slagging gasifiers is one of the most critical factors for a cost -effective operation. The paper introduces current status of coal gasification in China, lining structure of slagging gasifiers and performance of refractory lining. It also summarizes the major factors impacting on refractory wear in slagging coal gasifiers in four Chinese chemical plants, based on ten years of industrial experience. The utilizability is discussed in terms of cost -effectiveness of high chromia refractories and possibility of the alternatives.

  1. Validation of a fully automated high throughput liquid chromatographic/tandem mass spectrometric method for roxithromycin quantification in human plasma. Application to a bioequivalence study.

    Science.gov (United States)

    Kousoulos, Constantinos; Tsatsou, Georgia; Dotsikas, Yannis; Apostolou, Constantinos; Loukas, Yannis L

    2008-05-01

    A fully automated high-throughput liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed for the determination of roxithromycin in human plasma. The plasma samples were treated by liquid-liquid extraction (LLE) in 2.2 mL 96-deep-well plates. Roxithromycin and the internal standard clarithromycin were extracted from 100 microL of human plasma by LLE, using methyl t-butyl ether as the organic solvent. All liquid transfer steps were performed automatically using robotic liquid handling workstations. After vortexing, centrifugation and freezing, the supernatant organic solvent was evaporated and reconstituted. Sample analysis was performed by reversed-phase LC-MS/MS, with positive ion electrospray ionization, using multiple-reaction monitoring. The method had a very short chromatographic run time of 1.6 min. The calibration curve was linear for the range of concentrations 50.0-20.0x10(3) ng mL(-1). The proposed method was fully validated and it was proven to be selective, accurate, precise, reproducible and suitable for the determination of roxithromycin in human plasma. Therefore, it was applied to the rapid and reliable determination of roxithromycin in a bioequivalence study after per os administration of 300 mg tablet formulations of roxithromycin.

  2. Smelting reduction and kinetics analysis of magnetic iron in copper slag using waste cooking oil.

    Science.gov (United States)

    Li, Bo; Wang, Xubin; Wang, Hua; Wei, Yonggang; Hu, Jianhang

    2017-05-25

    To improve the recovery of copper, the viscosity of copper molten slag is decreased by the reduction of magnetic iron, which, in turn, accelerates the settling and separation of copper droplets from the slag. A new technology is proposed in which waste cooking oil is used as a reductant to reduce magnetic iron in the copper smelting slag and consequently reduce carbon emissions in the copper smelting process. A kinetic model of the reduction of magnetic iron in copper slag by waste cooking oil was built using experimental data, and the accuracy of the model was verified. The results indicated that the magnetic iron content in the copper slag decreased with increasing reduction time and an increase in temperature more efficiently reduced magnetic iron in the copper slag. The magnetic iron in the copper slag gradually transformed to fayalite, and the viscosity of the copper molten slag decreased as the magnetic iron content decreased during the reduction process. The reduction of magnetic iron in the copper molten slag using waste cooking oil was a first-order reaction, and the rate-limiting step was the mass transfer of Fe3O4 through the liquid boundary layer.

  3. Novel Approach for Modeling of Nonuniform Slag Layers and Air Gap in Continuous Casting Mold

    Science.gov (United States)

    Wang, Xudong; Kong, Lingwei; Yao, Man; Zhang, Xiaobing

    2017-02-01

    Various kinds of surface defects on the continuous casting slab usually originate from nonuniform heat transfer and mechanical behavior, especially during the initial solidification inside the mold. In this article, a model-coupled inverse heat transfer problem incorporating the effect of slag layers and air gap is developed to study the nonuniform distribution of liquid slag, solid slag, and air gap layers. The model considers not only the formation and evolution of slag layers and air gap but also the temperatures in the mold copper as measured by thermocouples. The simulation results from the model and the measured temperatures from experiments are shown to be in good agreement with each other. At the casting speed of 0.65 m/min, the liquid slag film disappears and transforms into solid slag entirely at about 400 mm away from meniscus, and an air gap begins to form. Until the mold exit, the maximum thickness of the solid slag layer and air gap gradually increases to 1.34 and 0.056 mm, respectively. The results illustrate that the magnitude and nonuniform distribution of the slag layers and air gap along the cross direction, correlating with heat flux between the shell and mold, eventually determine the temperature profiles of the mold hot face and slab surface. The proposed model may provide a convenient approach for analyzing nonuniform heat transfer and mechanical behaviors between the mold and slab in the real casting process.

  4. Rapid Dissolution of Quicklime into Molten Slag by Internally Formed Gas

    Science.gov (United States)

    Maruoka, Nobuhiro; Nogami, Hiroshi

    2017-02-01

    In steelmaking process, quicklime is used to produce CaO-based slag. Although rapid dissolution of quicklime is required for high-efficiency refining, it is known that the rate decreases when dicalcium silicate (C2S) layer forms around the quicklime by reacting with slag. The equation that driving force is the difference of CaO content between in slag and a liquid phase of slag saturated by C2S has been often used for estimating the dissolution rate of lime, in which this saturated value is thermodynamically determined. The authors, however, revealed that the quicklime used in actual operation showed much faster dissolving rate than that of completely calcined lime that is covered by C2S layer during dissolution into slag. This was caused by a gas formation due to a thermal decomposition of residual limestone existed in quicklime. In this study, the dissolution rate of quicklime with the gas formation is quantitatively investigated.

  5. High-Temperatures Rheometric Analysis Of Selected Heterogeneous Slag Systems

    Directory of Open Access Journals (Sweden)

    Migas P.

    2015-06-01

    Full Text Available It is known that the dynamic viscosity coefficient of slag – with an increased titanium compounds content in the reducing conditions of the blast furnace - may rapidly change. The products of the reduction reaction, precipitation and separation of titanium compounds are responsible for the thickening effect of the slag and the problems of permeability of blast furnace, causing anomalies in the dipping zone. The presence of solid components (particles in the melts determines the rheological character of the entire system. Identifying the rheological character of semi-solid slag systems provides opportunities for the development of mathematical modeling of liquid phase flows in a dripping zone of the blast furnace, allowing e.g to indentify the unstable parts of a metallurgical aggregate.

  6. Investigation of High-Temperature Slag/Copper/Spinel Interactions

    Science.gov (United States)

    De Wilde, Evelien; Bellemans, Inge; Campforts, Mieke; Guo, Muxing; Blanpain, Bart; Moelans, Nele; Verbeken, Kim

    2016-12-01

    An important cause for the mechanical entrainment of copper droplets in slags during primary and secondary copper production is their interaction with solid spinel particles, hindering the sedimentation of the copper droplets. In the present study, the interactions between the three phases involved (slag-Cu droplets-spinel solids) were investigated using an adapted sessile drop experiment, combined with detailed microstructural investigation of the interaction zone. An industrially relevant synthetic PbO-CaO-SiO2-Cu2O-Al2O3-FeO-ZnO slag system, a MgAl2O4 spinel particle, and pure copper were examined with electron microscopy after their brief interaction at 1523 K (1250 °C). Based on the experimental results, a mechanism depending on the interlinked dissolved Cu and oxygen contents within the slag is proposed to describe the origin of the phenomenon of sticking Cu alloy droplets. In addition, the oxygen potential gradient across the phases ( i.e., liquid Cu, slag, and spinel) appears to affect the Cu entrainment, as deduced from a microstructural analysis.

  7. Investigation of High-Temperature Slag/Copper/Spinel Interactions

    Science.gov (United States)

    De Wilde, Evelien; Bellemans, Inge; Campforts, Mieke; Guo, Muxing; Blanpain, Bart; Moelans, Nele; Verbeken, Kim

    2016-09-01

    An important cause for the mechanical entrainment of copper droplets in slags during primary and secondary copper production is their interaction with solid spinel particles, hindering the sedimentation of the copper droplets. In the present study, the interactions between the three phases involved (slag-Cu droplets-spinel solids) were investigated using an adapted sessile drop experiment, combined with detailed microstructural investigation of the interaction zone. An industrially relevant synthetic PbO-CaO-SiO2-Cu2O-Al2O3-FeO-ZnO slag system, a MgAl2O4 spinel particle, and pure copper were examined with electron microscopy after their brief interaction at 1523 K (1250 °C). Based on the experimental results, a mechanism depending on the interlinked dissolved Cu and oxygen contents within the slag is proposed to describe the origin of the phenomenon of sticking Cu alloy droplets. In addition, the oxygen potential gradient across the phases (i.e., liquid Cu, slag, and spinel) appears to affect the Cu entrainment, as deduced from a microstructural analysis.

  8. BUILDING MATERIALS AND PRODUCTS BASED ON SILICON MANGANESE SLAGS

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2016-05-01

    Full Text Available Raising of problem. Currently of particular relevance was given to the matter of introduction in manufacture of building materials and products, resource-saving techniques and technologies; integrated use of raw materials and materials that prevent or significantly reduce their harmful impact on the environment. This allows you to recycle hundreds of thousands of tons of the fiery liquid slags of silicon manganese and to develop effective structural materials that can replace metals, non-metallic building materials of natural origin, concretes, cast stone, plastics and refractories. Purpose. The study of the structure and properties of building materials and products from electric furnace slag of silicon manganese. Conclusion. Slags from the smelting of silicon manganese are classified as acidic. Their lime factor is in the range of 0.47–0.52. The composition of the slag located in the heterogeneous region SiO2 near the line of separation of cristobalite spread to the crystallization of wollastonite, according to the ternary system MnO-CaO-SiO2, which in consideration of their stability, allows the development of technology of building materials (gravel, sand, granulated slag, etc. and products (foundation blocks, road slabs, containers for transportation and storage of hazardous waste, and others.

  9. Effects of impurities in leaching liquid of phosphogypsum desulfurization slag on crystal form of calcium carbonate%磷石膏脱硫钙渣浸取液中杂质对碳酸钙晶型的影响

    Institute of Scientific and Technical Information of China (English)

    陈秋鸽; 王戬; 张志业; 王辛龙; 杨林; 钟本和; 杨秀山

    2016-01-01

    磷石膏脱硫钙渣是磷石膏化学分解后产生的以氧化钙为主要成分的尾渣。以氯化铵溶液浸取磷石膏脱硫钙渣并碳化浸取液以制备轻质碳酸钙是一种有效利用磷石膏脱硫钙渣中钙资源的方法。本文分析了该方法在不同氯化铵浓度下浸取液的组成、钙浸出率及pH,同时为了研究浸取液中NH4+、铁、铝、镁等对产品碳酸钙晶型的影响,配制了含有杂质离子的NH4Cl–NH3·H2O溶液,比较了其碳化产品与相同条件下脱硫钙渣碳化产品的晶型差异。结果表明,随氯化铵浓度升高,浸取液pH降低,铝含量降低,铁、镁含量升高。在氯化铵浓度范围内, NH4+对球霰石形成有促进作用,而铁、镁杂质对方解石形成有促进作用,由于铝离子存在形态不同,铝在1mol/L时对形成球霰石有促进作用,在大于1mol/L时对形成方解石有促进作用。当氯化铵浓度小于4mol/L时,各种杂质相互作用形成球霰石晶型,氯化铵浓度等于4mol/L时,各种杂质相互作用形成球霰石和方解石混合晶型。%Phosphogypsum(PG)desulfurization slag is the residue from chemical decomposition of PG, of which the main component is CaO. Leaching PG desulfurization slag with an ammonium chloride solution and carbonating with CO2 to prepare calcium carbonate is an effective way to utilize the calcium in the slag. In this paper,the composition,calcium leaching rate and pH of leaching liquid in different concentrations of ammonium chloride were analyzed. To find out the influence of ions such as ammonia,iron,aluminum and magnesium in the leaching liquid on the crystal form of calcium carbonate,NH4Cl-NH3·H2O solution containing impure ions were prepared and the XRD crystal forms of products were compared with the products obtained by PG desulfurization slag under the same conditions. It turned out that with the increasing of ammonium chloride concentration,pH value and content

  10. Evaluation of Secondary Steelmaking Slags and Their Relation with Steel Cleanliness

    Science.gov (United States)

    da Rocha, Vinicius Cardoso; Pereira, Julio A. M.; Yoshioka, Ayumi; Bielefeldt, Wagner V.; Vilela, Antônio C. F.

    2017-06-01

    Based on data provided from an industrial plant and FactSage commercial software use, a study of secondary refining slags and inclusion cleanliness was performed. Six heats of two slag series, namely, A and B, with average chemical composition (wt pct) of 43.00CaO-25.90SiO2-12.96Al2O3-18.13MgO for series A and 49.98CaO-23.88SiO2-10.11Al2O3-11.99MgO-4.03CaF2 for series B, were used for the study. Both series used DIN 38MnS6 modified steel. The effective viscosity, solid fraction, composition of the liquid fraction, and slag saturation degree in MgO (calculated through thermodynamic software) were related to the experimental results obtained for the inclusion cleanliness. The B slags showed lower effective viscosity than the A slags, due to their high liquid fraction. Regarding the capacity of slags in the inclusion removal, slag B5 resulted in the lowest inclusion density and was considered as the best choice among the slags studied. The inclusion species formed using B slags are constituted especially of CaO-Al2O3-SiO2 and MgO-Al2O3 and are Al2O3 rich. The presence of sulfide-type inclusions (AlMnS and CaS) were more pronounced among A slags.

  11. Slag Behavior in Gasifiers. Part II: Constitutive Modeling of Slag

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, Mehrdad [National Energy Technology Laboratory; Wang, Ping

    2013-02-07

    The viscosity of slag and the thermal conductivity of ash deposits are among two of the most important constitutive parameters that need to be studied. The accurate formulation or representations of the (transport) properties of coal present a special challenge of modeling efforts in computational fluid dynamics applications. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1,300 °C and 1,500 °C, the viscosity is approximately 25 Pa·s. As the operating temperature decreases, the slag cools and solid crystals begin to form. Since slag behaves as a non-linear fluid, we discuss the constitutive modeling of slag and the important parameters that must be studied. We propose a new constitutive model, where the stress tensor not only has a yield stress part, but it also has a viscous part with a shear rate dependency of the viscosity, along with temperature and concentration dependency, while allowing for the possibility of the normal stress effects. In Part I, we reviewed, identify and discuss the key coal ash properties and the operating conditions impacting slag behavior.

  12. Slag Behavior in Gasifiers. Part II: Constitutive Modeling of Slag

    Directory of Open Access Journals (Sweden)

    Mehrdad Massoudi

    2013-02-01

    Full Text Available The viscosity of slag and the thermal conductivity of ash deposits are among two of the most important constitutive parameters that need to be studied. The accurate formulation or representations of the (transport properties of coal present a special challenge of modeling efforts in computational fluid dynamics applications. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1,300 °C and 1,500 °C, the viscosity is approximately 25 Pa·s. As the operating temperature decreases, the slag cools and solid crystals begin to form. Since slag behaves as a non-linear fluid, we discuss the constitutive modeling of slag and the important parameters that must be studied. We propose a new constitutive model, where the stress tensor not only has a yield stress part, but it also has a viscous part with a shear rate dependency of the viscosity, along with temperature and concentration dependency, while allowing for the possibility of the normal stress effects. In Part I, we reviewed, identify and discuss the key coal ash properties and the operating conditions impacting slag behavior.

  13. A Proposal for a Novel Method to Measure the Diffusivity of Species in Slag

    Science.gov (United States)

    Muhmood, Luckman; Viswanathan, Nurni Neelakantan; Seetharaman, Seshadri

    2011-04-01

    The rate of reactions involved in steel-refining operations largely depend on the transport of species through the slag or metal phase at steel refining temperatures; the intrinsic reaction rates are expected to be high. Therefore, the study of diffusivity of species in slag is of great importance. The present work proposes a new methodology, in which experiments can be designed to determine the diffusivity of species in liquid slag. In this article, a mathematical description for the methodology is formulated and subsequently solved using numerical methods. This exercise will help in identifying appropriate bounds for experimental parameters for a desired accuracy. The proposed methodology is generic for any species in the liquid slag phase. However, diffusion of sulfur through slag has been illustrated as a case study. The order of magnitude for the diffusion coefficient for sulfur was taken from the classic works of Saito and Kawai, the sulfide capacity and sulfur partition ratio were retrieved from the works of Taniguchi et al., and the slag density was retrieved from earlier experimental results of the present authors. The slag density was obtained from earlier experimental results from the present group. The Henrian activity coefficients were retrieved from literature. Subsequent to the present work, the design of experiments and measurements carried out using the proposed methodology and the results obtained are presented as the second article on this subject.

  14. Products of steel slags an opportunity to save natural resources.

    Science.gov (United States)

    Motz, H; Geiseler, J

    2001-01-01

    In Germany, and in the most industrial countries, the use of blast furnace and steel slags as an aggregate for civil engineering, for metallurgical use and as fertiliser has a very long tradition. Since the introduction of the basic oxygen steel making furnace (BOF) process and the electric arc furnace (EAF) process the German steel industry started extensive research on the development of fields of application for BOF and EAF slags. These investigations have been mainly performed by Forschungsgemeinschaft Eisenhüttenschlacken e. V. (FEhS), the Research Association for blast furnace and steel slags. Today steel slags are well characterised and long-term experienced materials mainly used as aggregates for road construction (e.g. asphaltic or unbound layers), as armour-stones for hydraulic engineering constructions (e.g. stabilisation of shores), and as fertiliser for agriculture purposes. These multifarious fields of application could only be achieved because the steelworks influence the quality of slags by a careful selection of raw materials and a suitable process route. Furthermore, subsequent procedures like a treatment of the liquid slag, an appropriate heat treatment and a suitable processing have been developed to ensure that the quality of steel slags is always adequate for the end use. Depending on the respective field of application, the suitability of steel slags has to be proven by determining the technical properties, as well as the environmental compatibility. For this reason test methods have been developed to evaluate the technical properties especially the volume stability and the environmental behaviour. To evaluate the volume stability a suitable test (steam test) has been developed and the results from laboratory tests were compared with the behaviour of steel slags under practical conditions, e.g. in a road. To determine the environmental behaviour leaching tests have been developed. In the meanwhile most of these test methods are drafted or

  15. Effect of Slag on Titanium, Silicon, and Aluminum Contents in Superalloy During Electroslag Remelting

    Science.gov (United States)

    Jiang, Zhou-Hua; Hou, Dong; Dong, Yan-Wu; Cao, Yu-Long; Cao, Hai-Bo; Gong, Wei

    2016-04-01

    Many factors influence the chemical composition in electroslag remelting (ESR) steel, including atmosphere in crucible, melting rate, slag composition, deoxidation, and so on. Fluoride-based slag, which is exposed to liquid metal directly, influences the chemical composition of ESR ingots to a large extent. The present paper focuses on the effect of slag on the titanium, silicon, and aluminum contents in ingots based on the interaction of the slag and metal. In present work, superalloy of GH8825 and several slags containing different CaO contents have been employed for investigating the effect of slag on titanium, silicon, and aluminum contents in an electrical resistance furnace under argon atmosphere. Results indicate that the higher CaO content in slag has better capacity for avoiding loss of titanium caused by the reaction of titanium with silica in slag, especially in case of remelting superalloy with high titanium and low silicon content. The CaO has a great effect on the activities of TiO2, SiO2, and Al2O3. Thermodynamic analysis is applied to investigate the CaO behavior. Based on the ion and molecule coexistence theory of slag, activity model is established to calculate the activities of components containing titanium, silicon, and aluminum elements in a six-component slag consisting of CaO-CaF2-Al2O3-SiO2-TiO2-MgO. The components containing titanium, silicon, and aluminum in slag are mainly CaO·TiO2, 2CaO·SiO2, CaO·SiO2, CaO·Al2O3, and MgO·Al2O3. With the increase of CaO mass fraction in slag, the activity coefficient of SiO2 decreases significantly, whereas slightly change happens for Al2O3. As a result, the lg ({{γ_{{{{SiO}}2 }} } {/ {{{γ_{{{{SiO}}2 }} } {γ_{{{{TiO}}2 }} }}} {γ_{{{{TiO}}2 }} }}) decreases with increasing CaO content, which is better for preventing loss of titanium caused by the reaction of titanium with silica in slag. The slag with high CaO and appropriate TiO2 content is suitable for electroslag remelting of GH8825.

  16. Development of a fully integrated falling film microreactor for gas-liquid-solid biotransformation with surface immobilized O2 -dependent enzyme.

    Science.gov (United States)

    Bolivar, Juan M; Krämer, Christina E M; Ungerböck, Birgit; Mayr, Torsten; Nidetzky, Bernd

    2016-09-01

    Microstructured flow reactors are powerful tools for the development of multiphase biocatalytic transformations. To expand their current application also to O2 -dependent enzymatic conversions, we have implemented a fully integrated falling film microreactor that provides controllable countercurrent gas-liquid phase contacting in a multi-channel microstructured reaction plate. Advanced non-invasive optical sensing is applied to measure liquid-phase oxygen concentrations in both in- and out-flow as well as directly in the microchannels (width: 600 μm; depth: 200 μm). Protein-surface interactions are designed for direct immobilization of catalyst on microchannel walls. Target enzyme (here: d-amino acid oxidase) is fused to the positively charged mini-protein Zbasic2 and the channel surface contains a negatively charged γ-Al2 O3 wash-coat layer. Non-covalent wall attachment of the chimeric Zbasic2 _oxidase resulted in fully reversible enzyme immobilization with fairly uniform surface coverage and near complete retention of biological activity. The falling film at different gas and liquid flow rates as well as reactor inclination angles was shown to be mostly wavy laminar. The calculated film thickness was in the range 0.5-1.3 × 10(-4)  m. Direct O2 concentration measurements at the channel surface demonstrated that the liquid side mass transfer coefficient (KL ) for O2 governed the overall gas/liquid/solid mass transfer and that the O2 transfer rate (≥0.75 mM · s(-1) ) vastly exceeded the maximum enzymatic reaction rate in a wide range of conditions. A value of 7.5 (±0.5) s(-1) was determined for the overall mass transfer coefficient KL a, comprising a KL of about 7 × 10(-5)  m · s(-1) and a specific surface area of up to 10(5)  m(-1) . Biotechnol. Bioeng. 2016;113: 1862-1872. © 2016 Wiley Periodicals, Inc.

  17. Overview of Steel Slag Application and Utilization

    Directory of Open Access Journals (Sweden)

    Lim J.W.

    2016-01-01

    Full Text Available Significant quantities of steel slag are generated as waste material or byproduct every day from steel industries. Slag is produced from different types of furnaces with different operating conditions. Slag contains Ferrous Oxide, Calcium Oxide, Silica etc. Physical and chemical properties of slag are affected by different methods of slag solidification such as air cooled, steam, and injection of additives. Several material characterization methods, such as X-ray Diffraction (XRD, Scanned Electron Microscopy (SEM and Inductive Coupled Plasma (ICP-OES are used to determine elemental composition in the steel slag. Therefore, slags can become one of the promising materials in various applications such as in transportation industry, construction, cement production, waste water and water treatment. The various applications of steel slag indicate that it can be reused and utilized rather than being disposed to the landfill. This paper presents a review of its applications and utilization.

  18. Coal Slag Attack-A Review

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi

    2004-01-01

    Although slagging coal gasifiers have served the commercial systems of electricity and chemical fertilizer productions for more than ten years, refractory service life still is a critical factor for gasifier availability. Some investigations were attracted, focusing on coal slag attack on high chromia refractories. A general introduction is made in order to have further understanding about slag corrosion in coal gasification environment. Microstructural deterioration and wear process of high chromia refractory in slagging gasifiers are discussed.

  19. Viscosity estimation for slags containing calcium fluoride

    Institute of Scientific and Technical Information of China (English)

    Qifeng Shu; Jiayun Zhang

    2005-01-01

    Based on recently published experimental data, the Riboud model was modified for viscosity estimation of the slags containing calcium fluoride. The estimated values were in good agreement with measured data. Reasonable estimation can be achieved using the modified Riboud model for mould fluxes and ESR (eletro slag remelting) slags. Especially for ESR slags, the modified Riboud model can provide much more precise values than the original Riboud model.

  20. Mineral resource of the month: ferrous slag

    Science.gov (United States)

    ,

    2009-01-01

    The article offers information on mineral resource ferrous slag. Ferrous slag is produced through the addition of materials such as limestone and dolomite to blast and steel furnaces to remove impurities from iron ore and to lower the heat requirements for processes in iron and steel making. It is stated that the method of cooling is important for the market uses and value of ferrous slag. Some types of slag can be used in construction, glass manufacturing and thermal insulation.

  1. A fully automated effervescence assisted dispersive liquid-liquid microextraction based on a stepwise injection system. Determination of antipyrine in saliva samples.

    Science.gov (United States)

    Medinskaia, Kseniia; Vakh, Christina; Aseeva, Darina; Andruch, Vasil; Moskvin, Leonid; Bulatov, Andrey

    2016-01-01

    A first attempt to automate the effervescence assisted dispersive liquid-liquid microextraction (EA-DLLME) has been reported. The method is based on the aspiration of a sample and all required aqueous reagents into the stepwise injection analysis (SWIA) manifold, followed by simultaneous counterflow injection of the extraction solvent (dichloromethane), the mixture of the effervescence agent (0.5 mol L(-1) Na2CO3) and the proton donor solution (1 mol L(-1) CH3COOH). Formation of carbon dioxide microbubbles generated in situ leads to the dispersion of the extraction solvent in the whole aqueous sample and extraction of the analyte into organic phase. Unlike the conventional DLLME, in the case of EA-DLLME, the addition of dispersive solvent, as well as, time consuming centrifugation step for disruption of the cloudy state is avoided. The phase separation was achieved by gentle bubbling of nitrogen stream (2 mL min(-1) during 2 min). The performance of the suggested approach is demonstrated by determination of antipyrine in saliva samples. The procedure is based on the derivatization of antipyrine by nitrite-ion followed by EA-DLLME of 4-nitrosoantipyrine and subsequent UV-Vis detection using SWIA manifold. The absorbance of the yellow-colored extract at the wavelength of 345 nm obeys Beer's law in the range of 1.5-100 µmol L(-1) of antipyrine in saliva. The LOD, calculated from a blank test based on 3σ, was 0.5 µmol L(-1).

  2. Melting Behaviour of Ferronickel Slags

    Science.gov (United States)

    Sagadin, Christoph; Luidold, Stefan; Wagner, Christoph; Wenzl, Christine

    2016-12-01

    The industrial manufacturing of ferronickel in electric furnaces produces large amounts of slag with strong acidic character and high melting points, which seriously stresses the furnace refractory lining. In this study, the melting behavior of synthetically produced ferronickel slags on magnesia as refractory material was determined by means of a hot stage microscope. Therefore, slags comprising the main oxides SiO2 (35-70 wt.%), MgO (15-45 wt.%) and Fe2O3 (5-35 wt.%) were melted in a graphite crucible and afterwards analyzed by a hot stage microscope. The design of experiments, which was created by the statistic software MODDE®, included 20 experiments with varying slag compositions as well as atmospheres. The evaluation of the test results occurred at three different characteristic states of the samples like the softening point according to DIN 51730 and the temperatures at which the area of residual cross-section of the samples amounted to 30% and 40%, respectively, of the original value depending of their SiO2/MgO ratio and iron oxide content. Additionally, the thickness of the zone influenced by the slag was measured and evaluated.

  3. Slag Behavior in Gasifiers. Part I: Influence of Coal Properties and Gasification Conditions

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2013-02-01

    Full Text Available In the entrained-flow gasifiers used in integrated gasification combined cycle (IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter is entrained (as fly ash with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. To improve gasification availability through better design and operation of the gasification process, a better understanding of slag behavior and the characteristics of the slagging process is needed. Char/ash properties, gas compositions in the gasifier, the gasifier wall structure, fluid dynamics, and plant operating conditions (mainly temperature and oxygen/carbon ratio all affect slagging behavior. Because coal has varying ash content and composition, different operating conditions are required to maintain the slag flow and limit problems downstream. In Part I, we review the main types and the operating conditions of entrained-flow gasifiers and coal properties used in IGCC plants; we identify and discuss the key coal ash properties and the operating conditions impacting slag behavior; finally, we summarize the coal quality criteria and the operating conditions in entrained-flow gasifiers. In Part II, we discuss the constitutive modeling related to the rheological studies of slag flow.

  4. Smelting Oxidation Desulfurization of Copper Slags

    Institute of Scientific and Technical Information of China (English)

    LI Lei; HU Jian-hang; WANG Hua

    2012-01-01

    According to the mechanism of sulfur removal easily through oxidation, the process of smelting oxidation desulfurization of copper slags is studied, which supplies a new thinking for obtaining the molten iron of lower sulfur content by smelting reduction of copper slags. Special attention is given to the effects of the holding temperature, the holding time and CaF2, CaO addition amounts on the desulfurization rate of copper slags. The results indicate that the rate of copper slags smelting oxidation desulfurization depends on the matte mass transfer rate through the slag phase. After the oxidation treatment, sulfur of copper slags can be removed as SO2 efficiently. Amount of Ca2+ of copper slags affects the desulfurization rate greatly, and the slag desulfurization rate is reduced by adding a certain amount of CaF2 and CaO. Compared with CaF2, CaO is negative to slags sulfur removal with equal Ca2+ addition. Under the air flow of 0.3 U/min, the sulfur content of copper slags can be reduced to 0. 004 67% in the condition of the holding time of 3 min and the holding temperature of 1 500 ℃. The sulfur content of molten iron is reduced to 0. 000 8 % in the smelting reduction of treated slags, and the problem of high sulfur content of molten iron obtained by smelting reduction with copper slag has been successively solved.

  5. PERFORMANCE OF PULVERIZED SLAG-SUBSTITUTED CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The Portland cement is equivalently substituted by slag micropowders with various specific areas. The workability,activity and acid-corrosion resistance of the slag-substituted cements are investigated,the activation of gypsum is discussed,also the porosity and pore distribution of mortars of the slag micropowders cement are determined by mercury intrusion porosimetry.

  6. A fully liquid DTaP-IPV-Hep B-PRP-T hexavalent vaccine for primary and booster vaccination of healthy Mexican children.

    Science.gov (United States)

    Aquino, Amalia Guadalupe Becerra; Brito, Maricruz Gutiérrez; Doniz, Carlos E Aranza; Herrera, Juan Francisco Galán; Macias, Mercedes; Zambrano, Betzana; Plennevaux, Eric; Santos-Lima, Eduardo

    2012-10-05

    To evaluate an investigational, fully liquid hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-hepatitis B-Haemophilus influenzae type b (DTaP-IPV-Hep B-PRP-T: Hexaxim™) vaccine for primary and booster vaccination of healthy children in Mexico. Infants (N=1189) were randomized to receive one of three lots of the DTaP-IPV-Hep B-PRP-T vaccine or a licensed hexavalent control vaccine (Infanrix™ hexa) for primary vaccination at 2, 4 and 6 months. All participants who completed the primary series and agreed to participate in the booster part of the study received a dose of the investigational vaccine at 15-18 months of age. Validated serological assays and parental reports were used to assess immunogenicity and safety, respectively. Post-primary vaccination, ≥95.8% of participants in both the DTaP-IPV-Hep B-PRP-T and control groups were seroprotected (SP) against diphtheria, tetanus, poliovirus, hepatitis B and PRP, or had seroconverted (SC) to the pertussis toxin (PT) and filamentous hemagglutinin (FHA) pertussis antigens. The SP/SC rates induced by the three DTaP-IPV-Hep B-PRP-T lots were equivalent. No differences in SP/SC rates were observed between the pooled lots of investigational vaccine and the control vaccine. Antibody persistence at 15-18 months was comparable between groups, with strong increases in all antibody concentrations post-DTaP-IPV-Hep B-PRP-T booster. Both vaccines were well tolerated for primary vaccination, as was the booster dose of DTaP-IPV-Hep B-PRP-T. These study findings confirm the suitability of the combined, fully liquid DTaP-IPV-Hep B-PRP-T vaccine for inclusion in routine childhood vaccination schedules. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Characteristics of blast furnace slag leachate produced under reduced and oxidized conditions.

    Science.gov (United States)

    Schwab, A P; Hickey, J; Hunter, J; Banks, M K

    2006-01-01

    A laboratory study was conducted to determine the environmental conditions necessary to reproduce leachates observed emerging from blast furnace slag acting as the foundation of highways in northwest Indiana. The leachates in the field are often highly alkaline with a pungent sulfur odor, a distinct green or milky-white in color, and sulfate concentrations exceeding 2,000 mg/L. Slag was equilibrated in the laboratory under both oxidized and anoxic environments and at various slag:water ratios. Constant anoxic conditions were required to produce to green colors in the slag, but high sulfate concentrations were observed only when the suspensions were fully oxidized. Leachate from the study site appears to form as a result of a series of complex chemical reactions including fluctuating oxidized and reduced conditions.

  8. ArgonCube: a novel, fully-modular approach for the realization of large-mass liquid argon TPC neutrino detectors

    CERN Document Server

    Amsler, C; Asaadi, J; Auger, M; Barbato, F; Bay, F; Bishai, M; Bleiner, D; Borgschulte, A; Bremer, J; Cavus, E; Chen, H; De Geronimo, G; Ereditato, A; Fleming, B; Goldi, D; Hanni, R; Kose, U; Kreslo, I; La Mattina, F; Lanni, F; Lissauer, D; Luthi, M; Lutz, P; Marchionni, A; Mladenov, D; Nessi, M; Noto, F; Palamara, O; Raaf, J L; Radeka, V; Rudolph Von Rohr, Ch; Smargianaki, D; Soderberg, M; Strauss, Th; Weber, M; Yu, B; Zeller, G P; Zeyrek, M; CERN. Geneva. SPS and PS Experiments Committee; SPSC

    2015-01-01

    The Liquid Argon Time Projection Chamber is a prime candidate detector for future neutrino oscillation physics experiments, underground neutrino observatories and proton decay searches. A large international project based on this technology is currently being considered at the future LBNF facility in the United States on the very large mass scale of 40 kton. In this document, following the long standing R&D work conducted over the last years in several laboratories in Europe and in the United States, we intend to propose a novel Liquid Argon TPC approach based on a fully-modular, innovative design, the ArgonCube. The related R&D work will proceed along two main directions; one aimed at on the assessment of the proposed modular detector design, the other on the exploitation of new signal readout methods. Such a strategy will provide high performance while being cost-effective and robust at the same time. According to our plans, we will firstly realize a detector prototype hosted in a cryostat that is a...

  9. Slags in steel making; Kuonat teraeksen valmistuksessa

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Paeaetalo, M.; Karhu, P.; Jauhiainen, A.; Alamaeki, P.; Koski-Laine, S.; Ollila, J. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    At the first step of the project all stages of the steelmaking processes were viewed from the blast furnace to the continuous casting. Slag knowledge of each processes were collected into a guide, which is meant to help both production and research. At the same time the essential problems caused by slags in steelmaking were focused. At the second step the focus of this slag-project were transferred into the desulphurization, converter, ladle and tundish slags. Wide slag knowledge has been divided into smaller parts and applied versatile into the steelmaking process taking into account the metallurgical, economical and qualitative aspects. (orig.) SULA 2 Research Programme; 13 refs.

  10. Synthesis of steel slag ceramics:chemical composition and crystalline phases of raw materials

    Institute of Scientific and Technical Information of China (English)

    Li-hua Zhao; Wei Wei; Hao Bai; Xu Zhang; Da-qiang Cang

    2015-01-01

    Two types of porcelain tiles with steel slag as the main raw material (steel slag ceramics) were synthesized based on the CaO–Al2O3–SiO2 and CaO–MgO–SiO2 systems, and their bending strengths up to 53.47 MPa and 99.84 MPa, respectively, were obtained. The presence of anorthite,α-quartz, magnetite, and pyroxene crystals (augite and diopside) in the steel slag ceramics were very different from the composition of traditional ceramics. X-ray diffraction (XRD) and electron probe X-ray microanalysis (EPMA) results illustrated that the addition of steel slag reduced the temperature of extensive liquid generation and further decreased the firing temperature. The considerable contents of glass-modifying oxide liquids with rather low viscosities at high temperature in the steel slag ceramic adobes promoted element diffusion and crystallization. The results of this study demonstrated a new approach for extensive and effective recycling of steel slag.

  11. Analysis of the slag carry over from converter to the ladle during steel tapping; Analise da passagem de escoria do convertedor para a panela durante o vazamento do aco

    Energy Technology Data Exchange (ETDEWEB)

    Souza Costa, S.L. de; Almeida, C.X. de [USIMINAS, Ipatinga, MG (Brazil). Centro de Pesquisas

    1995-12-31

    Cold model experiments was carried out in order to study the slag carry over from converter to the ladle. Slag was simulated with diesel oil. It could be seen that 15% of total slag is carried in the beginning of tapping, 36% by vortex and 49% in the end of tapping. Full scale experiments have been performed. The utilization of slag cut methods is effective to preventing slag carry over, which can be reduced down to 6.5 kg/t of liquid steel 3 refs., 5 figs., 3 tabs.

  12. Study on Microstructure and Slag Corrosion Mechanism of High Chrome Bricks for Gasifier

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Research was focused on slag corrosion mechanism of high chrome bricks used for different types of gasifier by comparing the structure of high chrome bricks for petroleum coke gasifier and water-coal slurry gasifier with slag corroded testing brick and water coal slurry gasifier through Scanning Electron Microscope (SEM) examination and X-ray diffraction. Results show that for high chrome brick used for petroleum coke gasifier, corrosion is mainly caused by Cr2O3 in the brick and V2O5 in molten slag and liquid phase generation at low temperature; for high chrome brick used for water-coal slurry gasifier, corrosion is caused by dissolution of Cr2O3 in molten slag and corrosion of ZrO2. For LIRR-HK95 brick, it performs better petroleum coke corrosion resistance than the others due to the optimal composition and structure.

  13. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    Energy Technology Data Exchange (ETDEWEB)

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  14. Study on cementitious properties of steel slag

    Directory of Open Access Journals (Sweden)

    Zhu G.

    2013-01-01

    Full Text Available The converter steel slag chemical and mineral components in China’s main steel plants have been analysed in the present paper. The electronic microscope, energy spectrum analysis, X-ray diffraction analysis confirmed the main mineral compositions in the converter slag. Converter slag of different components were grounded to obtain a powder with specific surface area over 400m2/kg, making them to take place some part of the cement in the concrete as the admixture and carry out the standard tests. The results indicate that the converter slag can be used as cementitious materials for construction. Furthermore, physical mechanic and durability tests on the concrete that certain amount of cement be substituted by converter steel slag powder from different steel plants are carried out, the results show that the concrete with partial substitution of steel slag powder has the advantages of higher later period strength, better frost resistance, good wear resistance and lower hydration heat, etc. This study can be used as the technical basis for “Steel Slag Powder Used For Cement And Concrete”, “Steel Slag Portland Cement”, “Low Heat Portland Steel Slag Cement”, “Steel Slag Road Cement” in China, as well as a driving force to the works of steel slag utilization with high-value addition, circular economy, energy conservation and discharge reduction in the iron and steel industry.

  15. Investigation of Bubble-Slag Layer Behaviors with Hybrid Eulerian-Lagrangian Modeling and Large Eddy Simulation

    Science.gov (United States)

    Li, Linmin; Li, Baokuan

    2016-08-01

    In ladle metallurgy, bubble-liquid interaction leads to complex phase structures. Gas bubble behavior, as well as the induced slag layer behavior, plays a significant role in the refining process and the steel quality. In the present work, a mathematical model using the large eddy simulation (LES) is developed to investigate the bubble transport and slag layer behavior in a water model of an argon-stirred ladle. The Eulerian volume of fluid model is adopted to track the liquid steel-slag-air free surfaces while the Lagrangian discrete phase model is used for tracking and handling the dynamics of discrete bubbles. The bubble coalescence is considered using O'Rourke's algorithm to solve the bubble diameter redistribution and bubbles are removed after leaving the air-liquid interface. The turbulent liquid flow that is induced by bubble-liquid interaction is solved by LES. The slag layer fluactuation, slag droplet entrainment and spout eye open-close phenomenon are well revealed. The bubble diameter distribution and the spout eye size are compared with the experiment. The results show that the hybrid Eulerian-Lagrangian-LES model provides a valid modeling framework to predict the unsteady gas bubble-slag layer coupled behaviors.

  16. Difference in BOF Slag Splashing in US and China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some differences in slag splashing between BOF steel works in USand China were investigated. The slag composition, melting point, and mineralogical phases of final slags from both countries were studied. The control of slag superheat is important to an effective slag coating.

  17. The effect of CaF2 on thermodynamics of CaO-CaF2-SiO2(-MgO) slags

    Science.gov (United States)

    Choi, Chul-Hwan; Jo, Sung-Koo; Kim, Seon-Hyo; Lee, Kwang-Ro; Kim, Jeong-Tae

    2004-02-01

    To address the role of CaF2 in the CaO-CaF2-SiO2(-MgO) slag system employed for the production of low-pressure rotor steels, the thermodynamic aspects of the slag were investigated by equilibrating it with liquid iron at 1873 K in CaO or MgO crucibles. Presaturation of slag with an oxide block piece of CaO or MgO in a Pt crucible and application of a carbon paste to the outside of an oxide crucible were designed to prevent crucible failure during the slag-metal experiments. The liquidus isotherm and phase boundary of the preceding slag system were investigated using the slag-metal equilibria. Also, the effect of CaF2 on the sulfide capacity and the activity coefficient of Fe t O were of particular interest in controlling the sulfur level and cleanliness of low-pressure rotor steels.

  18. Modification of Inclusions in Molten Steel by Mg-Ca Transfer from Top Slag: Experimental Confirmation of the `Refractory-Slag-Metal-Inclusion (ReSMI)' Multiphase Reaction Model

    Science.gov (United States)

    Shin, Jae Hong; Park, Joo Hyun

    2017-08-01

    High-temperature experiments and Refractory-Slag-Metal-Inclusion (ReSMI) multiphase reaction simulations were carried out to determine the effect of the ladle slag composition on the formation behavior of non-metallic inclusions in molten steel. Immediately after the slag-metal reaction, magnesium migrated to the molten steel and a MgAl2O4 spinel inclusion was formed due to a reaction between magnesium and alumina inclusions. However, the spinel inclusion changed entirely into a liquid oxide inclusion via the transfer of calcium from slag to metal in the final stage of the reaction. Calcium transfer from slag to metal was more enhanced for lower SiO2 content in the slag. Consequently, the spinel inclusion was modified to form a liquid CaO-Al2O3-MgO-SiO2 inclusion, which is harmless under steelmaking conditions. The modification reaction was more efficient as the SiO2 content in the slag decreases.

  19. Two-dimensional coupled fluid and electrodynamic calculations for a MHD DCW channel with slag layers

    Science.gov (United States)

    Liu, B. L.

    1982-01-01

    A fully coupled, two dimensional numerical method of modeling linear, coal-fired MHD generators is developed for the case of a plasma flow bounded by a slag layer on the channel walls. The governing partial differential equations for the plasma flow, slag layer and electrodynamics are presented and their coupling discussed. An iterative, numerical procedure employing non-uniform computational meshes and appropriate tridiagonal matrix solution schemes for the equations is presented. The method permits the investigation of the mutual plasma flow-slag layer development for prescribed wall temperatures, electrode geometry, slag properties and channel loading. In particular, the slag layer-plasma interface properties which require prior specification in an uncoupled analysis comprise part of the solution in the present approach. Results are presented for a short diagonally connected generator channel and include contour plots of the electric potential and current stream function as well as transverse and axial profiles of pertinent plasma properties. The results indicate that a thin electrode slag layer can be maintained in the presence of reasonable current density levels.

  20. Analysis of the Rheological Behaviour of Selected Semi-Solid Slag Systems in Blast Furnace Flow Conditions

    Directory of Open Access Journals (Sweden)

    Migas P.

    2015-04-01

    Full Text Available The rheological properties of liquid and semi-solid systems of slag and hot metal in a blast furnace are extremely important from the perspective of their dripping in the unit. The rheological nature and the values of the dynamic viscosity coefficient of liquid and semi-solid phases - slag and hot metal - determine the permeability of the zones in which those systems exist. The modelling of dripping processes and e.g. static and dynamic holding/retention of liquid in the bed, requires an accurate description of the rheological behaviour of slag and iron systems. Determining the liquid flow through the lump bed of the blast furnace is based on the assumption that liquids in the unit in the whole range of their occurrence are similar to a Newtonian ideal liquid. This study presents an analysis of the findings of high-temperature rheometric measurements of CaO-SiO2-Al2O3-MgO systems, liquid, semi-solid slags of the blast furnace type doped with TiO2 and solids in the form of TiN. The tests were performed within a temperature range of 1310-1490°C. Also measurement results for glycerol solutions with concentrations of 86% and 100% at the ambient temperature, simulating blast furnace slags with various contents of solids - PC, anthracite - are presented.

  1. Fully automated determination of 74 pharmaceuticals in environmental and waste waters by online solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry.

    Science.gov (United States)

    López-Serna, Rebeca; Pérez, Sandra; Ginebreda, Antoni; Petrović, Mira; Barceló, Damià

    2010-12-15

    The present work describes the development of a fully automated method, based on on-line solid-phase extraction (SPE)-liquid chromatography-electrospray-tandem mass spectrometry (LC-MS-MS), for the determination of 74 pharmaceuticals in environmental waters (superficial water and groundwater) as well as sewage waters. On-line SPE is performed by passing 2.5 mL of the water sample through a HySphere Resin GP cartridge. For unequivocal identification and confirmation two selected reaction monitoring (SRM) transitions are monitored per compound, thus four identification points are achieved. Quantification is performed by the internal standard approach, indispensable to correct the losses during the solid phase extraction, as well as the matrix effects. The main advantages of the method developed are high sensitivity (limits of detection in the low ng L(-1) range), selectivity due the use of tandem mass spectrometry and reliability due the use of 51 surrogates and minimum sample manipulation. As a part of the validation procedure, the method developed has been applied to the analysis of various environmental and sewage samples from a Spanish river and a sewage treatment plant. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Disposal of High-Temperature Slags: A Review of Integration of Heat Recovery and Material Recycling

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai

    2016-09-01

    Nowadays with the continuous urbanization in China, the carbon emission and resource shortage have been serious issues, for which the disposal of blast furnace slags (BFS) and steel slags (SS) discharged from the metallurgical industry make up a significant strategy. The output of crude steel reached 823 Mt in China in 2014 and the thermal heat in these slags was equivalent to ~18 Mt of standard coal. Herein, the recent advances were systemically reviewed and analyzed, mainly from two respects, i.e., integration of heat recovery and material recycling and crystallization control of the slags. It was first found that for the heat recovery from BFS, the most intensively investigated physical method and chemical method were centrifugal granulation and gasification reaction, respectively. Furthermore, a two-step approach could contribute to a promising strategy for the treatment of slags, i.e., the liquid slags were first granulated into small particles, and then other further treatment was performed such as gasification reaction. With regard to SS, the effective disposal could be achieved using a selective crystallization and phase separation (SCPS) method, and moreover, the solid solution of 2CaO·SiO2 and the target phases could act as a promising enriched phase to extract the valuable elements.

  3. EFFECT OF REACTIVE MAGNESIUM OXIDE ON PROPERTIES OF ALKALI ACTIVATED SLAG GEOPOLYMER CEMENT PASTES

    Directory of Open Access Journals (Sweden)

    H. A. Abdel-Gawwad

    2015-03-01

    Full Text Available The effect of different proportions and different reactivities of MgO on the drying shrinkage and compressive strength of alkali activated slag pastes (AAS has been investigated. The slag was activated by 6 wt.% sodium hydroxide and liquid sodium silicate at ratio of 3:3 (wt.. The different reactivities of MgOs were produced from the calcination of hydromagnesite at different temperatures (550, 1000, 1250 C. The results showed that the reactivity of magnesium oxide decreases with increasing the calcination temperature. Also, the drying shrinkage of AAS was reduced by the replacement of slag with MgOs. The highly reactive MgO accelerated the hydration of AAS at early ages. The replacement of slag with 5% MgO550 increased one day compressive strength by ~26 % while MgO1250 had little effect. A significant increase in strength was observed after 7 days in case of replacement of slag with 5 % MgO1250. The MgO reacts with slag to form hydrotalcite likephases (Ht as detected by XRD, FTIR spectroscopy, TGA/DTG analysis and SEM.

  4. Theoretical and Experimental on Carbon Dioxide Sequestration Degree of Steel Slag

    Institute of Scientific and Technical Information of China (English)

    LI Jian-li; ZHANG Hui-ning; XU An-jun; CUI Jian; HE Dong-feng; TIAN Nai-yuan

    2012-01-01

    The limitation and experimental CO2 sequestration degree of steel slag is the focus. The theoretical and the practical COe sequestration degree was assessed under mild operating conditions. After calculation in theory, it can be found that the CO2 sequestration limitation degree for every kilogram steel slag is about 442 g when taking magne- sium into consideration, and the experimental CO2 sequestration degree for every kilogram slag is about 77 g, under the conditions that the liquid to solid ratio is 50 L/kg, CO2 flow is 0.5 L/min and the temperature of reaction is the ambient temperature. When solution NH4Cl and CHa COOH for experiments and other conditions keep the same, the actual potential CO2 sequestration for every kilogram slag is 69.3 g and 31.20 g respectively. Thus, optimization of process parameters like granularity of slag is necessary to enhance the carbon dioxide sequestration degree for steel slag.

  5. Effect of Temperature and Graphite Immersion Method on Carbothermic Reduction of Fayalite Slag

    Science.gov (United States)

    Mitrašinović, Aleksandar

    2017-09-01

    In this work, graphite flakes were used to reduce fayalite slag originated from the pyrometallurgical copper extraction process. Experiments were conducted with a significantly different contact area between graphite and slag at two temperatures, 1300°C and 1400°C. The process was continuously monitored via the concentration change of CO and CO2 in off-gas. Reduction rate values in experiments where 150-micron-diameter graphite flakes were submerged into the slag and left to float slowly to the top are about four times higher compared with when graphite flakes were dispersed at the top surface of liquid slag. The activation energy for instigating reduction was 302.61 kJ mol-1 and 306.67 kJ mol-1 in the case where graphite flakes were submerged into the slag and dispersed at the surface, respectively. The reduction process is characterized by two distinctive periods: an initial steep increase in the concentration of CO and CO2 controlled by the Boudouard reaction and a subsequent slow decrease of CO and CO2 concentrations in the off-gas controlled by mass transfer of reducible oxides from bulk to the gas-slag interface.

  6. Wettability of Silicon Carbide by CaO-SiO2 Slags

    Science.gov (United States)

    Safarian, Jafar; Tangstad, Merete

    2009-12-01

    The wettability of silicon carbide by liquid CaO-SiO2 slags that contain 47 to 60 wt pct SiO2 was studied using the sessile drop wettability technique. The experiments were carried out in Ar and CO atmospheres. A small piece of slag was melted on SiC substrates under different heating regimes up to 1600 °C. It was found that the wetting is not significantly dependent on the temperature and the heating rate. However, the wettability is relatively high, and the wetting is higher for slags that contain lower SiO2 concentrations. Moreover, the wettability between the slags and SiC is dependent on the gas phase composition, and it is higher in Ar than that in CO. When the SiO2 concentration changes from 47 pct wt to 60 pct wt, the wetting angle changes from 20 deg to 73 deg in Ar and from 58 deg to 87 deg in a CO atmosphere. The formation and bursting of gas bubbles also was observed after some contact time, which indicates that the wetting system is a reactive type. However, microscopic studies indicated that no metal phase exists at the slag/silicon-carbide interface. Therefore, it was concluded that chemical reactions between the slag and SiC take place and that SiO2 is slowly reduced to form CO and SiO gases. Based on the experimental data, the dependence of the Girifalco-Good coefficient on the slag composition and the relationship between the interfacial tension of CaO-SiO2 slags and SiC also were estimated.

  7. The Sulfide Capacity of Iron Oxide-Rich Slags

    Science.gov (United States)

    Motlagh, M.

    1988-03-01

    The relationship between the sulfide capacity of slags rich in iron oxide and the sulfur partition ratio between the metal and slag is strongly related to the slag's iron oxide concentration. For slags containing little or no lime, this relationship is linear for a constant concentration of iron oxide in the slag. The effect of silica on changes in the sulfide capacity of slags rich in iron oxide is similar to that of basic steel-making slags, particularly at low activity of silica in slag.

  8. A Brief Review of Viscosity Models for Slag in Coal Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, Mehrdad; Wang, Ping

    2011-11-01

    Many researchers have defined the phenomenon of 'slagging' as the deposition of ash in the radiative section of a boiler, while 'fouling' refers to the deposition of ash in the convective-pass region. Among the important parameters affecting ash deposition that need to be studied are ash chemistry, its transport, deposit growth, and strength development; removability of the ash deposit; heat transfer mechanisms; and the mode of operation for boilers. The heat transfer at the walls of a combustor depends on many parameters including ash deposition. This depends on the processes or parameters controlling the impact efficiency and the sticking efficiency. For a slagging combustor or furnace, however, the temperatures are so high that much of the coal particles are melted and the molten layer, in turn, captures more particles as it flows. The main problems with ash deposition are reduced heat transfer in the boiler and corrosion of the tubes. Common ways of dealing with these issues are soot blowing and wall blowing on a routine basis; however, unexpected or uncontrolled depositions can also complicate the situation, and there are always locations inaccessible to the use of such techniques. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1300 C and 1500 C, the viscosity is approximately 25 Pa {center_dot} s. As the operating temperature decreases, the slag cools and solid crystals begin to form. In such cases the slag should be regarded as a non-Newtonian suspension, consisting of liquid silicate and crystals. A better understanding of the rheological properties of the slag, such as yield stress and shear-thinning, are critical in determining the optimum operating conditions. To develop an accurate heat transfer model in any type of coal combustion or gasification process, the heat transfer and to some extent the rheological properties

  9. In-silico experiments on characteristic time scale at a shear-free gas-liquid interface in fully developed turbulence

    Science.gov (United States)

    Nagaosa, Ryuichi; Handler, Robert A.

    2011-12-01

    The purpose of this study is to model scalar transfer mechanisms in a fully developed turbulence for accurate predictions of the turbulent scalar flux across a shear-free gas-liquid interface. The concept of the surface-renewal approximation (Dankwerts, 1951) is introduced in this study to establish the predictive models for the interfacial scalar flux. Turbulent flow realizations obtained by a direct numerical simulation technique are employed to prepare details of three-dimensional information on turbulence in the region very close to the interface. Two characteristic time scales at the interface have been examined for exact prediction of the scalar transfer flux. One is the time scale which is reciprocal of the root-mean-square surface divergence, Tγ = langleγγrangle-1/2, where γ is the surface divergence. The other time scale to be examined is TS = Λ/V, where Λ is the zero-correlation length of the surface divergence as the interfacial length scale, and V is the root-mean-square velocity fluctuation in the streamwise direction as the interfacial velocity scale. The results of this study suggests that Tγ is slightly unsatisfactory to correlate the turbulent scalar flux at the gas-liquid interface based on the surface-renewal approximation. It is also found that the proportionality constant appear to be 0.19, which is different with that observed in the laboratory experiments, 0.34 (Komori, Murakami, & Ueda, 1989). It is concluded that the time scale, Tγ, is considered a different kind of the time scale observed in the laboratory experiments. On the other hand, the present in-silico experiments indicate that Ts predicts the turbulent scalar flux based on the surface-renewal approximation in a satisfactory manner. It is also elucidated that the proportionality constant for Ts is approximately 0.36, which is very close to that found by the laboratory experiments. This fact shows that the time scale Ts appears to be essentially the same as the time scale the

  10. Fully automated ionic liquid-based headspace single drop microextraction coupled to GC-MS/MS to determine musk fragrances in environmental water samples.

    Science.gov (United States)

    Vallecillos, Laura; Pocurull, Eva; Borrull, Francesc

    2012-09-15

    A fully automated ionic liquid-based headspace single drop microextraction (IL-HS-SDME) procedure has been developed for the first time to preconcentrate trace amounts of ten musk fragrances extensively used in personal care products (six polycyclic musks, three nitro musks and one polycyclic musk degradation product) from wastewater samples prior to analysis by gas chromatography and ion trap tandem mass spectrometry (GC-IT-MS/MS). Due to the low volatility of the ILs, a large internal diameter liner (3.4 mm i.d.) was used to improve the ILs evaporation. Furthermore, a piece of glass wool was introduced into the liner to avoid the entrance of the ILs in the GC column and a guard column was used to prevent analytical column damages. The main factors influencing the IL-HS-SDME were optimized. For all species, the highest enrichments factors were achieved using 1 μL of 1-octyl-3-methylimidazolium hexafluorophosphate ([OMIM][PF(6)]) ionic liquid exposed in the headspace of 10 mL water samples containing 300 g L(-1) of NaCl and stirred at 750 rpm and 60 °C for 45 min. All compounds were determined by direct injection GC-IT-MS/MS with a chromatographic time of 19 min. Method detection limits were found in the low ng mL(-1) range between 0.010 ng mL(-1) and 0.030 ng mL(-1) depending on the target analytes. Also, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations varying between 3% and 6% and 5% and 11%, respectively (n=3, 1 ng mL(-1)). The applicability of the method was tested with different wastewater samples from influent and effluent urban wastewater treatment plants (WWTPs) and one potable treatment plant (PTP). The analysis of influent urban wastewater revealed the presence of galaxolide and tonalide at concentrations of between 2.10 ng mL(-1) and 0.29 ng mL(-1) and 0.32 ng mL(-1) and waters from PTP only galaxolide was found at a concentration higher than MQL.

  11. A fully automated method for simultaneous determination of aflatoxins and ochratoxin A in dried fruits by pressurized liquid extraction and online solid-phase extraction cleanup coupled to ultra-high-pressure liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Campone, Luca; Piccinelli, Anna Lisa; Celano, Rita; Russo, Mariateresa; Valdés, Alberto; Ibáñez, Clara; Rastrelli, Luca

    2015-04-01

    According to current demands and future perspectives in food safety, this study reports a fast and fully automated analytical method for the simultaneous analysis of the mycotoxins with high toxicity and wide spread, aflatoxins (AFs) and ochratoxin A (OTA) in dried fruits, a high-risk foodstuff. The method is based on pressurized liquid extraction (PLE), with aqueous methanol (30%) at 110 °C, of the slurried dried fruit and online solid-phase extraction (online SPE) cleanup of the PLE extracts with a C18 cartridge. The purified sample was directly analysed by ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for sensitive and selective determination of AFs and OTA. The proposed analytical procedure was validated for different dried fruits (vine fruit, fig and apricot), providing method detection and quantification limits much lower than the AFs and OTA maximum levels imposed by EU regulation in dried fruit for direct human consumption. Also, recoveries (83-103%) and repeatability (RSD < 8, n = 3) meet the performance criteria required by EU regulation for the determination of the levels of mycotoxins in foodstuffs. The main advantage of the proposed method is full automation of the whole analytical procedure that reduces the time and cost of the analysis, sample manipulation and solvent consumption, enabling high-throughput analysis and highly accurate and precise results.

  12. The Effect of Slag on the Effectiveness of Phosphorus Removal from Ferrous Alloys Containing Carbon, Chromium and Nickel

    Directory of Open Access Journals (Sweden)

    Kawecka-Cebula E.

    2016-03-01

    Full Text Available The aim of this study was to determine the impact of slag composition on phosphorus removal from ferrous solutions containing carbon, chromium and nickel. Additions of cryolite, Na3AlF6, were applied for better fluxing and higher phosphate capacity of the slag. An X-ray analysis of final slags formed during dephosphorization of ferrous solutions containing chromium and nickel with CaO-CaF2 or CaO-CaF2-Na3AlF6 mixtures of different chemical compositions was carried out. The equilibrium composition of the liquid and the solid phase while cooling the slags from 1673K to 298K was computed using FactSage 6.2 software. The performed equilibrium computations indicated that the slags were not entirely liquid at those temperatures. The addition of cryolite causes a substantial increase of the liquid phase of the slag. It also has a favourable effect on the dephosphorization grade of hot metal. The obtained results were statistically processed and presented in the form of regression equations.

  13. Refractory-Slag-Metal-Inclusion Multiphase Reactions Modeling Using Computational Thermodynamics: Kinetic Model for Prediction of Inclusion Evolution in Molten Steel

    Science.gov (United States)

    Shin, Jae Hong; Chung, Yongsug; Park, Joo Hyun

    2017-02-01

    The refractory-slag-metal-inclusion multiphase reaction model was developed by integrating the refractory-slag, slag-metal, and metal-inclusion elementary reactions in order to predict the evolution of inclusions during the secondary refining processes. The mass transfer coefficient in the metal and slag phase, and the mass transfer coefficient of MgO in the slag were employed in the present multiphase reactions modeling. The "Effective Equilibrium Reaction Zone (EERZ) Model" was basically employed. In this model, the reaction zone volume per unit step for metal and slag phase, which is dependent on the `effective reaction zone depth' in each phase, should be defined. Thus, we evaluated the effective reaction zone depth from the mass transfer coefficient in metal and slag phase at 1873 K (1600 °C) for the desulfurization reaction which was measured in the present study. Because the dissolution rate of MgO from the refractory to slag phase is one of the key factors affecting the slag composition, the mass transfer coefficient of MgO in the ladle slag was also experimentally determined. The calculated results for the variation of the composition of slag and molten steel as a function of reaction time were in good agreement with the experimental results. The MgAl2O4 spinel inclusion was observed at the early to middle stage of the reaction, whereas the liquid oxide inclusion was mainly observed at the final stage of the refining reaction. The content of CaO sharply increased, and the SiO2 content increased mildly with the increasing reaction time, while the content of Al2O3 in the inclusion drastically decreased. Even though there is slight difference between the calculated and measured results, the refractory-slag-metal multiphase reaction model constructed in the present study exhibited a good predictability of the inclusion evolution during ladle refining process.

  14. Steel desulphurization with synthetic slag

    Directory of Open Access Journals (Sweden)

    Heput, T.

    2007-02-01

    Full Text Available Generally speaking, sulphur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the bath stirring condition upon the desulphurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulphurization was made with synthetic slag at one ladle while the other one was considered standard and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of: lime (50-75%, fluorine (0-17%, bauxite (0-32% and aluminous slag (8-22%. The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulphurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the unbubbled ones.

    En general, el azufre es considerado un elemento nocivo para la calidad del acero y, por eso, en la práctica, se toman todas las medidas de orden tecnológico para su eliminación del baño metálico. En este trabajo se analiza la influencia de la composición química, de la cantidad de escoria y del estado de agitación del baño sobre el proceso de desulfuración en la cuchara para fundir por tratamiento con escoria sintética. Los experimentos se han realizado en una acería evacuando el acero en dos ollas (en una cuchara se efectuó la desulfuración con escoria sintética y a la otra se consideró como patrón y en un acería eléctrica y para la formación de la escoria sintética se utilizó una mezcla producida según muchas recetas, formada por: cal (50-75%, fluorina (0-17%, bauxita (0-32% y escoria aluminosa (8-22%. Los datos han sido procesados en los programas de c

  15. Selective Sulfidation of Lead Smelter Slag with Sulfur

    Science.gov (United States)

    Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Qin, Wenqing

    2016-02-01

    The selective sulfidation of lead smelter slag with sulfur was studied. The effects of temperature, sulfur dosage, carbon, and Na salts additions were investigated based on thermodynamic calculation. The results indicated that more than 96 pct of zinc in the slag could be converted into sulfides. Increasing temperature, sulfur dosage, or Na salts dosage was conducive to the sulfidation of the zinc oxides in the slag. High temperature and excess Na salts would result in the more consumption of carbon and sulfur. Carbon addition not only promoted the selective sulfidation but reduced the sulfur dosage and eliminated the generation of SO2. Iron oxides had a buffering role on the sulfur efficient utilization. The transformation of sphalerite to wurtzite was feasible under reducing condition at high temperature, especially above 1273 K (1000 °C). The growth of ZnS particles largely depended upon the roasting temperature. They were significantly increased when the temperature was above 1273 K (1000 °C), which was attributed to the formation of a liquid phase.

  16. Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J.P.; Kwong, K.-S.; Powell, C.P.; Thomas, H.; Petty, A.V., Jr.

    2007-01-01

    Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575º C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed rate and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE’s Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace.

  17. The use of blast furnace slag

    Directory of Open Access Journals (Sweden)

    V. Václavík

    2012-10-01

    Full Text Available The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  18. The use of blast furnace slag

    OpenAIRE

    V. Václavík; V. Dirner; T. Dvorský; J. Daxner

    2012-01-01

    The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  19. Picture analysing method of slag foaming behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Juhart, M.; Peter, M.; Koch, K. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Metallurgy; Lamut, J. [Faculty of Natural Science and Technology, Univ. Ljubljana, Ljubljana (Slovenia)

    2001-03-01

    Hot tests of foaming behaviour of steelmaking slags were conducted on a laboratory scale up to 1760 C using a Tammann furnace. The foaming behaviour of the slags was quantified on the basis of a new measuring method. The volume increase and the progress of the foaming process can be continuously observed and calculated by means of picture analysis. The gas content of foaming slags was compared with the results of the measurements performed in steel plants. The influence of the magnesia content on the foaming behaviour is investigated. The chemical composition of the slag is beside the CO evolution the decisive factor influencing slag foaming behaviour. The highest volume increase values observed lie in the region of 2500% in relation to the initial volume. (orig.)

  20. Leaching of heavy metals from steelmaking slags

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J. F. P.; Pino, C. G.

    2006-07-01

    Leaching tests with EAF and Ladle slags were performed, using a flow through tests and the standard batch test DIN 38414-S4. The previous method was used to simulate the leaching behaviour of steel slags under landfill. the chemical analysis of the leachates during this period shows, in general, for both types of slag, and increase of heavy metal releases with ageing. Standard test method DIN 38414-S4 was used to evaluate leachability of heavy metals by water in unprocessed slags. After more than one year of trials, slang samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-though test, calcium and magnesium leached from solid slags are below 0.5% and all other metals below 0.1%. Leachates obtained with DIN 38414-S4 present, as expected, higher leaching values; however, these are inferior to 5% (Ca) and 1% (other elements). (Author) 12 refs.

  1. Recycling of the rare earth oxides from spent rechargeable batteries using waste metallurgical slags

    Directory of Open Access Journals (Sweden)

    Tang K.

    2013-01-01

    Full Text Available A high temperature process for recycling spent nickel-metal hydride rechargeable batteries has been recently developed at SINTEF/NTNU. The spent battery modules were first frozen with liquid nitrogen for the de-activation and brittle fracture treatment. The broken steel scraps and plastics were then separated by the mechanical classification and magnetic separation. The remaining positive and negative electrodes, together with the polymer separator, were heated to 600-800oC in order to remove the organic components and further separate the Ni-based negative electrode. XRF analyses indicate that the heat-treated materials consist mainly of nickel, rare earth and cobalt oxides. The valuable rare earth oxides were further recovered by the high-temperature slagging treatment. The waste metallurgical slags, consist mainly of SiO2 and CaO, were used as the rare earth oxide absorbent. After the high temperature slagging treatment, over 98% of nickel and cobalt oxides were reduced to the metal phase; meanwhile almost all rare earth oxides remain in the molten slags. Furthermore, EPMA and XRF analyses of the slag samples indicate that the rare earth oxides selectively precipitate in the forms of solid xSiO2•yCaO•zRe2O3. The matrix of slag phase is Re2O3 deficient, typically being less than 5 wt%. This provides a sound basis to further develop the high-temperature process of concentrating the Re2O3 oxides in slags.

  2. Crystallization Behavior and Growing Process of Rutile Crystals in Ti-Bearing Blast Furnace Slag

    Science.gov (United States)

    Zhang, Wu; Zhang, Li; Li, Yuhai; Li, Xin

    2016-09-01

    The aim of the present work is to elucidate crystallization and growing process of rutile crystals in Ti-bearing blast furnace slag. The samples were taken from the liquid slag and quenched at once at elevated temperatures in order to analyze phase transaction of titanium and grain size of rutile crystals. Crystallization and growing kinetics of rutile crystals under elevated temperature conditions were calculated, and the crystallization process of rutile crystals under isothermal conditions was expressed by Avrami equation. The effects of experimental parameters, such as experimental temperatures, SiO2 addition, cooling rate, crystal seed addition and oxygen flow, were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), the optimal conditions for rutile crystals to grow up were obtained. Distribution and movement state of rutile crystals in the slag were analyzed.

  3. Surface tension of expanded slag from steel manufacturing in electrical furnace

    Directory of Open Access Journals (Sweden)

    J. Łabaj

    2011-07-01

    Full Text Available In the article a research on the surface tension of slag was conducted from the process of obtaining steel in the electric furnace. Melting in the graphite melting crucible caused the slag to foam. The measurement of the surface tension is being conducted with method of rejection. They make the measurement of maximum power needed for the liquid to reject the working element of the apparatus from the surface. The research was conducted in the temperature of 1 673 – 1 723 K. The results of the measurements allowed to determine the surface tension of slag, which in the analysed scope of the temperature is being changed from 454 to 345 mN•m-1.

  4. A numerical model for chemical reaction on slag layer surface and slag layer behavior in entrained-flow gasifier

    Directory of Open Access Journals (Sweden)

    Liu Sheng

    2013-01-01

    Full Text Available The paper concerns with slag layer accumulation, chemical reaction on slag layer surface, and slag layer flow, heat and mass transfer on the wall of entrained-flow coal gasifier. A slag layer model is developed to simulate slag layer behaviors in the coal gasifier. This 3-D model can predict temperature, slag particle disposition rate, disposition particle composition, and syngas distribution in the gasifier hearth. The model is used to evaluate the effects of O2/coal ratio on slag layer behaviors.

  5. Hydrothermal synthesis of xonotlite from carbide slag

    Institute of Scientific and Technical Information of China (English)

    Jianxin Cao; Fei Liu; Qian Lin; Yu Zhang

    2008-01-01

    Carbide slag was used as the calcareous materials for the first time to prepare xonotlite via dynamic hydrothermal synthesis.The effects of influential factors including different calcination temperatures,pretreatment methods of the carbide slag and process param-eters of hydrothermal synthesis on the microstructure and morphology of xonotlite were explored using XRD and SEM techniques.The results indicate that the carbide slag after proper calcination could be used to prepare pure xonotlite;and different calcination tern-peratures have little effect on the crystallinity of synthesized xonotlitc,but have great impact on the morphology of secondary particles.The different pretreatment methods of the carbide slag pose great impact on the crystallinity and morphology of secondary particles of xonotlite.Xonotlite was also synthesized from pure CaO under the salne experimental conditions as that prepared from calcined carbide slag for comparison.Little amount of impurities in carbide slag has no effect on the mechanism of hydrothermal synthesizing xonotlite from carbide slag.

  6. Coexistence Theory of Slag Structure and Its Application to Calculation of Oxidizing Capability of Slag Melts

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by NFetO=NFeO+6NFe2O3, while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as NFetO=NFeO+6NFe2O3+8NFe3O4.

  7. Dissolution Behavior of Alumina-Based Inclusions in CaF2-Al2O3-CaO-MgO-SiO2 Slag Used for the Electroslag Metallurgy Process

    Directory of Open Access Journals (Sweden)

    Yanwu Dong

    2016-11-01

    Full Text Available Removal of non-metallic inclusions to CaF2-based slag is one of the most important functions of electroslag remelting. In this work, the dissolution behavior for alumina-based inclusions in CaF2-Al2O3-CaO-MgO-SiO2 slag has been investigated. Results indicate that the diffusion or permeability capacity of slag components into alumina particles is F−, Ca2+, Si4+, Mg2+, from strongest to weakest, for CaF2-Al2O3-CaO-MgO-SiO2 slag. Alumina inclusions react with F− in liquid slag at first and then react with CaO to form xCaO-yAl2O3 system. Subsequently, MgO substitutes for CaO to form a MgO-Al2O3 system layer surrounding the other product and reactant, and then enters the liquid slag. CaF2 can improve the dissolution capacity of slag to alumina inclusions. A complex region was formed between alumina-based particles and the slag, with different areas dominated by CaF2, CaO-Al2O3, CaO-SiO2 and MgO-Al2O3. The dissolution process of alumina particles in slag is different from the formation of compound inclusions originated from the Al-O deoxidization reaction.

  8. Novel Sessile Drop Software for Quantitative Estimation of Slag Foaming in Carbon/Slag Interactions

    Science.gov (United States)

    Khanna, Rita; Rahman, Mahfuzur; Leow, Richard; Sahajwalla, Veena

    2007-08-01

    Novel video-processing software has been developed for the sessile drop technique for a rapid and quantitative estimation of slag foaming. The data processing was carried out in two stages: the first stage involved the initial transformation of digital video/audio signals into a format compatible with computing software, and the second stage involved the computation of slag droplet volume and area of contact in a chosen video frame. Experimental results are presented on slag foaming from synthetic graphite/slag system at 1550 °C. This technique can be used for determining the extent and stability of foam as a function of time.

  9. Blast furnace slags as sorbents of phosphate from water solutions.

    Science.gov (United States)

    Kostura, Bruno; Kulveitová, Hana; Lesko, Juraj

    2005-05-01

    The paper is focused on the sorption of phosphorus from aqueous solutions by crystalline and amorphous blast furnace slags. Slag sorption kinetics were measured, adsorption tests were carried out and the effect of acidification on the sorption properties of slags was studied. The kinetic measurements confirmed that the sorption of phosphorus on crystalline as well as amorphous slags can be described by a model involving pseudo-second-order reactions. For all slag types, phosphorus sorption follows the Langmuir adsorption isotherm. The acid neutralizing capacities of crystalline and amorphous slags were determined. In the case of the crystalline slags, buffering intervals were found to exist during which the slag minerals dissolve in the sequence bredigite-gehlenite-diaspor. There is a high correlation (R2=0.9989) between ANC3.8 and the saturation capacities of crystalline and amorphous slags.

  10. Slags from steel production: Properties and their utilization

    Directory of Open Access Journals (Sweden)

    J. Vlcek

    2013-07-01

    Full Text Available During steel production a considerable amount of slags is produced. In addition to its usual processing, as recycling in device for steel production and preparation of aggregates, it is also possible to apply less common slag processing ways. Depending on cooling mode of the steel slags these may show some binding properties. Geopolymer type binders can be prepared from the slag using alkali activators or the hydraulic properties of the dicalciumsilicate present in the slag can be induced by water. The paper summarizes present state of material utilisation of the steel slags with focus on emphasize of the possible sources of the slag volume instability. The influence of process of slag cooling on its phase composition is documented. It was also found that slags from real sources show different parameters compared to samples obtained for laboratory examination.

  11. Electroreduction Kinetics for Molten Oxide Slags

    Institute of Scientific and Technical Information of China (English)

    GAO Yun-ming; CHOU Kuo-chih; GUO Xing-min; WANG Wei

    2007-01-01

    The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-circuit galvanic cell. The following galvanic cell was assembled in the present experiment: graphite rod, [O]Fe-C saturated|ZrO2(MgO)|Cu(l)+(FeO)(slag), and molybdenum wire. The FeO electroreduction reaction was studied through measuring short circuit current by controlling factors such as temperature, the FeO content in molten slags, and the external circuit resistance. An overall kinetics model was developed to describe the process of FeO electroreduction. It was found that the modeled curves were in good agreement with the experimental values. The new oxide reduction method in the metallurgy with controlled oxygen flow was proposed and the metallurgical theory with controlled oxygen flow was developed.

  12. A study on transformation of some transition metal oxides in molten steelmaking slag to magnetically susceptible compounds

    Directory of Open Access Journals (Sweden)

    Shatokha V.

    2013-01-01

    Full Text Available Sustainable development of steelmaking requires solving a number of environmental problems. Economically feasible and environmentally friendly recycling of slag wastes is of special concern. Research of the team representing National Metallurgical Academy of Ukraine, Royal Institute of Technology, Carnegie Mellon University and URS Corp revealed a possibility of the controlled phase transformations in the liquid silicate melts followed by formation of the magnetically susceptible compounds. This approach enables selective recovery of metal values from slag. In this paper, the results obtained and further research directions are discussed. A possibility to exploit physical properties of the transition metals, typical for the metallurgical slags (such as Fe, Mn, V and others, and corresponding specific properties of their compounds, such as non-stoichiometry, mixed valency, pseudomorphosis, thermodynamic stability etc, in production of value-added materials from slag wastes is discussed. The results of the studies of thermodynamics and kinetics of oxidation in slags followed by phase transformation with binary, ternary and complex oxides under various physicochemical conditions are discussed in the view of their application for production of the materials with predefined physical properties. Peculiarities of precipitation in slags with various basicities are analysed and demonstrate capacity of the proposed approach in the production of the material with a given structure and size - for example, nano-sized crystals with structure of spinel. The approaches towards industrial realization of the developed method are also discussed.

  13. Sulfide capacities of fayalite-base slags

    Science.gov (United States)

    Simeonov, S. R.; Sridhar, R.; Toguri, J. M.

    1995-04-01

    The sulfide capacities of fayalite-base slags were measured by a gas-slag equilibration technique under controlled oxygen and sulfur potentials similar to those encountered in the pyrometallurgical processing of nonferrous metals. The oxygen pressure range was from 10-9.5 to 10-11 MPa and the sulfur pressure range from 10-3 to 10-4.5 MPa, over a temperature range of 1473 to 1623 K. The slags studied were FeO-SiO2 at silica saturation and those with addition of CaO, MgO, and Al2O3 to determine their effect on sulfide capacities. For these slags, the sulfide capacities were found to vary from 10-3.3 to 10-5. The sulfide capacities increased with increasing temperature from 1473 to 1623 K. A comparison of the reported plant data on sulfur content of industrial slags shows good agreement with the present experimental results. The present data will be useful in estimating metal losses in slag due to metal sulfide entrainment in nonferrous smelters.

  14. Calculation of sulfide capacities of multicomponent slags

    Science.gov (United States)

    Pelton, Arthur D.; Eriksson, Gunnar; Romero-Serrano, Antonio

    1993-10-01

    The Reddy-Blander model for the sulfide capacities of slags has been modified for the case of acid slags and to include A12O3 and TiO2 as components. The model has been extended to calculate a priori sulfide capacities of multicomponent slags, from a knowledge of the thermodynamic activities of the component oxides, with no adjustable parameters. Agreement with measurements is obtained within experimental uncertainty for binary, ternary, and quinary slags involving the components SiO2-Al2O3-TiO2-CaO-MgO-FeO-MnO over wide ranges of composition. The oxide activities used in the computations are calculated from a database of model parameters obtained by optimizing thermodynamic and phase equilibrium data for oxide systems. Sulfur has now been included in this database. A computing system with automatic access to this and other databases has been developed to permit the calculation of the sulfur content of slags in multicomponent slag/metal/gas/solid equilibria.

  15. Validation of a novel, fully automated high throughput high-performance liquid chromatographic/tandem mass Spectrometric method for quantification of pantoprazole in human plasma.

    Science.gov (United States)

    Dotsikas, Yannis; Apostolou, Constantinos; Soumelas, Stefanos; Kolocouri, Filomila; Ziaka, Afroditi; Kousoulos, Constantinos; Loukas, Yannis L

    2010-01-01

    An automated high-throughput HPLC/MS/MS method was developed for the quantitative determination of pantoprazole in human plasma. Only 100 microL plasma was placed in 2.2 mL 96 deep-well plates, and both pantoprazole and omeprazole (IS) were extracted from human plasma by liquid-liquid extraction, using diethyl ether-dichloromethane (70:30, v/v) as the organic solvent. Robotic liquid-handling workstations were used for all liquid transfer and solution preparation steps and resulted in a short sample preparation time. After vortexing, centrifugation, and freezing, the supernatant organic solvent was evaporated and reconstituted in a small volume of reconstitution solution. Sample analysis was performed by utilizing the combination of RP-HPLC/MS/MS, with positive-ion electrospray ionization and multiple reaction monitoring detection. The chromatographic run time was set at 1.8 min with a flow rate of 0.6 mL/min on a Nucleosil octylsilyl (C8) analytical column. The method was proven to be sensitive, specific, accurate, and precise for the determination of pantoprazole in human plasma. The method was applied to a bioequivalence study after per os administration of a 40 mg pantoprazole gastric retentive tablet.

  16. Quantification and Modelling of Fugitive Dust Emissions From Nickel Slag

    Science.gov (United States)

    Sanderson, R. S.; McKenna Neuman, C.

    2009-05-01

    Mining and smelting operations in Northern Ontario, and indeed worldwide, introduce a number of unique sources of fugitive dust and other aerosol pollutants into the surrounding environment from smokestacks, tailings, and slag dumps exposed to wind erosion. Fugitive dust represents a potential health hazard, and as such, mining companies are required to maintain inventories of dust emissions associated with their operations. The purpose of this study was to fully characterize the wind-induced fugitive dust emission rates of nickel slag collected from a slag dump at a smelting facility in Northern Ontario, as dependent on wind speed, surface roughness, duration of weathering, effects of mechanical disturbance, and exposure to rain. PM10 flux rates were measured through combined field monitoring and wind tunnel simulation. In both settings, airborne dust concentrations downwind of the source were measured using four vertically distributed DustTrak aerosol monitors. Wind speed was measured in the wind tunnel using a micro-pitot tube mounted on a programmable traversing slide, and in the field, using five vertically distributed cup anemometers mounted on a mast. The profiles of PM10 and wind speed were used to compute the vertical emission rate (Fv) using a finite difference method. The PM10 emission rates simulated in the laboratory were found to directly overlap those measured on site at the smelting facility over a range of wind speeds, suggesting that Fv values measured in wind tunnel simulations can be used in dispersion modelling with a reasonable degree of confidence. Although showing a strong positive correlation with wind speed, PM10 emissions from nickel slag were found to demonstrate an exponential, temporal decay immediately following any form of mechanical disturbance that resulted in exposure of the silt fraction of the material. Winnowing of this fraction left behind an armoured surface of coarse, non-erodible clasts. It was further determined that

  17. Spontaneous Emulsification of a Metal Drop Immersed in Slag Due to Dephosphorization: Surface Area Quantification

    Science.gov (United States)

    Assis, Andre N.; Warnett, Jason; Spooner, Stephen; Fruehan, Richard J.; Williams, Mark A.; Sridhar, Seetharaman

    2015-04-01

    When a chemical reaction occurs between two immiscible liquids, mass transfer is continuously taking place at the liquid-liquid interface. Several studies have shown that if the species being exchanged between the two liquids are surface-active, a very pronounced decrease in interfacial tension can occur which can lead to a phenomenon called spontaneous emulsification. In steelmaking, this behavior has been observed for several reactions that involve the transfer of impurities from molten steel to a molten-oxide slag but little quantification has been made. This work focuses on spontaneous emulsification due to the dephosphorization of a Fe-P drop immersed in a basic oxygen furnace type slag. An Au-image furnace attached to a confocal scanning laser microscope was used to rapidly heat and cool the samples at different times, and X-ray computerized tomography was used to perform the surface area calculations of the samples where the slag/steel reaction was allowed to occur for distinct times. The results show that the surface area of the metal drop rapidly increases by over one order of magnitude during the first 60 seconds of the reaction while the chemical reaction is occurring at a fast rate. Once the reaction slows down, approximately after 60 seconds, the droplets start to coalesce back together minimizing the surface area and returning to a geometry close to its equilibrium shape.

  18. Heat Flux Through Slag Film and Its Crystallization Behavior

    Institute of Scientific and Technical Information of China (English)

    TANG Ping; XU Chu-shao; WEN Guang-hua; ZHAO Yan-hong; QI Xin

    2008-01-01

    An experimental apparatus for simulating copper mold is used to quantify the heat flux through the slag film and to obtain a solid slag for further determining its crystallization behavior.The result indicates that both the chemical composition of the mold powder and the cooling rate have an important influence on the heat flux through the slag film.With increasing the binary hasicity,the heat flux of slag film decreases at first,reaches the minimum at the basicity of 1.4,and then increases,indicating that the maximum binary basicity is about 1.4 for selecting"mild cooling"mold powder.The heat transfer through the slag film can be specified in terms of the crystalline ratio and the thickness of the slag film.Reerystallization of the solid slag occurs and must be considered as an important factor that may influence the heat transfer through the solid slag layer.

  19. Osmundiron, cleaved iron bars and slags (Osmundjern, kloder og kalotslagger)

    DEFF Research Database (Denmark)

    Buchwald, Vagn Fabritius

    1996-01-01

    Investigation of so-called Osmund iron, iron bars and slags from iron production in the medieval ages.......Investigation of so-called Osmund iron, iron bars and slags from iron production in the medieval ages....

  20. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Pathak

    2014-05-01

    Full Text Available Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS and this material is obtained from the blast furnace of cement plant, which is the byproduct of iron (from ACC plant, sindri. It is generally obtained in three shaped one is air cooled, foamed shaped and another is in granulated shaped. The use of by-product materials for stabilisation has environmental and economic benefits. Ground granulated blast furnace slag (GGBS material is used in the current work to stabilise soil (clay. The main objectives of this research were to investigate the effect of GGBS on the engineering property (optimum moisture content and maximum dry density, plastic limit, liquid limit, compaction, unconfined compressive strength, triaxial and California bearing ratio test of the soil and determine the engineering properties of the stabilised.

  1. Graphitization of Coke and Its Interaction with Slag in the Hearth of a Blast Furnace

    Science.gov (United States)

    Li, Kejiang; Zhang, Jianliang; Liu, Yanxiang; Barati, Mansoor; Liu, Zhengjian; Zhong, Jianbo; Su, Buxin; Wei, Mengfang; Wang, Guangwei; Yang, Tianjun

    2016-04-01

    Coke reaction behavior in the blast furnace hearth has yet to be fully understood due to limited access to the high temperature zone. The graphitization of coke and its interaction with slag in the hearth of blast furnace were investigated with samples obtained from the center of the deadman of a blast furnace during its overhaul period. All hearth coke samples from fines to lumps were confirmed to be highly graphitized, and the graphitization of coke in the high temperature zone was convinced to start from the coke surface and lead to the formation of coke fines. It will be essential to perform further comprehensive investigations on graphite formation and its evolution in a coke as well as its multi-effect on blast furnace performance. The porous hearth cokes were found to be filled up with final slag. Further research is required about the capability of coke to fill final slag and the attack of final slag on the hearth bottom refractories since this might be a new degradation mechanism of refractories located in the hearth bottom.

  2. Recycling and valorisation of stainless steel slags

    Energy Technology Data Exchange (ETDEWEB)

    Van Dessel, J. [Belgian Building Research Institute, Brussels (Belgium)

    2001-07-01

    The project described in this paper involves the collaboration of eleven partners. The project aims to create a value-added product by recovering usable non-ferrous metals from the production of stainless steel and use the recycled slag as a secondary material for road construction and concrete applications. The objective of the project is to return the metal contained in the slag to stainless steel production, and to treat the non-metallic slag, perhaps by a metallurgical process based upon direct plasma technology, prior to use in a variety of processes. The project also aims to investigate the environmental characteristics of the slag, which is essential for it to be used as secondary material. The major challenge appears to be the development of an improved process for separating the slag from the metallic particles in order to avoid the frequent breakdowns and significant repairs associated with use of the material. It is expected that using magnetic and density-based separation processes will reduce the cost of maintenance by about 20 per cent. Results achieved to date, and economic factors impacting on feasibility, are also discussed. 2 tabs., 3 figs.

  3. Use of slag for dye removal

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishna, K.R.; Viraraghavan, T. [Univ. of Regina, Saskatchewan (Canada). Faculty of Engineering

    1998-09-01

    Adsorption techniques employing activated carbon have been found to be reasonably effective in the removal of some of the ionic impurities in water. However, economic considerations may require the use of inexpensive sorbents which are either naturally available or available as waste products from manufacturing processes. Slag is one such waste product obtained during the manufacture of steel, and the present study investigates dye removal characteristics of slag from colored waters. Aqueous solutions prepared from commercial grade acid, basic, and disperse dyes were used in this study, and batch pH, kinetic, and isotherm studies were undertaken on a laboratory scale. The data were evaluated for applicability to the Langmuir, Freundlich, and BET isotherm models, and the removal capacity of slag was compared with that of granular activated carbon. Results indicated approximately 94% removal of the disperse dye by slag, compared with a removal of approximately 49% achieved by activated carbon. Removal of acid dyes (dyes containing anionic groups) was reasonably good (approximately 47 and 74%), though not as good as obtained using activated carbon (approximately 100%). Column studies were conducted with a disperse dye (nonionic, slightly soluble in water), and analysis of data showed a sorption capacity of 1.3 mg of disperse dye per gram of slag. However, effluent dye concentrations were found to be higher than the permissible levels for discharge to receiving waters.

  4. X-ray fluoroscopic observation of slag foaming; Slag no awadachi gensho no x sen toshi kansatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Y.; Tokumitsu, N. [Nippon Steel Corp., Tokyo (Japan)

    2001-01-01

    Slag foaming caused by slag/metal reaction in a graphite crucible was observed with X-ray fluoroscopic apparatus in order to make clear the effect of bubble size on the foam height and the distribution of bubbles in slag. It was observed that the foam layer was formed when CO bubbles evolved at slag/metal interface became less than approximately 2mm in diameter. The foam height increased with the decrease of bubble size even in case of almost the same gas evolution rate. The size of bubbles decreased with the increase of iron oxide Content in slag and the decrease of sulphur content. It is considered that the bubbles become smaller when slag is wettable with metal. Therefore, the physical properties of slag/metal interface also affect the foam height besides the surface tension or viscosity of slag because they change the bubble size. (author)

  5. Thermodynamic Model and Database for Sulfides Dissolved in Molten Oxide Slags

    Science.gov (United States)

    Kang, Youn-Bae; Pelton, Arthur D.

    2009-12-01

    A thermodynamic model has been developed in the framework of the modified quasichemical model in the quadruplet approximation to permit the calculation of solubilities of various gaseous species (sulfide, sulfate, nitride, carbide, water, etc.) in molten slags. The model calculates the solubilities solely from knowledge of the thermodynamic activities of the component oxides and the Gibbs energies of the pure liquid components (oxides, sulfides, sulfates, etc.). In the current article, it is shown that solubilities of sulfur as sulfide in Al2O3-CaO-FeO-Fe2O3-MgO-MnO-SiO2-TiO2-Ti2O3 multicomponent slags, which are predicted from the current model with no adjustable model parameters, are in good agreement with all available experimental data. The article also provides a thorough review of experimental sulfide capacity data for this system. The model applies at all compositions from pure oxides to pure sulfides and from basic to acidic slags. By coupling this database with other evaluated databases, such as those for molten metal and gaseous phases, and with general software for Gibbs energy minimization, practically important slag/metal/gas/solid equilibria can be computed such as S-distribution ratios.

  6. Investigation of Freeze-Linings in Copper-Containing Slag Systems: Part I. Preliminary Experiments

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2013-06-01

    Slag freeze-linings are increasingly used in industrial pyrometallurgical processes to insure that furnace integrity is maintained in aggressive high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat-transfer models. The focus of the present research is to determine the impact of slag chemistry and local process conditions on the microstructures, thickness, stability, and heat-transfer characteristics of the frozen deposit at steady-state conditions. The formation of the freeze-linings is studied under controlled laboratory conditions using an air-cooled "cold-finger" technique for Cu-Fe-Si-Al-O slag at equilibrium with metallic copper relevant to the industrial copper smelting processes. The phase assemblages and microstructures of the deposits formed in the cold-finger experiments differ significantly from those expected from phase equilibrium considerations. The freeze-lining deposits have been found, in general, to consist of several layers. Starting from the cold finger, these layers consist of glass; glass with microcrystalline precipitates; closed crystalline layer; and open crystalline layer. Even at steady-state conditions, there was no primary phase sealing layer of delafossite [Cu2O · (Al, Fe)2O3] present at the deposit/liquid interface—these observations differ markedly from those expected from phase equilibrium considerations. The findings have significant practical implications, and potential for the improved design and operation of industrial metallurgical furnaces.

  7. Activity Calculation in Complex Metallurgical Molten Slag Systems Based on Regular Solution Model

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The activity of FetO is very important in ironmaking and steelmaking process. In order to predict the activ- ity of Fe, O and optimize the operation conditions in ironmaking and steelmaking process, by application of regular so lution model in molten slag systems, FeO-Fe2 O3-SIO2 ternary system, FeO-Fe2 O3-SiO2-CaO and FeO-Fe2 O3-SiO2-NiO quaternary systems have been studied by the chemical equilibrium between H2/H20 gas mixture and liquid slag con tained in solid iron. The values of interaction energy between cations concerning steelmaking slags have been deter- mined by application of ferric-ferrous iron equilibrium and iron-ferric iron equilibrium. And then the activity of Fe, O can be calculated. The results show that the relative error is 3.9% in FeO-Fe203-SiO2 system and 18% in FeO- Fe203-SiO2 CaO system. The prediction of activities of FetO in the systems are in good agreement with the measure- ments and the regular solution model is valid for predicting the activity of FetO in complex molten slags systems. The activity of Fe, O in FeO-Fe20a-NiO system have not been tested presently, and the calculated result can not be assessed.

  8. CO2 sequestration by carbonation of steelmaking slags in an autoclave reactor.

    Science.gov (United States)

    Chang, E-E; Pan, Shu-Yuan; Chen, Yi-Hung; Chu, Hsiao-Wen; Wang, Chu-Fang; Chiang, Pen-Chi

    2011-11-15

    Carbon dioxide (CO(2)) sequestration experiments using the accelerated carbonation of three types of steelmaking slags, i.e., ultra-fine (UF) slag, fly-ash (FA) slag, and blended hydraulic slag cement (BHC), were performed in an autoclave reactor. The effects of reaction time, liquid-to-solid ratio (L/S), temperature, CO(2) pressure, and initial pH on CO(2) sequestration were evaluated. Two different CO(2) pressures were chosen: the normal condition (700 psig) and the supercritical condition (1300 psig). The carbonation conversion was determined quantitatively by using thermo-gravimetric analysis (TGA). The major factors that affected the conversion were reaction time (5 min to 12h) and temperature (40-160°C). The BHC was found to have the highest carbonation conversion of approximately 68%, corresponding to a capacity of 0.283 kg CO(2)/kg BHC, in 12h at 700 psig and 160°C. In addition, the carbonation products were confirmed to be mainly in CaCO(3), which was determined by using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) to analyze samples before and after carbonation. Furthermore, reaction kinetics were expressed with a surface coverage model, and the carbon footprint of the developed technology in this investigation was calculated by a life cycle assessment (LCA). Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Electrochemistry of oxygen ion transport in slag

    Institute of Scientific and Technical Information of China (English)

    鲁雄刚; 丁伟中; 李福燊; 李丽芬; 周国治

    2002-01-01

    A systematic experiment relating to the electrochemistry of oxygen ion transport in slag has been studied in lab.An equivalent circuit has been used to describe ion transfer between metal and slag in this paper and a kinetic model with electrochemical characteristic representing oxygen ion immigration has been worked out.The different experimental phenomena can be explained generally by this model.It can be seen that the theoretical results are in good agreement with experiments.The comparison of experimental data with model calculation proved that the electrochemical model is right.

  10. Limitation of Sulfide Capacity Concept for Molten Slags

    Science.gov (United States)

    Jung, In-Ho; Moosavi-Khoonsari, Elmira

    2016-04-01

    The sulfide capacity concept has been widely used in pyrometallurgy to define sulfur removal capacities of slags. Typically, the sulfide capacity is considered to be a unique slag property depending only on temperature regardless of partial pressures of oxygen and sulfur. In the present study, it is demonstrated that sulfide capacities of slags in particular those of Na2O-containing slags can vary with partial pressures of oxygen and sulfur due to large solubility of sulfide in Na2O-containing slag systems.

  11. Orgin of Slag from Early Medieval Age Furnaces in Nitra

    Directory of Open Access Journals (Sweden)

    Julius Dekan

    2005-01-01

    Full Text Available Two types of archaeological artefacts from remains of Early Medieval Age furnaces excavated in Nitra are analysed. They are supposed to originate from slag of glass and iron production. Employing Mossbauer spectrometry, iron crystallographic sites are identified and compared. In all samples, Fe2+ and Fe3+ structural positions were revealed. Some of the archeological artefacts including those that were supposed to originate from glass production show a presence of metallic iron and/or magnetic oxides. Based on the results of Mossbauer effect measurements performed at room temperature as well as 77 K (liquid nitrogen temperature analytical evidence is provided that the iron sites identified are not as those usually encountered in glasses. Consequently, a conclusion is proposed that neither of the investigated furnaces was used for glass production.

  12. Valorization of BOF Steel Slag by Reduction and Phase Modification: Metal Recovery and Slag Valorization

    Science.gov (United States)

    Liu, Chunwei; Huang, Shuigen; Wollants, Patrick; Blanpain, Bart; Guo, Muxing

    2017-03-01

    Basic oxygen furnace (BOF) steel slag is a main byproduct in steelmaking, and its valorization is therefore of considerable interest, from a metal-recovery perspective and from a residue-utilization perspective. In the present study, the carbothermic reduction of BOF slag was investigated systematically. The reductions of Fe- and P-containing phases (i.e., oxide and compounds) are discussed. Effects of Al2O3 and SiO2 additions on the solidification microstructure and mineralogy associated with the reduction processes were also investigated. The formation and growth of the extracted metallic phase are discussed, and the mineralogy of the residue slag is determined. We conclude that by controlling the additions under a rapid cooling condition, it is possible to extract metallic iron as high-grade metal and simultaneously to utilize the remaining slag for construction applications.

  13. Impact of electro slag remelting on 14 109 steel properties

    Directory of Open Access Journals (Sweden)

    Pribulová A.

    2017-03-01

    Full Text Available The Electro Slag Remelting (ESR is one of the remelting processes in the field of metal refinery. In this process, the slag plays various roles, such as heat generation, protection of melt, and chemical refining. The main objective of the experiments described in this article was to identify the most appropriate slag composition for the electro slag remelting of the steel in order to achieve the chemical composition compliant with the standard applicable to the given steel, minimum sulphur content, minimum contents of oxide and sulphide inclusions, as well as mechanical properties corresponding to the standard applicable to the steel STN 14 109. Ten electrodes were remelted, whereas the remelting was carried out under 8 slags. The used slags containing 70% of CaF2 and 30% of Al2O3 with different addition of CaO, the slags consisted of the same components as previous slags, whereas the ratio of individual components was 1:1:1, and with SiO2 and MgO and slag without Al2O3. With regard to all the above mentioned facts, the slag types which may be regarded as the most appropriate for the STN 14 109 steel remelting are the basic slags containing 70% of CaF2 - 30% of Al2O3 with added 30 and 45 weight % of CaO.

  14. Linear stability of horizontal, laminar fully developed, quasi-two-dimensional liquid metal duct flow under a transverse magnetic field and heated from below

    Science.gov (United States)

    Vo, Tony; Pothérat, Alban; Sheard, Gregory J.

    2017-03-01

    This study considers the linear stability of Poiseuille-Rayleigh-Bénard flows subjected to a transverse magnetic field, to understand the instabilities that arise from the complex interaction between the effects of shear, thermal stratification, and magnetic damping. This fundamental study is motivated in part by the desire to enhance heat transfer in the blanket ducts of nuclear fusion reactors. In pure magnetohydrodynamic flows, the imposed transverse magnetic field causes the flow to become quasi-two-dimensional and exhibit disturbances that are localized to the horizontal walls. However, the vertical temperature stratification in Rayleigh-Bénard flows feature convection cells that occupy the interior region, and therefore the addition of this aspect provides an interesting point for investigation. The linearized governing equations are described by the quasi-two-dimensional model proposed by Sommeria and Moreau [J. Fluid Mech. 118, 507 (1982), 10.1017/S0022112082001177], which incorporates a Hartmann friction term, and the base flows are considered fully developed and one-dimensional. The neutral stability curves for critical Reynolds and Rayleigh numbers, Rec and Rac, respectively, as functions of Hartmann friction parameter H have been obtained over 10-2≤H ≤104 . Asymptotic trends are observed as H →∞ following Rec∝H1 /2 and Rac∝H . The linear stability analysis reveals multiple instabilities which alter the flow both within the Shercliff boundary layers and the interior flow, with structures consistent with features from plane Poiseuille and Rayleigh-Bénard flows.

  15. Research and development of blasting abrasive made of steelmaking slag

    Institute of Scientific and Technical Information of China (English)

    TANG Oujing

    2015-01-01

    This study focuses on the development of a new type of nonmetallic steelmaking slag abrasive.The performance,processing,and application of steelmaking slag as a nonmetallic abrasive are introduced.The chemical composition,hardness,crushing value,and particle gradation of steelmaking slag are analyzed.A processing method for steelmaking slag as a blasting abrasive is suggested and evaluated.Compared with conventional abrasives such as copper ore sand and cast iron shot,processed steelmaking slag exhibits similar performance and can satisfy abrasive technical requirements.The derusting effect provided by steelmaking slag for a ship deck can reach the Sa2.0 level,and its recyclability is higher than that of copper ore sand.The derusting performance of steelmaking slag is similar to that of copper ore,and it can thus be used in repairing ship decks.

  16. Separation of Iron Droplets From Titania Bearing Slag

    Institute of Scientific and Technical Information of China (English)

    WANG Ming-yu; LOU Tai-ping; ZHANG Li; SUI Zhi-tong

    2008-01-01

    Owing to smelting vanadium-titanium magnetite ore, the amount of iron entrainment in slag as droplets is far higher than that in conventional BF slag. However, the iron droplets can be easily settled by blowing air into the molten slag. The results show that more than 80% of iron droplets in titania bearing slag can be settled and separated after treatment. The temperature rise of molten slag during the oxidizing process and the decreased viscosity caused by the component change of slag as well as air stirring in slag both accelerate the iron droplets settling. The vanadium content in the settled iron droplets and the original iron droplets was obtained by chemical analysis. The possible reason for the increased vanadium in the settled iron droplets was discussed by thermodynamic principles.

  17. Characteristics and environmental aspects of slag: a review

    Science.gov (United States)

    Piatak, Nadine M.; Parsons, Michael B.; Seal, Robert R., II

    2015-01-01

    Slag is a waste product from the pyrometallurgical processing of various ores. Based on over 150 published studies, this paper provides an overview of mineralogical and geochemical characteristics of different types of slag and their environmental consequences, particularly from the release of potentially toxic elements to water. This chapter reviews the characteristics of both ferrous (steel and blast furnace Fe) and non-ferrous (Ag, Cu, Ni, Pb, Sn, Zn) slag. Interest in slag has been increasing steadily as large volumes, on the order of hundreds of millions of tonnes, are produced annually worldwide. Research on slag generally focuses on potential environmental issues related to the weathering of slag dumps or on its utility as a construction material or reprocessing for secondary metal recovery. The chemistry and mineralogy of slag depend on the metallurgical processes that create the material and will influence its fate as waste or as a reusable product.

  18. A fully automated effervescence assisted dispersive liquid–liquid microextraction based on a stepwise injection system. Determination of antipyrine in saliva samples

    Energy Technology Data Exchange (ETDEWEB)

    Medinskaia, Kseniia; Vakh, Christina; Aseeva, Darina [Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, RU-198504 Saint Petersburg (Russian Federation); Andruch, Vasil, E-mail: vasil.andruch@upjs.sk [Department of Analytical Chemistry, University of P.J. Šafárik, SK-04154 Košice (Slovakia); Moskvin, Leonid [Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, RU-198504 Saint Petersburg (Russian Federation); Bulatov, Andrey, E-mail: bulatov_andrey@mail.ru [Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, RU-198504 Saint Petersburg (Russian Federation)

    2016-01-01

    A first attempt to automate the effervescence assisted dispersive liquid–liquid microextraction (EA-DLLME) has been reported. The method is based on the aspiration of a sample and all required aqueous reagents into the stepwise injection analysis (SWIA) manifold, followed by simultaneous counterflow injection of the extraction solvent (dichloromethane), the mixture of the effervescence agent (0.5 mol L{sup −1} Na{sub 2}CO{sub 3}) and the proton donor solution (1 mol L{sup −1} CH{sub 3}COOH). Formation of carbon dioxide microbubbles generated in situ leads to the dispersion of the extraction solvent in the whole aqueous sample and extraction of the analyte into organic phase. Unlike the conventional DLLME, in the case of EA-DLLME, the addition of dispersive solvent, as well as, time consuming centrifugation step for disruption of the cloudy state is avoided. The phase separation was achieved by gentle bubbling of nitrogen stream (2 mL min{sup −1} during 2 min). The performance of the suggested approach is demonstrated by determination of antipyrine in saliva samples. The procedure is based on the derivatization of antipyrine by nitrite-ion followed by EA-DLLME of 4-nitrosoantipyrine and subsequent UV–Vis detection using SWIA manifold. The absorbance of the yellow-colored extract at the wavelength of 345 nm obeys Beer's law in the range of 1.5–100 µmol L{sup −1} of antipyrine in saliva. The LOD, calculated from a blank test based on 3σ, was 0.5 µmol L{sup −1}. - Highlights: • First attempt to automate the effervescence assisted dispersive liquid–liquid microextraction. • Automation based on Stepwise injection analysis manifold in flow batch system. • Counterflow injection of extraction solvent and the effervescence agent. • Phase separation performed by gentle bubbling of nitrogen. • Application for the determination of antipyrine in saliva samples.

  19. Multi-Stage Control of Waste Heat Recovery from High Temperature Slags Based on Time Temperature Transformation Curves

    Directory of Open Access Journals (Sweden)

    Yongqi Sun

    2014-03-01

    Full Text Available This paper presents a significant method and a basic idea of waste heat recovery from high temperature slags based on Time Temperature Transformation (TTT curves. Three samples with a fixed CaO/SiO2 ratio of 1.05 and different levels of Al2O3 were designed and isothermal experiments were performed using a Single Hot Thermocouple Technique (SHTT. The TTT curves established through SHTT experiments described well the variation of slag properties during isothermal processes. In this study, we propose a multi-stage control method for waste heat recovery from high temperature slags, in which the whole temperature range from 1500 °C to 25 °C was divided into three regions, i.e., Liquid region, Crystallization region and Solid region, based on the TTT curves. Accordingly, we put forward an industrial prototype plant for the purpose of waste heat recovery and the potential of waste heat recovery was then calculated. The multi-stage control method provided not only a significant prototype, but also a basic idea to simultaneously extract high quality waste heat and obtain glassy phases on high temperature slags, which may fill the gap between slag properties and practical waste heat recovery processes.

  20. Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants ofk 6.372 and 1/n 1.739 for BFS, and ofk 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively.These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

  1. Microstructure characterisation of freeze linings formed in a copper slag cleaning slag

    Directory of Open Access Journals (Sweden)

    Jansson J.

    2015-01-01

    Full Text Available The initial growth rate of freeze linings on water-cooled elements submerged in molten iron silicate slag is fast. The freeze lining microstructure forming on water cooled steel surface in a high-silica, slag cleaning furnace slag of a direct-to-blister copper smelter is mostly glassy or amorphous. It contains 5-30 μm magnetite crystals, very small and larger copper droplets as well as small magnetite and silicate nuclei embedded in the glassy silica-rich matrix. Chemically the formed freeze linings are more silica-rich than the slag from which they were generated. Magnetite (spinel is the primary phase of the solidifying SCF slag but it does not form a continuous network through the freeze lining. Its strength is given by the intergranular silica-rich phase which initially is glassy or microcrystalline. Due to only partial slag reduction in the SCF process, large magnetite crystals are present in the freeze lining and seem to interact physically with copper droplets.

  2. Investigation of the Freeze-Lining Formed in an Industrial Copper Converting Calcium Ferrite Slag

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Jansson, Jani; Taskinen, Pekka; Hayes, Peter C.; Jak, Evgueni

    2014-06-01

    Pyrometallurgical coppermaking processes are operated under intensive reaction conditions; high process temperatures and vigorous bath agitation is used to increase the kinetics of reactions and to achieve high smelter throughput. Slag freeze-lining reactor wall protection is a widely used technology in coppermaking processes, such as flash smelting and converting reactors. Freeze-linings mitigate and resist the effects of thermal and chemical attack by aggressive slags. In this laboratory-based study, a water-cooled probe "cold finger" technique has been used to investigate freeze-lining formation with calcium ferrite slags in equilibrium with metallic copper; the slag composition reflects that used in the industrial copper flash converting furnace of Rio Tinto—Kennecott Utah Copper. The effects of probe immersion times on the thickness and microstructures in the freeze-lining deposits have been investigated. A range of complex oxide solutions and copper-containing phases have been found in the deposits. The phase assemblages formed from the industrial calcium ferrite slag in the steady-state deposit are very complex and information on the phase equilibria of the multi-component systems with addition of minor elements may not be available. Subsolidus and subliquidus phase equilibria in the Cu-Ca-Fe-O system at metallic copper saturation along with interpolated temperature across the deposit, microstructural changes and compositional trends in the phases in the deposit have been used to understand the formation and characteristics of the phases in the steady-state freeze-lining. Also, it has been shown that under steady-state conditions a dense sealing layer consisting primarily of the spinel primary phase is formed at the deposit/liquid interface; however, the interface temperature is below the liquidus temperature. The findings of the study have potentially important implications for the operation of the converting furnace and the design of freeze linings in

  3. Nieuwe wapens in de slag om groen

    NARCIS (Netherlands)

    Vreke, J.

    2010-01-01

    Groen verliest in en rond steden vaak de slag. Burgers vinden groene gebieden belangrijk, ze stimuleren beweging, bevorderen de integratie en maken huizen meer waard. Toch kiezen bestuurders uiteindelijk vaak toch voor ‘rood’ omdat dat geld en prestige oplevert. In deze bijdrage wordt verslag gedaan

  4. Quantification of 31 illicit and medicinal drugs and metabolites in whole blood by fully automated solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bjørk, Marie Kjærgaard; Simonsen, Kirsten Wiese; Andersen, David Wederkinck

    2013-01-01

    An efficient method for analyzing illegal and medicinal drugs in whole blood using fully automated sample preparation and short ultra-high-performance liquid chromatography–tandem mass spectrometry (MS/MS) run time is presented. A selection of 31 drugs, including amphetamines, cocaine, opioids......-phase extraction was performed using Strata X-C plates. Extraction time for 96 samples was less than 3 h. Chromatography was performed using an ACQUITY UPLC system (Waters Corporation, Milford, USA). Analytes were separated on a 100 mm × 2.1 mm, 1.7 μm Acquity UPLC CSH C18 column using a 6.5 min 0.1 % ammonia (25...... %) in water/0.1 % ammonia (25 %) in methanol gradient and quantified by MS/MS (Waters Quattro Premier XE) in multiple-reaction monitoring mode. Full validation, including linearity, precision and trueness, matrix effect, ion suppression/enhancement of co-eluting analytes, recovery, and specificity...

  5. Recent advances in understanding physical properties of metallurgical slags

    Science.gov (United States)

    Min, Dong Joon; Tsukihashi, Fumitaka

    2017-01-01

    Present-day knowledge of the structure and physical properties of metallurgical slags is summarized to address structure-property and inter-property relationships. Physical properties of slags including viscosity, electrical conductivity, and surface tension is reviewed focusing on the effect of slag structure, which is comprehensively evaluated using FT-IT, Raman, and MAS-NMR spectroscopy. The effect of the slag composition on slag structure and property is reviewed in detail: Compositional effect encompasses traditional concepts of basicity, network-forming behaviors of anions, and secondary impact of network-modifying cations. Secondary objective of this review is elucidating the mutual relationship between physical properties of slags. For instance, the relationship between slag viscosity and electrical conductivity is suggested by Walden's rule and discussed based on the experimental results. Slag foaming index is also introduced as a comprehensive understanding method of physical properties of slags. The dimensional analysis was made to address the effect of viscosity, density, and surface tension on the foaming index of slags.

  6. Synthesis and heavy metal immobilization behaviors of slag based geopolymer.

    Science.gov (United States)

    Yunsheng, Zhang; Wei, Sun; Qianli, Chen; Lin, Chen

    2007-05-08

    In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 degrees C for 8h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm(-1) shifts to lower wave number around 1007 cm(-1), and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals.

  7. Safety and immunogenicity of an investigational fully liquid hexavalent DTaP-IPV-Hep B-PRP-T vaccine at two, four and six months of age compared with licensed vaccines in Latin America.

    Science.gov (United States)

    Macías, Mercedes; Lanata, Claudio F; Zambrano, Betzana; Gil, Ana I; Amemiya, Isabel; Mispireta, Monica; Ecker, Lucie; Santos-Lima, Eduardo

    2012-08-01

    This trial assessed the safety of a fully liquid investigational hexavalent DTaP-IPV-Hep B-PRP-T vaccine containing 10 μg Hansenula polymorpha-derived recombinant hepatitis B (hep B) antigen for primary vaccination of infants at 2, 4 and 6 months of age compared with licensed comparators. Participants received the DTaP-IPV-Hep B-PRP-T vaccine (group 1, N = 1422) or licensed DTwP-Hep B//Hib (Tritanrix-Hep B/Hib) and oral poliovirus vaccines (group 2, N = 711). The incidence of severe fever (≥ 39.6°C rectal equivalent) in the 2 groups was compared statistically; reactogenicity was evaluated from parental reports. Anti-Hep B antibody titers were measured in a subset of participants (no hepatitis B vaccination at birth) 1 month after dose 3. The investigational vaccine was well tolerated. After any dose, fever (rectal equivalent temperature ≥ 38°C) was observed in 74.8% and 92.7% of participants in groups 1 and 2; severe fever was observed in 4.0% and 5.5% of participants. Solicited injection site and systemic reactions were numerically less frequent in group 1 than group 2, although this difference was not assessed statistically. In both groups, all participants included in the immunogenicity analysis achieved anti-Hep B ≥ 10 mIU/mL and ≥ 96.2% of participants achieved anti-Hep B ≥ 100 mIU/mL, although geometric mean titer was approximately 3-fold lower for the investigational vaccine. This new, fully liquid acellular pertussis hexavalent vaccine demonstrated less reactogenicity than the licensed comparator whole cell pertussis vaccine and was highly immunogenic for the new Hep B valence.

  8. Formation Mechanism of 2CaO·SiO2 and 3CaO·P2O5 Solid Solution in CaO-SiO2-FetO-P2O5 Slags

    Science.gov (United States)

    Dou, Xiaofei; Zhu, Mingmei; Lin, Tiancheng; Wang, Yu; Xie, Bin; Zhu, Bin; Zhou, Hong

    In this study, the formation of 2CaO·SiO2 and 3CaO·P2O5 solid solution (nC2S-C3P) in hot metal dephosphorization process is discussed. The variations of CaO and SiO2 mass, both in nC2S-C3P solid solution phase and liquid slag phase with increasing P2O5 mass in CaO-SiO2-FetO-P2O5 slags were calculated using Factsage software. CaO-SiO2-FeOt-P2O5 slag containing up to 18 % P2O5 was melted at 1823 K then cooled to 1673 K. The contents of CaO and SiO2 both in the solid solution phase and liquid slag phase of quenched samples were observed and analyzed by SEM/EDS. Both the calculated and experimental results show that the contents of CaO and SiO2 in the solid solution phase decreased, just opposite in the liquid slag phase, with increasing P2O5 content in the slags. Formation mechanism of nC2S-C3P solid solution in the slags was derived based on the ionic structure theory of molten slag. The SiO44- in the nC2S-C3P solid solution can be replaced by PO43- in the liquid phase resulting in the increasing of free Ca2+ and SiO44- in liquid phase.

  9. Rapid determination of parabens in seafood sauces by high-performance liquid chromatography: A practical comparison of core-shell particles and sub-2 μm fully porous particles.

    Science.gov (United States)

    Ye, Jing; Cao, Xiaoji; Cheng, Zhuo; Qin, Ye; Lu, Yanbin

    2015-12-01

    In this work, the chromatographic performance of superficially porous particles (Halo core-shell C18 column, 50 mm × 2.1 mm, 2.7 μm) was compared with that of sub-2 μm fully porous particles (Acquity BEH C18 , 50 mm × 2.1 mm, 1.7 μm). Four parabens, methylparaben, ethylparaben, propylparaben, and butylparaben, were used as representative compounds for calculating the plate heights in a wide flow rate range and analyzed on the basis of the Van Deemter and Knox equations. Theoretical Poppe plots were constructed for each column to compare their kinetic performance. Both phases gave similar minimum plate heights when using nonreduced coordinates. Meanwhile, the flat C-term of the core-shell column provided the possibilities for applying high flow rates without significant loss in efficiency. The low backpressure of core-shell particles allowed this kind of column, especially compatible with conventional high-performance liquid chromatography systems. Based on these factors, a simple high-performance liquid chromatography method was established and validated for the determination of parabens in various seafood sauces using the Halo core-shell C18 column for separation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Reduction Kinetics of Electric Arc Furnace Oxidizing Slag by Al-Fe Alloy

    Science.gov (United States)

    Lee, Jaehong; Oh, Joon Seok; Lee, Joonho

    2016-09-01

    Effects of temperature and slag basicity on the reduction rate of iron oxide in molten synthetic electric arc furnace oxidizing slag by Al-40 wt.%Fe alloy was investigated. An alloy sample was dropped into molten slag in an MgO crucible. When the initial slag temperature was 1723 K, there was no reduction. However, when the initial slag temperature was 1773 K and the slag basicity was 1.1, the reduction was initiated and the temperature of the slag rapidly increased. When the slag basicity was 1.1, increasing the initial slag temperature from 1773 K to 1823 K increases the reaction rate. As the slag basicity increased from 1.1 to 1.4 at 1773 K, the reaction rate increased. From SEM analysis, it was found that an Al2O3 or a spinel phase at the slag-metal interface inhibited the reaction at a lower temperature and a lower slag basicity.

  11. Leaching of heavy metals from steelmaking slags

    Directory of Open Access Journals (Sweden)

    Gomes, J. F. P

    2006-12-01

    Full Text Available Leaching tests with EAF and Ladle slags were performed, using a flow through test and the standard batch test DIN 38414-S4. The previous method was used to simulate the leaching behaviour of steel slags under landfill. The chemical analysis of the leachates during this period shows, in general, for both types of slag, an increase of heavy metal releases with ageing. Standard test method DIN 38414-S4 was used to evaluate leachability of heavy metals by water in unprocessed slags. After more than one year of trials, slag samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-through test, calcium and magnesium leached from solid slags are below 0.5% and all other metals below 0.1%. Leachates obtained with DIN 38414-S4 present, as expected, higher leaching values; however, these are inferior to 5 % (Ca and 1% (other elements.

    Este articulo contiene los resultados obtenidos en ensayos de lixiviación de escorias de acero (horno electrico y cuchara ejecutados siguiendo la metodologia de flujo dinámico así como el ensayo normalizado DIN 38414-S4. El primer ensayo intenta simular el comportamiento de lixiviación de las escorias en vertedero. Para las escorias ensayadas se han complementado los ensayos con el análisis químico de los lixiviados y se ha verificado un aumento de la liberación de metales pesados. El ensayo DIN 38414-S4 se ha utilizado para evaluar la lixiviación por agua de metales pesados, en muestras de escorias originales. Despues de un año de ensayos, se han observado niveles muy bajos de lixiviación. Los elementos mas lixiviados han sido calcio y magnesio. No obstante, en los ensayos de flujo dinámico, el calcio y el magnesio lixiviados de las escorias sólidas era menor de 0,5% y el resto de los otros metales era inferior a 0,1%. Los lixiviados obtenidos con el ensayo DIN 38414-S4 presentan, como era de esperar, valores

  12. A Preliminary Research of Slag Excavated at Shuzhuangtai, Zhenghan Ancient City Site%郑韩故城梳妆台出土炉渣初步研究

    Institute of Scientific and Technical Information of China (English)

    李延祥; 刘海宇; 杜宁; 蔡全法

    2012-01-01

    The slag samples from Shuzhuangtai at Zhenghan ancient city site, Xinzheng, Henan province have been examined and analyzed using scanning electron microscope with energy-dispersive spectrometry (SEM-EDS). Results indicate that slag from this site can be divided into three categories: slag from copper smelting, slag from lead smelting and slag from bronze melting. The slag is identified with good density, degree of silication, melting point and liquidity and low metal content. Furthermore, this paper gives a preliminary discussion of the smelting process and products.%本文运用扫描电子显微镜及能谱分析(SEM—EDS)等研究方法,对郑韩故城的炉渣样品进行科学分析。结果表明,炉渣可分三类,第一类炉渣为冶炼红铜产生的,第二类炉渣为冶炼金属铅产生的,第三类炉渣为熔炼锡青铜产生的。炉渣有合适的密度、硅酸度、熔点及良好的流动性,渣中金属量较低,熔炼的还原气氛较好。在此基础上,本文对冶炼工序及产品进行了分析和推断。

  13. Investigation on the Potentials of Cupola Furnace Slag in Concrete

    Directory of Open Access Journals (Sweden)

    Stephen Adeyemi Alabi

    2013-12-01

    Full Text Available The compressive strength of the concrete designed using blast cupola furnace slag and granulated cupola slag as a coarse aggregate and partial replacement for cement was investigated. A series of experimental studies were conducted involve concrete production in two stages. The first stage comprised of normal aggregate concrete (NAC produced with normal aggregates and 100% ordinary Portland cement (OPC. Meanwhile, the second stage involved production of concrete comprising of cupola furnace slag an aggregates with 100% ordinary Portland cement (OPC and subsequently with 2%, 4%, 6%, 8% and 10% cementitious replacement with granulated cupola furnace slag that had been grounded and milled to less than 75 µm diameter. The outcomes of compressive strength test conducted on the slag aggregate concrete (SAC with and without granulated slag cementitious replacement were satisfactory compared to normal aggregate concretes (NAC.

  14. Optimization of Blended Mortars Using Steel Slag Sand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of mortar made of ground granulated blast-furnace slag (GGBFS), gypsum,clinker and steel slag sand (<4.75 mm) was developed. The ratio of steel slag sand to GGBFS was 1:1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development.Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined.The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.

  15. Deoxidation Limits of Titanium Alloys during Pressure Electro Slag Remelting

    Science.gov (United States)

    Bartosinski, M.; Hassan-Pour, S.; Friedrich, B.; Ratiev, S.; Ryabtsev, A.

    2016-07-01

    This paper focuses on deoxidation of titanium alloys produced by aluminothermic reduction (ATR) and subsequent homogenizing and alloying by vacuum induction melting (VIM). The main goal of the performed research work is to outline the deoxidation limit during pressure electro slag remelting (PESR) of the described material. To obtain electrodes for deoxidation, a Ti-24Al-16V masteralloy was produced by ATR and afterwards melted in a 0.5 litre calcium- zirconate (lab scale) or 14 litres high purity calcia (pilot scale) crucibles with continuous addition of Ti-sponge after reaching liquid state in order to obtain a final Ti-6Al-4V alloy. During melting, in both cases evaporation of calcium was noticed. The cast ingots were analysed for oxygen using inert gas fusion method, matrix and alloying elements were analysed by XRF. Results show oxygen levels between 0.5 and 0.95 wt.-% for the ingots which were melted in calcium-zirconate crucibles and approx. 1 - 1.2 wt.-% for the material produced by utilization of calcia crucibles. The subsequent deoxidation was carried out in lab and pilot scale electroslag remelting furnaces using a commercially pure calcium fluoride slag and metallic calcium as deoxidation agent. It could be shown, that deoxidation of the highly contaminated material is possible applying this method to a certain limit. Pilot scale trials showed a reduction of oxygen contents by 1500 - 3500 ppm. Oxygen levels in lab scale trials showed weaker deoxidation effects. In order to describe the achieved deoxidation effects in a quantitative way, the analyzed oxygen contents of the obtained ingots are compared with calculated data resulting from a mathematical kinetic model. The modelled datasets are in good agreement with experimental oxygen values.

  16. Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

    Directory of Open Access Journals (Sweden)

    Zhengqi Guo

    2016-04-01

    Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

  17. Behavior of slag foaming caused by blowing gas in molten slags

    Energy Technology Data Exchange (ETDEWEB)

    Wu, K.

    2000-10-01

    The relationship between the height of foaming slag and blowing gas flow rate has been investigated at different temperature and with additives such as coal, coke, graphite and CaO, in order to understand the foaming phenomenon in most metallurgical processes comprehensively. On the basis of experimental results, the regressed foam behavior equations ({delta}=b(center dot)V{sup m}) were obtained. Those correlation coefficients were in range from 0.995 to 0.999. It means that the foam behavior equation can be used to describe foaming ability of the slag foaming caused by blowing gas quantitatively. The foaming index {sigma} is only a limited case for of the foam behavior equation and can be used only at high temperature and without additives for the foaming phenomenon caused by blowing gas. It was found also that the large carbonaceous particles could decrease the height of foaming slag, however the fine carbonaceous and CaO powder could increase it. The basicity of the slag affects the height of foaming slag. (author)

  18. Electrochemical Method to Accelerate Metal-Slag Reaction

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltage was applied between melt and slag. The bigger the contact area of the conductor with melts is, the faster the reaction rate is. With the increase of applied voltage which is beneficial for electron's migration between metal and slags, the rate and extent of reaction increase.

  19. Reduction of chromium oxide from slags

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Paredes, J.

    2005-12-01

    Full Text Available Experimental and theoretical work were performed to estimate the effect of slag basicity and amount of reducing agents on the reduction of chromium oxide from the slag which interacted with molten steel at 1,600 °C. The slag system contained CaO, MgO, SiO2, CaF2 and Cr2O3 together with Fe-alloys (Fe-Si and Fe-Si-Mg. The CaF2 and MgO contents in the slags were 10 mass % each; Cr2O3 was 25%. The amount of the ferroalloys ranged from 12.5 to 50 g per 100 g of slag. The (CaO+MgO/SiO2 ratio was held at 1 and 2. The Cr yield was determined using both Fe-alloys as reducing agents. Some estimations were made to determine the theoretical effect of temperature, slag basicity, (CaO+MgO/SiO2, and amount of reducing agents in the slag on the chromium recovery. The FACT (Facility for the Analysis of Chemical Thermodynamics computational package is used to determine the equilibrium between the slag and molten steel.

    En el presente trabajo se realiza un estudio teórico y experimental para determinar el efecto de la basicidad de la escoria y la cantidad de agentes reductores sobre la reducción de óxidos de cromo contenidos en la escoria, la cual está en contacto con acero líquido a 1.600 °C. La escoria se prepara con los reactivos CaO, MgO, SiO2, CaF2 y ferroaleaciones (Fe-Si y Fe-Si-Mg. Los contenidos de CaF2 y MgO en la escoria son de 10 %, cada uno, y el de Cr2O3 es 25 %. La cantidad de la ferroaleación varía de 12,5 a 50 g por cada 100 g de escoria. La relación (CaO+MgO/SiO2 tiene los valores de 1 y 2. Se determina la eficiencia de recuperación de cromo empleando los dos tipos de ferroaleaciones. Se realizaron cálculos para determinar el efecto teórico de la temperatura, la basicidad de la escoria, (CaO+MgO/SiO2, y la cantidad de agentes reductores sobre la reducci

  20. TRW Advanced Slagging Coal Combustor Utility Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The TRW Advanced Slagging Coal Combustor Demonstration Project consists of retrofitting Orange and Rockland (O R) Utility Corporation's Lovett Plant Unit No. 3 with four (4) slagging combustors which will allow the gas/ou desip unit to fire 2.5 sulfur coal. The slogging combustor process will provide NO[sub x] and SO[sub x] emissions that meet NSPS and New York State Envirommental Standards. TRW-CBU scope of work includes the engineering, design and supply of the slogging combustors, coal and limestone feed systems and a control system for these components. During this report period, the design activities for all systems progressed to permit the release of specifications and requests for proposals. Award of contracts for long-delivery items and major equipment are being placed to meet the revised program schedule.

  1. Thermochemistry of calcium oxide and calcium hydroxide in fluoride slags

    Science.gov (United States)

    Chattopadhyay, S.; Mitchell, A.

    1990-08-01

    Calcium oxide activity in binary CaF2-CaO and ternary CaF2-CaO-Al2O3 and CaF2-CaO-SiO2 slags has been determined by CO2-slag equilibrium experiments at 1400 °C. The carbonate ca-pacity of these slags has also been computed and compared with sulfide capacity data available in the literature. The similarity in trends suggests the possibility of characterizing carbonate capacity as an alternative basicity index for fluoride-base slags. Slag-D2O equilibrium experi-ments are performed at 1400°C with different fluoride-base slags to determine water solubility at two different partial pressures of D2O, employing a new slag sampling technique. A novel isotope tracer detection technique is employed to analyze water in the slags. The water solubility data found show higher values than the previous literature data by an order of magnitude but show a linear relationship with the square root of water vapor partial pressure. The activity of hydroxide computed from the data is shown to be helpful in estimating water solubility in in-dustrial electroslag remelting (ESR) slags.

  2. Chemical, Mineralogical, and Morphological Properties of Steel Slag

    Directory of Open Access Journals (Sweden)

    Irem Zeynep Yildirim

    2011-01-01

    Full Text Available Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF steelmaking, electric-arc-furnace (EAF steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD analyses and Scanning Electron Microscopy (SEM studies. The XRD patterns of both BOF and EAF(L slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.

  3. Evaluation of copper slag blast media for railcar maintenance

    Science.gov (United States)

    Sagers, N. W.; Finlayson, Mack H.

    1989-01-01

    Copper slag was tested as a blasting substitute for zirconium silicate which is used to remove paint from railroad cars. The copper slag tested is less costly, strips paint faster, is produced near the point of need, provides a good bonding surface for paint, and permits the operator to work in a more comfortable position, i.e., standing nearly erect instead of having to crouch. Outdoor blasting with the tested Blackhawk (20 to 40 mesh) copper slag is also environmentally acceptable to the State of Utah. Results of tests for the surface erosion rate with copper slag blasting are included.

  4. Evaluation of copper slag blast media for railcar maintenance

    Science.gov (United States)

    Sagers, N. W.; Finlayson, Mack H.

    1989-06-01

    Copper slag was tested as a blasting substitute for zirconium silicate which is used to remove paint from railroad cars. The copper slag tested is less costly, strips paint faster, is produced near the point of need, provides a good bonding surface for paint, and permits the operator to work in a more comfortable position, i.e., standing nearly erect instead of having to crouch. Outdoor blasting with the tested Blackhawk (20 to 40 mesh) copper slag is also environmentally acceptable to the State of Utah. Results of tests for the surface erosion rate with copper slag blasting are included.

  5. Artificial neural network model to predict slag viscosity over a broad range of temperatures and slag compositions

    Energy Technology Data Exchange (ETDEWEB)

    Duchesne, Marc A. [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada); Macchi, Arturo [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); Lu, Dennis Y.; Hughes, Robin W.; McCalden, David; Anthony, Edward J. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada)

    2010-08-15

    Threshold slag viscosity heuristics are often used for the initial assessment of coal gasification projects. Slag viscosity predictions are also required for advanced combustion and gasification models. Due to unsatisfactory performance of theoretical equations, an artificial neural network model was developed to predict slag viscosity over a broad range of temperatures and slag compositions. This model outperforms other slag viscosity models, resulting in an average error factor of 5.05 which is lower than the best obtained with other available models. Genesee coal ash viscosity predictions were made to investigate the effect of adding Canadian limestone and dolomite. The results indicate that magnesium in the fluxing agent provides a greater viscosity reduction than calcium for the threshold slag tapping temperature range. (author)

  6. Fully Automatic In-Syringe Magnetic Stirring-Assisted Dispersive Liquid-Liquid Microextraction Hyphenated to High-Temperature Torch Integrated Sample Introduction System-Inductively Coupled Plasma Spectrometer with Direct Injection of the Organic Phase.

    Science.gov (United States)

    Sánchez, Raquel; Horstkotte, Burkhard; Fikarová, Kateřina; Sklenářová, Hana; Maestre, Salvador; Miró, Manuel; Todolí, Jose-Luis

    2017-03-21

    A proof of concept study involving the online coupling of automatic dispersive liquid-liquid microextraction (DLLME) to inductively coupled plasma optical emission spectrometry (ICP OES) with direct introduction and analysis of the organic extract is herein reported for the first time. The flow-based analyzer features a lab-in-syringe (LIS) setup with an integrated stirring system, a Meinhard nebulizer in combination with a heated single-pass spray chamber, and a rotary injection valve, used as an online interface between the microextraction system and the detection instrument. Air-segmented flow was used for delivery of a fraction of the nonwater miscible extraction phase, 12 μL of xylene, to the nebulizer. All sample preparative steps including magnetic stirring assisted DLLME were carried out inside the syringe void volume as a size-adaptable yet sealed mixing and extraction chamber. Determination of trace level concentrations of cadmium, copper, lead, and silver as model analytes has been demonstrated by microextraction as diethyldithiophosphate (DDTP) complexes. The automatic LIS-DLLME method features quantitative metal extraction, even in troublesome sample matrixes, such as seawater, salt, and fruit juices, with relative recoveries within the range of 94-103%, 93-100%, and 92-99%, respectively. Furthermore, no statistically significant differences at the 0.05 significance level were found between concentration values experimentally obtained and the certified values of two serum standard reference materials.

  7. Durability of Alkali Activated Blast Furnace Slag

    Science.gov (United States)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  8. An SPH Study of Molten Matte-Slag Dispersion

    Science.gov (United States)

    Natsui, Shungo; Nashimoto, Ryota; Kumagai, Takehiko; Kikuchi, Tatsuya; Suzuki, Ryosuke O.

    2017-02-01

    The transient behaviors of two immiscible liquids, namely, molten matte and molten slag, with a high interfacial tension were investigated using the smoothed particle hydrodynamics model. Numerical simulations were performed using a discrete-element-type method that could track the movement of both the continuous liquid phase and the dispersed one directly. Numerical simulations were also performed for conditions corresponding to different interfacial tension and density values. Further, the predicted topological changes as well as the relationship between the physical properties and the droplet size distribution were investigated. It was found that, with an increase in the interfacial tension, the large droplets formed aggregate quickly with the bulk phase, owing to the buoyancy force. It was also found that the absolute value of the interfacial tension determines the interfacial area, suggesting that it also affects the droplet settling time. As such, we can conclude that the nonlinearly changed interface shape can easily become unstable as a result of only a slight change in the curvature.

  9. An SPH Study of Molten Matte-Slag Dispersion

    Science.gov (United States)

    Natsui, Shungo; Nashimoto, Ryota; Kumagai, Takehiko; Kikuchi, Tatsuya; Suzuki, Ryosuke O.

    2017-06-01

    The transient behaviors of two immiscible liquids, namely, molten matte and molten slag, with a high interfacial tension were investigated using the smoothed particle hydrodynamics model. Numerical simulations were performed using a discrete-element-type method that could track the movement of both the continuous liquid phase and the dispersed one directly. Numerical simulations were also performed for conditions corresponding to different interfacial tension and density values. Further, the predicted topological changes as well as the relationship between the physical properties and the droplet size distribution were investigated. It was found that, with an increase in the interfacial tension, the large droplets formed aggregate quickly with the bulk phase, owing to the buoyancy force. It was also found that the absolute value of the interfacial tension determines the interfacial area, suggesting that it also affects the droplet settling time. As such, we can conclude that the nonlinearly changed interface shape can easily become unstable as a result of only a slight change in the curvature.

  10. Viscosity model for fully liquid silicate melt

    Directory of Open Access Journals (Sweden)

    Zhang Guo-Hua

    2012-01-01

    Full Text Available A model for estimating the viscosity of silicate melt as derived in our previous paper is extended to the system containing MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, which can express the nonlinear variation of activation energy of viscosity with the composition. It is found that the optimized parameters of model which characterize the deforming ability of bonds around non-bridging oxygen decrease with increasing the bond strength of M-O bond expressed by I=2Q/RMz+ + rO2-2 (where Q is the valence of cation M; r is the radius. It is pointed out that viscosity is not only determined by the bond strength, but also by the radius of cation which is defined as the size effect. The radius of cation plays paradox roles in the two factors: smaller radius leads to a stronger bond, thus a higher viscosity; while cations with smaller radius are easier to diffuse when neglecting the interaction force, thus a lower viscosity will be.

  11. Comparative results of copper flotation from smelter slag and granulated smelter slag

    OpenAIRE

    Milanović, Dragan; Stanujkić, Dragiša; Ignjatović, Miroslav R.

    2013-01-01

    Smelter slag is obtained in the process of metallurgical converting of copper concentrate in the Smelter Plant in Bor, Serbia. Today, the reserves of this material are evaluated at about more of a year, with the average copper content of 0.6-0.9%. Production of copper concentrate by flotation of smelter slag has started in 2001. Flotation concentrate goes to the Copper Smelter once more for production of copper cathodes and the rough flotation tailings go to the flotation tailing dump. Copper...

  12. Evaluation of the slag regime and desulphurization of steel with synthetic slag containing Cr2O3

    OpenAIRE

    Socha, Ladislav; Bažan, Jiří; Morávka, Jan; Styrnal, Petr; Machovčák, Pavel; Opler, Aleš; Trefil, Antonín

    2014-01-01

    The paper focuses on an evaluation of the slag regime and steel desulphurisation in a ladle with the help of synthetic slags based on Al2O3 containing various mass amounts of Cr2O3 varying from 0.3 % to 3.0 %. The aim of the plant experiments was to assess the achieved results when using two types of synthetic slag focusing on the course of desulphurisation, an analysis of the achieved chemical composition of the slag and an evaluation of the influence of oxide Cr2O3 on the increase ...

  13. Byproduct aggregate. Copper slag aggregate, ferronickel slag aggregate; Fukusan kotsuzai. Do suragu kotsuzai, fuero nikkeru suragu kotsuzai

    Energy Technology Data Exchange (ETDEWEB)

    Kajiwara, Toshitaka

    1998-08-10

    Copper slag aggregate and ferronickel slag aggregate has not only usual substitute of sand or crushed sand but many features unlike sand or unlike crushed sand. It has many features unlike sand or crushed sand. It seems that especially, behavior of the particulates minute is features of deserving in addition, the examination in future. Of course, one feature also consists on the merit on the demerit by the use. And, copper slag aggregate, ferronickel slag aggregate have also limited the production place at the output of about 2 million annual production tons. These features are utilized, and in addition, wants to teach and want to receive the wider usage. (NEDO)

  14. Online coupling of fully automatic in-syringe dispersive liquid-liquid microextraction with oxidative back-extraction to inductively coupled plasma spectrometry for sample clean-up in elemental analysis: A proof of concept.

    Science.gov (United States)

    Horstkotte, Burkhard; Fikarová, Kateřina; Cocovi-Solberg, David J; Sklenářová, Hana; Solich, Petr; Miró, Manuel

    2017-10-01

    A proof of concept of a novel automatic sample cleanup approach for metal assays in troublesome matrixes as a front-end sample pre-treatment to inductively coupled plasma optical emission spectroscopy - ICP-OES - is herein presented. Target metals, namely, copper, lead, and cadmium were complexed in-system quantitatively using ammonium pyrrolidine dithiocarbamate (APDC) and transferred into a minute volume of toluene as extractant employing lab-in-syringe magnetic stirring-assisted dispersive liquid-liquid microextraction (LIS-MSA-DLLME). After discharge of the sample, the analytes were back-extracted into nitric acid and injected on-line into ICP-OES. To promote and expedite this process in-syringe, advantage was taken from oxidative decomposition of the chelate by potassium iodate, reported in this article for the first time. Experimental conditions for LIS-MSA-DLLME were optimized by Box-Benkhen multivariate analysis using the geometric mean of analyte recoveries as the desirability function. Times of extraction and back-extraction of 300s and 100s, respectively, pH 5.5 at 30mmol/L acetate, 300µL of extraction solvent, and 600µmol/L of APDC were finally applied. Online interfacing to ICP-OES for back-extract analysis yielded average repeatabilities for Cd, Cu, and Pb of 2.9%, 3.5%, and 3.5% with limits of detections (3s) of 1.9, 1.4, and 5.6ng/mL, respectively. Oxidative back-extraction was proven reliable for the determination of metal species in coastal seawater, surrogate digestive fluids and soil leachates with recovery values for Cd, Cu, and Pb ranging from 90% to 118%, 68% to 104%, and 86% to 112%, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Thermal expansion of slag and fly ash from coal gasification in IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    M. Aineto; A. Acosta; J.M.A. Rincon; M. Romero [University of Castilla La Mancha, Ciudad Real (Spain). Laboratory of Applied Mineralogy

    2006-11-15

    Integrated gasification in combined cycle (IGCC) is an electrical power generation system which is characterized to be a clean coal technology different than conventional process in combustible treatment. IGCC process gives rise to inorganic solid wastes in the form of vitreous slag and fly ashes with singular thermal properties. The gasification of the fuel takes place at high temperature and pressure in reducing atmosphere. Under that conditions, gases such as H{sub 2}, N{sub 2} or CO, which are the main components of the gas mixture in the gasifier, show a high solubility in the melt and during the cooling remain enclosed in the vitreous slag. When these wastes are afterward thermal treated in oxidizing conditions, two phenomena occur. The development of a crystalline phase by devitrification of the glassy matrix and the releasing of the enclosed gas, which starts at temperatures nearly to the softening point. At higher temperatures the bubbles with increasing kinetic energy tend to ascend with difficulty through the viscous liquid phase and promotes an expansive reaction, giving rise to a foam glass-ceramic product. This paper has been focused on the study of thermal expansion in slag and fly ash samples from the ELCOGAS IGCC power plant located in Puertollano (Spain). 18 refs., 11 figs., 1 tab.

  16. Kinetics and physico-chemical properties of alkali activated blast-furnace slag/basalt pastes

    Directory of Open Access Journals (Sweden)

    H. El Didamony

    2012-12-01

    Full Text Available Granulated blast-furnace slag (GBFS is a by-product of the metallurgical industry and consists mainly of lime and calcium–magnesium aluminosilicates that defined as the glassy granular material formed by rapid cooling of molten slag with excess water resulting in an amorphous structure. Alkali-activated slag (AAS binders have taken a great interest from researchers due to its manufacturing process which has important benefits from the point of view of the lower energy requirements and lower emission of greenhouse gases with respect to the manufacturing of Portland cement. In this study, GBFS was replaced by 20, 40 and 60 wt.% of basalt activated by 6 wt.% of alkali mixture composed of 1:1 sodium hydroxide (SH and liquid sodium silicate (LSS mixed with sea water and cured in 100% relative humidity up to 90 days. The physic-chemical parameters were studied by determination of setting time, combined water content, bulk density and compressive strength. As the amount of basalt increases the setting time as well as compressive strength decreases while the bulk density increases. The compressive strength values of dried pastes are greater than those of saturated pastes. The hydrated products are identified by TGA/DTG analysis, IR spectroscopy and scanning electron microscopy (SEM.

  17. The Form and Distribution of Al-Zn Slag in Galvalume Bath%热浸镀Galvalume熔池中铝锌渣的形态及分布

    Institute of Scientific and Technical Information of China (English)

    刘春富; 彭浩平; 苏旭平; 王建华

    2012-01-01

    The research results show that the iron content in aluminum zinc liquid is higher in the production state, and the difference between surface layer aluminum zinc slag and middle layer aluminum zinc slag is not obvious via the investigation of aluminum zinc liquid with slag in the surface layer, middle layer and the bottom of Galvalume molten bath in the production state and static states. The standing aluminum zinc molten bath surface layer hardly contains aluminum zinc slag, but in the middle layer, the mean diameter of alumi-num zinc slag particle under static states is greater than the particle under production state, the precipitation and growing up of aluminum zinc slag made the decreasing of the iron content in aluminum zinc liquid. There are a lot of aluminum zinc slags on the bottom of aluminum and zinc molten bath, and the aluminum zinc slag will accumulate and grow up continuously with the extension of time. It confirms that the aluminum zinc slag phase is zinciferous Τ5C phase via the component analysis.%通过对生产状态和静置状态下Galvalume熔池面层、中间层和底层的含渣铝锌液的研究,结果表明在生产状态时铝锌液中铁含量较高,面层和中间层铝锌渣差异不明显.静置铝锌熔池面层基本不含铝锌渣,但中间层出现的铝锌渣相对生产状态时渣粒平均直径要大,铝锌渣析出长大使得铝锌液中的铁含量降低.在铝锌池底部存在大量的铝锌渣,且铝锌渣随着时间的延长不断积聚长大.通过成分分析确定该铝锌渣相为含锌的τ5C相.

  18. China Customs Removed the Import Tax on Titanium Slag

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The long waited solution to the problem relating to the import of titanium slag has finally resolved. According to China Customs report, the import of titanium slag no longer requires tax payment as from January 1, 2007. This decision will help with the healthy development of China’s titanium industry and increase China’s competitiveness in the international marketplace.

  19. Crystallization of Synthetic Blast Furnace Slags Pertaining to Heat Recovery

    Science.gov (United States)

    Esfahani, Shaghayegh

    Heat recovery from blast furnace slags is often contradicted by another requirement, to generate amorphous slag for its use in cement production. As both the rate and extent of heat recovery and slag structure are determined by its cooling rate, a relation between the crystallization kinetics and the cooling conditions is highly desired. In this study, CaO-SiO2-Al2O3-MgO (CSAM) slags with different basicities were studied by Single Hot Thermocouple Technique (SHTT) during isothermal treatment and non-isothermal cooling. Their time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams were plotted and compared with each other. Furthermore, kinetic parameters such as the Avrami exponent (n), rate coefficient (K) and effective activation energy of crystallization (EA) were found by analysis of data obtained from in-situ observation of glassy to crystalline transformation and image analysis. Also, the dependence of nucleation and growth rates of crystalline phases were quantified as a function of time, temperature, and slag basicity. Together with the observations of crystallization front, they facilitated establishing the dominant mechanisms of crystallization. In addition to the experimental work, a mathematical model was developed and validated that predicts the amount of crystallization during cooling. A second mathematical model that calculates temperature history of slag during its cooling was coupled with the above model, to allow studying the effect of parameters such as the slag/air ratio and granule size on the heat recovery and glass content of slag.

  20. Refractory Degradation by Slag Attack in Coal Gasification

    Science.gov (United States)

    2009-02-01

    REFRACTORY DEGRADATION BY SLAG ATTACK IN COAL GASIFICATION Jinichiro Nakano 1,2 , Sridhar Seetharaman 1,2 , James Bennett 3 , Kyei-Sing...00-2009 4. TITLE AND SUBTITLE Refractory Degradation by Slag Attack in Coal Gasification 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  1. Treatment of LF slag to prevent powdering during cooling

    Directory of Open Access Journals (Sweden)

    Ghorai S.

    2017-01-01

    Full Text Available The polymorphic transformation of the monoclinic β-polymorph to the orthorhombic γ-polymorph of di-calcium silicate at around 500°C during cooling results in disintegration of slag. The slag generated, during the production of thermo mechanically treated steel in ladle furnace at M/s Tata Steel Limited, Jamshedpur, India, behaves in similar manner. An attempt has been made to prevent the crumbling of ladle furnace slag. The experiments were conducted in 10 kg air induction furnace. Various types of silica source were used to prevent the disintegration of ladle furnace slag by reducing the basicity and optimizing the additives amount. Apart from silica sources, other additives like borax and barium carbonate were also used to stabilize the β phase. Present investigation reveals that disintegration of ladle furnace slag can be prevented either by addition of 0.2% boarx or 2% barium carbonate. Dust formation can also be prevented by decreasing the ladle furnace slag basicity to about 1.7. Toxicity Characteristic Leaching Procedure test, of the borax and barium carbonate treated slag samples, indicates that barium carbonate treated slag cannot be used for the dusting prevention as it contains high level of barium.

  2. Study of Reaction Between Slag and Carbonaceous Materials

    Science.gov (United States)

    Maroufi, Samane; Mayyas, Mohannad; Mansuri, Irshad; O'Kane, Paul; Skidmore, Catherine; Jin, Zheshi; Fontana, Andrea; Sahajwalla, Veena

    2017-10-01

    The chemical interaction of a typical slag of EAF with three different carbon sources, coke, rubber-derived carbon (RDC), coke-RDC blend, was studied in atmospheric pressure at 1823 K (1550 °C). Using an IR-gas analyzer, off-gases evolved from the sample were monitored. While the coke-RDC blend exhibited the best reducing performance in reaction with molten slag, the RDC sample showed poor interaction with the molten slag. The gasification of the coke, RDC, and coke-RDC blend was also carried out under oxidizing conditions using a gas mixture of CO2 (4 wt pct) and Ar (96 wt pct) and it was shown that the RDC sample had the highest rate of gasification step C0 \\mathop{\\longrightarrow}\\limits{{k3 }}{CO} + nCf (11.6 site/g s (×6.023 × 1023/2.24 × 104)). This may be attributed to its disordered structure confirmed by Raman spectra and its nano-particle morphology observed by FE-SEM. The high reactivity of RDC with CO2 provided evidence that the Boudouard reaction was fast during the interaction with molten slag. However, low reduction rate of iron oxide from slag with RDC can be attributed to the initial weak contact between RDC and molten slag implying that the contact between carbonaceous matter and slag plays significant roles in the reduction of iron oxide from slag.

  3. Micronutrient availability from steel slag amendment in pine bark substrates

    Science.gov (United States)

    Steel slag is a byproduct of the steel industry that can be used as a liming agent, but also has a high mineral nutrient content. While micronutrients are present in steel slag, it is not known if the mineral form of the micronutrients would render them available for plant uptake. The objective of...

  4. Phase analytical studies of industrial copper smelting slags. Part I: Silicate slags

    Science.gov (United States)

    Rüffler, R.; Dávalos, J.

    1998-12-01

    The pyrometallurgical extraction of copper from sulfide ore concentrates is determined by the behaviour of the associated iron during smelting. Hence, 57Fe Mössbauer spectroscopy is an attractive tool for studying the phases in silicate slags from German and Chilean smelting plants. Other methods used were ore microscopy, electron microprobe analysis, and X-ray powder diffraction.

  5. Slag-Resistance of MgAlON Spinel

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The slag-resistance and microstructural changes after the slag tests of MgAlON spinel containing different amount of nitrogen were studied by means of crucible slag-resistant experiment, SEM and EDS in the work. The results show that the slag-resistance of MgAlON is dependent on the nitrogen content, and the optimum amount is 2.88%. The structure is not changed although the grains have been permeated by some silicon, calcium and iron. A glass phase which contained nitrogen formed in the metamorphic layer. The glass can improve the ability of the slag-resistance of MgAlON because of its higher viscosity.

  6. Chemical and mineralogical characterizations of a copper converter slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A copper converter slag was examined chemically and mineralogically to determine its existing phases, in particular those containing Co and Cu. The slag consists predominantly of fayalite and magnetite, together with some glass,chalcocite, and metallic copper. Copper is entrapped in the slag mostly as chalcocite and metallic copper, as well as trace copper oxide. There was no indication of any independent Co mineral in the slag, but Co was found to be enriched in fayalite and megnetite as solid solution, although Co was detected in all the phases of the slag by SEM-EDX (scanning electron microscopy equipped with model EDAX-9100 energy dispersive spectrometer) and WDS (model WDX-2A X-ray wave-length dispersive spectrometer).

  7. Characterization and Recovery of Valuables from Waste Copper Smelting Slag

    Science.gov (United States)

    Prince, Sarfo; Young, Jamie; Ma, Guojun; Young, Courtney

    Silicate slags produced from smelting copper concentrates contains valuables such as Cu and Fe as well as heavy metals such as Pb and As which are considered hazardous. In this paper, various slags were characterized with several techniques: SEM-MLA, XRD, TG-DTA and ICP-MS. A recovery process was developed to separate the valuables from the silicates thereby producing value-added products and simultaneously reducing environmental concerns. Results show that the major phases in air-cooled slag are fayalite and magnetite whereas the water-cooled slag is amorphous. Thermodynamic calculations and carbothermal reduction experiments indicate that most of Cu and Fe can be recovered from both types using minor amounts of lime and alumina and treating at 1350°C (1623K) or higher for 30 min. The secondary slag can be recycled to the glass and/or ceramic industries.

  8. Modeling and control of copper loss in smelting slag

    Science.gov (United States)

    Tan, Pengfu

    2011-12-01

    A series of technical improvements have been implemented to address the issue of high copper losses in rotary holding furnace (RHF) slag, which were experienced at the Xstrata Copper Smelter at Mount Isa in 2007 and 2008. The copper losses in smelting slag in the RHF were more than 3% in 2006 and 2007. Thermodynamic models and viscosity models have been applied in the operation of Xstrata Copper Smelter in Australia. The theory of RHF key performance indicators has also been developed to reduce the copper losses in RHF slag. The RHF KPIs Theory has been applied in Mount Isa Copper Smelter. The copper losses in RHF slag dropped from 3.1% in 2007 to 0.76% in April 2009. The average copper loss in RHF slag in 2009 and 2010 was about 0.9%.

  9. Catalysts derived from waste slag for transesterification

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Zhang; Wei Huang

    2011-01-01

    MgO-CaO/SiO2 solid catalysts derived from waste slag (WS) of metal magnesium plant were prepared.The catalytic performances were evaluated in the transesterification of rapeseed oil with methanol to biodiesel in a 500 mL three-necked reactor under atmospheric pressure.The basic strengh of the catalyst reached 22.0 measured by indicators accroding to Hammett scale.The results show that the MgO-CaO/SiO2 is an excellent catalyst for transesterification, and the conversion of rapeseed oil reach 98% under the optimum condition.

  10. Kinetics and mechanism of the barotropic lamellar gel/lamellar liquid crystal phase transition in fully hydrated dihexadecylphosphatidylethanolamine: a time-resolved x-ray diffraction study using pressure jump.

    Science.gov (United States)

    Cheng, A; Hummel, B; Mencke, A; Caffrey, M

    1994-07-01

    The kinetics and mechanism of the barotropic lamellar gel (L beta')/lamellar liquid crystal (L alpha) phase transition in fully hydrated 1,2-dihexadecyl-sn-glycero-3-phosphoethanolamine (DHPE) has been studied using time-resolved x-ray diffraction (TRXRD). The phase transition was induced by pressure jumps of varying amplitudes in both the pressurization and depressurization directions at controlled temperature (78 degrees C). Both low- and wide-angle diffracted x rays were recorded simultaneously in live time using an x-ray-sensitive image intensifier coupled to a CCD camera and Super-VHS videotape recorder. Such an arrangement allowed for the direct and quantitative characterization of the long- (lamellar repeat spacing) and short-range order (chain packing) during a kinetic experiment. The image-processed live-time x-ray diffraction data were fitted using a nonlinear least-squares model, and the parameters of the fits were monitored continuously throughout the transition. The pressure-induced transitions from the L alpha to the L beta' phase and from the L beta' to the L alpha phase was two-state (no formation of intermediates apparent during the transition) to within the sensitivity limits of the method. The corresponding transit time (the time during which both phases coexist) associated with the long- and short-range order of the pressurization-induced L alpha-to-L beta' phase transition decreased to a limiting value of approximately 50 ms with increasing pressure jump amplitude. This limiting value was close to the response time of the detector/recording system. Thus, the intrinsic transit time of this transition in fully hydrated DHPE at 78 degrees C was less than or equal to 50 ms. In contrast, the depressurization-induced L beta'-to-L alpha phase transition was slower, taking approximately 1 s to complete, and occurred with no obvious dependence of the transit time on pressure jump amplitude. In the depressurization jump experiment, the lipid responded

  11. The stabilizing treatment for the soluble manganese in manganese leaching slag%锰矿浸渣中可溶锰离子的稳定化处理研究

    Institute of Scientific and Technical Information of China (English)

    盘俊; 谢能银; 明宪权; 王雨红; 粟海锋

    2015-01-01

    为了解决日益严重的锰矿浸渣污染问题,采用在锰矿浸渣中添加硅酸钠为固化剂,研究锰矿浸渣中可溶锰离子的稳定化效果.通过正交实验和单因素实验,考察了反应温度、反应时间、液固比、pH值、硅酸钠添加量等因素对可溶锰离子稳定化效果的影响.结果表明:硅酸钠的用量对可溶锰离子稳定化效果的影响最大,较适宜的稳定化条件为:反应温度30℃,反应时间15 min,液固比5:1,pH值8,硅酸钠用量0.5 g.在此条件下,20.00 g锰矿浸渣中的可溶锰离子固化率达96.80%,通过浸出毒性测试得到滤液中锰残余浓度为0.99 mg/L,完全符合GB8978-96《污水综合排放标准》.%In order to solve the increasingly serious pollution of manganese leaching slag, the effect of stabilizing treatment for the soluble manganese ion in manganese leaching slag using sodium sili-cate as curing agent was investigated. The influences of reaction temperature, reaction time, liquid-solid ratio, pH and sodium silicate dosage on the stabilization effects of soluble manganese ions were studied by orthogonal and single-factor experiments. The results showed that the dosage of sodium silicate had a great effect on the stabilizing process. And the optimal conditions could get the curing rate about 96 . 80% with 20. 00 g manganese leaching slag under the conditions of reaction tempera-ture 30 ℃, reaction time 15 min, liquid-solid ratio 5:1, pH 8, sodium silicate dosage 0. 5 g. The toxicity test result showed that the residual concentration of manganese in filtrate was 0. 99 mg/L, it fully meet the requirement of integrated wastewater discharge standard GB8978-96 .

  12. Evolution of Inclusions in Fe-13Cr Treated by CaO-SiO2-Al2O3-Based Top Slag

    Science.gov (United States)

    Wang, Qi; Wang, Lijun; Zhai, Jun; Li, Jianmin; Chou, Kuo-Chih

    2017-02-01

    Experiments were carried out to determine the effect of Al2O3 in the slag of the CaO-SiO2-Al2O3-MgO-CaF2 system on the cleanness of Fe-13Cr stainless steel deoxidized by ferrosilicon. Increasing the Al2O3 content in basicity = 2.28 slag can reduce the usage of CaF2 and benefit the obtainment of a good kinetic condition for inclusion removal, but over 21 pct would lead to a higher total oxygen content in the melt and make the inclusion composition more complex. It is found that increasing basicity in 16 pct Al2O3 slag would have a good deoxidation ability and accelerate the transformation from high Al2O3 inclusions to low melting point CaO-Al2O3-SiO2-MgO system inclusions, but basicity over 2.58 would lead to high content of [Al] in liquid steel, which would promote the formation of MgO-Al2O3 inclusions. Therefore, it is not suitable to add a high content of Al2O3 into high-basicity slag. Adding Al2O3 into slag of 2.28 in basicity until a content of 16 pct could achieve inclusion plastication within 45 minutes without Ca treatment, which has potential application in industrial production.

  13. Viscosity and structure evolution of the SiO2-MgO-FeO-CaO-Al2O3 slag in ferronickel smelting process from laterite

    Directory of Open Access Journals (Sweden)

    Lv X.M.

    2017-01-01

    Full Text Available The SiO2 fractions in laterite-nickel ores are quite high, thus certain amount of lime should be used as fluxing material to achieve good fluidity and desulfurization capacity in industrial smelting process. However, this operation leads to an additional cost of lime. In addition, the increase of slag volume decreases the effective furnace volume. To avoid such problem, partial reduction of FeO has been suggested. Therefore, the high SiO2, low MgO and FeO and very little CaO slag is formed, which was less studied in the previous literature. Therefore, the viscosity and slag structure are investigated in the present study through FT-IR and Raman analysis methods. Experimental results show that the slag is a mixture of liquid and solid phases under the experimental temperature. The FT-IR and Raman spectra show that the fractions of the complex polymerization structure decrease significantly with the increase of FeO content and slag basicity, resulting in the decrease of apparent viscosity.

  14. On the Dissolution Behavior of Sulfur in Ternary Silicate Slags

    Science.gov (United States)

    Kang, Youn-Bae; Park, Joo Hyun

    2011-12-01

    Sulfur dissolution behavior, in terms of sulfide capacity ( C S), in ternary silicate slags (molten oxide slags composed of MO - NO - SiO2, where M and N are Ca, Mn, Fe, and Mg), is discussed based on available experimental data. Composition dependence of the sulfur dissolution, at least in the dilute region of sulfur, may be explained by taking into account the cation-anion first-nearest-neighbor (FNN) interaction (stability of sulfide) and the cation-cation second-nearest-neighbor (SNN) interaction over O anion (oxygen proportions in silicate slags). When the Gibbs energy of a reciprocal reaction MO + NS = MS + NO is positive, the sulfide capacity of slags with virtually no SiO2 or low SiO2 concentration decreases as the concentration of MO increases. However, in some slags, as SiO2 concentration increases, replacing NO by MO at a constant SiO2 concentration may increase sulfide capacity when the basicity of NO is less than that of MO. This phenomenon is observed as rotation of iso- C S lines in ternary silicate slags, and it is explained by simultaneous consideration of the stability of sulfide and oxygen proportions in the silicate slags. It is suggested that a solution model for the prediction of sulfide capacity should be based on the actual dissolution mechanism of sulfur rather than on the simple empirical correlation.

  15. Characterization and recovery of copper values from discarded slag.

    Science.gov (United States)

    Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

    2010-06-01

    In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery.

  16. Vanadium bioavailability in soils amended with blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Maja A., E-mail: maja.larsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Baken, Stijn, E-mail: stijn.baken@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Smolders, Erik, E-mail: erik.smolders@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Cubadda, Francesco, E-mail: francesco.cubadda@iss.it [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161 (Italy); Gustafsson, Jon Petter, E-mail: jon-petter.gustafsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Division of Land and Water Resources Engineering, KTH Royal Institute of Technology, Brinellvägen 28, 100 44 Stockholm (Sweden)

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg{sup −1}) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  17. Characterization of chilean copper slag smelting nineteenth century

    Directory of Open Access Journals (Sweden)

    Amin Nazer

    2016-12-01

    Full Text Available The aim of this work is to characterize four copper smelters slag nineteenth century, from abandoned landfills in Atacama Region - Chile, using the techniques of X-ray fluorescence (XRF, X-ray diffraction (XRD, scanning electron microscopy (SEM, particle analysis by laser diffraction (ADL, Fourier Transform Infrared Spectroscopy (FTIR and thermogravimetric analysis (TGA. Copper slags studied were chemically classified as acidic slags, this slags presented higher SiO2 content (38–49% than Fe2O3 (18–37% and a significant amount of CaO (8–26% and Al2O3 (8.5%. Mineralogy and structure was varied, presenting one of them an amorphous structure and the remaining three, a crystalline structure with partially amorphous character. The majority mineral phases presented in the copper slag were diopside, fayalite, magnetite, cristobalite and clinoferrosilita. Calcium levels indicate that the slags could have cementitious properties for use as a binder in construction materials. Moreover, the significant amount of slag available and CuO content (0.6–1.2% show that may be of interest as raw material for metal recovery.

  18. Vanadium bioavailability in soils amended with blast furnace slag.

    Science.gov (United States)

    Larsson, Maja A; Baken, Stijn; Smolders, Erik; Cubadda, Francesco; Gustafsson, Jon Petter

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg(-1)) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  19. Utilizing steel slag in environmental application - An overview

    Science.gov (United States)

    Lim, J. W.; Chew, L. H.; Choong, T. S. Y.; Tezara, C.; Yazdi, M. H.

    2016-06-01

    Steel slags are generated as waste material or byproduct every day from steel making industries.The potential environmental issues which are related with the slag dump or reprocessing for metal recovery are generally being focused in the research. However the chemistry and mineralogy of slag depends on metallurgical process which is able to determine whether the steel slag can be the reusable products or not. Nowadays, steel slag are well characterized by using several methods, such as X-ray Diffraction, ICP-OES, leaching test and many more. About the industrial application, it is mainly reused as aggregate for road construction, as armour stones for hydraulic engineering constructions and as fertilizers for agricultural purposes. To ensure the quality of steel slag for the end usage, several test methods are developed for evaluating the technical properties of steel slag, especially volume stability and environmental behaviour. In order to determine its environmental behaviour, leaching tests have been developed. The focus of this paper however is on those applications that directly affect environmental issues including remediation, and mitigation of activities that negatively impact the environment.

  20. UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

    Energy Technology Data Exchange (ETDEWEB)

    Vas Choudhry; Stephen Kwan; Steven R. Hadley

    2001-07-01

    The objective of the project entitled ''Utilization of Lightweight Materials Made from Coal Gasification Slags'' was to demonstrate the technical and economic viability of manufacturing low-unit-weight products from coal gasification slags which can be used as substitutes for conventional lightweight and ultra-lightweight aggregates. In Phase I, the technology developed by Praxis to produce lightweight aggregates from slag (termed SLA) was applied to produce a large batch (10 tons) of expanded slag using pilot direct-fired rotary kilns and a fluidized bed calciner. The expanded products were characterized using basic characterization and application-oriented tests. Phase II involved the demonstration and evaluation of the use of expanded slag aggregates to produce a number of end-use applications including lightweight roof tiles, lightweight precast products (e.g., masonry blocks), structural concrete, insulating concrete, loose fill insulation, and as a substitute for expanded perlite and vermiculite in horticultural applications. Prototypes of these end-use applications were made and tested with the assistance of commercial manufacturers. Finally, the economics of expanded slag production was determined and compared with the alternative of slag disposal. Production of value-added products from SLA has a significant potential to enhance the overall gasification process economics, especially when the avoided costs of disposal are considered.

  1. Fully automated analysis of four tobacco-specific N-nitrosamines in mainstream cigarette smoke using two-dimensional online solid phase extraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Jie; Bai, Ruoshi; Yi, Xiaoli; Yang, Zhendong; Liu, Xingyu; Zhou, Jun; Liang, Wei

    2016-01-01

    A fully automated method for the detection of four tobacco-specific nitrosamines (TSNAs) in mainstream cigarette smoke (MSS) has been developed. The new developed method is based on two-dimensional online solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE/LC-MS/MS). The two dimensional SPE was performed in the method utilizing two cartridges with different extraction mechanisms to cleanup disturbances of different polarity to minimize sample matrix effects on each analyte. Chromatographic separation was achieved using a UPLC C18 reversed phase analytical column. Under the optimum online SPE/LC-MS/MS conditions, N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were baseline separated with good peak shapes. This method appears to be the most sensitive method yet reported for determination of TSNAs in mainstream cigarette smoke. The limits of quantification for NNN, NNK, NAT and NAB reached the levels of 6.0, 1.0, 3.0 and 0.6 pg/cig, respectively, which were well below the lowest levels of TSNAs in MSS of current commercial cigarettes. The accuracy of the measurement of four TSNAs was from 92.8 to 107.3%. The relative standard deviations of intra-and inter-day analysis were less than 5.4% and 7.5%, respectively. The main advantages of the method developed are fairly high sensitivity, selectivity and accuracy of results, minimum sample pre-treatment, full automation, and high throughput. As a part of the validation procedure, the developed method was applied to evaluate TSNAs yields for 27 top-selling commercial cigarettes in China. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Processing of Phosphorus Slag with Recovery of Rare Earth Metals and Obtaining Silicon Containing Cake

    Science.gov (United States)

    Karshigina, Zaure; Abisheva, Zinesh; Bochevskaya, Yelena; Akcil, Ata; Sharipova, Aynash; Sargelova, Elmira

    2016-10-01

    The present research is devoted to the processing of slag generating during the yellow phosphorus production. In this paper are presented studies on leaching of phosphorus production slag by nitric acid with recovery of rare earth metals (REMs) into solution. REMs recovery into the solution achieved 98 % during the leaching process with using 7.5 mol/L of HNO3, liquid-to-solid ratio is 2.6:1, temperature is 60°C, process duration is 1 hour and stirrer speed is 500 rpm. Behaviour during the leaching of associated components such as calcium, aluminium, and iron was studied. After the leaching cake contains ∼⃒75-85 % of SiO2 and it might be useful for obtaining of precipitated silicon dioxide. With the purpose of separation from the impurities, recovery and concentrating of REMs, the obtained solution after leaching was subjected to extraction processing methods. The influence of ratio of organic and aqueous phases (O: A) on the extraction of rare earth metals by tributyl phosphate (TBP) with concentrations from 20 up to 100 % was studied. The REMs extraction with increasing TBP concentration under changes O:A ratio from 1:20 down to 1:1 into the organic phase from the solutions after nitric acid leaching increased from 22.2 up to 99.3%. The duration effect of REMs extraction process was studied by tributyl phosphate. It is revealed that with increasing of duration of the extraction process from 10 to 30 minutes REMs recovery into the organic phase almost did not changed. The behaviour of iron in the extraction process by TBP was studied. It was found that such accompanying components as calcium and aluminium by tributyl phosphate didn't extracted. To construct isotherm of REMs extraction of by tributyl phosphate was used variable volume method. It was calculated three-step extraction is needed for REMs recovery from the solutions after nitric acid leaching of phosphorus production slag. The process of the three-steps counter current extraction of rare earth

  3. Boron removal from molten silicon using sodium-based slags

    Institute of Scientific and Technical Information of China (English)

    Yin Changhao; Hu Bingfeng; Huang Xinming

    2011-01-01

    Slag refining,as an important option for boron removal to produce solar grade silicon (SOG-Si) from metallurgical grade silicon (MG-Si),has attracted increasing attention.In this paper,Na2CO3-SiO2 systems were chosen as the sodium-based refining slag materials for boron removal from molten silicon.Furthermore,the effect of Al2O3 addition for boron removal was studied in detail,which showed that an appropriate amount of Al2O3 can help retention of the basicity of the slags,hence improving the boron removal rate.

  4. Study on Apparent Viscosity and Structure of Foaming Slag

    Science.gov (United States)

    Martinsson, Johan; Glaser, Björn; Sichen, Du

    2016-10-01

    Foaming slag was generated using induction heating. The foam was found non-Newtonian having much higher apparent viscosity compared to the dynamic viscosity of pure slag. Quenched foam was examined. The appearance of the foaming slag was very different from silicone oil-gas foam. The size of gas bubbles ranged from 0.1 to 4 mm (while in the case of silicone oil, 1 to 2 mm). The gas fraction in the foam was considerably lower than in the case of silicone oil.

  5. Optimizing of Work Arc Furnace to Decopperisation of Flash Slag

    Directory of Open Access Journals (Sweden)

    Bydałek A.W.

    2015-09-01

    Full Text Available Discusses an attempt to optimize the operation of an electric furnace slag to be decopperisation suspension of the internal recycling process for the production of copper. The paper presents a new method to recover copper from metallurgical slags in arc-resistance electric furnace. It involves the use of alternating current for a first period reduction, constant or pulsed DC in the final stage of processing. Even distribution of the electric field density in the final phase of melting caused to achieve an extremely low content of metallic copper in the slag phase. They achieved by including the economic effects by reducing the time reduction.

  6. An approach for phosphate removal with quartz sand, ceramsite, blast furnace slag and steel slag as seed crystal.

    Science.gov (United States)

    Qiu, Liping; Wang, Guangwei; Zhang, Shoubin; Yang, Zhongxi; Li, Yanbo

    2012-01-01

    The phosphate removal abilities and crystallization performance of quartz sand, ceramsite, blast furnace slag and steel slag were investigated. The residual phosphate concentrations in the reaction solutions were not changed by addition of the ceramsite, quartz sand and blast furnace slag. The steel slag could provide alkalinity and Ca(2+) to the reaction solution due to its hydration activity, and performed a better phosphate removal performance than the other three. Under the conditions of Ca/P 2.0, pH 8.5 and 10 mg P/L, the phosphate crystallization occurred during 12 h. The quartz sand and ceramsite did not improve the phosphate crystallization, but steel slag was an effective seed crystal. The phosphate concentration decreased drastically after 12 h after addition of steel slag, and near complete removal was achieved after 48 h. The XRD analysis showed that the main crystallization products were hydroxyapatite (HAP) and the crystallinity increased with the reaction time. Phosphate was successfully recovered from low phosphate concentration wastewater using steel slag as seed material.

  7. Effect of P2O5 and FetO on the Viscosity and Slag Structure in Steelmaking Slags

    Science.gov (United States)

    Wang, Z. J.; Shu, Q. F.; Sridhar, S.; Zhang, M.; Guo, M.; Zhang, Z. T.

    2015-04-01

    The present paper investigates the influence of P2O5 and FetO on the viscosity and structure of steelmaking slags. An understanding of the viscous behavior and structure of FetO-bearing smelting slags is essential to control the dephosphorization in steelmaking process and to efficiently recycle the phosphorus from steelmaking slags. It is found that the viscosity of CaO-SiO2-Al2O3-MgO-FetO-P2O5 slags slightly increases with increasing P2O5 content, while the viscosity decreases with increasing FetO content. The degree of the polymerization of quenched slags, determined from Raman spectra, is found to increase with increasing P2O5 content and decrease with increasing FetO content. It is also noted that the peaks of Raman spectra between 800 and 1200 cm-1 were nearly absent at the FetO content of 22.46 wt pct; whereas according to 29Si MAS-NMR and FTIR analysis, it is clearly seen that the [SiO4]-tetrahedra-related peaks existed even for the same slag. This may confirm that small quantities of extra-framework iron species can absorb the Raman scattering and damp the Raman signal intensity and the presence of FetO in the slag does not necessarily eliminate [SiO4]-tetrahedra.

  8. Transport properties of fully screened Kondo models

    NARCIS (Netherlands)

    Hörig, Christoph B M; Mora, Christophe; Schuricht, Dirk

    2014-01-01

    We study the nonequilibrium transport properties of fully (exactly) screened Kondo quantum dots subject to a finite bias voltage or a finite temperature. First, we calculate the Fermi-liquid coefficients of the conductance for models with arbitrary spin, i.e., its leading behavior for small bias vol

  9. A Model Study of Inclusions Deposition, Macroscopic Transport, and Dynamic Removal at Steel-Slag Interface for Different Tundish Designs

    Science.gov (United States)

    Chen, Chao; Ni, Peiyuan; Jonsson, Lage Tord Ingemar; Tilliander, Anders; Cheng, Guoguang; Jönsson, Pär Göran

    2016-06-01

    This paper presents computational fluid dynamics (CFD) simulation results of inclusions macroscopic transport as well as dynamic removal in tundishes. A novel treatment was implemented using the deposition velocity calculated by a revised unified Eulerian deposition model to replace the widely used Stokes rising velocity in the boundary conditions for inclusions removal at the steel-slag interface in tundishes. In this study, the dynamic removal for different size groups of inclusions at different steel-slag interfaces (smooth or rough) with different absorption conditions at the interface (partially or fully absorbed) in two tundish designs was studied. The results showed that the dynamic removal ratios were higher for larger inclusions than for smaller inclusions. Besides, the dynamic removal ratio was higher for rough interfaces than for smooth interfaces. On the other hand, regarding the cases when inclusions are partially or fully absorbed at a smooth steel-slag interface, the removal ratio values are proportional to the absorption proportion of inclusions at the steel-slag interface. Furthermore, the removal of inclusions in two tundish designs, i.e., with and without a weir and a dam were compared. Specifically, the tundish with a weir and a dam exhibited a better performance with respect to the removal of bigger inclusions (radii of 5, 7, and 9 μm) than that of the case without weir and dam. That was found to be due to the strong paralleling flow near the middle part of the top surface. However, the tundish without weir and dam showed a higher removal ratio of smaller inclusions (radius of 1 μm). The reason could be the presence of a paralleling flow near the inlet zone, where the inclusions deposition velocities were much higher than in other parts.

  10. Chemical stabilization of chromate in blast furnace slag mixed cementitious materials.

    Science.gov (United States)

    Meena, Amanda H; Kaplan, Daniel I; Powell, Brian A; Arai, Yuji

    2015-11-01

    Cement waste form (CWF) technology is among the leading approaches to disposing of metals and liquid low-level nuclear waste in the United States. One such material, saltstone, includes slag, fly ash and Portland cement to enhance the immobilization of contaminants (e.g., Cr, (99)Tc) in alkaline liquid wastes. To evaluate the stability of such redox sensitive contaminants in saltstone, the effects of slag as a source of reductant on Cr immobilization was evaluated in aged (<300 d) saltstone monoliths. Specifically, we investigated the effects of artificial cement pore waters on the Cr release and the spatially resolved Cr chemical state analysis using synchrotron based microfocused X-ray microprobe analysis. The microprobe analysis indicated the heterogeneous distribution of insoluble Cr(III)-species in saltstone. Although at most of 20% Crtotal was leached at the top few (2-3) millimeter depth, the release of Cr(VI) was small (<5%) at 5-30 mm with slight changes, indirectly suggesting that Cr is likely present as insoluble Cr(III) species throughout the depths. The study suggests that this saltstone formulation can effectively retain/immobilize Cr under the oxic field condition after ⩽300 d of aging time.

  11. The behavior of sulfur in industrial pyrometallurgical slags

    Science.gov (United States)

    Nagamori, Meguru

    1994-08-01

    Dissolution of sulfur in industrial slags, even at such a low level as 1 mass% S or so, increases the solubility of certain valuable metals by an order of magnitude. The phenomenon is accounted for in terms of Flood-Førland-Grjotheim's model for dianionic salt solutions, whereas its rigorous analysis requires the digaseous Gibbs-Duhem integration. In the research described here, the distribution of sulfur among gas, slag, and metallic iron phases in the bath smelting of iron ore was computer-simulated based on a two-sites model coupled with sulfide capacity data. The solubilities of Ag, Cu, Co, and Ni in industrial slags are reviewed by applying the sulfidic-oxidic dissolution model to copper-matte smelting, nickel-slag cleaning (Falconbridge, Canada), and the imperial smelting process for zinc and lead (Hachinohe, Japan).

  12. Removal of phosphate from aqueous solution with blast furnace slag.

    Science.gov (United States)

    Oguz, Ensar

    2004-10-18

    Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. The specific surface area of the blast furnace slag was 0.4m(2)g(-1). The removal of phosphate predominantly has taken place by a precipitation mechanism and weak physical interactions between the surface of adsorbent and the metallic salts of phosphate. In this study, phosphate removal in excess of 99% was obtained, and it was concluded that blast furnace slag is an efficient adsorbent for the removal of phosphate from solution.

  13. Vaporization Studies from Slag Surfaces Using a Thin Film Technique

    Science.gov (United States)

    Seetharaman, Seshadri; Shyrokykh, Tetiana; Schröder, Christina; Scheller, Piotr R.

    2013-08-01

    The investigations of vanadium vaporization from CaO-SiO2-FeO-V2O5 thin film slags were conducted using the single hot thermocouple technique (SHTT) with air as the oxidizing atmosphere. The slag samples were analyzed after the experiments by SEM/EDX. The vanadium content was found to decrease as a function of time. The loss of vanadium from the slag film after 30 minutes of oxidation was approximately 18 pct and after 50 minutes, it was nearly 56 pct. The possible mechanism of vanadium loss would be the surface oxidation of vanadium oxide in the slag, VO x to V5+, followed by surface evaporation of V2O5, which has a high vapor pressure at the experimental temperature.

  14. Properties of Industrial Slag as Fine Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    A. Ananthi

    2015-04-01

    Full Text Available The main objective of this paper is to use the industrial waste such as bottom ash and Weld Slag (WS as the partial replacement for fine aggregates in concrete. This paper presents the chemical analysis and strength properties of industrial solid waste such as bottom ash, weld slag 1 (WS 1 and weld slag 2 (WS 2. Their chemical compositions were identified by X-ray powder diffraction (XRD analysis. The qualitative and quantitative elemental analysis of the bottom ash and weld slag was recognized by energy dispersive X-ray analysis and their morphology were studied by Scanning Electron Microscope (SEM. The compressive strength of concrete with 10% replacement of fine aggregate to the industrial waste shows higher strength than the normal concrete and hence this industrial waste can be used as fine aggregate in concrete.

  15. Activity of Reducing Steel Slag of EAF

    Institute of Scientific and Technical Information of China (English)

    GUO Chinhsiang; HWANG Chaolung; LIN Tingyi

    2011-01-01

    Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF)steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C2S, C3S, C2F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO3 content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

  16. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  17. Desulfurization ability of refining slag with medium basicity

    Science.gov (United States)

    Yu, Hui-xiang; Wang, Xin-hua; Wang, Mao; Wang, Wan-jun

    2014-12-01

    The desulfurization ability of refining slag with relative lower basicity ( B) and Al2O3 content ( B = 3.5-5.0; 20wt%-25wt% Al2O3) was studied. Firstly, the component activities and sulfide capacity ( C S) of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution ( L S). Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO ( a CaO), with no deterioration of C S compared with conventional desulfurization slag. The measured L S between high-strength low-alloyed (HSLA) steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

  18. Slagging and Fouling Characteristics of HRSG for Ferrosilicon Electric Furnaces

    OpenAIRE

    2015-01-01

    The slagging and fouling characteristics of the heat recovery steam generator (HRSG) for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the ash samples. The results show that low melting point salt Na 2 SO 4 and composit...

  19. Preparation of Glass Ceramic Based on Granulated Slag and Cullet

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The glass-ceramic was prepared on the basis of materials of granulated slag containing high-calcium oxide and cullet.The content of granulated slag ranges from 50%-60%wt in the glass compositions. The samples were analyzed by DTA, SEM and XRD.The results show that the main crystal phase of the glass-ceramic is β-CaSiO3,Which is in scattering fiber or column form.The applying properties have also been measured.

  20. Chloride ion transport performance in slag mortar under fatigue loading

    Institute of Scientific and Technical Information of China (English)

    WANG CaiHui; SUN Wei; JIANG JinYang; HAN JianDe; YE BangTu

    2012-01-01

    The transport performance of chloride ion in slag cement mortar was investigated experimentally.In the self-designed experiment,fatigue loading was coupled simultaneously with ion transportation process,the diffusion law of chloride ion was obtained by titration and the AE (acoustic emission) technique was employed to detect the real-time damage distribution in the mortar specimen.The results for fatigue stress levels of 0.3,0.4 and 0.5 and slag contents of 0,10%,30% and 50% showed that fatigue loading accelerated the diffusion of chloride ion in mortar and the acceleration effect increased with the increase in stress levels.Slag addition was found to improve anti-chloride ion erosion performance effectively with the best substitution level at 30%,because the inhibition effect of slag on chloride ion diffusion diminished when the slag content exceeded 30%.The comparative experiments indicated that dynamic load has a significant effect on the transport performance of chloride ion in slag cement mortar.

  1. Growth promotion effect of steelmaking slag on Spirulina platensis

    Science.gov (United States)

    Nogami, R.; Tam, L. T.; Anh, H. T. L.; Quynh, H. T. H.; Thom, L. T.; Nhat, P. V.; Thu, N. T. H.; Hong, D. D.; Wakisaka, M.

    2016-04-01

    A growth promotion effect of steelmaking slag on Spirulina platensis M135 was investigated. The growth promotion effect was obtained that was 1.27 times greater than that obtained by the control by adding 500 mg L-1 of steelmaking slag and culturing for 60 days. The lipid content decreased in a concentration-dependent manner with steelmaking slag, whereas the carbohydrate content remained constant. The protein content of S. platensis M135 increased in a concentration-dependent manner with steelmaking slag when cultured at day 45. The superoxide dismutase activity of S. platensis M135 exhibited a decreasing trend in a time-dependent manner and an increasing trend in the control. The superoxide dismutase activity was lower than that of the control at day 1 but was higher at day 30. No genetic damage was observed up to 500 mg L-1 of steelmaking slag at 30 days of culture. Recovery from genetic damage was observed at 1,000 mg L-1 of steelmaking slag but not at higher concentrations.

  2. Recovery of copper and cobalt from ancient slag.

    Science.gov (United States)

    Bulut, Gülay

    2006-04-01

    About 2.5 million tonnes of copper smelter slag are available in Küre, northern part of Turkey. This slag contains large amounts of metallic values such as copper and cobalt. A representative slag sample containing 0.98% Cu, 0.49% Co and 51.47% Fe was used in the experimental studies. Two different methods, direct acid leaching and acid baking followed by hot water leaching were used for recovering Cu and Co from the slag. The effects of leaching time, temperature and acid concentration on Cu- and Co-dissolving efficiencies were investigated in the direct acid leaching tests. The optimum leaching conditions were found to be a leaching time of 2 h, acid concentration of 120 g L(-1), and temperature of 60 degrees C. Under these conditions, 78% Cu and 90% Co were extracted. In the acid baking + hot water leaching tests, 74% Co was dissolved after 1 h of roasting at 200 degrees C using a 3:1 acid:slag ratio, whereas the Cu-dissolving efficiency was 79% and the total slag weight loss was approximately 50%.

  3. Effect of factors on the extraction of boron from slags

    Science.gov (United States)

    Zhang, Peixin; Sui, Zhitong

    1995-04-01

    The effects of slag composition, additive agent, and heat treatment on the crystal morphologies, the crystallization behavior, and the efficiency of extraction of boron (EEB) from slags were investigated by chemical analysis, polarization microscope, and X-ray diffraction (XRD) as well as differential thermal analysis (DTA). The EEB varied with the slag composition. The farther the slag composition deviated from the line between 2MgO · B2O3 and 2MgO · SiO2 in the MgO-B2O3-SiO2 system, the lower the EEB. The EEB was directly related to the precipitating characteristics of the boron component in the slags. The EEB was high if the boron component existed in the form of a crystalline phase, otherwise the EEB was low when boron was in the form of an amorphous phase. The EEB from MgO-Al2O3-CaO-B2O3-SiO2 slag varied with the temperature of heat treatment; the highest EEB appeared at 1100 °C. The EEB and the crystallinities were increased by addition of TiO2 and MOx (M = Mg, Ca, Fe, Si). The effect of MOx was more notable than that of TiO2.

  4. Portland cement-blast furnace slag blends in oilwell cementing applications

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D.T.; DiLullo, G.; Hibbeler, J. [and others

    1995-12-31

    Recent investigations of blast furnace slag cementing technologies. have been expanded to include Portland cement/blast furnace slag blends. Mixtures of Portland cement and blast furnace slag, while having a long history of use in the construction industry, have not been used extensively in oilwell cementing applications. Test results indicate that blending blast furnace slag with Portland cement produces a high quality well cementing material. Presented are the design guidelines and laboratory test data relative to mixtures of blast furnace slag and Portland cements. Case histories delineating the use of blast furnace slag - Portland cement blends infield applications are also included.

  5. Carbothermic Reduction Reactions at the Metal-Slag Interface in Ti-Bearing Slag from a Blast Furnace

    Science.gov (United States)

    Wang, Yao-Zu; Zhang, Jian-Liang; Liu, Zheng-Jian; Du, Cheng-Bo

    2017-08-01

    Carbothermic reduction reactions at the metal-slag interface and the mechanisms of iron loss during the smelting of vanadium-bearing titanomagnetite in a blast furnace are still not clear as a result of the limited ability to observe the high-temperature zone of a blast furnace. The chemical composition of a Ti-bearing slag was determined by x-ray fluorescence and x-ray diffraction. The interfaces were characterized by scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy. The interfacial chemical reactions were deduced based on the characterization results and on the thermodynamic calculations performed using Factsage 6.4. The results indicated that the forms of iron in the slag were iron droplets wetted by Ti(C x , N1-x ), mechanically separated by iron and iron oxide. The different forms possessed unique characteristics and were formed by different mechanisms. Iron droplets wetted by Ti(C x , N1-x ) were generated through a series of interfacial reactions between TiO2 in the slag and [C] and [N] in the metal. Iron droplets without attached Ti(C x , N1-x ) were mainly located on the edges of pores and were attributed to the reduction of Fe x O in the slag. Insufficient reduction of iron-bearing minerals made it difficult for iron droplets to aggregate and separate from the slag, which created an Fe x O-enriched zone.

  6. 转炉钢渣热态改性对镁质耐火材料的侵蚀行为%Corrosion behavior of hot modified BOF slag to magnesia based refractory crucible

    Institute of Scientific and Technical Information of China (English)

    代文彬; 李宇; 苍大强; 郭鹏

    2013-01-01

    以镁质坩埚为试验容器,配制碱度分别为1.2、1.5、1.7、1.9、2.2、2.4的改性钢渣并放置于坩埚中,以10℃·min-的速率升温至1 570℃并保温30 min加热熔化.研究了热态改性钢渣对镁质坩埚的侵蚀,并采用光学显微镜、SEM、EDS和XRD进一步分析了侵蚀行为.分析表明:改性钢渣对镁质耐火材料的侵蚀反应主要在熔渣-坩埚界面处进行,熔渣碱度≤1.5时耐火材料侵蚀加重;由于钢渣中铁离子渗透进方镁石晶体内,形成弥散分布的颗粒状富FeO固溶体和含FeO方镁石基质相,这两种物相受内部FeO、MgO质量比和钢渣中Al2O3含量的影响,选择性地同渣中不同化学组分进行反应而脱落溶解至钢渣中.%Six kinds of modified BOF slag with varied basicities (1. 2,1. 5,1.7,1. 9,2. 2,2.4,respectively) were prepared,put in six separate magnesia crucibles,heated to 1 570 ℃at 10℃· min-1 holding for 30 min. The corrosion of the hot modified slags to the magnesia crucible was analyzed with optical microscope ,SEM,EDS and XRD. Analysis shows that the corrosion reaction of magnesia crucible by the modified slags mainly occurs in the slag-crucible interface,and when the basicity of liquid slag is ≤1.5 the corrosion of crucible gets severe;Fe ions in liquid slag penetrate into the periclase crystals forming the dispersed granular FeO-rich solid solution and FeO-containing periclase matrix phase,and they selectively react with different components of liquid slag and dissolve in the slag affected by their mass ratio of FeO to MgO and the AI2O3 content in liquid slag.

  7. Molybdate adsorption from steel slag eluates by subsoils.

    Science.gov (United States)

    Matern, K; Rennert, T; Mansfeldt, T

    2013-11-01

    Steel slags are industrial by-products which are generated in large amounts worldwide, e.g. 150-230×10(6) Mg in 2012, and which are partly used for construction. Molybdenum (Mo) can be added during steel processing in order to harden the steel. The objective of this study was to evaluate the adsorption behaviour of molybdate (MoO4(2-)) from slag eluates in subsoils. Molybdate batch adsorption experiments were carried out with eluates obtained from two different kinds of steel slags (i) LD slag (Linz-Donawitz operation, LDS) and (ii) electric arc furnace slag (EAF) to assess the risk that may arise from the contamination of groundwater by the leaching of molybdate. Six different subsoils were chosen in order to provide a wide range of chemical properties (pH 4.0-7.6; dithionite-extractable Fe 0.73-14.7 g kg(-1)). Molybdate adsorption experiments were carried out at the pH of the steel slag eluates (pH 11-12) as well as at pH values adjusted to the soil pH. The data were evaluated with the Freundlich equation. Molybdate adsorption exhibited a maximum near pH 4 for steel slag eluates adjusted to the soil pH, and decreased rapidly with increasing pH until adsorption was virtually zero at pH>11. Adsorption was greater for soils with high amounts of dithionite-extractable Fe oxides. The extent and behaviour of molybdate adsorption from both eluates was similar. After a reaction time of 24h, the pH of the EAF slag eluate was lower than that of the LD steel slag eluate, which was caused by different acid buffer capacities. Some soils were able to decrease the pH of the EAF slag eluates by about 4 pH units, enhancing the adsorption of molybdate. Transport simulations indicated that molybdate discharge is low in acidic soils.

  8. Ablation characteristics and reaction mechanism of insulation materials under slag deposition condition

    Science.gov (United States)

    Guan, Yiwen; Li, Jiang; Liu, Yang

    2017-07-01

    Current understanding of the physical and chemical processes involved in the ablation of insulation materials by highly aluminized solid propellants is limited. The study on the heat transfer and ablation principle of ethylene propylene diene monomer (EPDM) materials under slag deposition condition is essential for future design or modification of large solid rocket motors (SRMs) for launch application. In this paper, the alumina liquid flow pattern and the deposition principle in full-scale SRM engines are discussed. The interaction mechanism between the alumina droplets and the wall are analyzed. Then, an experimental method was developed to simulate the insulation material ablation under slag deposition condition. Experimental study was conducted based on a laboratory-scale device. Meanwhile, from the analysis of the cross-sectional morphology and chemical composition of the charring layer after ablation, the reaction mechanism of the charring layer under deposition condition was discussed, and the main reaction equation was derived. The numerical simulation and experimental results show the following. (i) The alumina droplet flow in the deposition section of the laboratory-scale device is similar to that of a full-scale SRM. (ii) The charring layer of the EPDM insulator displays a porous tight/loose structure under high-temperature slag deposition condition. (iii) A seven-step carbothermal reduction in the alumina is derived and established under high-pressure and high-temperature environment in the SRM combustion chamber. (iv) The analysis using thermodynamic software indicates that the reaction of the alumina and charring layer initially forms Al4C3 during the operation. Then, Al element and Al2OC compound are subsequently produced with the reduction in the release of gas CO as well with continuous environmental heating.

  9. Mineral precipitation and dissolution at two slag-disposal sites in northwestern Indiana, USA

    Science.gov (United States)

    Bayless, E.R.; Schulz, M.S.

    2003-01-01

    Slag is a ubiquitous byproduct of the iron- and steel-refining industries. In northwestern Indiana and northeastern Illinois, slag has been deposited over more than 52 km2 of land surface. Despite the widespread use of slag for fill and construction purposes, little is known about its chemical effects on the environment. Two slagdisposal sites were examined in northwestern Indiana where slag was deposited over the native glacial deposits. At a third site, where slag was not present, background conditions were defined. Samples were collected from cores and drill cuttings and described with scanning electron microscopy and electron microprobe analysis. Ground-water samples were collected and used to assess thermodynamic equilibria between authigenic minerals and existing conditions. Differences in the mineralogy at background and slag-affected sites were apparent. Calcite, dolomite, gypsum, iron oxides, and clay minerals were abundant in native sediments immediately beneath the slag. Mineral features indicated that these minerals precipitated rapidly from slag drainage and co-precipitated minor amounts of non-calcium metals and trace elements. Quartz fragments immediately beneath the slag showed extensive pitting that was not apparent in sediments from the background site, indicating chemical weathering by the hyperalkaline slag drainage. The environmental impacts of slag-related mineral precipitation include disruption of natural ground-water flow patterns and bed-sediment armoring in adjacent surface-water systems. Dissolution of native quartz by the hyperalkaline drainage may cause instability in structures situated over slag fill or in roadways comprised of slag aggregates.

  10. Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete.

    Science.gov (United States)

    Lee, Han-Seung; Wang, Xiao-Yong; Zhang, Li-Na; Koh, Kyung-Taek

    2015-03-18

    Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions.

  11. Characterization of Ladle Furnace Slag from Carbon Steel Production as a Potential Adsorbent

    Directory of Open Access Journals (Sweden)

    Ankica Rađenović

    2013-01-01

    Full Text Available A promising type of steel slag for applications is the ladle furnace (LF slag, which is also known as the basic slag, the reducing slag, the white slag, and the secondary refining slag. The LF slag is a byproduct from further refining molten steel after coming out of a basic oxygen furnace (BOF or an electric arc furnace (EAF. The use of the LF slag in further applications requires knowledge of its characteristics. The LF slag characterization in this paper has been performed using the following analytical methods: chemical analysis by energy dispersive spectrometry (EDS, mineralogical composition by X-ray diffraction (XRD, surface area properties by the Brunauer-Emmett-Teller (BET and the Barrett-Joyner-Halenda (BJH methods, surface chemistry by infrared absorption (FTIR spectroscopy, and morphological analysis by scanning electron microscopy (SEM. The results showed that the main compounds are calcium, silicon, magnesium, and aluminium oxides, and calcium silicates under their various allotropic forms are the major compounds in the LF slag. Surface area properties have shown that the LF slag is a mesoporous material with relatively great BET surface area. The ladle furnace slag is a nonhazardous industrial waste because the ecotoxicity evaluation by its eluate has shown that the LF slag does not contain constituents which might in any way affect the environment harmfully.

  12. Slagging and Fouling Characteristics of HRSG for Ferrosilicon Electric Furnaces

    Directory of Open Access Journals (Sweden)

    Yungang Wang

    2015-02-01

    Full Text Available The slagging and fouling characteristics of the heat recovery steam generator (HRSG for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF, X-ray powder diffraction (XRD and scanning electron microscope (SEM were used to analyze the ash samples. The results show that low melting point salt Na2SO4 and composite salts Na (AlSi3O8 and 3K2SO4·CaSO4 deposit on the superheater tube walls in aerosol form and solidify to form the initial slag layer. With the continuous deposition of the low melting point compounds, more and more ash particles in the flue gas adhere to the slag surface to form a thicker slag. Low melting point composite salt NaO·Al2O3·SiO2 is absorbed on the evaporator tube walls in aerosol form. With the deposition of NaO·Al2O3·SiO2, more and more ash particles are absorbed to form the fouling. Since there is less space between pin-finned tubes, the large iron-rich slag particles are easily deposited on tube walls and fin surfaces, which is advantageous to the fouling process. There are large quantities of superfine ash particles in the flue gas that easily adhere to other particles or tube walls, which facilitates the slagging and fouling process.

  13. Desulfurization ability of refining slag with medium basicity

    Institute of Scientific and Technical Information of China (English)

    Hui-xiang Yu; Xin-hua Wang; Mao Wang; Wan-jun Wang

    2014-01-01

    The desulfurization ability of refining slag with relative lower basicity (B) and Al2O3 content (B=3.5−5.0;20wt%−25wt%Al2O3) was studied. Firstly, the component activities and sulfide capacity (CS) of the slag were calculated. Then slag−metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution (LS). Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO−Al2O3−SiO2−MgO system with the basicity of about 3.5−5.0 and the Al2O3 content in the range of 20wt%−25wt%has high activity of CaO (aCaO), with no deterioration of CS compared with conventional desulfurization slag. The measured LS between high-strength low-alloyed (HSLA) steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt%and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt%is 350 and 275, respectively. The new slag with a basicity of about 3.5−5.0 and an Al2O3 content of about 20wt%has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

  14. Skid resistance performance of asphalt wearing courses with electric arc furnace slag aggregates.

    Science.gov (United States)

    Kehagia, Fotini

    2009-05-01

    Metallurgical slags are by-products of the iron and steel industry and are subdivided into blast furnace slag and steel slag according to the different steel-producing processes. In Greece, slags are mostly produced from steelmaking using the electric arc furnace process, and subsequently are either disposed in a random way or utilized by the cement industry. Steel slag has been recently used, worldwide, as hard aggregates in wearing courses in order to improve the skidding resistance of asphalt pavements. At the Highway Laboratory, Department of Civil Engineering of Aristotle University of Thessaloniki research has been carried out in the field of steel slags, and especially in electric arc furnace (EAF) slag, to evaluate their possible use in highway engineering. In this paper, the recent results of anti-skidding performance of steel slag aggregates in highway pavements are presented.

  15. Influence of Basicity and MgO on Fluidity and Desulfurization Ability of High Aluminum Slag

    Science.gov (United States)

    Wang, Ping; Meng, Qing-min; Long, Hong-ming; Li, Jia-xin

    2016-08-01

    The viscosity of experimental slag, which was mixed based on the composition of a practical blast furnace slag, was measured in this paper. The influence of Al2O3 and MgO content, basicity R2 = w(CaO)/w(SiO2) on the fluidity of slag was studied. The stepwise regression analysis in SPSS was used to reveal the relationship between sulfur distribution coefficient LS and slag composition as well as furnace temperature. The results show that increasing of MgO up to 12% can decrease the slag viscosity. The w(MgO) should be controlled below 8% when there is 20% Al2O3 in the slag. Temperature of hot metal and content of CaO in slag are the two dominant factors on the desulfurization capacity of slag.

  16. Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

    Institute of Scientific and Technical Information of China (English)

    WANG Xian; CAI Qing-Sheng

    2006-01-01

    The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1)of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

  17. Reactions Between MgO-C Refractory, Molten Slag and Metal

    National Research Council Canada - National Science Library

    Li, Zushu; Mukai, Kusuhiro; Tao, Zainan

    2000-01-01

    The behavior of MgO-C refractory-slag-metal system, which is caused by the reactions such as the dissolution of MgO and graphite in the refractory into slag and metal respectively and the generation...

  18. Android Fully Loaded

    CERN Document Server

    Huddleston, Rob

    2012-01-01

    Fully loaded with the latest tricks and tips on your new Android! Android smartphones are so hot, they're soaring past iPhones on the sales charts. And the second edition of this muscular little book is equally impressive--it's packed with tips and tricks for getting the very most out of your latest-generation Android device. Start Facebooking and tweeting with your Android mobile, scan barcodes to get pricing and product reviews, download your favorite TV shows--the book is positively bursting with practical and fun how-tos. Topics run the gamut from using speech recognition, location-based m

  19. On Fully Homomorphic Encryption

    OpenAIRE

    Fauzi, Prastudy

    2012-01-01

    Fully homomorphic encryption is an encryption scheme where a party can receive encrypted data and perform arbitrary operations on this data efficiently.The data remains encrypted throughout, but the operations can be done regardless, without having to know the decryption key.Such a scheme would be very advantageous, for example in ensuring the privacy of data that is sent to a third-party service.This is in contrast with schemes like Paillier where you can not perform a multiplication of encr...

  20. New welding fluxes based on silicomanganese slag for deposition and welding of canopies and crib bed of mine support

    Science.gov (United States)

    Kryukov, R. E.; Kozyrev, N. A.; Usoltsev, A. A.; Kozyreva, O. E.

    2017-09-01

    The paper considers the possibility of efficient use of silicomanganese slag for the production of welding fluxes. The results of studying the use of metallurgical wastes as components of welding fluxes are given. Analysis of the results of mechanical properties of the samples made it possible to determine the optimum content of the pulverized fraction less than 0.45 mm in the flux. The composition and technology of manufacturing a new welding flux using slag of silicomanganese production was developed. The effect of fractional composition on the welding-technological properties of fluxes was studied. The optimal content of liquid glass in the flux, which allows a favorable complex of mechanical properties to be obtained, is 20-30%. To reduce the level of contamination of the weld metal with non-metallic oxide inclusions and to increase the mechanical properties of the welded joint, it is proposed to introduce a carbon-fluorine-containing additive FD-UFS into fluxes based on the slag.

  1. Development of Glass Ceramics Made From Ferrous Tailings and Slag in China

    Institute of Scientific and Technical Information of China (English)

    LIU Cheng-jun; SHI Pei-yang; ZHANG Da-yong; JIANG Mao-fa

    2007-01-01

    A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.

  2. 木薯渣发酵饲料的工艺筛选%Screening of technology in cassava slag fermentation feed

    Institute of Scientific and Technical Information of China (English)

    艾必燕; 刘长忠; 陈建康; 杨扬; 米本中; 黄倩妮; 樵星芳

    2012-01-01

    Using cassava slag as the main raw material, with aspergillus, trichoderma viride and rhizopus R2 for fermentation strains, the test is to optimize cassava slag fermentation technology producing tropina feed. The appropriate conditions of cassava slag fermentation are that adding amount of liquid spawn is 3%, adding amount of nitrogen source is 10%, fermentation temperature is 37 ℃, fermentation time is 4 days. Cassava slag is a mixture, its highest level of non-nitrogen compounds is 78.7%, main component is soluble starch compounds (such as monosaccharide and starch), but its crude protein content is very low, amino acid composition is extremely uneven, it has poor effect to feed cassava slag directly, so most of the cassava slag cannot be used, which not only causes the waste of resources, but also seriously pollutes environment. Processing cassava slag into feed materials can make full use of the waste in starch industry, it is favorable to the environment protection, and it also can significantly reduce the cost of feed, improve the utilization value and economic benefits of cassava slag.%以木薯生产中产生的废渣为主要原料,以黑曲霉、绿色木霉和根霉R2为发酵菌种,优化木薯渣发酵生产菌体蛋白饲料的工艺.初步确定了木薯渣发酵的适宜条件,即液体菌种添加量为3%,氮源添加量为20%,发酵温度37℃,发酵时间为4d,经试验验证,此发酵条件下发酵饲料中粗蛋白含量较高,可达到蛋白饲料对蛋白质含量的要求.通过处理木薯渣变为动物的饲料原料,不仅可充分利用淀粉工业的废弃物,有利于环境保护,而且可显著降低饲养成本,从而提高了木薯渣的利用价值和经济效益.

  3. Selective Sulfidation of Lead Smelter Slag with Pyrite and Flotation Behavior of Synthetic ZnS

    Science.gov (United States)

    Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Zhang, Tianfu; Qin, Wenqing

    2016-08-01

    The selective sulfidation of lead smelter slag with pyrite in the presence of carbon and Na salts, and the flotation behavior of synthetic ZnS were studied. The effects of temperature, time, pyrite dosage, Na salts, and carbon additions were investigated based on thermodynamic calculation, and correspondingly, the growth mechanism of ZnS particles was studied at high temperatures. The results indicated that the zinc in lead smelter slag was selectively converted into zinc sulfides by sulfidation roasting. The sulfidation degree of zinc was increased until the temperature, time, pyrite, and carbon dosages reached their optimum values, under which it was more than 95 pct. The growth of ZnS particles largely depended upon roasting temperature, and the ZnS grains were significantly increased above 1373 K (1100 °C) due to the formation of a liquid phase. After the roasting, the zinc sulfides generated had a good floatability, and 88.34 pct of zinc was recovered by conventional flotation.

  4. Studying the Hydration of a Retarded Suspension of Ground Granulated Blast-Furnace Slag after Reactivation

    Directory of Open Access Journals (Sweden)

    Nick Schneider

    2016-11-01

    Full Text Available This article presents a combined use of a retarder (d-gluconic acid and an alkaline activator (sodium hydroxide in a binder system based on ground granulated blast-furnace slag. The properties of the retarder are extending the dormant hydration period and suppressing the generation of strength-giving phases. Different retarder concentrations between 0.25 and 1.00 wt.% regulate the intensity and the period of the retardation and also the characteristics of the strength development. The activator concentration of 30 and 50 wt.% regulates the overcoming of the dormant period and thereby the solution of the slag and hence the formation of the hydration products. The research objective is to produce a mineral binder system based on two separate liquid components. The highest concentration of retarder and activator generates the highest compressive strength and mass of hydration products—after 90 days of hydration a compressive strength of more than 50 N/mm2. The main phases are calcium silicate hydrate and hydrotalcite. Generally, the combination of retarder and activator shows a high potential in the performance increase of the hydration process.

  5. Coal ash fusion temperatures - new characterization techniques and implications for slagging and fouling

    Energy Technology Data Exchange (ETDEWEB)

    Wall, T.F.; Creelman, R.A.; Gupta, R.P.; Gupta, S.K.; Coin, C.; Lowe, A. [University of Newcastle, Newcastle, NSW (Australia). CRC for Black Coal Utilisation

    1998-09-01

    The ash fusion test (AFT) is the accepted test for the propensity of coal ash to slag in the furnace. The well-documented shortcomings of this technique for estimating the fusion temperature of coal ash are its subjective nature and poor accuracy. Alternative measurements based on the shrinkage and electrical conductivity of heating samples are therefore examined here with laboratory ash prepared at about 800{degree}C in crucibles, as well as combustion ash samples from power stations. Sensitive shrinkage measurements indicate temperatures of rapid change which correspond to the formation of liquid phases that can be identified on ternary phase diagrams. The existence and extent of formation of these phases, as quantified by the magnitude of `peaks` in the test, provide alternative ash fusion temperatures. The peaks from laboratory ashes and corresponding combustion ashes derived from the same coals show clear differences which may be related to the evaporation of potassium during combustion and the reactions of the mineral residues to form combustion ash. A preliminary evaluation of data from nine power stations indicates that shrinkage measurements can provide an alternative approach to characterizing slagging. 15 refs., 9 figs., 2 tabs.

  6. Pyrometallurgical slags as a potential source of selected metals recovery

    Directory of Open Access Journals (Sweden)

    K. Nowińska

    2014-10-01

    Full Text Available Complex analysis of concentration and form of occurrence such metals as Zn, Pb, Fe and Cu in slags formed during a current zinc production in the Imperial Smelting Process (ISP is a possible basis for development of optimal recovery technology. For this purpose studies of slags from the current production of the Shaft Furnace Unit and of the Lead Refining of the “Miasteczko Śląskie” Zinc Smelting Plant were carried out. The studies results show that slags includes high concentrations of: Zn from 0,064 % to 1,680 %, Pb from 10,56 % to 50,71 %, Fe from 0,015 % to 2,576 %, Cu from 7,48 % to 64,95 %, and change in a broad range. This slags show significant heterogeneity, caused by intermetallic phases (Zn - Pb, Cu - Zn, Cu - Pb formed on the surface thereof. It is so possible that slag can be a potential source of this metals recovery.

  7. Preparation of calcium silicate absorbent from iron blast furnace slag.

    Science.gov (United States)

    Brodnax, L F; Rochelle, G T

    2000-09-01

    Calcium silicate hydrate (CSH) solids were prepared from hydrated lime and iron blast furnace slag in an aqueous agitated slurry at 92 degrees C. While it was hoped a minimal lime/slag ratio could be used to create near-amorphous CSH, the surface area of the product improved by increasing the lime/slag weight ratio to 2. The addition of gypsum to the lime/slag system dramatically improved the formation of surface area, creating solids with 139 m2/g after 30 hr of reaction when only a minimal amount of lime was present. The SO2 reactivity of solids prepared with gypsum greatly exceeded that of hydrated lime, achieving greater than 70-80% conversion of the alkalinity after 1 hr of reaction with SO2. The use of CaCl2 as an additive to the lime/slag system, in lieu of gypsum, also produced high-surface-area solids, 115 m2/g after 21 hr of reaction. However, the SO2 reactivity of these sorbents was relatively low given the high surface area. This emphasized that the correlation between surface area and SO2 reactivity was highly dependent on the solid phase, which was subsequently dependent on slurry composition.

  8. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  9. Preparation of Slag Wool by Integrated Waste-Heat Recovery and Resource Recycling of Molten Blast Furnace Slags: From Fundamental to Industrial Application

    Directory of Open Access Journals (Sweden)

    Dawei Zhao

    2014-05-01

    Full Text Available The present paper investigated the process of the slag wool fabrication using high temperature blast furnace (BF slag modified by coal ash (CA. The liquidus temperature and viscosity of the slag system with different mass ratios of BF slag and CA were measured through an inner cylinder rotation method. The approximate mass ratio used to fabricate the slag wool was therefore determined and slag wool was then successfully prepared with a high-speed air injection method in the laboratory. The effect of mBF/m ratio, slag temperature for injection and air pressure on the preparation of slag wool was systematically investigated. The mechanical and thermal properties were also studied to confirm the long-term working conditions of the slag wool. An industry-scale slag wool production application was established. The energy consumption and the pollutant generation, were analyzed and compared with the traditional production method, which indicated a 70% reduction in energy consumption and a 90% pollution emission decrease.

  10. Size-dependent enrichment of waste slag aggregate fragments abraded from asphalt concrete.

    Science.gov (United States)

    Takahashi, Fumitake; Shimaoka, Takayuki; Gardner, Kevin; Kida, Akiko

    2011-10-30

    Authors consider the environmental prospects of using melted waste slag as the aggregate for asphalt pavement. In particular, the enrichment of slag-derived fragments in fine abrasion dust particles originated from slag asphalt concrete and its size dependency were concerned. A series of surface abrasion tests for asphalt concrete specimens, containing only natural aggregates as reference or 30 wt% of substituted slag aggregates, were performed. Although two of three slag-asphalt concretes generated 1.5-3.0 times larger amount of abrasion dust than the reference asphalt concrete did, it could not be explained only by abrasion resistance of slag. The enrichment of slag-derived fragments in abrasion dust, estimated on the basis of the peak intensity of quartz and heavy metal concentrations, had size dependency for all slag-asphalt concretes. Slag-derived fragments were enriched in abrasion dust particles with diameters of 150-1000 μm. Enrichment factors were 1.4-2.1. In contrast, there was no enrichment in abrasion dust particles with diameter less than 75 μm. This suggests that prior airborne-size fragmentation of substituted slag aggregates does not need to be considered for tested slag aggregates when environmental risks of abrasion dust of slag-asphalt pavement are assessed.

  11. Effects of slag and fly ash in concrete in chloride environment

    NARCIS (Netherlands)

    Polder, R.B.

    2012-01-01

    This paper addresses experience from The Netherlands with blast furnace slag and fly ash in concrete in chloride contaminated environments, both from the field and the laboratory. Use of slag produced in The Netherlands started in the 1930s and CEM III/B LH HS, with typically 70% slag, became the do

  12. Fully Awake Breast Reduction.

    Science.gov (United States)

    Filson, Simon A; Yarhi, Danielle; Ramon, Yitzhak

    2016-11-01

    The authors present 25 cases and an in-depth 4-minute video of fully awake aesthetic breast reduction, which was made possible by thoracic epidural anesthesia. There are obvious and important advantages to this technique. Not only does this allow for intraoperative patient cooperation (i.e., patient self-positioning and opinion for comparison of breasts), meaning a shorter and more efficient intraoperative time, there also is a reduction in postoperative pain, complications, recovery, and discharge times. The authors have also enjoyed great success and no complications with this technique in over 150 awake abdominoplasty/total body lift patients. The authors feel that the elimination of the need for general anesthesia by thoracic epidural sensorial-only anesthesia is a highly effective and efficient technique, with very few disadvantages/complications, providing advantages to both patients and surgeons. Therapeutic, IV.

  13. AISI/DOE Technology Roadmap Program: Removal of Residual Elements in The Steel Ladle by a Combination of Top Slag and Deep Injection Practice

    Energy Technology Data Exchange (ETDEWEB)

    S. Street; K.S. Coley; G.A. Iron

    2001-08-31

    The objective of this work was to determine if tin could be removed from liquid steel by a combination of deep injection of calcium and a reducing top-slag practice. The work was carried out in three stages: injection of Ca wire into 35 Kg heats in an induction furnace under laboratory condition; a fundamental study of the solubility of Sn in the slag as a function of oxygen potential, temperature and slag composition; and, two full-scale plant trials. During the first stage, it was found that 7 to 50% of the Sn was removed from initial Sn contents of 0.1%, using 8 to 16 Kg of calcium per tonne of steel. The Sn solubility study suggested that low oxygen potential, high basicity of the slag and lower temperature would aid Sn removal by deep injection of Ca in the bath. However, two full-scale trials at the LMF station in Dofasco's plant showed virtually no Sn removal, mainly because of very low Ca consumption rates used (0.5 to 1.1 Kg/tonne vs. 8 to 16 Kg/tonne used during the induction furnace study in the laboratory). Based on the current price of Ca, addition of 8 to 16 Kg/tonne of steel to remove Sn is too cost prohibitive, and therefore, it is not worthwhile to pursue this process further, even though it may be technically feasible.

  14. Structure and Vibrational Spectra of Slags Produced from Radioactive Waste

    Science.gov (United States)

    Malinina, G. A.; Stefanovsky, S. V.

    2014-05-01

    The structure of the anionic motif of aluminosilicate and aluminoborosilicate glasses containing simulated slags from a solid radioactive waste incinerator was studied by IR and Raman spectroscopy. Spectra of melted slag were consistent with Si-O tetrahedra with various numbers of bridging O ions and Al-O tetrahedra embedded in the Si-O network in the slag vitreous and crystalline phases (nepheline, nagelschmidtite). Vibrations of doubly and triply bound Si-O tetrahedra and Al-O tetrahedra embedded between them were mainly responsible for the spectra as the content of sodium disilicate fl ux and the glass fraction in the materials increased. Addition of sodium tetraborate fl ux caused the appearance of B-O vibrations of predominantly three-coordinate B and a tendency toward chemical differentiation preceding phase separation.

  15. Vanadium removal from LD converter slag using bacteria and fungi.

    Science.gov (United States)

    Mirazimi, S M J; Abbasalipour, Z; Rashchi, F

    2015-04-15

    Removal of vanadium from Linz-Donawits (LD) converter slag was investigated by means of three different species of microbial systems: Acidithiobacillus thiooxidans (autotrophic bacteria), Pseudomonas putida (heterotrophic bacteria) and Aspergillus niger (fungi). The bioleaching process was carried out in both one-step and two-step process and the leaching efficiencies in both cases were compared. Formation of inorganic and organic acids during the leaching process caused mobilization of vanadium. In order to reduce toxic effects of the metal species on the above mentioned microorganisms, a prolonged adaptation process was performed. Both bacteria, A. thiooxidans and P. putida were able to remove more than 90% of vanadium at slag concentrations of 1-5 g L(-1) after 15 days. Also, the maximum achievable vanadium removal in the fungal system was approximately 92% at a slag concentration of 1 g L(-1) after 22 days.

  16. Effects of slag fineness on durability of mortars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS)replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects,exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Consequently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.

  17. Pyrochemical recovery of plutonium from calcium fluoride reduction slag

    Science.gov (United States)

    Christensen, D.C.

    A pyrochemical method of recovering finely dispersed plutonium metal from calcium fluoride reduction slag is claimed. The plutonium-bearing slag is crushed and melted in the presence of at least an equimolar amount of calcium chloride and a few percent metallic calcium. The calcium chloride reduces the melting point and thereby decreases the viscosity of the molten mixture. The calcium reduces any oxidized plutonium in the mixture and also causes the dispersed plutonium metal to coalesce and settle out as a separate metallic phase at the bottom of the reaction vessel. Upon cooling the mixture to room temperature, the solid plutonium can be cleanly separated from the overlying solid slag, with an average recovery yield on the order of 96 percent.

  18. Synthesis and Characteristics of Anorthite Ceramics from Steelmaking Slag

    Science.gov (United States)

    Li, Bowen; He, Mingsheng; Hwang, Jiann-Yang; Gan, Wangui

    Steelmaking slag is an alkaline solid waste consisting mainly oxides of calcium, iron, silicon, magnesium, and aluminum. Its large quantity and chemical property makes it challenging for recycling the material in various industrial applications. In this study, hot-poured steelmaking slag was used to prepare ceramics. After mixing with kaolin and quartz, ceramic products were synthesized via sintering. The appropriate sintering temperature is 1200°C. XRD analysis showed the major mineral phases were anorthite and pyroxene. SEM images showed that the new crystal particles were uniformly formed and distributed. Reaction mechanisms were discussed.

  19. Modeling the service life of slag concrete exposed to chlorides

    Directory of Open Access Journals (Sweden)

    O.A. Hodhod

    2014-03-01

    A partial replacement of OPC with 50% WCS in OPC paste mixes resulted in an increase in the amount of calcium silicate hydrate (CSH by 57%, a decrease in the amount of calcium hydroxide (CH by 66%, and a decrease in the amount of capillary pores by 57%, compared to those in the pure OPC matrix. In addition, the research results demonstrate that increasing Cs from 1% to 5% resulted in dramatically decreasing the service life of OPC/slag concrete, where the amount of decreasing reaches about 71%. Also, the service life of concrete increases with increasing slag content.

  20. Steelmaking slag beneficiation by magnetic separator and impacts on sinter quality

    Directory of Open Access Journals (Sweden)

    Bölükbaşı Ö.S.

    2014-01-01

    Full Text Available Basic oxygen furnaces (BOF slag is the main problem at all iron and steel factories. About more than 6 million tons/year of BOF slag has been accumulated from the waste stockyards in Turkey. Dumps slags can be revaluated by a processing technology which makes it possible to obtain products that meet the requirements of sintering and blast furnace production. The slags with particle size of -10 mm were enriched by the magnetic separator resulting and increase in Fe grade from 18% to 33%. The use of BOF slag in sinter blend provided additional Mn, CaO, MgO and introduced a good solution to environmental problems.

  1. Characterization of ancient Indian iron and entrapped slag inclusions using electron, photon and nuclear microprobes

    Indian Academy of Sciences (India)

    P Dillmann; R Balasubramaniam

    2001-06-01

    Compositional and structural information were obtained from an ancient 1600-year old Indian iron using microprobe techniques (EDS, XRD and PIXE). Several different local locations in the iron matrix and in the entrapped slag inclusions were analyzed. The P content of the metallic iron matrix was very heterogeneous. Lower P contents were observed in the regions near slag inclusions. This was correlated to the dephosphorization capacity of the slag. The crystallized phases identified in the slag inclusions were wüstite and fayalite. The compositions of the slag inclusions were relatively homogeneous.

  2. Future Resources for Eco-building Materials: I.Metallurgical Slag

    Institute of Scientific and Technical Information of China (English)

    XU Delong; LI Hui

    2009-01-01

    In order to make an effectivily recycle use of iron and steel slags that are main industrial wastes generated in Chinese metallurgical industry,the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed,such as preparing cement-steel slag blended cement with steel slag after metal recovery,using the fine powder of blast furnace slag (BFS)for manufacturing slag cement and high performance concrete.A further research on using these available resources more efficiently were discussed.

  3. Fully electric waste collection

    CERN Multimedia

    Anaïs Schaeffer

    2015-01-01

    Since 15 June, Transvoirie, which provides waste collection services throughout French-speaking Switzerland, has been using a fully electric lorry for its collections on the CERN site – a first for the region!   Featuring a motor powered by electric batteries that charge up when the brakes are used, the new lorry that roams the CERN site is as green as can be. And it’s not only the motor that’s electric: its waste compactor and lifting mechanism are also electrically powered*, making it the first 100% electric waste collection vehicle in French-speaking Switzerland. Considering that a total of 15.5 tonnes of household waste and paper/cardboard are collected each week from the Meyrin and Prévessin sites, the benefits for the environment are clear. This improvement comes as part of CERN’s contract with Transvoirie, which stipulates that the firm must propose ways of becoming more environmentally friendly (at no extra cost to CERN). *The was...

  4. Effect of Al2O3 on the Viscosity and Structure of CaO-SiO2-MgO-Al2O3-FetO Slags

    Science.gov (United States)

    Wang, Zhanjun; Sun, Yongqi; Sridhar, Seetharaman; Zhang, Mei; Guo, Min; Zhang, Zuotai

    2015-04-01

    The present paper provided a fundamental investigation on the effect of Al2O3 on the viscosity and structure of CaO-SiO2-MgO-Al2O3-FetO slags for the purpose of efficiently recycling the valuable elements from the steelmaking slags. The results show that the viscosity of CaO-SiO2-Al2O3-MgO-FetO slags slightly increases with increasing Al2O3 content. The degree of the polymerization (DOP) of quenched slags, determined from Raman spectra and magic angle spinning-nuclear magnetic resonance, is also found to increase with increasing Al2O3 content. It can be deduced that the increasing DOP can promote the formation of gehlenite phase (Ca2Al2SiO7), thus facilitating the formation of higher phosphorous (or vanadium) contained solid solution ( n'Ca2SiO4·Ca3((P or V)O4)2). As Al2O3 content increases up to a specific value, the charge compensating ions which present near [AlO4]-tetrahedra and [FeO4]-tetrahedra are not fully supplied due to the scarcity of Ca2+. In this case, the existing Fe3+ in the melt cannot completely form [FeO4]-tetrahedra and part of Fe3+ would form [FeO6]-octahedra to substitute Ca2+ to modify the slags.

  5. Corrosion Mechanism of Ladle Furnace Refining Slag to Fired MgO-CaO Bricks

    Institute of Scientific and Technical Information of China (English)

    ZHU Boquan; FANG Binxiang; ZHANG Wenjie; LI Xiangcheng; WAN Hongbo

    2010-01-01

    Corrosion effect of ladle furnace(LF)refining slag on fired MgO-CaO bricks with about 34% CaO was studied by static crucible method,and corrosion mechanism was analyzed by techniques of scan electron micrograph,energy dispersive spectrometer,and X-ray dif-fraction.The results show that: MgO-CaO bricks exhibit excellent corrosion resistance but poor penetration in reaction zone results in volume expansion forming MgO-CaO bricks increases liquid phases which accelerates corrosion of the bricks; a protective layer of 2CaO·SiO2 formed on reaction interface prevents penetration of C2F to the bricks.

  6. Fully integrated, fully automated generation of short tandem repeat profiles

    Science.gov (United States)

    2013-01-01

    Background The generation of short tandem repeat profiles, also referred to as ‘DNA typing,’ is not currently performed outside the laboratory because the process requires highly skilled technical operators and a controlled laboratory environment and infrastructure with several specialized instruments. The goal of this work was to develop a fully integrated system for the automated generation of short tandem repeat profiles from buccal swab samples, to improve forensic laboratory process flow as well as to enable short tandem repeat profile generation to be performed in police stations and in field-forward military, intelligence, and homeland security settings. Results An integrated system was developed consisting of an injection-molded microfluidic BioChipSet cassette, a ruggedized instrument, and expert system software. For each of five buccal swabs, the system purifies DNA using guanidinium-based lysis and silica binding, amplifies 15 short tandem repeat loci and the amelogenin locus, electrophoretically separates the resulting amplicons, and generates a profile. No operator processing of the samples is required, and the time from swab insertion to profile generation is 84 minutes. All required reagents are contained within the BioChipSet cassette; these consist of a lyophilized polymerase chain reaction mix and liquids for purification and electrophoretic separation. Profiles obtained from fully automated runs demonstrate that the integrated system generates concordant short tandem repeat profiles. The system exhibits single-base resolution from 100 to greater than 500 bases, with inter-run precision with a standard deviation of ±0.05 - 0.10 bases for most alleles. The reagents are stable for at least 6 months at 22°C, and the instrument has been designed and tested to Military Standard 810F for shock and vibration ruggedization. A nontechnical user can operate the system within or outside the laboratory. Conclusions The integrated system represents the

  7. Corrosion of ceramics for slag removal in IGCC-power plants; Korrosion von Keramiken fuer die Fluessigascheabscheidung in IGCC-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Fuerst, Denny

    2012-06-12

    Coal gasification and the subsequent production of electricity from syngas in combined-cycle powerplants allows plant efficiencies of up to 43% (LHV). Existing technologies allow up to 50% in the short term. Efficiencies beyond 50% however, require concepts and technologies that still need a certain amount of research and development. One such method to raise plant efficiencies would be a high temperature (at temperatures above the melting point of the ash) syngas cleaning. To effectively utilize the heat from the syngas and enable high turbine inlet temperatures, it is necessary to remove slag particles from the hot gas. The feasibility of such a hot syngas cleaning has been successfully demonstrated for the Pressurized Pulverized Coal Combustion (PPCC) by passing the hot gas through a bed of ceramic balls for slag removal. In order to apply this concept to IGCC powerplants the slag resistance of various ceramic materials had to be investigated under gasifying conditions. Therefore, lab-made ceramics and commercially available refractory materials where treated with liquid slag at 1600 C in a number of reducing atmospheres. At first, three synthetic slags with different basicity were used and after evaluating the results, selected materials were treated with a gasifier slag under continuous conditions. It was shown that both slag and ceramic have to be adjusted to ensure a sufficient corrosion resistance of the ceramic bed for slag removal. Furthermore, the impact of the porosity of the utilized ceramic on the corrosion resistance was shown. The composition of the reducing atmosphere (mainly the partial pressure of Oxygen) affected both physical and chemical properties of the slag via slag components that could easily be reduced or oxidized. The materials most suitable for use in slag separation were found to be dense chromium oxide and other ceramics containing a high amount of chromium oxide. [German] Mit Kohlevergasung und der anschliessenden Stromerzeugung in

  8. Corrosion of ceramics for slag removal in IGCC-power plants; Korrosion von Keramiken fuer die Fluessigascheabscheidung in IGCC-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Fuerst, Denny

    2012-06-12

    Coal gasification and the subsequent production of electricity from syngas in combined-cycle powerplants allows plant efficiencies of up to 43% (LHV). Existing technologies allow up to 50% in the short term. Efficiencies beyond 50% however, require concepts and technologies that still need a certain amount of research and development. One such method to raise plant efficiencies would be a high temperature (at temperatures above the melting point of the ash) syngas cleaning. To effectively utilize the heat from the syngas and enable high turbine inlet temperatures, it is necessary to remove slag particles from the hot gas. The feasibility of such a hot syngas cleaning has been successfully demonstrated for the Pressurized Pulverized Coal Combustion (PPCC) by passing the hot gas through a bed of ceramic balls for slag removal. In order to apply this concept to IGCC powerplants the slag resistance of various ceramic materials had to be investigated under gasifying conditions. Therefore, lab-made ceramics and commercially available refractory materials where treated with liquid slag at 1600 C in a number of reducing atmospheres. At first, three synthetic slags with different basicity were used and after evaluating the results, selected materials were treated with a gasifier slag under continuous conditions. It was shown that both slag and ceramic have to be adjusted to ensure a sufficient corrosion resistance of the ceramic bed for slag removal. Furthermore, the impact of the porosity of the utilized ceramic on the corrosion resistance was shown. The composition of the reducing atmosphere (mainly the partial pressure of Oxygen) affected both physical and chemical properties of the slag via slag components that could easily be reduced or oxidized. The materials most suitable for use in slag separation were found to be dense chromium oxide and other ceramics containing a high amount of chromium oxide. [German] Mit Kohlevergasung und der anschliessenden Stromerzeugung in

  9. Explore the Water-cooled Slag Cooler Drum Master Cylinder Structure%滚筒水冷式冷渣机主筒结构探讨

    Institute of Scientific and Technical Information of China (English)

    吴浪

    2014-01-01

    在锅炉系统中,冷渣机对高温炉渣的冷却起着重要的作用,而滚筒水冷式冷渣机因其自身所具有的一些优点得到了较为广泛的应用。在滚筒水冷式冷渣机中,其主筒结构对其性能和工作效率等都会产生直接的影响。针对生产的实际需求,对滚筒水冷式冷渣机进行改进和完善时,要充分考虑主筒结构设计和所要改善的问题,从而使其能够更好地发挥冷却作用。%In the boiler system, slag cooler for cooling high-temperature slag plays an important role, and the cold cylinder water-cooled slag machine has its own advantages has been more widely used. In the cylinder water-cooled slag cooler in the main tube structures have a direct impact on their performance and work efficiency will be. When the actual demand for the production of cylinder water-cooled slag cooler to improve and perfect, to fully consider the master cylinder and the structural design issues to be improved, making it better able to exert a cooling effect.

  10. Replacement of Natural Fine Aggregate With Air Cooled Blast Furnace Slag An Industrial By Product

    Directory of Open Access Journals (Sweden)

    Dr. B. Krishna Rao

    2015-07-01

    Full Text Available The aim of the investigation is to replace natural fine aggregatewith Air Cooled Blast Furnace Slag in OPC concrete. At present, nearly million tons of slag is being produced in the steel plants, in India. The generation of slag would be dual problem in disposal difficulty and environmental pollution. Some strategies should be used to utilize the slag effectively. Considering physical properties of metallurgical slags and a series of possibilities for their use in the field of civil constructions, this report demonstrates the possibilities of using air cooled blast furnace slag as partial replacement of sand in concrete. A total of five concrete mixes, containing 0%, 12.5%, 25%, 37.5% and 50% partial replacement of regular sand with air cooled blast furnace slag are investigated in the laboratory. These mixes were tested to determine axial compressive strength, split tensile strength, and flexural strength for 7days, 28days, 56days and 90days.

  11. Waste activated sludge hydrolysis and acidification: A comparison between sodium hydroxide and steel slag addition.

    Science.gov (United States)

    Zhang, Ying; Zhang, Chaojie; Zhang, Xuan; Feng, Leiyu; Li, Yongmei; Zhou, Qi

    2016-10-01

    Alkaline treatment with steel slag and NaOH addition were investigated under different pH conditions for the fermentation of waste activated sludge. Better performance was achieved in steel slag addition scenarios for both sludge hydrolysis and acidification. More solubilization of organic matters and much production of higher VFA (volatile fatty acid) in a shorter time can be achieved at pH10 when adjusted by steel slag. Higher enzyme activities were also observed in steel slag addition scenarios under the same pH conditions. Phosphorus concentration in the supernatant increased with fermentation time and pH in NaOH addition scenarios, while in contrast most phosphorus was released and captured by steel slag simultaneously in steel slag addition scenarios. These results suggest that steel slag can be used as a substitute for NaOH in sludge alkaline treatment.

  12. Petrochemistry of coal ash slags. I. Formation of melilite and a high temperature glass from a calcium-rich, silica-deficient slag

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.; Barbie, D.L.; Christensen, O.D.; Kerner, F.R.

    1977-01-01

    Pilot plant studies are being conducted of a fixed-bed slagging coal gasification process. Lignite from the Indianhead mine is reacted with steam and oxygen in a gasifier at hearth zone temperatures over 1650/sup 0/C. Slag samples were subjected to chemical and petrographic analysis. Layers of layered slag modules were analyzed; the inner layers contain abundant melilite while the outer core is a glass. Results show that the characteristics of the coal ash slag can be affected by temperature fluctuations in the gasifier hearth, and that chemical, flow, and heat transfer behavior are all susceptible to change as a result. 8 figs., 3 tables. (DLC)

  13. Testing fully depleted CCD

    Science.gov (United States)

    Casas, Ricard; Cardiel-Sas, Laia; Castander, Francisco J.; Jiménez, Jorge; de Vicente, Juan

    2014-08-01

    The focal plane of the PAU camera is composed of eighteen 2K x 4K CCDs. These devices, plus four spares, were provided by the Japanese company Hamamatsu Photonics K.K. with type no. S10892-04(X). These detectors are 200 μm thick fully depleted and back illuminated with an n-type silicon base. They have been built with a specific coating to be sensitive in the range from 300 to 1,100 nm. Their square pixel size is 15 μm. The read-out system consists of a Monsoon controller (NOAO) and the panVIEW software package. The deafualt CCD read-out speed is 133 kpixel/s. This is the value used in the calibration process. Before installing these devices in the camera focal plane, they were characterized using the facilities of the ICE (CSIC- IEEC) and IFAE in the UAB Campus in Bellaterra (Barcelona, Catalonia, Spain). The basic tests performed for all CCDs were to obtain the photon transfer curve (PTC), the charge transfer efficiency (CTE) using X-rays and the EPER method, linearity, read-out noise, dark current, persistence, cosmetics and quantum efficiency. The X-rays images were also used for the analysis of the charge diffusion for different substrate voltages (VSUB). Regarding the cosmetics, and in addition to white and dark pixels, some patterns were also found. The first one, which appears in all devices, is the presence of half circles in the external edges. The origin of this pattern can be related to the assembly process. A second one appears in the dark images, and shows bright arcs connecting corners along the vertical axis of the CCD. This feature appears in all CCDs exactly in the same position so our guess is that the pattern is due to electrical fields. Finally, and just in two devices, there is a spot with wavelength dependence whose origin could be the result of a defectous coating process.

  14. Dephosphorization of Steelmaking Slag by Leaching with Acidic Aqueous Solution

    Science.gov (United States)

    Qiao, Yong; Diao, Jiang; Liu, Xuan; Li, Xiaosa; Zhang, Tao; Xie, Bing

    2016-09-01

    In the present paper, dephosphorization of steelmaking slag by leaching with acidic aqueous solution composed of citric acid, sodium hydroxide, hydrochloric acid and ion-exchanged water was investigated. The buffer solution of C6H8O7-NaOH-HCl system prevented changes in the pH values. Kinetic parameters including leaching temperature, slag particle size and pH values of the solution were optimized. The results showed that temperature has no obvious effect on the dissolution ratio of phosphorus. However, it has a significant effect on the dissolution ratio of iron. The dephosphorization rate increases with the decrease of slag particle size and the pH value of the solution. Over 90% of the phosphorus can be dissolved in the solution while the corresponding leaching ratio of iron was only 30% below the optimal condition. Leaching kinetics of dephosphorization follow the unreacted shrinking core model with a rate controlled step by the solid diffusion layer, the corresponding apparent activation energy being 1.233 kJ mol-1. A semiempirical kinetic equation was established. After leaching, most of the nC2S-C3P solid solution in the steelmaking slag was selectively dissolved in the aqueous solution and the iron content in the solid residue was correspondingly enriched.

  15. Aluminium salt slag characterization and utilization--a review.

    Science.gov (United States)

    Tsakiridis, P E

    2012-05-30

    Aluminium salt slag (also known as aluminium salt cake), which is produced by the secondary aluminium industry, is formed during aluminium scrap/dross melting and contains 15-30% aluminium oxide, 30-55% sodium chloride, 15-30% potassium chloride, 5-7% metallic aluminium and impurities (carbides, nitrides, sulphides and phosphides). Depending on the raw mix the amount of salt slag produced per tonne of secondary aluminium ranges from 200 to 500 kg. As salt slag has been classified as toxic and hazardous waste, it should be managed in compliance with the current legislation. Its landfill disposal is forbidden in most of the European countries and it should be recycled and processed in a proper way by taking the environmental impact into consideration. This paper presents a review of the aluminium salt slag chemical and mineralogical characteristics, as well as various processes for metal recovery, recycling of sodium and potassium chlorides content back to the smelting process and preparation of value added products from the final non metallic residue.

  16. ECOLOGICAL AND TECHNOLOGYCAL ASPECTS OF ASH AND SLAG WASTES UTILIZATION

    Directory of Open Access Journals (Sweden)

    Tatyana Aleksandrova

    2017-07-01

    Full Text Available The article presents the results of investigation focused on the utilization of ash and slag wastes (ASW in Russia including investigation of chemical and physical properties of ASW and processing products. Many factors influence the technological properties of ash and slag materials: naturals, processes and environments. The integrated treatment of ash and slag wastes of both stored and re-formed types will allow obtaining the following commercial products: coal concentrate, iron concentrate, aluminosilicate cenospheres, aluminosilicate product. In this study we have analyzed the methods for separation of ASW iron-containing part using the different types of the magnetic separation from the ash and slag material from one of the combined heat and power plant (CHPP in the Russian Far East Federal District. The greatest interest is the dry magnetic separation with travelling electromagnetic field. The subject of research was a sample taken from one of ash dump of CHPP in the Far East. In the study iron concentrate containing Fetotal = 64% was obtained recovery 68% in the low intensity (up to 5 kOe travelling magnetic field.

  17. The Interfacial Transition Zone in Alkali-Activated Slag Mortars

    Directory of Open Access Journals (Sweden)

    Rackel eSan Nicolas

    2015-12-01

    Full Text Available The interfacial transition zone (ITZ is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz aggregates and alkali activated slag binders in the context of mortar specimens. Backscattered electron images (BSE generated in an environmental scanning electron microscope (ESEM are used to identify unreacted binder components, reaction products and porosity in the zone surrounding aggregate particles, by composition and density contrast. X-ray mapping is used to exclude the regions corresponding to the aggregates from the BSE image of the ITZ, thus enabling analysis of only the binder phases, which are segmented into binary images by grey level discrimination. A distinct yet dense ITZ region is present in the alkali-activated slag mortars, containing a reduced content of unreacted slag particles compared to the bulk binder. The elemental analysis of this region shows that it contains a (C,N-A-S-H gel which seems to have a higher content of Na (potentially deposited through desiccation of the pore solution and a lower content of Ca than the bulk inner and outer products forming in the main binding region. These differences are potentially important in terms of long-term concrete performance, as the absence of a highly porous interfacial transition zone region is expected to provide a positive influence on the mechanical and transport properties of alkali-activated slag concretes.

  18. Micronutrient availability from steel slag amendment in peatmoss substrates

    Science.gov (United States)

    The objective of this research was to determine the suitability of a steel slag product for supplying micronutrients to container-grown floriculture crops. Geranium (Pelargonium xhortorum 'Maverick Red') and tomato (Solanum lycopersicon 'Megabite') were grown in 11.4 cm containers with a substrate ...

  19. Slagging in a pulverised-coal-fired boiler

    Energy Technology Data Exchange (ETDEWEB)

    Devir, G.P.; Pohl, J.H.; Creelman, R.A. [University of Queensland, St. Lucia, Qld. (Australia). Dept. of Chemical Engineering

    2000-07-01

    This paper describes a technique to evaluate the severity of slagging of a coal in a pulverised-coal-fired boiler. There are few data in the literature on the nature of in-situ boiler slags, their rate of growth and/or their strength properties relevant to sootblowing. The latter is thought to be of more concern to boiler operators and gives rise to the significance of selecting suitable strength tests. As well as standardised methods for characterising pulverised coal performance in a boiler, several novel and less popular techniques are discussed in detail. A suite of three sub-bituminous coals from the Callide Coalfields, Biloela (600 km north of Brisbane), has been selected for slagging tests in the 350 MW{sub e} units of Callide 'B' power station. Disposable air-cooled mild steel slagging probes have been constructed to simulate the conditions for deposit formation in the boiler region. To date, tests for one of these coals has been completed and preliminary results are presented. Once testing for the remaining coals has been completed, it is anticipated that the differences exhibited in deposit growth and strength may be correlated with typical variations in physical and chemical properties of the pulverised coal.

  20. Micronutrientes in the sugarcane irrigated: correction of the soil with siderurgical slag

    Directory of Open Access Journals (Sweden)

    Napoleão Esberard de Macêdo Beltrão

    2009-12-01

    Full Text Available The beneficial effects of manuring with siderurgical slag has been researched in several species, mainly among grassy such as sugarcane (Saccharum officinarum L.. The experiment was installed in the field, using one of the most representative sugarcane soils of Alagoas State, was cultivated in Dystrophic AGREY ARGISSOIL. The siderurgical slag source was containing 11% of soluble SiO2. The objective this research was quantify foliate micronutrients in the sugarcane and pH of soil due siderurgical slag application submitted the different irrigation water in São Sebastião city. For such the design was band of randomizered blocks, with five doses of siderurgical slags (band and five water (sub band and four repetitions. The analyzed variables were the micronutrients concentrations (Zn, Cu, Fe and Mn in the leaf. The slag application increased the concentrations significantly foliate of Zn while concentrations of Cu and Fe decreased. The foliate concentration of Mn, in the interaction of slag and irrigation water, it decreased in the cane plants and first it would beat, when the factor was slag inside of irrigation water however, when the factor was sheets inside of slag, there was increase of the concentration this element us of the cycles. The foliate concentration of Mn, due the interactive effect of slag and irrigation water, decreased in the first cut. However, when the factor was irrigation water inside of slag, there was increase of concentration of this in the two cycles.

  1. Diffusion of hexavalent chromium in chromium-containing slag as affected by microbial detoxification.

    Science.gov (United States)

    Wang, Yunyan; Yang, Zhihui; Chai, Liyuan; Zhao, Kun

    2009-09-30

    An electrochemical method was used to determine the diffusion coefficient of chromium(VI) in chromium-containing slag. A slag plate was prepared from the original slag or the detoxified slag by Achromobacter sp. CH-1. The results revealed that the apparent diffusion coefficient of Cr(VI) was 4.4 x 10(-9)m(2)s(-1) in original slag and 2.62 x 10(-8)m(2)s(-1) in detoxified slag. The results implied that detoxification of chromium-containing slag by Achromobacter sp. CH-1 could enhance Cr(VI) release. Meanwhile, the results of laboratory experiment showed that the residual total Cr(VI) in slag decreased from an initial value of 6.8 mg g(-1) to 0.338 mg g(-1) at the end of the detoxification process. The Cr(VI) released from slag was also reduced by Achromobacter sp. CH-1 strain since water soluble Cr(VI) in the leachate was not detected after 4 days. Therefore, Achromobacter sp. CH-1 has potential application for the bio-detoxification of chromium-containing slag.

  2. An alternative approach for reusing slags from a plasma vitrification process

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Y.-M. [Department of Safety Health and Environmental Engineering, Chung Hwa University of Medical Technology, 89, Wenhwa 1st St., Rende Shiang, Tainan County 71703, Taiwan (China)], E-mail: yiming@mail.hwai.edu.tw; Tseng, H.-J. [Department of Foundry Engineering, National Tainan Industrial Vocational High School, Tainan 71075, Taiwan (China); Chang, J.-E. [Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Wang, J.-W.; Wang, C.-T. [Department of Safety Health and Environmental Engineering, Chung Hwa University of Medical Technology, 89, Wenhwa 1st St., Rende Shiang, Tainan County 71703, Taiwan (China); Chen, H.-T. [Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2008-08-15

    Vitrification is widely applied to transform hazardous materials into inert slags. Raising the value of the recycled slag is an important issue from an economic point of view. In this study, an alternative approach for mixing a plasma slag with unsaturated polyester resin for making the dough-like molding composites is proposed. Physical properties, including ultimate tensile strength, Rockwell hardness, and the elongation at break, were measured to evaluate the characteristics of the composites. A scanning electron microscope and an X-ray diffractometer were used to examine the micro characteristics of the specimens. The chemical stability of the composites was estimated using the toxicity characteristic leaching procedure and a hot water bathing process. In an optimal slag loading (mass ratio of slag to unsaturated polyester resin) ranged from 0.1 to 0.2, the slag powder improved the physical properties of the composites. With an increased slag loading, excess slag powder weakened the structure of the resin, reducing the ultimate tensile strength and Rockwell hardness. The acid and water bathing tests indicated that the resin is decomposed in a hot environment. However, the slag was not destructed nor were the hazardous metals leached out. The results show that the molding method is an effective technology to recycle the slag.

  3. 独居石与独居石渣利用研究进展%Research Progress on the Utilization of Monazite and Monazite Slag

    Institute of Scientific and Technical Information of China (English)

    肖勇; 陈月华

    2016-01-01

    介绍了独居石精矿冶炼技术由浓硫酸分解法到液碱分解法的发展历程,对主流工艺液碱分解法的优化研究进行了总结,对独居石渣的形成进行分析.概括了处理独居石渣回收铀、钍与稀土的酸法工艺、碱法工艺和综合回收工艺的研究进展,并对综合回收工艺中的渣浸出、有价成分分离和尾矿处理等三个主流程进行了阐述.%This paper introduces the development process of monazite concentrate smelting methods from concentrated sulfuric acid technology to liquid alkali technology.The optimization on mainstream liquid alkali technology is summarized and the formed monazite slag is analyzed.The recent research review of recovering uranium,thorium and rare earth from monazite slag through acid technology,alkali technology and comprehensive technology is summarized.Furthermore,three main processes of comprehensive technology about slag leaching,valuable components separating and tailings disposing are also discussed.

  4. Comparison of a new high-resolution monolithic column with core-shell and fully porous columns for the analysis of retinol and α-tocopherol in human serum and breast milk by ultra-high-performance liquid chromatography.

    Science.gov (United States)

    Kučerová, Barbora; Krčmová, Lenka; Solichová, Dagmar; Plíšek, Jiří; Solich, Petr

    2013-07-01

    The reduction of analysis time, cost, and improvement of separation efficiency are the main requirements in the development of high-throughput assay methods in bioanalysis. It can be achieved either by ultra-high-performance liquid chromatography (UHPLC) using stationary phases with small particles (separation efficiency, peak shape, resolution, time of analysis, consumption of mobile phase, and lifetime of columns were calculated and compared. The main purpose of the study was to find a new, not only economical option of separation of liposoluble vitamins for routine practice.

  5. Study on Adsorption Behaviors of Cr(Ⅵ) in Sewage by Lemon Slag%柠檬渣吸附污水中铬(Ⅵ)的工艺研究

    Institute of Scientific and Technical Information of China (English)

    冉敬; 黄秀丽; 汪阳平; 任沁; 沈王庆

    2015-01-01

    为了研究柠檬渣对污水中铬(Ⅵ)的吸收工艺,用10%的H2SO4对柠檬渣进行了改性,比较了改性柠檬渣与原柠檬渣的吸附性能,并利用单因素法,考察了吸附剂的量、反应时间、反应温度、溶液的pH和恒温振荡器的振速对吸附效果的影响。结果表明,改性柠檬渣的吸附性能要优于原柠檬渣;在一定条件下,改性柠檬渣与污水的适宜液固比为10 g/L;改性柠檬渣与原料柠檬渣的适宜反应时间为90 min;改性柠檬渣的反应温度为45℃;溶液的适宜pH为4;改性柠檬渣与原柠檬渣的恒温振荡器的振速分别取150 r/min和100 r/min。%To study the adsorption process of Cr(Ⅵ) in sewage, lemon slag was modified by 10% H2SO4, then the adsorp-tion capability of modified lemon slag and original lemon slag were compared. The effects of absorbent dosage, adsorption time, temperature, pH and oscillator vibration velocity were investigated by single factor method. The results showed that the adsorption properties of modified lemon slag were better than the original slag. Under certain conditions, the suitable ratio of solid to liquid ( m modified lemon slag to Vsewage ) was 10g/L. The best reaction time of the modified lemon slag and the original slag was both 90 min; and the oscillator vibration velocity was 150 r/min and 100 r/min,respectively. The best reac-tion temperature of the modified lemon slag was 45 ℃; and the pH of the liquor was 4.

  6. Local corrosion of magnesia-chrome refractory at slag-metal interface; Yoyu slag metal kaimen ni okeru magnesia / chrom shitsu taikabutsu no kyokubu sonsho

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Z.; Mukai, K.; Ogata, M. [Kyushu Inst. of Tech., Kitakyushu, Fukuoka (Japan)

    1998-09-01

    The corrosion mode of refractory depending on the chemical dissolution of molten slag-metal, a component of refractory is classified mainly into the corrosion of inner slag phase body and inner metal phase body, and local corrosion at slag surface and slag-metal interface, and local corrosion at the interface of different type of refractories. Among them, local corrosion occurring at the slag-metal interface is a serious problem that effects the life of refractory, and these recent years research regarding the prevention of this type of local corrosion has been closed up. So far, number of researches regarding the local corrosion of solid oxides at slag-metal interface has been carried out. However, these are all based on close single component and research regarding the practical oxides with multiple components and multiporous characteristic has not been carried out. In this research, practical magnesia-chrome refractory (CaO-SiO2-Al203-FetO) slag-metal system is described and revelation of local corrosion phenomena at slag-metal interface was studied. 17 refs., 14 figs., 2 tabs.

  7. Recycling of industrial waste and performance of steel slag green concrete

    Institute of Scientific and Technical Information of China (English)

    LI Yun-feng; YAO Yan; WANG Ling

    2009-01-01

    Workability and mechanical properties of steel slag green concrete with different types of steel slag and different dosages of admixtures were investigated. The effectiveness of steel slag powder on suppressing alkali aggregate reaction (AAR) expansion was assessed using the method of ASTM C441 and accelerated test method. Experimental results show that mechanical properties can be improved further due to the synergistic effect and mutual activation when compound mineral admixtures with steel slag powder and blast-furnace slag powder are mixed into concrete, in addition, about 50% decrease in expansion rate of mortar bars with mineral admixtures can be achieved in AAR tests. Mineral admixtures with steel slag powder as partial replacement for Portland cement in concrete is an effective means for controlling expansion due to AAR.

  8. The effect of primary copper slag cooling rate on the copper valorization in the flotation process

    Directory of Open Access Journals (Sweden)

    Aleksandar Mihajlović

    2015-06-01

    Full Text Available Technological procedure of slow cooling slag from primary copper production is applied in the purpose of copper recovery in the level of 98.5% to blister. This technological procedure is divided into two phases, first slow cooling of slag on the air for 24 hours, and then accelerated cooling with water for 48 hours. Within the research following methods were used: calculation of nonstationary slag cooling, verification of the calculation using computer simulation of slag cooling in the software package COMSOL Multiphysics and experimental verification of simulation results. After testing of the experimentally gained samples of slowly cooled slag it was found that this technological procedure gives the best results in promoting growth or coagulation of dispersed particles of copper sulfide and copper in the slag, thereby increasing the utilization of the flotation process with a decrease of copper losses through very fine particles.

  9. The estimation of the reaction stimulators influence into the extraction slag conditions

    Directory of Open Access Journals (Sweden)

    A. W. Bydałek

    2010-04-01

    Full Text Available Slag stimulators was analysed used the DTA methods. In the paper a method of determining the reduction capability of slag solutions wasused. The analysis of slag stimulators concertinaing of the chloride and fluoride compositions are showed. There are the oxides complexesused in to the slag composition for the purpose to establish two indicators in reduction processes: EW - indicator showing the direction and intensity of reaction in to the slag composition, and r - indicator of the rate of coal consumption. There are possible and purposeful the construction optimization programme engaging all of the phisics chemical influence the slags in processes of melting metals alloys. The proposed results, ranges of areas on graphs of phase equilibria's, demonstrative on the optimum values, will be verified in laboratory conditions and industrial. The initiation the new data the gathered base will be built in system of open base enabling.

  10. PRECIPITATION AND GROWTH OF PEROVSKITE PHASE IN TITANIUM BEARING BLAST FURNACE SLAG

    Institute of Scientific and Technical Information of China (English)

    Z.Z. Guo; T.P. Lou; L. Zhang; L.N. Zhang; Z.T. Sui

    2007-01-01

    The effects of transformation of slag composition and additive agents on the morphology, the crystal in the Ti-bearing blast furnace slags were investigated. As the morphology of perovskite is dispersed in molten slags, the crystal growth mechanism of the melting of fine dendrites and the coarsening of large grains exist throughout the solidification of molten slags. With the increase of CaO and Fe2O3 content, VF of perovskite obviously increases. However, high basicity leads to the viscosity of slag, which results in the reduction of the average equivalent diameter (AED). The experimental results showed that the presence of the additives CaF2 and MnO efficiently decreased the viscosity of the slags, and obviously improved the morphology of perovskite and promoted its growth.

  11. Corrosion behavior of steel in concrete made with slag-blended cement

    Energy Technology Data Exchange (ETDEWEB)

    Dehghanian, C. [Univ. of Technology, Isfahan (Iran, Islamic Republic of). Dept. of Chemical Engineering

    1999-03-01

    Concretes formulated with slag as a partial replacement for cement were used to evaluate the corrosion behavior of steel embedded in concrete, resistivity, and the compressive strength of the concrete. Corrosion rates and pitting corrosion of steel in concrete with up to 30% slag and exposed to sodium chloride (NaCl) solutions decreased. Slag-blended cement concrete increased concrete resistivity. A water-to-cement ratio <0.55 and submersion in water for a period of 18 days gave the best chloride (Cl{sup {minus}}) diffusion resistance from the external salt solutions. Compressive strength of the concrete decreased with addition of slag in the early ages of the concrete. After 5 months of age, compressive strength of the concrete increased with addition of slag. This trend continued with up to 30% slag addition.

  12. Modification of steelmaking slag by additions of salts from aluminum production

    Science.gov (United States)

    Walker, David C.

    The most common slag fluidizer in steelmaking is fluorspar, a mineral primarily composed of CaF2. Because of increasing consumption and decreasing availability of cheap fluorspar, steelmakers are seeking alternative means of achieving slag fluidity. One possible alternative to fluorspar is spent salt from secondary aluminum production. This salt is obtained from the used flux in remelting aluminum scrap and dross. This material is widely available and considered toxic (meaning that use in steelmaking helps to reduce environmental impacts from disposal). This project is an investigation of spent salt as a replacement for fluorspar in slag-fluidizing applications by viscosity measurements and weight loss measurements at high temperatures (to evaluate the amounts of gases are formed). In addition, characterization of raw materials and melted slags by XRD, chemical analysis, and EPMA have been undertaken. The spent salt addition has a positive effect on slag fluidity, and shows promise for use in slags.

  13. Hydrocarbon characterization experiments in fully turbulent fires.

    Energy Technology Data Exchange (ETDEWEB)

    Ricks, Allen; Blanchat, Thomas K.

    2007-05-01

    As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. The model for the fuel evaporation rate in a liquid fuel pool fire is significant because in well-ventilated fires the evaporation rate largely controls the total heat release rate from the fire. A set of experiments are outlined in this report which will provide data for the development and validation of models for the fuel regression rates in liquid hydrocarbon fuel fires. The experiments will be performed on fires in the fully turbulent scale range (> 1 m diameter) and with a number of hydrocarbon fuels ranging from lightly sooting to heavily sooting. The importance of spectral absorption in the liquid fuels and the vapor dome above the pool will be investigated and the total heat flux to the pool surface will be measured. The importance of convection within the liquid fuel will be assessed by restricting large scale liquid motion in some tests. These data sets will provide a sound, experimentally proven basis for assessing how much of the liquid fuel needs to be modeled to enable a predictive simulation of a fuel fire given the couplings between evaporation of fuel from the pool and the heat release from the fire which drives the evaporation.

  14. Optimisation of the slag mode in the ladle during the steel processing of secondary metallurgy

    OpenAIRE

    Socha, Ladislav; Bažan, Jiří; Gryc, Karel; Morávka, Jan; Styrnal, Petr; Pilka, Václav; Piegza, Zbygněv

    2013-01-01

    Optimisation of the slag mode in the ladle with the help of briquetted fluxing agents, based on Al2O3 under various technological conditions is the object of this paper. The aim of the industrial experiments was to assess the possibility of achieving the optimum chemical composition of the slag that would improve the kinetic conditions of the refining ladle slag during the treatment in secondary metallurgy units. Industrial experiments were focused on comparing the influences of d...

  15. Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.

    Directory of Open Access Journals (Sweden)

    Dongfeng Ning

    Full Text Available It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae, including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.

  16. A novel process for comprehensive utilization of vanadium slag

    Science.gov (United States)

    Liu, Li-ying; Du, Tao; Tan, Wen-jun; Zhang, Xin-pu; Yang, Fan

    2016-02-01

    Traditional processes for treating vanadium slag generate a huge volume of solid residue and a large amount of harmful gas, which cause serious environmental problems. In this study, a new process for the comprehensive utilization of vanadium slag was proposed, wherein zeolite A and a V2O5/TiO2 system were synthesized. The structural properties of the as-synthesized zeolite A and the V2O5/TiO2 system were characterized using various experimental techniques, including X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and infrared spectroscopy. The results reveal that zeolite A and the V2O5/TiO2 system are successfully obtained with high purity. The results of gas adsorption measurements indicate that the prepared zeolite A exhibits high selectivity for CO2 over N2 and is a candidate material for CO2 capture from flue-gas streams.

  17. Effect of Superfine Slag Powder on HPC Properties

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A superfine slag powder (SP) made from granulated blast furnace slag incorporating activators by using special millingtechnique, was used as supplementary cementitious material in high performance concrete (HPC), replacing part ofthe mass of normal Portland cement. The effects of the SP on the workability, mechanical and crack self-healingproperties of HPC were studied. The hydration process and microstructure characteristics were investigated by X-raydiffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The crack self-healing capacitywas evaluated by Brazilian test. The test results indicate that the SP has especially supplementary effect on waterreducing and excellent property of better control of slump loss. The concrete flowability increases remarkably withthe increase of SP replacement level in the range of 20% to 50%. The compressive and splitting tensile strengthsof HPC containing SP are higher than the corresponding strength of the control concrete at all ages. The crackself-healing ability is highly dependent on SP content of HPC.

  18. Alkali based slagging: a case study from Leigh Creek

    Energy Technology Data Exchange (ETDEWEB)

    R.A. Creelman; J. Bamberry; L.A. Juniper; C. Ward [University of Western Sydney, Penrith South, NSW (Australia)

    2003-07-01

    A systematic study was undertaken at NRG Port Augusta Power station in South Australia to determine the cause of ash deposition (slagging) in the boilers. Conventional wisdom suggests that iron in the ash is generally a major player in furnace ash deposition; however, mineralogical and chemical analyses of the deposits showed that the binding phase was plagioclase feldspar, dominated by the sodic feldspar albite. The study resulted in recognition that the cause of the formation of ash deposits in the North Flinders furnaces was the result of the ingestion of sodium and calcium into the melt that bound the deposits. This finding was a breakthrough in understanding the deposition process within these furnaces, and emphasises that not all slagging is iron related and that systematic studies of deposits, coal and ash make fundamental contributions to understanding the ash deposition mechanisms. 9 refs., 5 figs., 2 tabs.

  19. 高铝渣对济钢3200m3高炉冶炼的影响%Influence of High Al2O3 Slag on Operation of 3 200 m3 BF in Jinan Steel

    Institute of Scientific and Technical Information of China (English)

    王军

    2015-01-01

    To the characteristics of high Al2O3 slag with higher viscosity, poor liquidity, and poor desulphurization ability, by adjusting the thermal system and distributing system, the Mg/Al ratio in the slag is controlled lager than 0.6 by increasing the MgO content in sintering, the MgO content in the slag is made between 8%-11%, the overall operation of 3 200 m3 BF in Jinan Steel can fit smelting requirement with high Al2O3 slag. Under the condition of slag ratio increase by 43 kg/t, the silicon in the pig iron was decreased, the desulphurization ability of the slag was strengthened and third grade iron was eliminated basically.%针对高铝渣特有的黏度高、流动性差、脱硫能力差的特点,济钢3 200 m3高炉通过调整热制度和布料制度,在烧结时提高MgO含量,控制渣中镁铝比>0.6,使渣中MgO含量在8%~11%,高炉的整体操作炉型适应了高铝渣的冶炼要求.在渣铁比升高43 kg/t的条件下,高炉生铁含硅降低,炉渣脱硫能力增强,基本杜绝了三类铁.

  20. Use of ancient copper slags in Portland cement and alkali activated cement matrices.

    Science.gov (United States)

    Nazer, Amin; Payá, Jordi; Borrachero, María Victoria; Monzó, José

    2016-02-01

    Some Chilean copper slag dumps from the nineteenth century still remain, without a proposed use that encourages recycling and reduces environmental impact. In this paper, the copper slag abandoned in landfills is proposed as a new building material. The slags studied were taken from Playa Negra and Púquios dumps, both located in the region of Atacama in northern Chile. Pozzolanic activity in lime and Portland cement systems, as well as the alkali activation in pastes with copper slag cured at different temperatures, was studied. The reactivity of the slag was measured using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), electrical conductivity and pH in aqueous suspension and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, copper slag-Portland cement mortars with the substitution of 25% (by weight) of cement by copper slag and alkali-activated slag mortars cured at 20 and 65 °C were made, to determine the compressive strength. The results indicate that the ancient copper slags studied have interesting binding properties for the construction sector.

  1. Environmental impacts of asphalt mixes with electric arc furnace steel slag.

    Science.gov (United States)

    Milačič, Radmila; Zuliani, Tea; Oblak, Tina; Mladenovič, Ana; Ančar, Janez Šč

    2011-01-01

    Electric arc furnace (EAF) steel slag can be used as an alternative high-quality material in road construction. Although asphalts with slag aggregates have been recognized as environmentally acceptable, there is a lack of data concerning the potential leaching of toxic Cr(VI) due to the highly alkaline media of EAF slag. Leaching of selected water extractable metals from slag indicated elevated concentrations of total chromium and Cr(VI). To estimate the environmental impacts of asphalt mixes with slag, leachability tests based on diffusion were performed using pure water and salt water as leaching agents. Compact and ground asphalt composites with natural aggregates, and asphalt composites in which the natural aggregates were completely replaced by slag were prepared. The concentrations of total chromium and Cr(VI) were determined in leachates over a time period of 6 mo. After 1 and 6 mo, the concentrations of some other metals were also determined in the leachates. The results indicated that chromium in leachates from asphalt composites with the addition of slag was present almost solely in its hexavalent form. However, the concentrations were very low (below 25 μg L) and did not represent an environmental burden. The leaching of other metals from asphalt composites with the addition of slag was negligible. Therefore, the investigated EAF slag can be considered as environmentally safe substitute for natural aggregates in asphalt mixes.

  2. SLAG CHARACTERIZATION AND REMOVAL USING PULSE DETONATION TECHNOLOGY DURING COAL GASIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    DR. DANIEL MEI; DR. JIANREN ZHOU; DR. PAUL O. BINEY; DR. ZIAUL HUQUE

    1998-07-30

    Pulse detonation technology for the purpose of removing slag and fouling deposits in coal-fired utility power plant boilers offers great potential. Conventional slag removal methods including soot blowers and water lances have great difficulties in removing slags especially from the down stream areas of utility power plant boilers. The detonation wave technique, based on high impact velocity with sufficient energy and thermal shock on the slag deposited on gas contact surfaces offers a convenient, inexpensive, yet efficient and effective way to supplement existing slag removal methods. A slight increase in the boiler efficiency, due to more effective ash/deposit removal and corresponding reduction in plant maintenance downtime and increased heat transfer efficiency, will save millions of dollars in operational costs. Reductions in toxic emissions will also be accomplished due to reduction in coal usage. Detonation waves have been demonstrated experimentally to have exceptionally high shearing capability, important to the task of removing slag and fouling deposits. The experimental results describe the parametric study of the input parameters in removing the different types of slag and operating condition. The experimental results show that both the single and multi shot detonation waves have high potential in effectively removing slag deposit from boiler heat transfer surfaces. The results obtained are encouraging and satisfactory. A good indication has also been obtained from the agreement with the preliminary computational fluid dynamics analysis that the wave impacts are more effective in removing slag deposits from tube bundles rather than single tube. This report presents results obtained in effectively removing three different types of slag (economizer, reheater, and air-heater) t a distance of up to 20 cm from the exit of the detonation tube. The experimental results show that the softer slags can be removed more easily. Also closer the slag to the exit of

  3. A Microstructure Based Strength Model for Slag Blended Concrete with Various Curing Temperatures

    Directory of Open Access Journals (Sweden)

    Li-Na Zhang

    2016-01-01

    Full Text Available Ground granulated blast furnace slag, which is a byproduct obtained during steel manufacture, has been widely used for concrete structures in order to reduce carbon dioxide emissions and improve durability. This paper presents a numerical model to evaluate compressive strength development of slag blended concrete at isothermal curing temperatures and time varying curing temperatures. First, the numerical model starts with a cement-slag blended hydration model which simulates both cement hydration and slag reaction. The accelerations of cement hydration and slag reaction at elevated temperatures are modeled by Arrhenius law. Second, the gel-space ratios of hardening concrete are calculated using reaction degrees of cement and slag. Using a modified Powers’ gel-space ratio strength theory, the strength of slag blended concrete is evaluated considering both strengthening factors and weakening factors involved in strength development process. The proposed model is verified using experimental results of strength development of slag blended concrete with different slag contents and different curing temperatures.

  4. Effects of Carbo-Nitridation Process of Ti-Bearing Blast Furnace Slag on Iron Content

    Science.gov (United States)

    Shi, Z.; Zhang, X. M.; Xu, Y.

    In order to prepare corrosion-resistant refractory material, experiment chooses Ti-bearing Blast Furnace Slag as raw materials which were treated by the method of carbo-nitridation. Finally, the corrosion resistance properties of the material can be improved by this method. The carbo-nitridation process affects the iron content of the slag in the study, which have a beneficial effect on the synthesis of Ti (C. N). The results indicated that the iron content of the slag significantly increased in process of Ti (C. N) synthesis: and the iron content of slag showed an upward trend with the increase of holding time.

  5. Gasification slag rheology and crystalline phase formation in titanium-calcium-alumina-silica-rich glass

    Energy Technology Data Exchange (ETDEWEB)

    Brooker, D.D. [Texaco, Inc., Beacon, NY (United States); Oh, M.S. [Hongik Univ., Seoul (Korea, Republic of)

    1996-10-01

    The Texaco Gasification Process employs a high temperature and pressure slagging gasifier, in which the viscosity of the slag plays a key role in determining operating conditions. The empirical models available in the literature as well as laboratory testing have concentrated on low titanium feeds. During the gasification of waste material, titanium oxide will become an important element in controlling the ash and slag behavior. Slag viscosity was measured at temperatures in the range of 1150-1500{degrees}C under reducing atmosphere with 0-30% titanium in combination with calcium-alumina-silica rich feeds to gain a better understanding of the slag theology. The slag viscosities with most titanium-rich slags showed the behavior of a crystalline slag with T{sub cv} of 1250{degrees}C. Crystalline phase analyses of the slag samples revealed that titanium oxide crystal will nucleate, but the glass phase is dominated by calcium-titanium-silicate and calcium-alumina-silicate glasses which have low melting points.

  6. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    Directory of Open Access Journals (Sweden)

    Živković Živan

    2009-01-01

    Full Text Available This paper presents the results of multi-linear regression analysis (MLRA of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3 and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974. This indicates that slag composition and content of copper in the matte influences the copper losses in the waste slag with the probability of 95 %.

  7. Stabilization effects of surplus soft clay with cement and GBF slag

    Institute of Scientific and Technical Information of China (English)

    LU Jiang; Chirdchanin MODMOLTIN; Katsutada ONITSUKA

    2004-01-01

    Utilization of industrial waste and surplus construction soft clay as construction material was recommended, and many attempts at geotechnical waste utilization were undertaken. This study aimed at the application of cement and a kind of industrial wastes, i.e. granulated blast furnace slag, on stabilization of surplus soft clay. The results showed that the cement and slag can successfully stabilize Ariake clays even though this high organic clay fails to be stabilized by lime and cement. Addition of slag in cement for stabilization induces higher strength than cement alone for longer curing time. The application of the cement with slag is more suitable than cement alone for stabilization because of economical consideration.

  8. Use of copper slag in glass-epoxy composites for improved wear resistance.

    Science.gov (United States)

    Biswas, Sandhyarani; Satapathy, Alok

    2010-07-01

    Copper slag is a by-product obtained during matte smelting and refining of copper. The common management options for copper slag are recycling, recovery of metal and production of value-added products. In the present study using copper slag as a filler in glass-epoxy composites, the tensile modulus increased from 8.77 GPa to 9.64 GPa when using up to 10 wt% of copper slag but on further addition of copper slag (up to 20 wt%), the tensile modulus started to decrease down to 7.11 GPa. Similar trends were observed in the case of flexural strength and interlaminar shear strength. With the incorporation of copper slag particles, the impact strength increased about 10-15%. This work includes the processing, characterization and study of the erosion behaviour of a class of such copper slag filled glass-epoxy composites based on Taguchi's experimental approach to characterise erosion behaviour. The results show that peak erosion takes place at an impingement angle of 60 degrees for the unfilled composites whereas for the copper slag filled glass-epoxy composites it occurs at a 45 degrees impingement angle. This paper considers the possible utilisation of copper slag as filler material for the preparation of composite materials and preparation of added-value products such as abrasive tools, cutting tools and railroad ballast.

  9. Technological progress on detoxification and comprehensive utilization of chromium-containing slag

    Institute of Scientific and Technical Information of China (English)

    柴立元; 何德文; 于霞; 刘恢; 闵小波; 陈为亮

    2002-01-01

    Chromium salt is an important industrial material, but vast waste slag containing chrome(Ⅵ) is brought out in the process of its production. The slag is seriously harmful to environments and human health. The technologies on detoxification and comprehensive utilization of chromium-containing slag were summarized abroad and at home. And various methods were also described for the detoxification mechanism, technology process, and practical application effects in detail. A new concept for detoxification of chromium-containing slag, furthermore, was put forward by using microorganism.

  10. The Early Strength of Slag Cements with Addition of Hydrate Microcrystals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of hydrate microcrystals such as calcium silicate hydrates (CSH) and ettringite on the early strength of slag cements was studied.The authors explored the possibility of improving the early strength of the slag cement by applying crystal seed technology.It is shown that slag crystal seeds make the early strength of the cement increased due to the action of hydrate crystal seeds,which speed up the hydration of clinker minerals in the nucleation of ettringite.Therefore,the early strength of the slag cement is obviously improved.

  11. Use of steel slag as a granular material: volume expansion prediction and usability criteria.

    Science.gov (United States)

    Wang, George; Wang, Yuhong; Gao, Zhili

    2010-12-15

    The theoretical equation for predicting volume expansion of steel slag is deduced based on both chemical reaction and physical changes of free lime in steel slag during the hydration process. Laboratory volume expansion testing is conducted to compare the results with the theoretical volume expansion. It is proved that they correlated well. It is furthermore experimentally proved that certain volume expansion of steel slag can be absorbed internally by the void volume in bulk steel slag under external surcharge weight making the apparent volume expansion equal zero. The minimum (lowest) absorbable void volume is approximately 7.5%, which is unrelated to the free lime content. A usability criterion is then developed based on the volume expansion of steel slag (%) and the minimum percentage of the volume that can take the volume expansion of steel slag (%). Eventually the criterion (relationship) is established based on the free lime content, the specific gravity and bulk relative gravity of a specific steel slag sample. The criteria can be used as guidance and specification for the use of steel slag and other expansion-prone nonferrous slags, copper, nickel for instance as a granular material in highway construction.

  12. Comparison of possibilities the blast furnace and cupola slag utilization by concrete production

    Directory of Open Access Journals (Sweden)

    D. Baricová

    2010-04-01

    Full Text Available In process of pig iron and cast iron production secondary raw materials and industrial wastes are formed The most abundant secondaryproduct originating in these processes are furnace slag. Blast furnace slag and cupola furnace slag originates from melting of gangue parts of metal bearing materials, slag forming additions and coke ash. In general, slag are compounds of oxides of metallic and non-metallic elements, which form chemical compounds and solutions with each other and also contain small volume of metals, sulfides of metals and gases. Chemical, mineralogical and physical properties of slag determinate their utilisation in different fields of industry.The paper presents results from the research of the blast furnace and cupola furnace slag utilization in the concrete production. Pilotexperiments of the concrete production were performed, by that the blast furnace and cupola furnace slag with a fractions of 0–4mm;4–8mm; 8–16mm were used as a natural substitute. A cupola furnace slag and combination of the blast furnace and cupola furnace slagwere used in the experiments. The analysis results show that such concretes are suitable for less demanding applications.

  13. Performance of steel-making slag concrete reinforced with fibers

    OpenAIRE

    Ortega-López Vanesa; Fuente-Alonso José Antonio; Skaf Marta; Santamaría Amaia; Aragón Ángel; Manso Juan Manuel

    2017-01-01

    In this research, the possibility of making concrete reinforced with fibers and manufactured with recycled aggregates from carbon steel production was explored. Electric arc furnace slag (EAFS) was used as coarse and medium aggregate, and part of the sand sizes. Metallic and synthetic fibers were added in different amounts. Initially, the properties of EAFS and their suitability to be used in the manufacture fiber reinforced concrete were analysed. Then, a series of fiber reinforced concrete ...

  14. Experimental Research on Calcium Aluminate Desulphurizer Slags%铝酸钙脱硫渣系的实验研究

    Institute of Scientific and Technical Information of China (English)

    袁守谦; 郭强; 王伟; 梁德安

    2011-01-01

    The desulphurizer of CaO-Al2O3-CaF2 was researched in laboratory. The results show that increasing the contents of pre-melted desulphurizer can increase the velocity and ratio of desulfurization. In the meanwhile, elevating temperature of liquid steel can increase desulfurization degree; the S-content can decrease to a relative low level (0.026wt) in 10 minutes at 1620℃. The desulphurization effect using calcium aluminate desulphurizer slags with CaO is superior to that using pure 12CaO. 7Al2O3 slag, while the additive amount of CaO is 10wt , the desulphurizatien effect is best. Therefore the calcium aluminate desulphurizer slags with CaO can be used as a high efficient, high speed and an environmental friendly desulphurizer.%在实验室的条件下,对用CaO、Al2O3、CaF2为原料配制的钢水脱硫剂进行了实验研究.研究发现,增加预熔脱硫剂量,可提高脱硫速度,增大脱硫率.提高钢水温度可以增大脱硫效率,在1620℃下,10min就可将钢液中的硫降低到0.026wt%的较低水平.添加CaO的铝酸钙预熔渣的脱硫效果明显优于纯12CaO·7Al2O3渣系,加氧化钙含量为10wt%时,整体脱硫效果最好.此预熔合成渣原料将可能成为一种高效、快速、环保的脱硫剂.

  15. Slag characterization and removal using pulse detonation for coal gasification. Quarterly research report, July 1--September 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Z.; Mei, D.; Biney, P.O.; Zhou, J.; Ali, M.R.

    1996-10-25

    Boiler slagging and fouling as a result of inorganic impurities in combustion gases being deposited on heat transfer tubes have caused severe problems in coal-fired power plant operation. These problems are fuel, system design, and operating condition dependent. Conventional slag and ash removal methods include the use of in situ blowing or jet-type devices such as air or steam soot blowers and water lances. Pulse detonation technology for the purpose of removing slag and fouling deposits in coal-fired utility power plant boilers offers great potential. The detonation wave technique based on high impact velocity with sufficient energy and thermal shock on the slag deposited on gas contact surfaces offers a convenient, inexpensive, yet efficient and effective way to supplement existing slag removal methods. These detonation waves have been demonstrated experimentally to have exceptionally high shearing capability important to the task of removing slag and fouling deposits. Several tests have been performed with single shot detonation wave at University of Texas at Arlington to remove the slag deposit. To hold the slag deposit samples at the exit of detonation tube, two types of fixture was designed and fabricated. They are axial arrangement and triangular arrangement. The slag deposits from the utility boilers have been used to prepare the slag samples for the test. The experimental results show that the single shot detonation wave is capable of removing the entire slag (types of slag deposited on economizer, and air-heater, i.e., relatively softer slags) and 30% of the reheater slag (which is harder) even at a distance of 6 in. from the exit of a detonation engine tube. Wave strength and slag orientation also have different effects on the chipping off of the slag. The annual report discusses about the results obtained in effectively removing the slag.

  16. Sulfide Capacity in Ladle Slag at Steelmaking Temperatures

    Science.gov (United States)

    Allertz, Carl; Sichen, Du

    2015-12-01

    Sulfide capacity measurements were conducted at 1823 K and 1873 K (1550 °C and 1600 °C) for the quaternary Al2O3-CaO-MgO-SiO2 system, for typical compositions used in the ladle in steelmaking. A copper-slag equilibrium was used under controlled oxygen and sulfur potentials. The sulfide capacity is strongly dependent on the composition and it was found to increase with the basic oxides, while it decreases with increase of the acidic components. It was found that CaO is more effective in holding sulfur in the slag compared to MgO when replacing SiO2. For the present slag compositions, Al2O3 and SiO2 behaved similar with respect to sulfur, and no considerable effect could be recorded when replacing one for the other. The sulfide capacity was also found to be strongly dependent on the temperature, increasing with temperature. The present results were compared with industrial data from the ladle, after vacuum treatment, and they were in good agreement.

  17. Alternative concrete based on alkali-activated slag

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2008-09-01

    Full Text Available This article reports the results of related to on the performance of concrete made with waterglass (Na2SiO3•nH2O + NaOH-activated Colombian granulated blast furnace slag. The mechanical strength and durability properties this alkali-activated slag concrete (AAS were compared to the properties of ordinary Portland cement concrete (OPC with the same proportion of binder, which ranged from 340 to 512 kg per m3 of concrete. The results indicated that increasing the proportion of slag led to improvements in the properties studied.El propósito de este artículo es dar a conocer los resultados de la evaluación del comportamiento de mezclas de hormigón producidas a partir de la activación con waterglass (Na2SiO3•nH2O + NaOH de una escoria siderúrgica granulada de alto horno colombiana. Las propiedades mecánicas y de durabilidad de los hormigones activados alcalinamente (AAS se comparan con las correspondientes mezclas de hormigón de cemento Portland (OPC producidas con igual proporción de ligante. Estas proporciones variaron entre 340 y 512 kg por m3 de hormigón. Los resultados obtenidos indican que incrementos en la proporción de la escoria contribuye a la mejora de las propiedades evaluadas.

  18. Blasted copper slag as fine aggregate in Portland cement concrete.

    Science.gov (United States)

    Dos Anjos, M A G; Sales, A T C; Andrade, N

    2017-07-01

    The present work focuses on assessing the viability of applying blasted copper slag, produced during abrasive blasting, as fine aggregate for Portland cement concrete manufacturing, resulting in an alternative and safe disposal method. Leaching assays showed no toxicity for this material. Concrete mixtures were produced, with high aggregate replacement ratios, varying from 0% to 100%. Axial compressive strength, diametrical compressive strength, elastic modulus, physical indexes and durability were evaluated. Assays showed a significant improvement in workability, with the increase in substitution of fine aggregate. With 80% of replacement, the concrete presented lower levels of water absorption capacity. Axial compressive strength and diametrical compressive strength decreased, with the increase of residue replacement content. The greatest reductions of compressive strength were found when the replacement was over 40%. For tensile strength by diametrical compression, the greatest reduction occurred for the concrete with 80% of replacement. After the accelerated aging, results of mechanic properties showed a small reduction of the concrete with blasted copper slag performance, when compared with the reference mixture. Results indicated that the blasted copper slag is a technically viable material for application as fine aggregate for concrete mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Application of Improved HMM Algorithm in Slag Detection System

    Institute of Scientific and Technical Information of China (English)

    TAN Da-peng; LI Pei-yu; PAN Xiao-hong

    2009-01-01

    To solve the problems of ladle slag detection system (SDS),such as high cost,short service life,and inconvenient maintenance,a new SDS realization method based on hidden Markov model (HMM) was put forward.The physical process of continuous casting was analyzed,and vibration signal was considered as the main detecting signal according to the difference in shock vibration generated by molten steel and slag because of their difference in density.Automatic control experiment platform oriented to SDS was established,and vibration sensor was installed far away from molten steel,which could solve the problem of easy power consumption by the sensor.The combination of vector quantization technology with learning process parameters of HMM was optimized,and its revaluation formula was revised to enhance its recognition effectiveness.Industrial field experiments proved that this system requires low cost and little rebuilding for current devices,and its slag detection rate can exceed 95 %.

  20. The Chloride Permeability of Persulphated Phosphogypsum-Slag Cement Concrete

    Institute of Scientific and Technical Information of China (English)

    HUANG Youqiang; LU Jianxin; CHEN Feixiang; SHUI Zhonghe

    2016-01-01

    The chloride permeability and microstructure of persulphated phosphogypsum-slag cement concrete (PPSCC), the Portland slag cement concrete (PSCC) and ordinary Portland cement concrete (OPCC) were investigated comparatively. Some test methods were used to evaluate the chloride permeability and explain the relationship between the permeability and microstructure of concrete. The results show that the resistance to chloride penetration in PPSCC is signiifcantly better than that in OPCC, the reasons are as follows: 1) the slag in PPSCC is activated by clinker (alkali activation) and phosphogypsum (sulfate activation), forming more low Ca/Si C-S-H gel and gel pores below 10 nm than OPCC, improving the resistance to chloride penetration; 2) the hydration products of PPSCC have a much stronger binding capacity for chloride ions; and 3) in the same mix proportion, PPSCC has a better workability without large crystals calcium hydroxide in the hydration products, the interfacial transition zone (ITZ) is smoother and denser, which can cut off the communicating pores between the pastes and aggregates.

  1. Alkali Aggregate Reaction in Alkali Slag Cement Mortars

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By means of "Mortar Bar Method",the ratio of cement to aggregate was kept as a constant 1∶2.25,the water-cement ratio of the mixture was 0.40,and six prism specimens were prepared for each batch of mixing proportions with dimensions of 10×10×60mm3 at 38±2℃ and RH≥95%, the influences of content and particle size of active aggregate, sort and content of alkali component and type of slag on the expansion ratios of alkali-activated slag cement(ASC) mortars due to alkali aggregate reaction(AAR) were studied. According to atomic absorption spectrometry,the amount of free alkali was measured in ASC mortars at 90d.The results show above factors affect AAR remarkably,but no dangerous AAR will occur in ASC system when the amount of active aggregate is below 15% and the mass fraction of alkali is not more than 5% (Na2O).Alkali participated in reaction as an independent component, and some hydrates containing alkali cations were produced, free alkalis in ASC system can be reduced enormously.Moreover,slag is an effective inhibitor, the possibility of generating dangerous AAR in ASC system is much lower at same conditions than that in ordinary Portland cement system.

  2. Simulation of past exposure in slag wool production.

    Science.gov (United States)

    Fallentin, B; Kamstrup, O

    1993-08-01

    A survey of the working conditions at a Danish slag wool production factory during the early technological phase in the 1940s is presented. No exposure data, however, are available for that period. So, a full-scale simulation of the past production of slag wool has been performed. Air monitoring was carried out in the working area around the cupola furnace. The aim was to measure exposure to air pollutants other than fibres. Such exposure might have confounded a possible association between lung cancer and exposure to fibres, in the early technological phase of slag wool production. The simulation experiment demonstrated exposure to PAH, a known lung carcinogen. The effect of other concurrent exposures is difficult to assess. Time-weighted average concentrations of particulate material ranged between 12.9 and 49.1 mg m-3 at the upper decks around the cupola. Corresponding concentrations of the dominant metals zinc and lead were 4.4-22.7 mg Zn m-3 and 0.9-4.7 mg Pb m-3. Significant concentrations of PAH up to 269 micrograms PAH m-3 (4 micrograms BaP m-3) occurred during ignition of the cupola furnace. The carbon monoxide level reached 270 ppm also during ignition.

  3. Speciation of copper in the thermally stabilized slag

    Energy Technology Data Exchange (ETDEWEB)

    Tuan, Y.-J. [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Paul Wang, H., E-mail: wanghp@mail.ncku.edu.t [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Chang, J.-E. [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Chao, C.-C. [Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Tsai, C.-K. [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2010-07-21

    The Taiwan universities laboratory hazardous wastes have been treated by incineration at the temperature range of 1173-1273 K. By X-ray absorption near edge structure (XANES) spectroscopy, mainly CuO and CuSO{sub 4} are found in the incineration bottom and fly ashes. The incineration fly ash can be stabilized thermally at 1773 K in the plasma melting reaction chamber (integrated with the incinerator), and converted to slag. The concentration of leachable copper in the slag is reduced significantly mainly due to the fact that copper is encapsulated in the SiO{sub 2} matrix. In addition, the refined extended X-ray adsorption fine structure (EXAFS) spectra of copper also indicate formation of the Cu-O-Si species in the slag as the bond distances of 1.95 A for Cu-O and 2.67 A for O-Si are observed. This work exemplifies utilization of the synchrotron X-ray absorption spectroscopy to facilitate the thermal stabilization treatments of the fly ash hazardous waste using the plasma melting method.

  4. Estimation of slagging in furnaces; Kuonaavuuden ennustaminen kivihiilen poelypoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, T.; Jaeaeskelaeinen, K.; Oeini, J.; Koskiahde, A.; Jokiniemi, J.; Pyykkoenen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-10-01

    Understanding and estimation of slagging in furnaces is essential in the design of new power plants with high steam values or in modifications like low-NO{sub x} retrofits in existing furnaces. Major slagging yields poor efficiency, difficult operation and high maintenance costs of the plant. The aim of the project is to develop a computational model for slagging in pulverized coal combustion. The model is based on Computer Controlled Scanning Electron Microscopy (CCSEM) analysis of mineral composition of the coal and physical models for behaviour of minerals inside a furnace. The analyzed mineral particles are classified to five composition classes and distributed to calculational coal particles if internal minerals of coal. The calculational coal particles and the external minerals are traced in the furnace to find out the behaviour of minerals inside the furnace. If the particle tracing indicates that the particle hits the heat transfer surface of the furnace the viscosity of the particle is determined to see if particle is sticky. The model will be implemented to 3D computational fluid dynamics based furnace simulation environment Ardemus which predicts the fluid dynamics, heat transfer and combustion in a furnace. (orig.)

  5. Interfacial tension studies between Fe-Cu-Ni sulfide and halo-norilsk basalt slag system

    Institute of Scientific and Technical Information of China (English)

    SU Shangguo; Jim Mungall; WANG Jian; GENG Ke

    2005-01-01

    The interfacial tension of the matte/halo-Norilsk basalt slag systems of FeS-Cu2S-Ni3S2 and FeO-FeS were investigated using the sessile drop technique. The results indicate that interfacial tension decreases with increasing copper and nickel contents in the matte of FeS-Cu2S-Ni3S2 system while it increases with increasing oxygen content in the matte of FeO-FeS system. It is inferred from these results that two conditions are critical for the formation of giant Cu-Ni sulfide deposits. One is that mafic-ultramafic parent magma of sulfide deposits should be rich in copper and nickel where due to the low interfacial tension, it is difficult to form sulfide droplet in the early stage of magma evolution. In other words, sulfide liquid conglomeration occurs more difficultly. The other condition is that the magma emplacement should be shallow; and a lot of faults occur in the magma emplacement field. Since oxygen content is high in the environment, interfacial tension is high, which helps sulfide liquid conglomeration and consequently Cu-Ni sulfide deposits form.

  6. Schwinger boson approach to the fully screened Kondo model.

    Science.gov (United States)

    Rech, J; Coleman, P; Zarand, G; Parcollet, O

    2006-01-13

    We apply the Schwinger boson scheme to the fully screened Kondo model and generalize the method to include antiferromagnetic interactions between ions. Our approach captures the Kondo crossover from local moment behavior to a Fermi liquid with a nontrivial Wilson ratio. When applied to the two-impurity model, the mean-field theory describes the "Varma-Jones" quantum phase transition between a valence bond state and a heavy Fermi liquid.

  7. Distribution of Phosphorus between CaO-CaF2 Slag and Fe-C-P Melt

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-xiang; ZHOU Jian-jian; DU Xiao-jian

    2005-01-01

    The equilibrium distribution ratio of phosphorus between CaO-CaF2 molten slag and Fe-C-P melt at 1450 ℃ was measured. The phosphate capacity of slag and the activity coefficient of phosphorus oxide were calculated.

  8. Thermodynamic simulation of the effect of slag chemistry on the corrosion behavior of alumina-chromia refractory

    Institute of Scientific and Technical Information of China (English)

    Shi-xian Zhao; Bin-li Cai; Hong-gang Sun; Gang Wang; Hong-xia Li; and Xiao-yan Song

    2016-01-01

    The corrosion behavior of alumina–chromia refractory against two kinds of industrial slags (coal slag and iron smelting slag) at 1550°C was investigated via thermodynamic simulations. In the proposed simulation model, the initial slag first attacks the matrix and sur-face aggregates and subsequently attacks the inner aggregates. The simulation results indicate that the slag chemistry strongly affects the phase formation and corrosion behavior of the refractory brick. Greater amounts of alumina were dissolved and spinel solid phases formed when the brick interacted with iron smelting slag. These phenomena, as well as the calculated lower viscosity, may lead to much deeper penetration than that exhibited by coal slag and to more severe corrosion compared to that induced by coal slag. The thermodynamic calcula-tions well match the experimental observations, demonstrating the efficiency of the proposed simulation model for evaluating the corrosion behavior of alumina–chromia refractory.

  9. Carbon fibre-reinforced, alkali-activated slag mortars

    Directory of Open Access Journals (Sweden)

    Garcés, P.

    2007-12-01

    Full Text Available The paper describes the effect of carbon fibre on alkaliactivated slag mortar (AAS mechanical strength, volume stability and reinforcing steel corrosion, compared to its effect on the same properties in Portland cement (PC properties. Mechanical strength and volume stability tests were performed as set out in the respective Spanish UNE standards. The corrosion rate of steel embedded in the specimens studied was determined from polarization resistance analysis. One of the findings of the study performed was that carbon fibre failed to improve AAS or CP mortar strength. As far as volume stability is concerned, the inclusion of carbon fibres in AAS with a liquid/solid ratio of 0.5 reduced drying shrinkage by about 50%. The effect of carbon fibre on PC mortars differed from its effect on AAS mortars. Studies showed that in the presence of carbonation, steel corrosion reached higher levels in carbon-fibre reinforced AAS mortars; the inclusion of 1% carbon fibre improved corrosion resistance perceptibly in these same mortars, however, when exposed to chloride attack.Se ha estudiado el efecto de la incorporación de fibras de carbón en el comportamiento mecánico, estabilidad de volumen y nivel de corrosión de la armadura en morteros de escorias activadas alcalinamente (AAS. Se evalúa la influencia de las fibras de carbón en el comportamiento de morteros alcalinos en comparación con el efecto que producen en morteros de Portland (CP. Los ensayos mecánicos y de estabilidad de volumen se han realizado según lo establecido en la norma UNE que los regula. Se ha utilizado la técnica de la Resistencia a la Polarización para determinar la velocidad de corrosión del acero embebido en las muestras estudiadas. Como consecuencia del estudio realizado, se ha podido concluir que la adición de fibras de carbón a morteros de AAS y CP no mejora las características resistentes de los mismos. En relación con la estabilidad de volumen, la incorporación de

  10. Geophysical Investigation of Buried Slag at the Parrot Tailings Site, Butte, Montana

    Science.gov (United States)

    Ha, C. D. M.; Shepherd, K.; Mack, A.; Rutherford, B. S.; Speece, M. A.

    2016-12-01

    Butte, Montana, has served as an important mining district for more than 120 years. This area contains historic mine waste from decades of unregulated mining practices. In July 1881, the Parrot smelter in Butte started operations and was soon processing ore and producing copper. The Parrot smelter also had a concentrating plant that treated the ore prior to smelting. The Parrot smelter wastes (slag and tailings) were later covered with Berkeley Pit crushed quartz monzonite overburden. The slag is bricked because it was deposited hot and, as a consequence forms a laterally extensive, cohesive, hard body that is difficult to remove without blasting. With the mine waste being covered by unknown quantities of overburden and soil throughout the area, and core data being limited and expensive to retrieve, the only economical method of discovery is geophysics. Several geophysical techniques were used to determine the lateral boundaries and depth of the buried slag body. The geophysical methods used were seismic, gravity, electromagnetic induction, and magnetics. Not all of these geophysical surveys produced useful results due to the nature of the slag. For instance, electromagnetic induction could not distinguish between the slag and adjacent tailings; and, the microgravity profiles showed only a small gravitational field variation caused by the density contrast between slag and the surrounding tailings, sediment and granitic cover. On the other hand, the seismic surveys resulted in unexpected first arrival times that distinctly showed velocity variations due to the slag. In addition, the slag body produced a large magnetic response. Unpublished, proprietary well data allowed us to model the slag body from our magnetic data. This model was confirmed by projecting velocity tomograms, that we created using seismic diving waves, onto our magnetic models. Model results were combined to form a three-dimensional image of the slag body. These results will be used to help

  11. Recycling of residual IGCC slags and their benefits as degreasers in ceramics.

    Science.gov (United States)

    Iglesias Martín, I; Acosta Echeverría, A; García-Romero, E

    2013-11-15

    This work studies the evolution of IGCC slag grains within a ceramic matrix fired at different temperatures to investigate the effect of using IGCC slag as a degreaser. Pressed ceramic specimens from two clay mixtures are used in this study. The M1 mixture is composed of standard clays, whereas the M2 mixture is composed of the same clay mixture as M1 mixture but contains 15% by weight IGCC slag. The amount of IGCC slag added coincides with the amount of slag typically used as a degreaser in the ceramic industry. Specimens are fired at 950 °C, 1000 °C, 1050 °C, 1100 °C and 1150 °C. The mineralogical composition and the IGCC slag grain shape within the ceramic matrix are determined by X-ray diffraction, polarized light microscopy and scanning electron microscopy. The results reveal that the surface of the slag grains is welded to the ceramic matrix while the quartz grains are separated, which causes increased water absorption and reduces the mechanical strength. IGCC slag, however, reduces water absorption. This behaviour is due to the softening temperature of the slag. This property is quite important from an industrial viewpoint because IGCC slag can serve as an alternative to traditional degreasing agents in the ceramic building industry. Additionally, using IGCC slag allows for the transformation of waste into a secondary raw material, thereby avoiding disposal at landfills; moreover, these industrial wastes are made inert and improve the properties of ceramics.

  12. Synthesis of TiO2 visible light catalysts with controllable crystalline phase and morphology from Ti-bearing electric arc furnace molten slag.

    Science.gov (United States)

    Li, Yang; Liu, Lulu; Guo, Min; Zhang, Mei

    2016-09-01

    TiO2 visible light catalysts with different crystalline phases and morphologies were synthesized from titanium-bearing electric arc furnace molten slag (Ti-bearing EAF slag) by using a simple acidolysis process. The effects of the pH of the HCl solution, liquid to solid ratio (RL/S, HCl solution to the residue ratio, mL/g) and acidolysis time on the micro-morphology and crystalline phase of as-prepared TiO2 photocatalysts were systematically investigated. The results indicated that with decreasing pH in the HCl solution and increasing RL/S, the crystalline phase and micro-morphology of the obtained TiO2 nanostructures tended to transform from anatase type TiO2 with spherical nanoparticle structures to rutile type TiO2 with needle-like nanorod structures. The acidolysis time had little influence on the crystalline phase but great impact on the size of the obtained TiO2. The growth mechanism of TiO2 from Ti-bearing EAF slag during the acidolysis process was also discussed. In addition, the influence of RL/S on the photocatalytic properties of the synthesized nanostructured TiO2 was studied. The results showed that the photodegradation efficiency for Rhodamine B solution could reach 91.00% in 120min when the RL/S was controlled at 50:1.

  13. The Dissolution Kinetics of MgO into CaO-MgO-Fe2O3 Slag

    Science.gov (United States)

    Wei, Ruirui; Lv, Xuewei; Yue, Zhiwen; Xiang, Shenglin

    2017-02-01

    Calcium ferrite is the main binding phase for high-basicity sinter. The production and structure of calcium ferrite greatly influence the quality of the sinter. With the change in gangue composition, MgO becomes an important factor in the generation of calcium ferrite. In this study, the rotating cylinder method was used to study the dissolution kinetics of MgO into CaO-MgO-Fe2O3 melt. The experimental variables included the temperature, the initial composition of the melt, the Fe2O3/CaO mass ratio, the rotation time, and the rotation speed. The results indicate that the dissolution rate increases with increasing dissolution time, temperature, and rotation speed but decreases with increasing MgO content and Fe2O3/CaO mass ratio in the initial slag. The dissolution rate was observed to increase and then decrease with the addition of SiO2 in the initial slag. The activation energy and diffusion coefficient for MgO dissolution were found to range from 117.31 to 234.24 kJ mol-1 and from 1.03 × 10-6 to 1.18 × 10-5 cm2 s-1, respectively. The concentration difference between the solid and liquid phases is the main driving force for dissolution, but the viscosity and magnesium ion diffusivity of the melt also affect the process.

  14. Direct Extraction of Ti and Ti Alloy from Ti-Bearing Dust Slag in Molten CaCl2

    Science.gov (United States)

    Chen, Chaoyi; Zhao, Chong; Li, Junqi; Yang, Shufeng

    2016-06-01

    Using process of solid oxygen-ion conducting membrane (SOM), titanium metal and its alloy can be prepared directly from Ti-bearing dust slag by immersing it in the molten CaCl2 at 1,100℃, which has been proposed by constant voltage of 3.5 V for 2-6 h. The dust slag was ball-milled and pressed into pellets, then employed as the cathode, while the liquid copper, which was saturated with graphite powder and encased in yttria-stabilized zirconia (YSZ) tube, acted as the anode. The effect of forming pressure and electrolytic time on products was analyzed. The results show that the content of titanium increased with electrolytic time and the characteristic morphology presents as granule. Ti-Fe alloy can be obtained from Ti-Fe residue by 6 h electrolysis. For titanium-rich residue, when the forming pressure of pellets decreased from 6 to 3 MPa, only electrolysis for more than 4 h can completely remove the oxygen, and pure titanium is obtained by 6 h electrolysis. Besides, there is an unprecedented finding that the porous cathode is conducive to the removal of impurity elements.

  15. Utilization of lightweight materials made from coal gasification slags. Quarterly report, December 1, 1995--February 28, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The project scope consists of collecting a 20-ton sample of slag (primary slag), processing it for chart removal, and subjecting it to pyroprocessing to produce expanded slag aggregates of various size gradations and unit weights, ranging from 12 to 50 lb/fg{sup 3}. A second smaller slag sample will be used for confirmatory testing. The expanded slag aggregates will then be tested for their suitability in manufacturing precast concrete products (e.g., masonry blocks and roof tiles) and insulating concrete, first at the laboratory scale and subsequently in commercial manufacturing plants. These products will be evaluated using ASTM and industry test methods. Technical data generated during production and testing of the products will be used to assess the overall technical viability of expanded slag production. In addition, a market assessment will be made based on an evaluation of both the expanded slag aggregates and the final products, and market prices for these products will be established in order to assess the economic viability of these utilization technologies. Relevant cost data for physical and pyroprocessing of slag to produce expanded slag aggregates will be gathered for comparison with (1) the management and disposal costs for slag or similar wastes and (2) production costs for conventional materials which the slag aggregates would replace. This will form the basis for an overall economic evaluation of expanded slag utilization technologies.

  16. Experimental Investigation of Gas/Slag/Matte/Tridymite Equilibria in the Cu-Fe-O-S-Si System in Controlled Atmospheres: Development of Technique

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hidayat, Taufiq; Hayes, Peter C.; Jak, Evgueni

    2017-08-01

    The majority of primary pyrometallurgical copper making processes involve the formation of two immiscible liquid phases, i.e., matte product and the slag phase. There are significant gaps and discrepancies in the phase equilibria data of the slag and the matte systems due to issues and difficulties in performing the experiments and phase analysis. The present study aims to develop an improved experimental methodology for accurate characterisation of gas/slag/matte/tridymite equilibria in the Cu-Fe-O-S-Si system under controlled atmospheres. The experiments involve high-temperature equilibration of synthetic mixtures on silica substrates in CO/CO2/SO2/Ar atmospheres, rapid quenching of samples into water, and direct composition measurement of the equilibrium phases using Electron Probe X-ray Microanalysis (EPMA). A four-point-test procedure was applied to ensure the achievement of equilibrium, which included the following: (i) investigation of equilibration as a function of time, (ii) assessment of phase homogeneity, (iii) confirmation of equilibrium by approaching from different starting conditions, and (iv) systematic analysis of the reactions specific to the system. An iterative improved experimental methodology was developed using this four-point-test approach to characterize the complex multi-component, multi-phase equilibria with high accuracy and precision. The present study is a part of a broader overall research program on the characterisation of the multi-component (Cu-Fe-O-S-Si-Al-Ca-Mg), multi-phase (gas/slag/matte/metal/solids) systems with minor elements (Pb, Zn, As, Bi, Sn, Sb, Ag, and Au).

  17. Study of Phase Relations of ZnO-Containing Fayalite Slag Under Fe Saturation

    Science.gov (United States)

    Shi, Huayue; Chen, Liugang; Malfliet, Annelies; Jones, Peter Tom; Blanpain, Bart; Guo, Muxing

    2016-10-01

    A ZnO-containing fayalite-based slag can be formed in copper smelting from secondary raw materials and its high viscosity is a common issue that hinders slag tapping. In this work, the crystallization behavior of the industrial slag was observed in situ by confocal laser scanning microscopy. Solid precipitation was found to be the major cause of the poor slag fluidity. The phase relations in the industrial slag system ZnO-"FeO"-SiO2-Al2O3-CaO (CaO/SiO2 = 0.05, Al2O3/SiO2 = 0.15) were investigated by quenching the samples after reaching equilibrium at 1423 K (1150 °C) under iron saturation. The equilibrium composition of the phases was determined with electron probe micro-analysis. The effect of individual components, such as FeO, ZnO, and CaO on the phase equilibrium of the slag system has been quantitatively studied. The relation between the solid-phase fraction and the chemical composition of the slag has been revealed. Suggestions to modify the slag composition toward low viscosity are provided.

  18. Physico-chemical characterization of steel slag. Study of its behavior under simulated environmental conditions.

    Science.gov (United States)

    Navarro, Carla; Díaz, Mario; Villa-García, María A

    2010-07-15

    The chemical and mineralogical composition of steel slag produced in two ArcelorMittal steel plants located in the North of Spain, as well as the study of the influence of simulated environmental conditions on the properties of the slag stored in disposal areas, was carried out by elemental chemical analysis, XRF, X-ray diffraction, thermal analysis, and scanning electron microscopy with EDS analyzer. Spectroscopic characterization of the slag was also performed by using FTIR spectroscopy. Due to the potential uses of the slag as low cost adsorbent for water treatment and pollutants removal, its detailed textural characterization was carried out by nitrogen adsorption-desorption at 77 K and mercury intrusion porosimetry. The results show that the slag is a crystalline heterogeneous material whose main components are iron oxides, calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate), elemental iron, and quartz. The slags are porous materials with specific surface area of 11 m(2)g(-1), containing both mesopores and macropores. Slag exposure to simulated environmental conditions lead to the formation of carbonate phases. Carbonation reduces the leaching of alkaline earth elements as well as the release of the harmful trace elements Cr (VI) and V. Steel slags with high contents of portlandite and calcium silicates are potential raw materials for CO(2) long-term storage.

  19. Superconducting magnetic separation of ground steel slag powder for recovery of resources

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, H. W.; Kim, J. J.; Kim, Young Hun [Andong National University, Andong (Korea, Republic of); Ha, D. W. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of); Choi, J. H. [Dept. of Environmental Engineering, Catholic University of Pusan, Pusan (Korea, Republic of)

    2017-03-15

    Steel slag has been considered as an industrial waste. A huge amount of slag is produced as a byproduct and the steel slag usually has been dumped in a landfill site. However the steel slag contains valuable resources such as iron, copper, manganese, and magnesium. Superconducting magnetic separation has been applied on recovery of the valuable resources from the steel slag and this process also has intended to reduce the waste to be dumped. Cryo-cooled Nb-Ti superconducting magnet with 100 mm bore and 600 mm of height was used as the magnetic separator. The separating efficiency was evaluated in the function of magnetic field. A steel slag was ground and analyzed for the composition. Iron containing minerals were successfully concentrated from less iron containing portion. The separation efficiency was highly dependent on the particle size giving higher separating efficiency with finer particle. The magnetic field also effects on the separation ratio. Current study showed that an appropriate grinding of slag and magnetic separation lead to the recovery of metal resources from steel slag waste rather than dumping all of the volume.

  20. Substrate pH and butterfly bush response to dolomitic lime or steel slag amendment

    Science.gov (United States)

    Steel slag is a fertilizer amendment with a high concentration of calcium oxide, and thus capable of raising substrate pH similar to dolomitic lime. Steel slag, however, contains higher concentrations of some nutrients, such as iron, manganese, and silicon, compared to dolomitic lime. The objectiv...

  1. Heavy metal adsorption changes of EAF steel slag after phosphorus adsorption.

    Science.gov (United States)

    Song, Guanling; Cao, Lijing; Chen, Xiao; Hou, Wenhua; Wang, Qunhui

    2012-01-01

    A kind of electric arc furnace (EAF) steel slag was phosphated, and its isothermal and dynamic adsorptions of copper, cadmium, and lead ions were measured to determine if heavy metal adsorption changes after phosphorus adsorption. The surface area increased greatly after the slag was phosphated. Isothermal adsorption experiments showed that the theoretical Q(max) of the EAF steel slag on Cu(2+), Cd(2+), and Pb(2+) improved 59, 50, and 89% respectively after it was phosphated. Dynamic adsorption results showed that the greatest adsorption capacities of unit volume of Cu(2+), Cd(2+), and Pb(2+) were 2.2, 1.8, and 1.8 times that of the column packed with original EAF steel slag when the column was packed with phosphate EAF steel slag at the same heavy metal ion concentration. The breakthrough time, the exhaustion time and elution efficiency of the column also increased when the column was packed with phosphated EAF steel slag compared with that packed with original EAF steel slag. Phosphorus adsorption could further improve the heavy metal ion adsorption of the EAF steel slag.

  2. Behaviour of fibre reinforced concrete using steel slag coarse aggregate produced in Qatar

    Directory of Open Access Journals (Sweden)

    Alnahhal Wael

    2017-01-01

    Full Text Available The state of Qatar suffers from the shortage of natural resources needed for concrete production. Therefore, it is essential to investigate the feasibility of using by-product recycled materials as aggregates to maintain the concrete construction industry. Several types of recyclable materials are currently used in concrete. One of the potential resources of recycled concrete is steel slag. Knowing that Steel slag is the most significant solid waste generated by Qatar Steel Company in Qatar, replacing of natural coarse aggregate with steel slag aggregate will have a significant environmental and economic impact to the state of Qatar. This paper presents the compression and flexural test results of different concrete mixes made of steel slag coarse aggregate combined with a newly developed basalt chopped fibres. The parameters investigated included the volume fraction of the fibre used and the type of coarse aggregates (natural aggregates “Gabbro” and steel slag aggregates. Plain concrete specimens containing natural coarse aggregates and steel slag aggregates with no fibres added were also tested to serve as control. Test results showed that adding the basalt chopped fibres to the concrete mixes enhanced their flexural tensile strengths at different percentages. In addition, the compressive strength of concrete made with steel slag aggregate was higher than that made with natural gabbro aggregate. Test results clearly showed that steel slag aggregates can be used as sustainable and eco-friendly alternative materials in concrete structures.

  3. The Effect of Solid Constituent Particle Size Distributions on TP-H1148 Propellant Slag

    Science.gov (United States)

    May, Douglas H.; Miles, William L.; Taylor, David S.; Rackham, Jon L.

    1997-01-01

    Special aluminum and ammonium perchlorate (AP) particle size distributions were prepared for a matrix of five-inch diameter, center-perforated (CP) motor tests to measure the aluminum oxide slag response in Space Shuttle Reusable Solid Rocket Motor (RSRM) propellant. Previous tests of TP-H1148 propellant in five-inch CP spin motors have shown a correlation between aluminum particle size and generated slag. The motors for this study were cast from thirteen five-gallon propellant mixes which used five particle size levels of aluminum powder, five of unground AP and three of ground AP. Aluminum had the greatest effect on slag formation, the more coarse fractions causing greater slag quantities and larger slag particles. Unground AP had about half the effect of aluminum with the coarser fractions again producing more and larger sized slag particles. The variation in ground AP did not have a significant effect on slag formation. Quench bomb tests showed the same trends as the spin motors, that is, larger aluminum and AP particle size distributions generated larger slag particles leaving the propellant surface. Cured propellant mechanical properties were also impacted by particle size variation.

  4. Slag optimization in charcoal blast furnaces; Otimizacao de escorias de altos-fornos a carvao vegetal

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Luiz Fernando Andrade de; Tavares, Roberto Parreiras; Figueira, Renato Minelli; Lopes, Leonardo Braga Polido; Goncalves, Alexandre Ferreira [Associacao Brasileira de Metais (ABM), Sao Paulo, SP (Brazil)

    1987-12-31

    In this work, it is shown the optimum composition of charcoal blast furnace slag using phase diagrams. The results are compared with industrial data and some possible changes in slag composition and mass are also suggested. (author) 3 refs., 5 figs., 3 tabs.

  5. EFFECT OF USING STEEL SLAG AGGREGATE ON MECHANICAL PROPERTIES OF CONCRETE

    Directory of Open Access Journals (Sweden)

    Sultan A. Tarawneh

    2014-01-01

    Full Text Available This study presents an evaluation of the physical and mechanical properties and characteristics of steel slag aggregate concrete in comparison with the typical crushed limestone stone aggregate concrete. Hardened concrete consist of more than 70% aggregate due to the high demand in building construction and the increase of the amount of disposed waste material, suppliers and researchers are exploring the use of alternative materials which could preserve natural sources and save the environment. In this study, steel slag was used as an aggregate replacement in conventional concrete mixes. Steel slag which is mainly consists of calcium carbonate is produced as a by-product during the oxidation process in steel industry. Steel slag was selected due to its characteristics, which are almost similar to conventional aggregates and the fact that it is easily obtainable as a by-product of the steel industry. As a result, utilization of steel slag will save natural resources and clean environment. Furthermore, results have shown that slag aggregate has better abrasion factor and impact value than conventional aggregate. Thorough investigation of the results have indicated that the amount of increase in compressive strength at age of 7 days are much more than that of age 28 days for all types of aggregate replacement. This indicates that the added slag could work as accelerator at early age while at 28 days age, the effect is reduced. The fine slag replacement scores the highest effect.

  6. Heat Recovery from High Temperature Slags: A Review of Chemical Methods

    Directory of Open Access Journals (Sweden)

    Yongqi Sun

    2015-03-01

    Full Text Available Waste heat recovery from high temperature slags represents the latest potential way to remarkably reduce the energy consumption and CO2 emissions of the steel industry. The molten slags, in the temperature range of 1723–1923 K, carry large amounts of high quality energy. However, the heat recovery from slags faces several fundamental challenges, including their low thermal conductivity, inside crystallization, and discontinuous availability. During past decades, various chemical methods have been exploited and performed including methane reforming, coal and biomass gasification, and direct compositional modification and utilization of slags. These methods effectively meet the challenges mentioned before and help integrate the steel industry with other industrial sectors. During the heat recovery using chemical methods, slags can act as not only heat carriers but also as catalysts and reactants, which expands the field of utilization of slags. Fuel gas production using the waste heat accounts for the main R&D trend, through which the thermal heat in the slag could be transformed into high quality chemical energy in the fuel gas. Moreover, these chemical methods should be extended to an industrial scale to realize their commercial application, which is the only way by which the substantial energy in the slags could be extracted, i.e., amounting to 16 million tons of standard coal in China.

  7. Characterization and activation of the slag of El Hadjar's blast furnaces by clinkers

    Energy Technology Data Exchange (ETDEWEB)

    Guetteche, M.N.; Houari, H. [Constantine Univ. (France)

    2001-07-01

    The El Hadjar steel plant in Algeria produces about 430,000 tons of slag annually. This paper presents a study in which the granular slag of El Hadjar's blast furnace was characterized using a variety of analytical methods that made it possible to calculate hydraulic indices. El Hadjar slag is being promoted in the construction industry in an effort to address environmental concerns regarding the production of portland cement which is very energy intensive and which contributes to major greenhouse gas emissions into the atmosphere. The use of slag as an addition to portland cement or the manufacturing of clinker free binder would make this waste into a valuable product. Chemical analysis, x-ray diffraction, differential thermal analysis, Fourier transformer infrared spectrometry and conductimetry were used to better understand the vitreous structure of the slag and its hydraulic reactivity. Prismatic test tubes were used for the mechanical tests which involved clinkers of various grinding rates of slag. The results showed that slag is reactive and that the evolution of mechanical resistance to grinding is very sensitive. It was also shown that long term mechanical performance of the slag based ingredients are of significant interest to the cement and concrete industry. 9 refs., 9 tabs., 5 figs.

  8. Microstructure and Composition of Hydration Products of Ordinary Portland Cement with Ground Steel-making Slag

    Institute of Scientific and Technical Information of China (English)

    LI Yong-xin; CHEN Yi-min; ZHANG Hong-tao; HE Xing-yang; WEI Jiang-xiong; ZHANG Wen-sheng

    2003-01-01

    The effect of ground steel-making slag on microstructure and composition of hydration products of ordinary Portland cement (OPC) was investigated by mercury intrusion porosimetry ( MIP ), X- ray diffraction (XRD) and differential thermal analysis (DTA). Results show that ground steel-making slag is a kind of high activity mineral additives and it can raise the longer-age strength of OPC mortar. The total porosity and average pore diameter of OPC paste with groand steel-making slag increase with the increase of the amount of ground steelmaking slag replacing OPC at various ages, while after 28 days most pores in OPC paste with ground steel-making slag do not influeace the strength because the diameter of those pores is in the rang of 20 to 50nm. The hydration mechanism of ground steel-making slag is similar to that of OPC but different from that of fly ash and blast furnace slag. The hydration products of ground steel-making slag contain quite a lot of Ca( OH)2 in long age.

  9. Removal kinetics of phosphorus from synthetic wastewater using basic oxygen furnace slag.

    Science.gov (United States)

    Han, Chong; Wang, Zhen; Yang, He; Xue, Xiangxin

    2015-04-01

    Removal kinetics of phosphorus through use of basic oxygen furnace slag (BOF-slag) was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial pH, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant (kobs) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial pH, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage. A linear dependence of kobs on total removed phosphorus (TRP) was established with kobs=(3.51±0.11)×10(-4)×TRP. Finally, it was suggested that the Langmuir-Rideal (L-R) or Langmuir-Hinshelwood (L-H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.

  10. The Effect of Oxygen Potential on the Sulfide Capacity for Slags Containing Multivalent Species

    Science.gov (United States)

    Allertz, Carl; Selleby, Malin; Sichen, Du

    2016-10-01

    The dependence of sulfide capacity on the oxygen partial pressure for slags containing multivalent species was investigated experimentally using a slag containing vanadium oxide. Copper-slag equilibration experiments were carried out at 1873 K (1600 °C) in the approximate oxygen partial pressure range 10-15.4 to 10-9 atm. The sulfide capacity was found to be strongly dependent on the oxygen potential in this slag system, increasing with the oxygen partial pressure. The sulfide capacity changed by more than two orders of magnitude over the oxygen partial pressure range. The effect of changing oxygen partial pressure was found to be much greater than the effect of changing slag composition at a fixed oxygen partial pressure.

  11. Precipitation of metallic chromium during rapid cooling of Cr2O3 slags

    Directory of Open Access Journals (Sweden)

    J. Burja

    2017-01-01

    Full Text Available The slag systems of CaO-SiO2- Cr2O3 and Al2O3-CaO-MgO-SiO2- Cr2O3 were analyzed. These slag systems occur in the production of stainless steel and are important from the process metallurgy point of view. Synthetic slag samples with different chromium oxide content were prepared and melted. The melted slag samples where then rapidly cooled on large steel plates, so that the high temperature microstructure was preserved. The samples were analyzed by scanning electron microscopy (SEM and X-ray diffraction (XRD. The precipitation of different chromium oxide phases was studied, but most importantly the precipitation of metallic chromium was observed. These findings help us interpret industrial slag samples.

  12. Cementing properties of steel slag activated by sodium silicates and sodium hydroxide

    Institute of Scientific and Technical Information of China (English)

    Wen Ni; En Wang; Jianping Li; Han Sun

    2005-01-01

    Steel slag which is mainly composed of γ-CasSiO4 and other silicates or alumino-silicates is activated by sodium silicates and sodium hydroxide. The powders of such steel slag are usually inert to hydrate and subsequently have very low ability of cementing. But when sodium silicates and sodium hydroxide are used as activators the steel slag shows very good properties of cementing. When activated with NaOH solution the hardened slurry of the steel slag has a compressive strength of 11.13 MPa after being cured for 28 days. When activated with Na2SiO3 solution the samples after being cured for 28 days have an average compressive strength of 40.23 MPa. While the steel slag slurry which is only mixed with water has a compressive of 0.88 MPa after being cured for 28 days.

  13. Study on Mechanism of Reaction Between AOD Slag and Rebonded Magnesite—Chrome Brick

    Institute of Scientific and Technical Information of China (English)

    ZHAOYuxi; HEXiaoping

    2000-01-01

    The influence of the composition of AOD slag on the corrosion of rebonded magnesite-chrome brick has been studied by analyzing the residual bricks at the tuyere zone of AOD .It indicates that the corrosion degree increased with the increase of the basicity of slag and decreased with the increase of the content of MgO ,Cr2O3 and Al2O3 in slag.And the addition of refractories to slag up to satura-tion could decrease the corrosion abiliy of sag.It is important to make a resonable slagmaking rule and ensure the percentage of MgO in slag more than 11wt% for pro-longing the service life of lining.

  14. Laboratory Investigation of Fatigue Characteristics of Asphalt Mixtures with Steel Slag Aggregates

    Directory of Open Access Journals (Sweden)

    Hassan Ziari

    2015-01-01

    Full Text Available There are many steel-manufacturing factories in Iran. All of their byproducts, steel slag, are dumped randomly in open areas, causing many environmentally hazardous problems. This research is intended to study the effectiveness of using steel slag aggregate (SSA in improving the engineering properties, especially fatigue life of Asphalt Concrete (AC produced with steel slag. The research started by evaluating the physical properties of the steel slag aggregate. Then the 13 types of mixes which contain steel slag in portion of fine aggregates or in portion of coarse aggregates or in all portions of aggregates were tested. The effectiveness of the SSA was judged by the improvement in Marshall stability, indirect tensile strength, resilient modulus, and fatigue life of the AC samples. It was found that replacing the 50% of the limestone coarse or fine aggregate by SSA improved the mechanical properties of the AC mixes.

  15. Effect of Fine Steel Slag Powder on the Early Hydration Process of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Hydration heat evolution, non-evaporative water, setting time and SEM tests were performed to investigate the effect of fine steel slag powder on the hydration process of Portland cement and its mechanism.The results show that the effect of fine steel slag powder on the hydration process of Portland cement is closely related to its chemical composition, mineral phases, fineness, etc.Fine steel slag powder retards the hydration of portland cement at early age.The major reason for this phenomenon is the relative high content of MgO , MnO2, P2 O5in steel slag, and MgO solid solved in C3 S contained in steel slag.

  16. Synthesis and adsorption property of zeolite FAU/LTA from lithium slag with utilization of mother liquid☆

    Institute of Scientific and Technical Information of China (English)

    Guo Lin; Qiang Zhuang; Qun Cui; Haiyan Wang; Huqing Yao

    2015-01-01

    Co-crystalline zeolite FAU/LTA-0 was synthesized by hydrothermal method from lithium slag. To make the most of excess silicon and alkali sources in mother liquid derived from FAU/LTA-0, zeolite FAU/LTA-1b was synthesized in the same method with the use of mother liquid by adding a certain amount of aluminum source. Influences of different adding ways of aluminum source and recycling dosages of mother liquid on synthesis of zeolites FAU/LTA with mother liquid were investigated. The phase, microstructure and thermostability of FAU/LTA-0 and FAU/LTA-1b were characterized by XRD, SEM and TG-DTA. The calcium and magnesium cation exchange capacities (CECs) of the zeolites were determined. The results have shown that co-crystalline zeolite can be synthesized with the use of mother liquid by adding aluminum source after 2 h of reaction. Compared with FAU/LTA-0, the crystal twinning structure of FAU/LTA-1b became weaker, the grain size was smaller, and the thermostability was better. With a lower dosage of mother liquid, the content of P-type impurity in product decreased significantly, and the content of LTA phase increased. The reuse rate of mother liquid can reach 48%. The CECs of FAU/LTA-1b-150 can reach 343 mg CaCO3·g−1 and 180 mg MgCO3·g−1, showing more excellent adsorption capacities than FAU/LTA-0 and commercial zeolite 4A. The full recycling use of mother liquid to synthesize zeolite FAU/LTA which can be applied for detergent not only improves resource utilization but also reduces production cost.

  17. Verification of Steelmaking Slags Iron Content Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang

    2006-10-04

    The steel industry in the United States generates about 30 million tons of by-products each year, including 6 million tons of desulfurization and BOF/BOP slag. The recycling of BF (blast furnace) slag has made significant progress in past years with much of the material being utilized as construction aggregate and in cementitious applications. However, the recycling of desulfurization and BOF/BOP slags still faces many technical, economic, and environmental challenges. Previous efforts have focused on in-plant recycling of the by-products, achieving only limited success. As a result, large amounts of by-products of various qualities have been stockpiled at steel mills or disposed into landfills. After more than 50 years of stockpiling and landfilling, available mill site space has diminished and environmental constraints have increased. The prospect of conventionally landfilling of the material is a high cost option, a waste of true national resources, and an eternal material liability issue. The research effort has demonstrated that major inroads have been made in establishing the viability of recycling and reuse of the steelmaking slags. The research identified key components in the slags, developed technologies to separate the iron units and produce marketable products from the separation processes. Three products are generated from the technology developed in this research, including a high grade iron product containing about 90%Fe, a medium grade iron product containing about 60% Fe, and a low grade iron product containing less than 10% Fe. The high grade iron product contains primarily metallic iron and can be marketed as a replacement of pig iron or DRI (Direct Reduced Iron) for steel mills. The medium grade iron product contains both iron oxide and metallic iron and can be utilized as a substitute for the iron ore in the blast furnace. The low grade iron product is rich in calcium, magnesium and iron oxides and silicates. It has a sufficient lime value and

  18. Verification of Steelmaking Slags Iron Content Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang

    2006-10-04

    The steel industry in the United States generates about 30 million tons of by-products each year, including 6 million tons of desulfurization and BOF/BOP slag. The recycling of BF (blast furnace) slag has made significant progress in past years with much of the material being utilized as construction aggregate and in cementitious applications. However, the recycling of desulfurization and BOF/BOP slags still faces many technical, economic, and environmental challenges. Previous efforts have focused on in-plant recycling of the by-products, achieving only limited success. As a result, large amounts of by-products of various qualities have been stockpiled at steel mills or disposed into landfills. After more than 50 years of stockpiling and landfilling, available mill site space has diminished and environmental constraints have increased. The prospect of conventionally landfilling of the material is a high cost option, a waste of true national resources, and an eternal material liability issue. The research effort has demonstrated that major inroads have been made in establishing the viability of recycling and reuse of the steelmaking slags. The research identified key components in the slags, developed technologies to separate the iron units and produce marketable products from the separation processes. Three products are generated from the technology developed in this research, including a high grade iron product containing about 90%Fe, a medium grade iron product containing about 60% Fe, and a low grade iron product containing less than 10% Fe. The high grade iron product contains primarily metallic iron and can be marketed as a replacement of pig iron or DRI (Direct Reduced Iron) for steel mills. The medium grade iron product contains both iron oxide and metallic iron and can be utilized as a substitute for the iron ore in the blast furnace. The low grade iron product is rich in calcium, magnesium and iron oxides and silicates. It has a sufficient lime value and

  19. Study on Behaviour of Concrete Mix Replaceing Fine Aggregate With Steel Slag At Different Properties

    Directory of Open Access Journals (Sweden)

    P.Sateesh Kumar

    2015-11-01

    Full Text Available This paper aims to study experimentally, the effect of partial replacement of fine aggregate by steel slag (ss, on the various strength and durability properties of concrete by using the mix designs .the optimum percentage of replacement of fine aggregate by steel slag is found. Workability of concrete gradually decreases, as the percentage of replacement increases which is found using slump test. Compressive strength, tensile strength, flexural strength and durability tests such as acid resistant’s, using HCL,H2SO4 and rapid chloride penetration, are experimentally investigated. The results indicate that for conventional concrete, partial replacement of concrete by steel slag improves the compressive, tensile, flexural strength. The mass loss in cubes after immersion in acids is found to be very low. Deflection in the RCC beams gradually increases, as the load on the beam increases, for the replacement. The degree of fluoride ion penetrability is assessed based on the limits given in ASTM C 1202. The viability of use of steel slag in concrete is found. Waste management is one of the most common and challenging problems in the world. The steel making industry has generated substantially solid waste. Steel slag is a residue obtained in steel making operation. This paper deals with the implementation of steel slag as an effective replacement for sand. Steel slag ,which is consider as the solid waste pollutant, can be used for road construction ,clinker raw materials, filling materials etc. In this work, steel slag used as replacement for sand, which is also major component concrete mixture. This method can be implement for producing hallow blocks, solid blocks, paver blocks, concrete structures etc. Accordingly, advantages can be achieved by using steel slag instead of natural aggregates this will also encourage other researchers to find another field of using steel slag.

  20. Evaluation of copper slag to catalyze advanced oxidation processes for the removal of phenol in water

    Energy Technology Data Exchange (ETDEWEB)

    Huanosta-Gutierrez, T. [Instituto de Ingenieria, Coordinacion de Ingenieria Ambiental, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, Coyoacan 04510, Mexico, D.F. (Mexico); Dantas, Renato F., E-mail: falcao@angel.qui.ub.es [Departament d' Enginyeria Quimica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Ramirez-Zamora, R.M. [Instituto de Ingenieria, Coordinacion de Ingenieria Ambiental, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, Coyoacan 04510, Mexico, D.F. (Mexico); Esplugas, S. [Departament d' Enginyeria Quimica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer We evaluate the use of an industrial residue (copper slag) as catalyst in water treatment. Black-Right-Pointing-Pointer The copper slag was effective to remove organic pollutants (phenol) from water. Black-Right-Pointing-Pointer During experimentation, Cu and Fe leaching were not higher than the acceptable levels. Black-Right-Pointing-Pointer Slag/H{sub 2}O{sub 2}/UV and slag/H{sub 2}O{sub 2} treatments promoted biodegradability increment of the contaminated water. Black-Right-Pointing-Pointer The control of the reaction time would minimize the environmental impact of the produced effluents in terms of acute toxicity. - Abstract: The aim of this work was to evaluate the use of copper slag to catalyze phenol degradation in water by advanced oxidation processes (AOPs). Copper slag was tested in combination with H{sub 2}O{sub 2} (slag/H{sub 2}O{sub 2}) and H{sub 2}O{sub 2}/UV (slag/H{sub 2}O{sub 2}/UV). The studied methods promoted the complete photocatalytic degradation of phenol. Besides, they were able to reduce about 50% the TOC content in the samples. Slag/H{sub 2}O{sub 2}/UV and slag/H{sub 2}O{sub 2} treatments have favored biodegradability increment along the reaction time. Nevertheless, the irradiated method achieved higher values of the biodegradability indicator (BOD{sub 5}/TOC). The toxicity assessment indicated the formation of more toxic compounds in both treatments. However, the control of the reaction time would minimize the environmental impact of the effluents.

  1. CO2 sequestration utilizing basic-oxygen furnace slag: Controlling factors, reaction mechanisms and V-Cr concerns.

    Science.gov (United States)

    Su, Tung-Hsin; Yang, Huai-Jen; Shau, Yen-Hong; Takazawa, Eiichi; Lee, Yu-Chen

    2016-03-01

    Basic-oxygen furnace slag (BOF-slag) contains >35% CaO, a potential component for CO2 sequestration. In this study, slag-water-CO2 reaction experiments were conducted with the longest reaction duration extending to 96hr under high CO2 pressures of 100-300kg/cm(2) to optimize BOF-slag carbonation conditions, to address carbonation mechanisms, and to evaluate the extents of V and Cr release from slag carbonation. The slag carbonation degree generally reached the maximum values after 24hr slag-water-CO2 reaction and was controlled by slag particle size and reaction temperature. The maximum carbonation degree of 71% was produced from the experiment using fine slag of ≤0.5mm under 100°C and a CO2 pressure of 250kg/cm(2) with a water/slag ratio of 5. Vanadium release from the slag to water was significantly enhanced (generally >2 orders) by slag carbonation. In contrast, slag carbonation did not promote chromium release until the reaction duration exceeded 24hr. However, the water chromium content was generally at least an order lower than the vanadium concentration, which decreased when the reaction duration exceeded 24hr. Therefore, long reaction durations of 48-96hr are proposed to reduce environmental impacts while keeping high carbonation degrees. Mineral textures and water compositions indicated that Mg-wüstite, in addition to CaO-containing minerals, can also be carbonated. Consequently, the conventional expression that only considered carbonation of the CaO-containing minerals undervalued the CO2 sequestration capability of the BOF-slag by ~20%. Therefore, the BOF-slag is a better CO2 storage medium than that previously recognized.

  2. Chordal Graphs are Fully Orientable

    CERN Document Server

    Lai, Hsin-Hao

    2012-01-01

    Suppose that D is an acyclic orientation of a graph G. An arc of D is called dependent if its reversal creates a directed cycle. Let m and M denote the minimum and the maximum of the number of dependent arcs over all acyclic orientations of G. We call G fully orientable if G has an acyclic orientation with exactly d dependent arcs for every d satisfying m <= d <= M. A graph G is called chordal if every cycle in G of length at least four has a chord. We show that all chordal graphs are fully orientable.

  3. Fabrication of slag-glass composite with controlled porosity

    Directory of Open Access Journals (Sweden)

    Ranko Adziski

    2008-06-01

    Full Text Available The preparation and performance of porous ceramics made from waste materials were investigated. Slag from thermal electrical plant Kakanj (Bosnia and Herzegovina with defined granulations: (0.500÷0.250 mm; (0.250÷0.125 mm; (0.125÷0.063 mm; (0.063÷0.045 mm and 20/10 wt.% of the waste TV screen glass with a granulation <0.063 mm were used for obtaining slag-glass composites with controlled porosity. The one produced from the slag powder fraction (0.125÷0.063 mm and 20 wt.% TV screen glass, sintered at 950°C/2h, was considered as the optimal. This system possesses open porosity of 26.8±1.0%, and interconnected pores with the size of 250–400 μm. The values of E-modulus and bending strength of this composite were 10.6±0.6 GPa and 45.7±0.7 MPa, respectively. The coefficient of thermal expansion was 8.47·10-6/°C. The mass loss in 0.1M HCl solution after 30 days was 1.2 wt.%. The permeability and the form coefficient of the porous composite were K0=0.12 Da and C0=4.53·105 m-1, respectively. The porous composite shows great potential to be used as filters, diffusers for water aeration, dust collectors, acoustic absorbers, etc.

  4. Sulfide capacities of MnO-SiO2 slags

    Science.gov (United States)

    Reddy, Ramana G.; Blander, Milton

    1989-04-01

    Sulfide capacities of binary MnO-SiO2 slags at 1773 and 1923 K were calculated thermodynamically. Only known data, such as the standard free energy of formation of MnO and MnS and activities of MnO in the melt, are used in making calculations based on fundamental concepts. Excellent agreement is found between our calculations and published experimental data. Correlations of sulfide capacities, based on optical basicity using Pauling electronegativities or empirically deduced optical basicities, differ from the experimental data in both magnitude and concentration dependence. Our method provides useful predictions of sulfide capacities a priori.

  5. Computer recognition of slag property diagrams in ternary systems

    Institute of Scientific and Technical Information of China (English)

    Jinxiong Lu; Li Wang; Jiongming Zhang; Xinhua Wang

    2004-01-01

    In order to take data information from the slag property diagram in a ternary system automatically and actually, a picture recognition and drawing software has been developed by Visual Basic 6.0 based on the image coding principle of computer system and the graphics programming method of VB. This software can transform the ternary system isopleth diagram from bitmap format to data file and establish a corresponding database which can be applied to rapidly retrieve a mass of data and make correlative thermodynamics or kinetics calculation. Besides, it still has the function of drawing the ternary system diagram which can draw different kinds of property parameters in the same diagram.

  6. SYNTHESIS OF ZEOLITES FROM INCINERATION ASH AND SLAG

    Directory of Open Access Journals (Sweden)

    Michał Łach

    2017-02-01

    Full Text Available The work concerns the possibility of the use of secondary waste from waste incineration processes for the production of zeolites. The study used fly ash and slag from national waste incineration plants. The test materials were subjected to hydrothermal alkaline activation in aqueous solution of sodium hydroxide, the molar concentrations of the various variants. The research revealed the usefulness of this type of material for the synthesis of zeolites –obtained sodalite. Presents the results of analyzes of the SEM / EDS and XRD for the most efficient synthesis processes.

  7. A Model for Dissolution of Lime in Steelmaking Slags

    Science.gov (United States)

    Sarkar, Rahul; Roy, Ushasi; Ghosh, Dinabandhu

    2016-08-01

    In a previous study by Sarkar et al. (Metall. Mater. Trans. B 46B:961 2015), a dynamic model of the LD steelmaking was developed. The prediction of the previous model (Sarkar et al. in Metall. Mater. Trans. B 46B:961 2015) for the bath (metal) composition matched well with the plant data (Cicutti et al. in Proceedings of 6th International Conference on Molten Slags, Fluxes and Salts, Stockholm City, 2000). However, with respect to the slag composition, the prediction was not satisfactory. The current study aims to improve upon the previous model Sarkar et al. (Metall. Mater. Trans. B 46B:961 2015) by incorporating a lime dissolution submodel into the earlier one. From the industrial point of view, the understanding of the lime dissolution kinetics is important to meet the ever-increasing demand of producing low-P steel at a low basicity. In the current study, three-step kinetics for the lime dissolution is hypothesized on the assumption that a solid layer of 2CaO·SiO2 should form around the unreacted core of the lime. From the available experimental data, it seems improbable that the observed kinetics should be controlled singly by any one kinetic step. Accordingly, a general, mixed control model has been proposed to calculate the dissolution rate of the lime under varying slag compositions and temperatures. First, the rate equation for each of the three rate-controlling steps has been derived, for three different lime geometries. Next, the rate equation for the mixed control kinetics has been derived and solved to find the dissolution rate. The model predictions have been validated by means of the experimental data available in the literature. In addition, the effects of the process conditions on the dissolution rate have been studied, and compared with the experimental results wherever possible. Incorporation of this submodel into the earlier global model (Sarkar et al. in Metall. Mater. Trans. B 46B:961 2015) enables the prediction of the lime dissolution rate

  8. Mechanisms of hydrogen sulfide removal by ground granulated blast furnace slag amended soil.

    Science.gov (United States)

    Xie, Mengyao; Leung, Anthony Kwan; Ng, Charles Wang Wai

    2017-02-06

    Ground granulated blast furnace slag (GGBS) amended soil has been found able to remove gaseous hydrogen sulfide (H2S). However, how H2S is removed by GGBS amended soil and why GGBS amended soil can be regenerated to remove H2S are not fully understood. In this study, laboratory column tests together with chemical analysis were conducted to investigate and reveal the mechanisms of H2S removal process in GGBS amended soil. Sulfur products formed on the surface of soil particle and in pore water were quantified. The test results reveal that the reaction between H2S and GGBS amended soil was a combined process of oxidation and acid-base reaction. The principal mechanism to remove H2S in GGBS amended soil was through the formation of acid volatile sulfide (AVS), elemental sulfur and thiosulfate. Soil pH value decreased gradually during regeneration and reuse cycles. It is found that the AVS plays a significant role in H2S removal during regeneration and reuse cycles. Adding GGBS increased the production of AVS and at the same time suppressed the formation of elemental sulfur. This mechanism is found to be more prominent when the soil water content is higher, leading to increased removal capacity.

  9. Selective enrichment of TiO2 and precipitation behavior of perovskite phase in titania bearing slag

    Institute of Scientific and Technical Information of China (English)

    WANG Ming-yu; ZHANG Lin-nan; ZHANG Li; SUI Zhi-tong; TU Gan-feng

    2006-01-01

    The effects of additive agents and growth behavior of perovskite phase as well as temperature change of slag at semi industry scale test were studied. The results show that the increase of steel slag does good to titania enrichment, however, it isn't useful for the growth and coarsening of the perovskite phase. The additive Si-Fe powder can promote titania enrichment and make perovskite phase grow up easily. While air is blown into the molten slag, the reduced components in slag are oxidized and the released heat raises the temperature of slag.

  10. Structure and properties of the slags of continuous converting of copper nickel-containing mattes and concentrates: II. Effect of the SiO2/CaO ratio on the structure and liquidus temperature of the slags

    Science.gov (United States)

    Pigarev, S. P.; Tsymbulov, L. B.; Selivanov, E. N.; Chumarev, V. M.

    2012-03-01

    The structure and liquidus temperature of the SiO2-CaO-Al2O3-FeO x -Cu2O-NiO slags that form during continuous converting of copper mattes and concentrates into blister copper are analyzed. The slag melt compositions are varied over a wide SiO2/CaO range. The slags are studied by X-ray diffraction, scanning electron microscopy, and electron-probe microanalysis. The liquidus temperature of the slags is determined by differential thermal analysis. It is found that, depending on the SiO2/CaO ratio, the structure and liquidus temperature of the slags change and the forms of copper in a slag also change. The SiO2/CaO range in a slag is recommended for the process of continuous converting of a copper nickel-containing sulfide raw materials.

  11. Mechanical and leaching behaviour of slag-cement and lime-activated slag stabilised/solidified contaminated soil.

    Science.gov (United States)

    Kogbara, Reginald B; Al-Tabbaa, Abir

    2011-05-01

    Stabilisation/solidification (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of ground granulated blast furnace slag (GGBS) for S/S treatment of contaminated soils, although it has been shown to be effective in ground improvement. This study sought to investigate the potential of GGBS activated by cement and lime for S/S treatment of a mixed contaminated soil. A sandy soil spiked with 3000mg/kg each of a cocktail of heavy metals (Cd, Ni, Zn, Cu and Pb) and 10,000mg/kg of diesel was treated with binder blends of one part hydrated lime to four parts GGBS (lime-slag), and one part cement to nine parts GGBS (slag-cement). Three binder dosages, 5, 10 and 20% (m/m) were used and contaminated soil-cement samples were compacted to their optimum water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability and acid neutralisation capacity (ANC) tests with determination of contaminant leachability at the different acid additions. UCS values of up to 800kPa were recorded at 28days. The lowest coefficient of permeability recorded was 5×10(-9)m/s. With up to 20% binder dosage, the leachability of the contaminants was reduced to meet relevant environmental quality standards and landfill waste acceptance criteria. The pH-dependent leachability of the metals decreased over time. The results show that GGBS activated by cement and lime would be effective in reducing the leachability of contaminants in contaminated soils. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Effect of Slag Composition on the Distribution Behavior of Pb between FetO-SiO2 (-CaO, Al2O3) Slag and Molten Copper

    Science.gov (United States)

    Heo, Jung Ho; Park, Soo-Sang; Park, Joo Hyun

    2012-10-01

    The distribution behavior of Pb between molten copper and FetO-SiO2 (-CaO, Al2O3) slags was investigated at 1473 K (1200 °C) and p_{{{{O}}2 }} = 10^{ - 10} {{atm}} in view of the reaction mechanism of Pb dissolution into the slag. Furthermore, the lead capacity of the slag was estimated from the experimental results. The distribution ratio of Pb ( L Pb) decreases with increasing CaO content ( 6 mass pct) irrespective of Fe/SiO2 ratio (1.4 to 1.7). However, the addition of alumina into a slag with Fe/SiO2 = 1.5 linearly decreases the L Pb, whereas a minimum value is observed at about 4 mass pct Al2O3 at Fe/SiO2 = 1.3. The log L Pb continuously decreases with increasing Fe/SiO2 ratio, and the addition of Al2O3 (5 to 15 mass pct) into the silica-saturated iron silicate slag (Fe/SiO2 < 1.0) yields the highest Pb distribution ratio. This is mainly due to a decrease in the FeO activity even at silica saturation. The log L Pb linearly decreases by increasing the log (Fe3+/Fe2+) value. The Pb distribution ratio increases and the excess free energy of PbO decreases with increasing Cu2O content in the slag. However, from the viewpoint of copper loss into the slag, the silica-saturated system containing small amounts of alumina is strongly recommended to stabilize PbO in the slag phase at a low Cu2O content. The lead capacity was defined in the current study and shows a linear correlation with the activity of FeO in a logarithmic scale, indicating that the concept of lead capacity is a good measure of absorption ability of Pb in iron silicate slags, and the activity of FeO can be a good basicity index in iron silicate slag.

  13. Iron blast furnace slag/hydrated lime sorbents for flue gas desulfurization.

    Science.gov (United States)

    Liu, Chiung-Fang; Shih, Shin-Min

    2004-08-15

    Sorbents prepared from iron blast furnace slag (BFS) and hydrated lime (HL) through the hydration process have been studied with the aim to evaluate their reactivities toward SO2 under the conditions prevailing in dry or semidry flue gas desulfurization processes. The BFS/HL sorbents, having large surface areas and pore volumes due to the formation of products of hydration, were highly reactive toward SO2, as compared with hydrated lime alone (0.24 in Ca utilization). The sorbent reactivity increased as the slurrying temperature and time increased and as the particle size of BFS decreased; the effects of the liquid/solid ratio and the sorbent drying conditions were negligible. The structural properties and the reactivity of sorbent were markedly affected by the BFS/HL ratio; the sorbent with 30/70 ratio had the highest 1 h utilization of Ca, 0.70, and SO2 capture, 0.45 g SO2/g sorbent. The reactivity of a sorbent was related to its initial specific surface area (Sg0) and molar content of Ca (M(-1)); the 1 h utilization of Ca increased almost linearly with increasing Sg0/M. The results of this study are useful to the preparation of BFS/HL sorbents with high reactivity for use in the dry and semidry processes to remove SO2 from the flue gas.

  14. Carbothermic Reduction of Titanium-Bearing Blast Furnace Slag

    Science.gov (United States)

    Zhen, Yu-Lan; Zhang, Guo-Hua; Chou, Kuo-Chih

    2016-03-01

    The carbothermic reduction experiments were carried out for titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company in argon atmosphere at high temperatures. The effects of reduction temperature, isothermal treatment time and carbon content on the formation of TiC were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD pattern results showed that MgAl2O4 phase disappeared and the main phase of the reduced sample was TiC when the reduction temperature was higher than 1,773 K. The SEM pictures showed that the reduction rate of the titanium-bearing blast furnace slag could be increased by enhancing the temperature and the C content (carbon ratio ≤1.0). Furthermore, it was also found that TiC had the tendency of concentrating around the iron. The effects of additives such as Fe and CaCl2 on the formation of TiC were also studied in the present study.

  15. Optimization for blast furnace slag dry cooling granulation device

    Science.gov (United States)

    Dazhan, Sheng; Yali, Wang; Ruiyun, Wang; Suping, Cui; Xiaoyu, Ma

    2017-03-01

    Since the large accumulation amount of blast furnace slag (BFS) with recycling value, it has become a hot topic for recovery utilization. Compared with the existing various BFS granulation process, the dry granulation process can promote the use of blast furnace granulated slag as cement substitute and concrete admixtures. Our research group developed a novel dry cooling granulation experiment device to treat BFS. However, there are still some problems to be solved. The purpose of this research is to improve the cooling and granulation efficiency of the existing dry type cooling equipment. This topic uses the FLUENT simulation software to study the impact of the number of air inlet on the cooling effect of the device. The simulation result is that the device possessing eight air inlets can increase the number of hot and cold gas exchanged, resulting in a better cooling effect. According to the power consumption, LCA analysis was carried out on the cooling granulation process. The results show that the device equipped eight air inlets not only improved the original equipment cooling granulation effect, but also increased resource utilization ratio, realized energy-saving and emission reduction.

  16. Titania preparation from soda roasted slag using sulfuric acid solution

    Directory of Open Access Journals (Sweden)

    El-Sayed A. Manaa

    2016-11-01

    Full Text Available This work deals with treatment of the sodium titanate cake results from roasted titania slag using 60% sulfuric acid solution. The working sample produced by roasting titania slag with NaCO3 at 850 °C. After roasting V and Cr species as impurities in the roasted sample are converted to water soluble species as NaVO3 and Na2CrO4 before acid treatment however, the insoluble sodium titanate products (NaFeTiO4, Na8Ti5O14, Na6Ti2O7 and Na2TiO4 are then subjected to H2SO4 acid dissolution. The produced sulfate solution is subjected to hydrolysis step in presence of oxalic acid as a reducing agent. The hydrolyzed precipitate after filtration and washing with H2SO4 solution and warm water is dried at 100 °C and calcinated at 850 °C to prepare high pure TiO2 (99.8% besides removing ferrous sulfate (FeSO4 as a byproduct from the sulfate solution.

  17. Performance of steel-making slag concrete reinforced with fibers

    Directory of Open Access Journals (Sweden)

    Ortega-López Vanesa

    2017-01-01

    Full Text Available In this research, the possibility of making concrete reinforced with fibers and manufactured with recycled aggregates from carbon steel production was explored. Electric arc furnace slag (EAFS was used as coarse and medium aggregate, and part of the sand sizes. Metallic and synthetic fibers were added in different amounts. Initially, the properties of EAFS and their suitability to be used in the manufacture fiber reinforced concrete were analysed. Then, a series of fiber reinforced concrete mixtures were developed incorporating EAFS, and they were compared with the reference mixtures, made with conventional components plus fibers and made with EAFS without fibers. A series of tests were performed, including concepts such as consistency, compressive strength, flexural strength, splitting tensile strength, resistance to water penetration or toughness. The results show that it is possible to make a suitable steel-slag concrete reinforced with fibers, complying with the standard requirements for it use in pavements and slab, and improving their proprieties respect to the control mixtures.

  18. Novel sintered ceramic materials incorporated with EAF carbon steel slag

    Science.gov (United States)

    Karayannis, V.; Ntampegliotis, K.; Lamprakopoulos, S.; Papapolymerou, G.; Spiliotis, X.

    2017-01-01

    In the present research, novel sintered clay-based ceramic materials containing electric arc furnace carbon steel slag (EAFC) as a useful admixture were developed and characterized. The environmentally safe management of steel industry waste by-products and their valorization as secondary resources into value-added materials towards circular economy have attracted much attention in the last years. EAF Carbon steel slag in particular, is generated during the manufacture of carbon steel. It is a solid residue mainly composed of rich-in- Fe, Ca and Si compounds. The experimental results show that the beneficial incorporation of lower percentages of EAFC up to 6%wt. into ceramics sintered at 950 °C is attained without significant variations in sintering behavior and physico-mechanical properties. Further heating up to 1100 °C strongly enhances the densification of the ceramic microstructures, thus reducing the porosity and strengthening their mechanical performance. On the other side, in terms of thermal insulation behavior as well as energy consumption savings and production cost alleviation, the optimum sintering temperature appears to be 950 °C.

  19. Effect of electric arc furnace slag on growth and physiology of maize (Zea mays L.).

    Science.gov (United States)

    Radić, Sandra; Crnojević, Helena; Sandev, Dubravka; Jelić, Sonja; Sedlar, Zorana; Glavaš, Katarina; Pevalek-Kozlina, Branka

    2013-12-01

    Basic slag, used in this study as a potential source of certain nutrients, is a byproduct of the production of steel in electric arc furnace (EAF). A pot experiment with two nutrient-poor substrates was conducted to investigate to compare the effect of EAF steel slag and fertilizers NPK + F e on growth and availability of specific nutrients to maize. Mineral content of both substrate and plant leaves, growth, chlorophyll fluorescence and photosynthetic pigments were measured following six weeks of cultivation. As steel slag also contains trace amounts of heavy metals, certain oxidative parameters (antioxidative enzyme activities and lipid peroxidation) were evaluated as well. The steel slag improved soil mineral composition, increased above ground maize biomass by providing Fe, Mn, Mg, K and partly P and improved photosynthetic parameters. The potential phytotoxicity of EAF slag containing substrates was not determined as evaluated by MDA (malondialdehyde), GR (glutathione reductase) and APX (ascorbate peroxidase) levels. The obtained results show that EAF steel slag is comparable to NPK + F e in supplying nutrients for maize growth, indicating the potential of EAF steel slag as an inexpensive and non-phytotoxic nutrient supplier especially in poor soils.

  20. Hydration characteristics and environmental friendly performance of a cementitious material composed of calcium silicate slag.

    Science.gov (United States)

    Zhang, Na; Li, Hongxu; Zhao, Yazhao; Liu, Xiaoming

    2016-04-05

    Calcium silicate slag is an alkali leaching waste generated during the process of extracting Al2O3 from high-alumina fly ash. In this research, a cementitious material composed of calcium silicate slag was developed, and its mechanical and physical properties, hydration characteristics and environmental friendly performance were investigated. The results show that an optimal design for the cementitious material composed of calcium silicate slag was determined by the specimen CFSC7 containing 30% calcium silicate slag, 5% high-alumina fly ash, 24% blast furnace slag, 35% clinker and 6% FGD gypsum. This blended system yields excellent physical and mechanical properties, confirming the usefulness of CFSC7. The hydration products of CFSC7 are mostly amorphous C-A-S-H gel, rod-like ettringite and hexagonal-sheet Ca(OH)2 with small amount of zeolite-like minerals such as CaAl2Si2O8·4H2O and Na2Al2Si2O8·H2O. As the predominant hydration products, rod-like ettringite and amorphous C-A-S-H gel play a positive role in promoting densification of the paste structure, resulting in strength development of CFSC7 in the early hydration process. The leaching toxicity and radioactivity tests results indicate that the developed cementitious material composed of calcium silicate slag is environmentally acceptable. This study points out a promising direction for the proper utilization of calcium silicate slag in large quantities.

  1. Some Insights to the Reuse of Dredged Marine Soils by Admixing with Activated Steel Slag

    Directory of Open Access Journals (Sweden)

    Chee-Ming Chan

    2014-01-01

    Full Text Available Regular dredging is necessary for the development of coastal regions and the maintenance of shipping channels. The dredging process dislodges sediments from the seabed, and the removed materials, termed dredged marine soils, are generally considered a geowaste for dumping. However, disposal of the dredged soils offshores can lead to severe and irreversible impact on the marine ecosystem, while disposal on land often incurs exorbitant costs with no guarantee of zero-contamination. It is therefore desirable to reuse the material, and one option is solidification with another industrial waste, that is, steel slag. This paper describes the exploratory work of admixing dredged marine soil with activated steel slag for improvement of the mechanical properties. An optimum activation concentration of NaOH was introduced to the soil-slag mixture for uniform blending. Specimens were prepared at different mix ratios then left to cure for up to 4 weeks. The unconfined compressive strength test was conducted to monitor the changes in strength at predetermined intervals. It was found that the strength does not necessarily increase with higher steel slag content, indicating an optimum slag content required for the maximum solidification effect to take place. Also, regardless of the slag content, longer curing time produces greater strength gain. In conclusion, steel slag addition to dredged sediments can effectively strengthen the originally weak soil structure by both the “cementation” and “filler” effects, though the combined effects were not distinguished in the present study.

  2. Thermodynamic and Experimental Investigations of High-Temperature Refractory Corrosion by Molten Slags

    Science.gov (United States)

    Wagner, Christoph; Wenzl, Christine; Gregurek, Dean; Kreuzer, Daniel; Luidold, Stefan; Schnideritsch, Holger

    2017-02-01

    Corrosion mechanisms between MgO refractory substrates and FeNi slags were investigated. The FeNi slags taken into consideration represent a simple synthetically mixed slag with specific oxides and a real slag from a ferroalloy producer. The MgO refractory substrates with the specimens of FeNi slag were heated in a hot-stage microscope at 10 K/min from room temperature to three different temperatures 1573 K, 1723 K, and 1923 K (1300 °C, 1450 °C, and 1650 °C). The experiments were carried out under a controlled gas atmosphere that simulates the relevant process conditions. The corrosion mechanisms of each system were followed by scanning electron microscope analyses. The results obtained showed that slag corrosion dominates, with a pronounced partial dissolution of refractory fines forming Mg-silicates of type forsterite. It was also observed that iron oxide present in the slag diffused into the coarse refractory grains forming magnesiowustite. Finally, the results obtained were compared with those predicted by FACTSAGE software to understand the corrosion mechanisms and draw implications for improving the refractory performance and lifetime.

  3. Effect of blast furnace slag on self-healing of microcracks in cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haoliang, E-mail: haoliang.huang@tudelft.nl [Microlab, Faculty of Civil Engineering and Geosciences, Delft University of Technology (Netherlands); Ye, Guang [Microlab, Faculty of Civil Engineering and Geosciences, Delft University of Technology (Netherlands); Magnel Laboratory for Concrete Research, Department of Structural Engineering, Ghent University (Belgium); Damidot, Denis [Université Lille Nord de France (France); EM Douai, LGCgE-MPE-GCE, Douai (France)

    2014-06-01

    The physico-chemical process of self-healing in blast furnace slag cement paste was investigated in this paper. With a high slag content i.e., 66% in cement paste and saturated Ca(OH)₂ solution as activator, it was found that the reaction products formed in cracks are composed of C-S-H, ettringite, hydrogarnet and OH–hydrotalcite. The fraction of C-S-H in the reaction products is much larger than the other minerals. Large amount of ettringite formed in cracks indicates the leaching of SO₄⁻² ions from the bulk paste and consequently the recrystallization. Self-healing proceeds fast within 50 h and then slows down. According to thermodynamic modeling, when the newly formed reaction products are carbonated, the filling fraction of crack increases first and then decreases. Low soluble minerals such as silica gel, gibbsite and calcite are formed. Compared to Portland cement paste, the potential of self-healing in slag cement paste is higher when the percentage of slag is high. Highlights: • Self-healing reaction products in slag cement paste were characterized. • Self-healing reaction products formed in time were quantified with image analysis. • Self-healing in slag cement paste was simulated with a reactive transport model. • Effect of carbonation on self-healing was investigated by thermodynamic modeling. • Effect of slag on self-healing was discussed based on experiments and simulation.

  4. Thermodynamic and Experimental Investigations of High-Temperature Refractory Corrosion by Molten Slags

    Science.gov (United States)

    Wagner, Christoph; Wenzl, Christine; Gregurek, Dean; Kreuzer, Daniel; Luidold, Stefan; Schnideritsch, Holger

    2016-12-01

    Corrosion mechanisms between MgO refractory substrates and FeNi slags were investigated. The FeNi slags taken into consideration represent a simple synthetically mixed slag with specific oxides and a real slag from a ferroalloy producer. The MgO refractory substrates with the specimens of FeNi slag were heated in a hot-stage microscope at 10 K/min from room temperature to three different temperatures 1573 K, 1723 K, and 1923 K (1300 °C, 1450 °C, and 1650 °C). The experiments were carried out under a controlled gas atmosphere that simulates the relevant process conditions. The corrosion mechanisms of each system were followed by scanning electron microscope analyses. The results obtained showed that slag corrosion dominates, with a pronounced partial dissolution of refractory fines forming Mg-silicates of type forsterite. It was also observed that iron oxide present in the slag diffused into the coarse refractory grains forming magnesiowustite. Finally, the results obtained were compared with those predicted by FACTSAGE software to understand the corrosion mechanisms and draw implications for improving the refractory performance and lifetime.

  5. Uranium recovery from slags of metallic uranium; Recuperacao de uranio em escorias de uranio metalico

    Energy Technology Data Exchange (ETDEWEB)

    Fornarolo, F.; Frajndlich, E.U.C.; Durazzo, M. [Instituto de Pesquisas Energeticas e Nucleares (CNEN/IPEN-SP), Sao Paulo, SP (Brazil). Centro de Combustiveis Nucleares], e-mail: ffornar@ipen.br

    2006-07-01

    The Center of the Nuclear Fuel of the Institute of Nuclear Energy Research - IPEN finished the program of attainment of fuel development for research reactors the base of Uranium Scilicet (U{sub 3} Si{sub 2}) from Hexafluoride of Uranium (UF{sub 6}) with enrichment 20% in weight of {sup 235}U. In the process of attainment of the league of U 3 Si 2 we have as Uranium intermediate product the metallic one whose attainment generates a slag contend Uranium. The present work shows the results gotten in the process of recovery of Uranium in slags of calcined slags of Uranium metallic. Uranium the metallic one is unstable, pyrophoricity and extremely reactive, whereas the U{sub 3}O{sub 8} is a steady oxide of low chemical reactivity, what it justifies the process of calcination of slags of Uranium metallic. The calcination of the Uranium slag of the metallic one in oxygen presence reduces Uranium metallic the U{sub 3}O{sub 8}. Experiments had been developed varying it of acid for Uranium control and excess, nitric molar concentration gram with regard to the stoichiometric leaching reaction of temperature of the leaching process. The 96,0% income proves the viability of the recovery process of slags of Uranium metallic, adopting it previous calcination of these slags in nitric way with low acid concentration and low temperature of leaching. (author)

  6. Investigation on the Copper Content of Matte Smelting Slag in Peirce-Smith Converter

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The copper contents and its existing forms in the slags duri ng the slag-making stage of Peirce-Smith converters in Guixi Smelter, Jiangxi Province, China have been investigated. The investigation was based on plant trials with the corresponding thermodynamic calculation s and kinetic considerations. From the plant data, the total copper co ntent in the slags was in the range of 2% to 8 % (mass fraction). The mechanical entrainment of matte drops has been found to be the main ca use of the copper loss. The suspension index, defined as the ratio of the mass fraction of copper in suspended matte drops in the slag to th at in bulk of the matte phase, has been adopted to quantify the matte entrainment. The values of this parameter estimated in this work have been found mainly within a range of 2.5%€?.0%. The Fe3O4 content in t he slag has been estimated to be the most important factor, among othe rs, influencing the separation of slag with matte and, consequently, t he copper loss from the slag.

  7. Ecotoxicity of Concretes with Granulated Slag from Gray Iron Pilot Production as Filler

    Directory of Open Access Journals (Sweden)

    Helena Hybská

    2017-05-01

    Full Text Available This paper focuses on research concerning the ecotoxicological properties of granulated slag from the pilot production of gray iron with red mud addition and concrete composites with the application of this slag. Red mud is a hazardous waste generated in the production of aluminium oxide. Negative ecotoxicological tests are, therefore, one of the basic prerequisites for the ability to use granulated slag from gray iron pilot production. Granulated slag and concrete composite samples with various ratios of granulated slag have been subject to ecotoxicity tests: determining root growth inhibition in the highly-cultivated plant Sinapis alba, and determining acute toxicity in Daphnia magna. The results of ecotoxicological testing of granulated slag from gray iron standard production and gray iron pilot production with the additive were, according to the standard (STN 83 8303, negative. Additionally, the results of ecotoxicological tests of concrete composites were negative, with the exception of a 50% substitution of fine aggregate with slag from gray iron pilot production.

  8. Converter slag-coal cinder columns for the removal of phosphorous and other pollutants.

    Science.gov (United States)

    Yang, Jian; Wang, Su; Lu, Zhibo; Yang, Jian; Lou, Shanjie

    2009-08-30

    A mixture of converter slag and coal cinder as adsorbent for the removal of phosphorous and other pollutants was studied in the paper. The maximum P adsorption capacity, pH of solution, contact time and initial phosphate concentration were evaluated in batch experiments for the two materials firstly. The data of P sorption were best fitted to Langumir equation, and the maximum adsorption capacities of converter slag and coal cinder were 2.417 and 0.398 mg P/g, respectively. The pH of solutions with converter slag and coal cinder changed dramatically with time and closed to 8 in 8h, and the influence of initial pH on phosphate removal by coal cinder was more significant than by converter slag. Phosphate removal rate by converter slag decreased with increase of initial phosphate concentrations. Subsequently, two flow-through columns (Column 1#, V(converter slag):V(coal cinder)=1:5; Column 2#, V(converter slag):V(coal cinder)=1:3) were operated for the removal of phosphorous and other pollutants from the effluents of a vermifilter for nearly eleven months. Results indicated the average removal efficiency of total phosphorus, dissolved phosphorus, COD and NH(4)(+)-N by Column 1# were 44%, 56%, 31% and 67%, and by Column 2# were 42%, 54%, 24% and 57%, respectively. Column 1# had higher removal efficiency for P and other pollutants.

  9. Investigations of the surface tension of coal ash slags under gasification conditions; Untersuchungen zur Oberflaechenspannung von Kohleschlacken unter Vergasungsbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, Tobias

    2011-10-26

    produces heavily scattering output. The measurement arrangement was run in an almost fully automated fashion which resulted in an immense amount of obtained surface tension data. Maximum bubble pressure experiments were conducted at the University of Osaka, Japan, on selected real ash samples. Due to a far longer time required for determining bubble pressures in comparison to taking drop pictures, only a small number of temperatures could be studied abroad. The results show the surface tension to be in the range from 200 mN/m to 500 mN/m which is in accordance with data taken from the literature. While three discrete temperature intervals of particular slag behaviour could be identified in sessile drop experiments, results of maximum bubble pressure trials suggest the surface tension to be lower under inert conditions compared to a reducing atmosphere. The outcomes generated in Japan additionally show a better agreement to surface tensions forecasted by model calculations. Fe{sub 2}O{sub 3} being considered to have a pronounced influence on slag characteristics is made responsible for such observations. As soon as pressure is applied, the surface tension is found to decrease significantly. In order to visualise the data obtained by means of the sessile drop technique, regression functions were employed that can be implemented into future design calculations on hot gas cleaning facilities. (orig.)

  10. 高铝中钛高炉渣脱硫的动力学机制%Desulphurization Dynamics Mechanism of Blast Furnace Slag With Medium Titanium and High Alumina Content

    Institute of Scientific and Technical Information of China (English)

    张淑会; 穆红旺; 孙艳芹; 吕庆

    2012-01-01

    以现场高炉渣化学成分为基准,利用纯化学试剂制备试验渣样,研究了高铝中钛型高炉渣脱硫的动力学过程,确定了其脱硫的动力学参数。结果表明,当反应温度一定时,铁水中硫含量w([S])随脱硫反应时间的延长而降低。试验条件下,高铝中钛渣脱硫过程属于二级反应,其限制性环节是硫在熔渣中的扩散。熔渣中硫的传质系数βS随着温度的升高而增大,硫在熔渣中的扩散活化能ED为127.03kJ/mol。%On the basis of the compositions of blast furnace(BF) slag at field,the desulphurization dynamics process was researched for BF slag with medium titanium and high alumina content,which was fabricated from pure chemical agents.The dynamics parameters of desulphurization were obtained.Results show that the sulfur content in liquid iron(w([S])) decreases with the elongation of desulphurization reaction time when the temperature is constant.Under the experimental conditions,the desulphurization process of BF slag with medium titanium and high alumina content belongs to second-order reaction,the restricted step of which is sulfur diffusion in the fused slag.The mass transfer coefficient(βS) rises with increasing the reaction,and the diffusion activation energy(ED) of sulfur element in fused slag is 127.03 kJ/mol.

  11. Kinetics of the dissolution of zinc sulfide in an oxidizing slag

    Science.gov (United States)

    Gupta, Suresh K.

    1990-10-01

    A new concept has been developed for the production of zinc from zinc and complex zinc concentrates. It is a two-stage process involving oxidation of zinc sulfide to oxide and dissolution into slag and the fuming of zinc from the slag by injecting carbonaceous materials into it to produce zinc vapors which can be subsequently condensed in a lead-splash condenser such as those used in the Imperial Smelting Process (ISP). In this paper, the effects of the quantity of air, temperature, and concentrate feed rate have been discussed on the production of zinc-rich slag, which is the first stage of the proposed process.

  12. [Study on quantificational analysis method for the non-crystalline content in blast furnace slag].

    Science.gov (United States)

    Yan, Ding-Liu; Guo, Pei-Min; Qi, Yuan-Hong; Zhang, Chun-Xia; Wang, Hai-Feng; Dai, Xiao-Tian

    2008-02-01

    Quantificational analysis method for the non-crystalline and crystalline contents in blast furnace slag was studied by means of X-ray diffraction. The process of quantificational analysis method includes standard samples preparation, samples preparation, X-ray diffraction measurement and data treatment. The data treatment includes integration areas of non-crystalline curve and crystalline peaks in certain diffraction angle range, linear fitting and quantificational coefficient determination. The preparation methods of standard samples for X-ray diffraction of blast furnace slag were proposed, including 100% crystalline sample and 100% non-crystalline sample. The 100% crystalline sample can be obtained by heating blast furnace slag for 12 h at 1 000-1 200 degrees C, and the 100% non-crystalline sample can be obtained by quenching the molten slag with enough water. The X-ray diffraction method of quantificational analysis of non-crystalline content in blast furnace slag was proposed with the 100% non-crystalline and 100% crystalline standard samples, and the quantificational coefficient can be obtained by linear regression on the integration areas of non-crystalline curve and crystalline peaks of X-ray diffraction in the 2-theta range 20 degrees-40 degrees. This method is suitable for the blast furnace slag with the non-crystalline content over 80%. The non-crystalline and crystalline contents of original blast furnace slag are obtained by combining the X-ray diffraction results and mathematical treatment, and this method is suitable for the blast furnace slag with the non-crystalline content over 90%, whose process includes preparing the 100% crystalline standard sample by heating blast furnace slag for 12 h at 1000-1200 degrees C, samples preparation with the 0.02 interval in the 0-0.1 mass ratio range of 100% crystalline to original slag, X-ray diffraction measurement of the samples prepared and data treatment using iterative linear regression. The

  13. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    OpenAIRE

    2015-01-01

    This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA), artificial neural networks (ANNs) and adaptive netw...

  14. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    OpenAIRE

    2009-01-01

    This paper presents the results of multi-linear regression analysis (MLRA) of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3) and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974). This indicates that slag composition and content of copper in t...

  15. Influence of Environmental Factors on the Volume Change of Blended Cement Containing Steel Slag

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the condition of 20 ℃, 5% sulfate liquor curing, standard tap water curing and 50% RH curing-three different curing environments, the volume change of steel slag blended cement influenced by environmental factors was studied. With steel slag addition 10%, 30%, 50%, from 90 days to 356 days, the relationship of shrinkage and three different curing environments is: dry curing environment>tap water curing environment>sulfate curing environment. But, the sample shrinkage in 28 days has much difference with the curing environment, which has no obvious orderliness. The different effects on blended cement containing steel slag in different environmental factors were analyzed using SEM.

  16. Utilization of steel melting electric arc furnace slag for development of vitreous ceramic tiles

    Indian Academy of Sciences (India)

    Ritwik Sarkar; Nar Singh; Swapan Kumar Das

    2010-06-01

    Steel melting through electric arc furnace route is gaining popularity due to its many advantages, but generates a new waste, electric arc furnace slag, which is getting accumulated and land/mine filling and road construction are the only utilization. This slag has been tried to be value added and utilized to develop vitreous ceramic tiles. Slag, to the extent of 30–40 wt% with other conventional raw materials, were used for the development in the temperature range 1100–1150°C. The fired products showed relatively higher density with shorter firing range and good strength properties. Microstructural and EDAX studies were also done to evaluate the developed products.

  17. Composite cements containing natural pozzolan and granulated blast furnace slag

    Directory of Open Access Journals (Sweden)

    Irassar, E. F.

    2006-09-01

    Full Text Available For reasons of market demand and Portland cement production,the manufacture of cements with two or more separately ground additions to produce customized cements is becoming common practice.When pozzolan or slag content in this type of cements is high, however, the initial strength of the resulting product may be adversely impacted. This problem can be minimized by activating one or both of the replacement materials. The present study analyzes the effect of Portland cement additions such as physically activated natural pozzolan(up to 20% and/or granulated blast furnace slag (up to 35% on mortar flexural and compressive strength. The results show that higher strength is attained in ternary than binary cements. Initially (2 and 7 days, the highest compressive strengths are reached by mortars with up to 13% natural pozzolan and 5% slag, whereas at later ages mortars with larger proportions of additions are found to perform best.Debido a las exigencias del mercado y de la producción de cemento Portland, es cada vez más frecuente la elaboración de cementos con dos o más adiciones a partir de la molienda separada de sus constituyentes, dando origen a la formulación de los cementos a medida.Cuando el contenido de adiciones es alto, la utilización de puzolana y escoria en este tipo de cementos presenta la peculiaridad de disminuir la resistencia inicial del cemento resultante. Sin embargo, si algunas o ambas adiciones se activan, este problema puede minimizarse. En este trabajo se analiza la influencia de la incorporación al cemento Portland de puzolana natural (hasta 20% activada físicamente y/o escoria granulada de alto horno (hasta 35% sobre la resistencia a flexión y a compresión de morteros. Los resultados indican que los cementos ternarios presentan un mejor comportamiento resistente que los cementos binarios. Las máximas resistencias a compresión en las primeras edades (2 y 7 díasse alcanzan con hasta 13% de puzolana natural y 5% de

  18. 高炉渣改性作为矿渣棉原料的试验%Experimental Research of Slag Wool Producing With Blast Furnace Slag

    Institute of Scientific and Technical Information of China (English)

    郭强; 袁守谦; 刘军; 李海潮

    2011-01-01

    研究了不同酸度条件下,随着高炉熔渣中主要成分的变化,其黏度和表面张力对高炉渣作为矿渣棉原料的影响,并对其影响机制进行了探讨。结果表明,Al2O3和SiO2增加时,黏度增加,表面张力也随之加大,利于制取较长的矿渣棉纤维。%In this paper,the effect of viscosity and surface tension of furnace slag as slag wool material is studied in different acidity coefficient,with changing of the blast furnace slag in the main component.The influence mechanism had also been discussed.The results show that the slag viscosity decreases with the increase of Al2O3 content,at the same time,surface tension decreases too which benefits to make longer slag wool fibers.

  19. Randomized, Controlled, Multicenter Study of the Immunogenicity and Safety of a Fully Liquid Combination Diphtheria–Tetanus Toxoid–Five-Component Acellular Pertussis (DTaP5), Inactivated Poliovirus (IPV), and Haemophilus influenzae Type b (Hib) Vaccine Compared with a DTaP3-IPV/Hib Vaccine Administered at 3, 5, and 12 Months of Age

    Science.gov (United States)

    Silfverdal, Sven Arne; Boisnard, Florence; Thomas, Stéphane; Mwawasi, Grace; Reynolds, Donna

    2013-01-01

    This study compared the levels of immunogenicity and safety of diphtheria–tetanus toxoid–five-component acellular pertussis (DTaP5), inactivated poliovirus (IPV), and Haemophilus influenzae type b (Hib) (DTaP5-IPV-Hib) and DTaP3-IPV/Hib vaccines for study participants 3, 5, and 12 months of age. Post-dose 3 noninferiority criteria comparing DTaP5-IPV-Hib to DTaP3-IPV/Hib using rates of seroprotection were demonstrated against diphtheria, tetanus, and polio types 1 to 3, but not for polyribosylribitol phosphate (PRP). While PRP did not meet noninferiority criteria, the seroprotection rate and geometric mean concentration (GMC) were high, indicating a clinically robust immune response. GMCs or titers for other antigens (including pertussis) and the safety profiles were generally similar between groups. Fully liquid DTaP5-IPV-Hib can be administered using the 3-, 5-, and 12-month vaccination schedule. (This study has been registered at ClinicalTrials.gov under registration no. NCT00287092.) PMID:23966556

  20. Randomized, controlled, multicenter study of the immunogenicity and safety of a fully liquid combination diphtheria-tetanus toxoid-five-component acellular pertussis (DTaP5), inactivated poliovirus (IPV), and haemophilus influenzae type b (Hib) vaccine compared with a DTaP3-IPV/Hib vaccine administered at 3, 5, and 12 months of age.

    Science.gov (United States)

    Vesikari, Timo; Silfverdal, Sven Arne; Boisnard, Florence; Thomas, Stéphane; Mwawasi, Grace; Reynolds, Donna

    2013-10-01

    This study compared the levels of immunogenicity and safety of diphtheria-tetanus toxoid-five-component acellular pertussis (DTaP(5)), inactivated poliovirus (IPV), and Haemophilus influenzae type b (Hib) (DTaP(5)-IPV-Hib) and DTaP(3)-IPV/Hib vaccines for study participants 3, 5, and 12 months of age. Post-dose 3 noninferiority criteria comparing DTaP(5)-IPV-Hib to DTaP(3)-IPV/Hib using rates of seroprotection were demonstrated against diphtheria, tetanus, and polio types 1 to 3, but not for polyribosylribitol phosphate (PRP). While PRP did not meet noninferiority criteria, the seroprotection rate and geometric mean concentration (GMC) were high, indicating a clinically robust immune response. GMCs or titers for other antigens (including pertussis) and the safety profiles were generally similar between groups. Fully liquid DTaP(5)-IPV-Hib can be administered using the 3-, 5-, and 12-month vaccination schedule. (This study has been registered at ClinicalTrials.gov under registration no. NCT00287092.).

  1. Physics of Fully Depleted CCDs

    CERN Document Server

    Holland, S E; Kolbe, W F; Lee, J S

    2014-01-01

    In this work we present simple, physics-based models for two effects that have been noted in the fully depleted CCDs that are presently used in the Dark Energy Survey Camera. The first effect is the observation that the point-spread function increases slightly with the signal level. This is explained by considering the effect on charge-carrier diffusion due to the reduction in the magnitude of the channel potential as collected signal charge acts to partially neutralize the fixed charge in the depleted channel. The resulting reduced voltage drop across the carrier drift region decreases the vertical electric field and increases the carrier transit time. The second effect is the observation of low-level, concentric ring patterns seen in uniformly illuminated images. This effect is shown to be most likely due to lateral deflection of charge during the transit of the photogenerated carriers to the potential wells as a result of lateral electric fields. The lateral fields are a result of space charge in the fully...

  2. Evaluation of steel slag coarse aggregate in hot mix asphalt concrete.

    Science.gov (United States)

    Ahmedzade, Perviz; Sengoz, Burak

    2009-06-15

    This paper presents the influences of the utilization of steel slag as a coarse aggregate on the properties of hot mix asphalt. Four different asphalt mixtures containing two types of asphalt cement (AC-5; AC-10) and coarse aggregate (limestone; steel slag) were used to prepare Marshall specimens and to determine optimum bitumen content. Mechanical characteristics of all mixtures were evaluated by Marshall stability, indirect tensile stiffness modulus, creep stiffness, and indirect tensile strength tests. The electrical sensitivity of the specimens were also investigated in accordance with ASTM D257-91. It was observed that steel slag used as a coarse aggregate improved the mechanical properties of asphalt mixtures. Moreover, volume resistivity values demonstrated that the electrical conductivity of steel slag mixtures were better than that of limestone mixtures.

  3. Effect of the cooling rate on the phase composition and structure of copper matte converting slags

    Science.gov (United States)

    Selivanov, E. N.; Gulyaeva, R. I.; Udoeva, L. Yu.; Belyaev, V. V.; Pankratov, A. A.

    2009-08-01

    The effect of the cooling rate on the phase composition and microstructure of copper matte converting slags is studied by X-ray diffraction, combined thermogravimetry and calorimetry, mineragraphy, and electron-probe microanalysis. The compositions of oxide and sulfide phases are determined, and the forms of nonferrous metals in slags cooled at a rate of 0.3 and 900°C/s are revealed. At high cooling rates of the slags, iron silicate glass is shown to form apart from sulfide phases. Repeated heating of the slags leads to the development of devitrification, “cold” crystallization, and melting. A decrease in the cooling rate favors an increase in the grain sizes in oxides (magnetite, iron silicates) and sulfides (bornite-, sphalerite, and galena-based solid solutions).

  4. Increasing the efficiency of ladle desulfurization of steel by using regenerated slags

    Energy Technology Data Exchange (ETDEWEB)

    Bigeev, V.A.; Petrov, L.V.; Vdovin, K.N.; Kotii, V.N.; Deryabin, A.V.

    1988-05-01

    The volume of steel subjected to ladle desulfurization can be increased by regenerating spent synthetic slags and returning them to the production cycle. Two problems encountered in the restoration of the desulfurizing properties of the slags are the need to reduce the content of the oxides of silicon and iron and remove sulfur to the 0.03-0.06 level. Difficulties and solutions of both problems are discussed and a scheme for regeneration is proposed which uses oxidation and reduction processes and considers such parameters as ladle and furnace lining protection and metal and slag separation measures. The scheme makes the expanded efficiency of ladle desulfurization of steel with regenerated slag a realistic option and will be recommended for introduction after the individual process and design parameters have been refined.

  5. Fluid Flow and Interfacial Phenomenon of Slag and Metal in Continuous Casting Tundish With Argon Blowing

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; ZHU Miao-yong; ZHOU Hai-bing; WANG Ying

    2008-01-01

    The fluid flow and the interracial phenomenon of slag and metal in tundish with gas blowing were studied with mathematical and physical modeling,and the effects of gas flowrate,the placement of porous beam for the generation of bubbles,and the combination of flow control devices on the flow and slag-metal interface were investigated.The results show that the position of gas bubbling has a significant effect on the flow in tundish,and the placement of porous beam and gas flowrate are the two main factors affecting the entrapment of slag in tundish.The closer the porous beam to the weir,the more reasonable is the flow,which is in favor of the control of slag entrapment in tundish.

  6. Utilizing of the metallurgical slag for production of cementless concrete mixtures

    Directory of Open Access Journals (Sweden)

    D. Baricová

    2012-10-01

    Full Text Available In process of pig iron, steel and cast iron production besides main product, also secondary products are formed, that have character of secondary raw materials and industrial wastes. The most abundant secondary product originating in the metallurgical process is furnace slag. Total amount of accured slag, also its chemical, mineralogical, physical – chemical properties and similarity with natural stones predestinate its utilisation in different fields of industry. The contribution deals with production of cementless concrete mixtures, where the main parts were formed by blast furnace granulated slag grinded and different gravel slag from blast furnace, oxygen converter and electric arc furnace. As activators of solidification different kinds of water glass were tested.

  7. Cleaning of waste smelter slags and recovery of valuable metals by pressure oxidative leaching.

    Science.gov (United States)

    Li, Yunjiao; Perederiy, Ilya; Papangelakis, Vladimiros G

    2008-04-01

    Huge quantities of slag, a waste solid product of pyrometallurgical operations by the metals industry are dumped continuously around the world, posing a potential environmental threat due to entrained values of base metals and sulfur. High temperature pressure oxidative acid leaching of nickel smelter slags was investigated as a process to facilitate slag cleaning and selective dissolution of base metals for economic recovery. Five key parameters, namely temperature, acid addition, oxygen overpressure, solids loading and particle size, were examined on the process performance. Base metal recoveries, acid and oxygen consumptions were accurately measured, and ferrous/ferric iron concentrations were also determined. A highly selective leaching of valuable metals with extractions of >99% for nickel and cobalt, >97% for copper, >91% for zinc and metals, hematite and virtually zero sulfidic sulfur seems to be suitable for safe disposal. The process seems to be able to claim economic recovery of base metals from slags and is reliable and feasible.

  8. Short review on the origin and countermeasure of biomass slagging in grate furnace

    Directory of Open Access Journals (Sweden)

    Yiming eZhu

    2014-02-01

    Full Text Available Given the increasing demand for energy consumption, biomass has been more and more important as a new type of clean renewable energy source. Biomass direct firing is the most mature and promising utilization method to date, while it allows a timely solution to slagging problems. Alkali metal elements in the biomass fuel and the ash fusion behavior, as the two major origins contributing to slagging during biomass combustion, are analyzed in this paper. The slag presents various layered structures affected by the different compositions of ash particles. Besides, the high-temperature molten material which provides a supporting effect on the skeletal structure in biomass ash was proposed to evaluate the ash fusion characteristics. In addition, numerous solutions to biomass slagging, such as additives, fuel pretreatment and biomass co-firing, were also discussed.

  9. Improving the behavior of body roads by the use of gravel-slag mixture

    Science.gov (United States)

    Hadinane, Hocine; Oucief, Hocine; Merzoud, Mouloud

    2016-07-01

    The accumulation of wastes industrial stemming of the iron and steel industry has influenced negatively the environment. The adopted policy had for mission to eliminate these undesirable wastes by recycling them by their utilization in adequate areas. The objective of this work is to study the mechanical behavior of a gravel-slag based on crystallized and granulated slag, activated by lime. One will be interested in the study of resistance to punching and the bearing ratio of this slag through Proctor tests, CBR and by compression, tensile tests, for use in the layers of pavement (Foundation and base layers). The obtained result on gravel-slag show considerable performances, compared with natural aggregates point of resistance and thickness of the layers. Its utilization in the road area has allowed therefore the recycling these industrial wastes, to decrease the pollution, to use a minimum noble product requiring important exploitation energy and an economy on layers of surface realized with costly materials (bituminous concrete).

  10. Decomposition of acid dissolved titanium slag from Australia by sodium hydroxide

    Institute of Scientific and Technical Information of China (English)

    FENG Yang; WANG Jinggang; WANG Lina; QI Tao; XUE Tianyan; CHU Jinglong

    2009-01-01

    The kinetics of the decomposition of acid dissolved titanium slag with a sodium hydroxide system under atmospheric pressure was studied. The effect of reaction temperature, particle size and NaOH-to-slag mass ratio on titanium extraction was investigated. The results show that temperature and particle size have significant influence on titanium extraction. The experimental data of titanium extraction show that the shrinking core model with chemical reaction controlled process is most applicable for the decomposition of slag, with an apparent activation energy of 62.4 kJ·mol~(-1). Approximately 85 wt.%-90 wt.% of the titanium can be extracted from the slag under the optimal conditions. In addition, the purity of titanium dioxide obtained in the product is up to 98.5 wt.%.

  11. Smelting chlorination method applied to removal of copper from copper slags

    Institute of Scientific and Technical Information of China (English)

    李磊; 王华; 胡建杭

    2015-01-01

    In order to reasonably utilize the iron resources of copper slags, the smelting chlorination process was used to remove copper from copper slags. Higher holding temperature and O2 flow rate are beneficial to increasing copper removal rate. However, the Cu2O mode is formed by the reaction of surplus O2 and CuCl with O2 flow rate increasing over 0.4 L/min, causing CuCl volatilization rate and copper removal rate to decrease. The resulting copper removal rate of 84.34%is obtained under the optimum conditions of holding temperature of 1573 K, residence time of 10 min, CaCl2 addition amount of 0.1 (mass ratio of CaCl2 and the copper slag) and oxygen flow rate of 0.4 L/min. The efficient removal of copper from copper slags through chlorination is feasible.

  12. Anisotropy of Expansion Coefficient and Slag Resistance of Spinel Carbon Bricks

    Institute of Scientific and Technical Information of China (English)

    YANG Ding'ao; YUAN Shouqian; JIANG Mingxue; DONG Sunzhen; ZHAO Zijian

    2006-01-01

    Effects of the pressure direction on the thermal expansion and slag corrosion resistance were investigated and anisotropic microstructures of flaky graphite in spinel carbon bricks were examined. The experimental results show that slag corrosion velocities in the direction parallel to the pressure direction display a decrease of 34% compared to those in the vertical direction. Meantime, the linear expansion coefficient in the direction parallel to the pressure direction is 2.45 times as large as that in the vertical pressure direction. Slag corrosion velocities of spinel carbon bricks soaked in the AOD melting slag display a 46%-47% decrease compared to those of magnesia carbon bricks. The microstructure observation shows that spinel carbon bricks have a high degree of preferred orientation.

  13. Corrosion Resistance of MgO-C Based Refractory to Slag Containing Titania

    Institute of Scientific and Technical Information of China (English)

    LIU Qing-cai; SUN Ya-li; DU Yun-gui; CHEN Deng-fu

    2004-01-01

    The interaction between the slag containing titanium oxides (TiO2 of 2.0 %-20.0 %) and a MgO-C based refractory was investigated by immersion test. The relationship between TiO2 content in slag and corrosion rate of the refractory was studied. The microstructure and compositions of the corroded refractory were analyzed by SEM and X-ray diffraction. The corrosion mechanism of MgO-C based refractory in the slag containing titanium was proposed, and the effects of TiO2 content, slag basicity (ωCaO/ωSiO2) and temperature in molten bath on the corrosion rate of the refractory were obtained.

  14. Dissolution Kinetics of Magnesitic-Dolomite and Magnesite-Chrome Refractories in Secondary Steelmaking Slags

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhaoyou; WU Xuezhen; YE Fangbao

    2007-01-01

    Dissolution kinetics of magnesitic-dolomite and magnesite-chrome refractories in secondary steelmaking slags was studied by means of the rotating cylinder method under forced convection. Materials investigated include four magnesitic-dolomite samples (MgO content 40% to 93% ) and two magnesite-chrome samples ( co-clinkered and semi-rebonded ). Synthetic slags simulative of VOD and AOD slags with varying basicity (0. 6-2. 68) are used. The experiments are carried out in Ar atmosphere at different temperatures (1 600 ℃-1 750 ℃ ) and revolumicrostructure of specimens (before and after slag tests)are studied by optical microscopy, SEM and EPMA.Based on our experimental results the mechanism and kinetics of the dissolution process are discussed.

  15. Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues

    Energy Technology Data Exchange (ETDEWEB)

    Murray, A.M.

    1999-02-10

    This paper reports on the chemical characterization of the sand, slag, and crucible (SS and C) residues and the fluoride residues that may be shipped from the Rocky Flats Environmental Technology Site (RFETS) to Savannah River Site (SRS).

  16. Synthesis of Calcium Silicate Hydrate based on Steel Slag with Various Alkalinities

    Institute of Scientific and Technical Information of China (English)

    WANG Shuping; PENG Xiaoqin; GENG Jianqiang; LI Bin; WANG Kaiyu

    2014-01-01

    This study aimed to improve the hydraulic potential properties of the slag. Therefore, a method of dynamic hydrothermal synthesis was applied to synthesize calcium silicate hydrate. The phases and nanostructures were characterized by XRD, FTIR, TEM, and BET nitrogen adsorption. The influence of alkalinity of steel slag on its structures and properties was discussed. The experimental results show that, the main product is amorphous calcium silicate hydrate gel with flocculent or fibrous pattern with a BET specific surface area up to 77 m2/g and pore volume of 0.34 mL/g. Compared with low alkalinity steel slag, calcium silicate hydrate synthesized from higher alkalinity steel slag is prone to transform to tobermorite structure.

  17. Computational Modeling of Arc-Slag Interaction in DC Furnaces

    Science.gov (United States)

    Reynolds, Quinn G.

    2016-11-01

    The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

  18. PRODUCTION OF PAVING BLOCK AND KERB INCORPORATING BLASTFURNACE SLAG

    Directory of Open Access Journals (Sweden)

    İsa YÜKSEL

    2007-02-01

    Full Text Available This paper presents results of an experimental study about partial substitution of granulated blast-furnace slag (GBFS as fine aggregate in production of concrete paving blocks and kerbs. GBFS is replaced sand for different GBFS/sand ratios in concrete during production of kerb and paving block specimens. Some tests orienting towards strength and durability were applied on these specimens including control specimens that are produced with normal concrete. Then, the results of tested properties of GBFS-replaced specimens and control specimens were compared. GBFS decreases the compressive strength of paving blocks and kerbs according to the results. However, some durability properties which are more important than strength for these elements are improved with GBFS replacement. The most improved property was abrasion resistance. It is concluded that it is feasible to use GBFS in paving block and kerb production with an optimum replacement ratio for these specimens.

  19. Computational Modeling of Arc-Slag Interaction in DC Furnaces

    Science.gov (United States)

    Reynolds, Quinn G.

    2017-02-01

    The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

  20. Alkaline activated slag cements. Determination of reaction degree

    Directory of Open Access Journals (Sweden)

    Fernández-Jiménez, A.

    2001-03-01

    Full Text Available The aim of the present work was to evaluate the validity of non-calorimetric different methods, used in the determination of reaction degree of alkaline activated slag pastes. The methods used were: (a chemical separation by methanol-salicylic acid; (b determination of the weight loss mass between 100-600°C in TG curves, associated to chemically combined water; (c quantification of the -74 ppm signal in 29Si MAS-NMR spectra. The parameters considered in the process were: nature of the alkaline activator (Waterglass, Na2CO3 and NaOH, activator concentration (4% and 3% Na2O in mass with respect to the slag, curing temperature (25 and 45°C, slag specific surface (460 and 900 m2/kg and time of reaction (from 7 days to 18 months. The results obtained indicate that none of the three methods is definitive but complementary and they provide to follow the reactive evolution of the alkaline activated slag cements. The method based on the quantification of the -74 ppm signal in the 29Si MAS NMR is the most suitable method.

    El objetivo del presente trabajo fue evaluar la validez de diferentes métodos, no calorimétricos, utilizados en la determinación del grado de reacción de pastas de escoria activada alcalinamente. Los métodos utilizados fueron: (a método de separación química por disolución en metanol ácido-salicílico; (b determinación de las pérdidas de masa entre 100-600°C en las curvas de TG, pérdidas asociadas a la cantidad de agua químicamente combinada: (c cuantificación de la señal de -74 ppm de los espectros de 29Si RMN MAS. Las variables consideradas en el proceso fueron: naturaleza del activador alcalino (Waterglass, Na2CO3 y NaOH, concentración del activador (4% y 3% de Na2O en masa respecto a la escoria, temperatura de curado (25 y 45°C, superficie específica de la escoria (460 y 900 m2/kg y

  1. Measurement of Moisture Content in Sand, Slag, and Crucible Materials

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.H.

    1999-09-20

    The deinventory process at Rocky Flats (RFETS) has included moisture content measurements of sand, slag, and crucible (SSC) materials by performing weight loss measurements at 210 degrees - 220 degrees Celsius on representative samples prior to packaging for shipment. Shipping requirements include knowledge of the moisture content. Work at the Savannah River Technology Center (SRTC) showed that the measurement at 210 degrees - 220 degrees Celsius did not account for all of the moisture. The objective of the work in this report was to determine if the measurement at 210 degrees - 220 degrees Celsius at RFETS could be used to set upper bounds on moisture content and therefore, eliminate the need for RFETS to unpack, reanalyze and repack the material.

  2. Investigations on phosphorus recovery and reuse as soil amendment from electric arc furnace slag filters.

    Science.gov (United States)

    Bird, Simon C; Drizo, Aleksandra

    2009-11-01

    Electric arc furnace (EAF) steel slag has been identified as an effective filter material for the removal of phosphorus (P) from both point and non-point sources. To determine the feasibility of land-applying P saturated EAF steel slag this study was undertaken to investigate (i) saturated EAF steel slag material's potential as a P fertilizer or soil amendment and (ii) P desorption and metals leachate from saturated EAF steel slag material to surface runoff. Medicago sativa (alfalfa) was planted in a nutrient depleted washed sand media. Phosphorus was added either as saturated EAF steel slag or as a standard commercial phosphate fertilizer in order to assess the plant availability of the P from saturated EAF steel slag. Four different P application levels were tested: a low (20 lbs acre furrow slice(-1) (5.5 g P m(-3))) two medium (40 and 60 lbs. acre f.s.(-1) (11 and 16.5 g P m(-3))) and a high (120 lbs. acre f.s.(-1) (33 g P m(-3))). The above-ground biomass of half of the plants was harvested after 5 weeks and the second half at 10 weeks. All treatments regardless of the P source used showed high rates of germination. At the first harvest period (5 weeks) significantly higher above-ground biomass (p < 0.01) was seen at the 3 highest P amendment rates in treatments with triple super phosphate fertilizer (TSP) than with EAF steel slag. However, by the second harvest (10 weeks) only the highest amendment rate of TSP showed a significantly higher amount of biomass (p < 0.01), suggesting that EAF steel slag might be an effective slow release P source. In a second experiment, a rain simulator was used to assess desorption of DRP, TP and metals from a saturated and semi-saturated EAF steel slag. The results revealed that the total amounts of DRP and TP released to surface runoff from EAF steel slag were negligible when compared to the total quantities of P retained by this material. Overall the results from this study demonstrated that once the EAF steel slag filter

  3. Late Bronze age metallurgy in the Italian Eastern Alps: copper smelting slags and mine exploitation

    OpenAIRE

    2013-01-01

    At the end of the second millennium B.C., the extractive metallurgy of copper in Trentino (Italy) achieved a peak of technological efficiency and mass production, as evidenced by the large number of metallurgical sites and the huge amount of slags resulting from the smelting activities. Though different scholars proposed several smelting process models, so far an agreed interpretation of the whole process is lacking. Over 70 slags from the Luserna, Transacqua and Segonzano sites (all l...

  4. Prediction of coal slag foaming under gasification conditions by thermodynamic equilibrium calculations

    Energy Technology Data Exchange (ETDEWEB)

    Lim, S.; Oh, M. [Hongik University, Seoul (Republic of Korea). School of Chemical Engineering

    2007-09-15

    In slagging gasifiers, slag foaming can cause serious operational problems, so there is a need for investigation into the conditions causing slag foaming. Viscosity experiments were carried out examining viscosity, extent of swelling and Fe formation. Although extensive swelling was not observed, FeO reduction was observed under an N{sub 2}/CO gas atmosphere, but not under CO{sub 2}/CO. In order to predict FeO reduction conditions in the gasifier, a model for an adiabatic equilibrium gasifier was developed. The gas composition, the amount of gas to slag, and PO{sub 2} were calculated for a slurry-feed gasifier, and the results of the calculation were used to predict the reduction of FeO in slag by using FactSage. Under typical gasification conditions for Denisovsky coal, the predicted -O{sub 2} in the gasifier was not low enough to cause FeO reduction. The FactSage simulation for the viscometer conditions predicted no FeO reduction under a CO/CO{sub 2} atmosphere, but did predict Fe formation under CO/N{sub 2} conditions. At a 20% CO concentration, FeO reduction starts at temperatures above 1,600{sup o}C. Since the slag has a low viscosity at 1,600{sup o}C, the oxygen bubble may have escaped as it formed. Therefore, slag foaming, caused by FeO reduction in the slag, can only occur when the right conditions of viscosity and oxygen partial pressure are met.

  5. The Revovery of Copper and Cobalt from Oxidized Copper Ore and Converter Slag

    OpenAIRE

    ZİYADANOĞULLARI, Berrin; ZİYADANOĞULLARI, Recep

    1999-01-01

    The aim of this study was to develop a method for obtaining copper and cobalt from oxidized copper ore and converter slag. In order to convert the copper and cobalt into sulfate compounds the main step was to roast the samples obtained by sulfurization and transfer the samples into solution. First the oxidized copper ore was roasted, followed by the mixture of converter slag and oxidized copper ore. Since the levels of copper and cobalt were low, the sulfurization process was carri...

  6. Utilization of lightweight materials made from coal gasification slags. Quarterly report, September 1--November 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    In previous projects, Praxis investigated the utilization of as-generated slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, the authors found that it would be extremely difficult for as-generated slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1,400 and 1,700 F. These results confirmed the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for various applications. The project goals are to be accomplished in two phases: Phase 1, comprising the production of LWA and ULWA from slag at the large pilot scale, and Phase 2, which involves commercial evaluation of these aggregates in a number of applications. This document summarizes the Phase 2 accomplishments to date along with the major accomplishments from Phase 1.

  7. Evaluation on chemical stability of lead blast furnace (LBF) and imperial smelting furnace (ISF) slags.

    Science.gov (United States)

    Yin, Nang-Htay; Sivry, Yann; Guyot, François; Lens, Piet N L; van Hullebusch, Eric D

    2016-09-15

    The leaching behavior of Pb and Zn from lead blast furnace (LBF) and imperial smelting furnace (ISF) slags sampled in the North of France was studied as a function of pHs and under two atmospheres (open air and nitrogen). The leaching of major elements from the slags was monitored as a function of pH (4, 5.5, 7, 8.5 and 10) under both atmospheres for different slag-water interaction times (1 day and 9 days). The leaching results were coupled with a geochemical model; Visual MINTEQ version 3.0, and a detailed morphological and mineralogical analysis was performed on the leached slags by scanning and transmission electron microscopy (SEM and TEM). Significant amounts of Ca, Fe and Zn were released under acidic conditions (pH 4) with a decrease towards the neutral to alkaline conditions (pH 7 and 10) for both LBF and ISF slags. On the other hand, Fe leachability was limited at neutral to alkaline pH for both slags. The concentrations of all elements increased gradually after 216 h compared to initial 24 h of leaching period. The presence of oxygen under open-air atmosphere not only enhanced oxidative weathering but also encouraged formation of secondary oxide and carbonate phases. Formation of carbonates and clay minerals was suggested by Visual MINTEQ which was further confirmed by SEM & TEM. The hydration and partial dissolution of hardystonite, as well as the destabilization of amorphous glassy matrix mainly contributed to the release of major elements, whereas the spinel related oxides were resistant against pH changes and atmospheres within the time frame concerned for both LBF and ISF slags. The total amount of Pb leached out at pH 7 under both atmospheres suggested that both LBF and ISF slags are prone to weathering even at neutral environmental conditions.

  8. Spatial distribution of chromium in soils contaminated by chromium-containing slag

    Institute of Scientific and Technical Information of China (English)

    HUANG Shun-hong; PENG Bing; YANG Zhi-hui; CHAI Li-yuan; XU You-ze; SU Chang-qing

    2009-01-01

    To evaluate the metal chromium (Cr) contamination of soil at a chromium-containing slag site by ferrochromium production, the contaminated sites, under slag heap, in the vicinity of slag heap and arable soils near the outlet of sewer channel, and unpolluted site 5 km away from one ferroalloy plant in Hunan Province, China, were selected. The concentrations of total Cr and water soluble Cr in bulk soil samples and profile depth samples were determined. The results show that the soils in the vicinity of slag heap have the highest total Cr content followed by the soils under the slag heap and near the outlet of sewer channel of the factory. The mean concentrations of total Cr in the top soils at above three contaminated locations exceed the critical level of Secondary Environmental Quality Standard for Soil in China by 3.5, 5.4 and 1.8 times. In most Cr polluted soils, total Cr has a relative accumulation in soil depth of 40-60 cm, but this trend is not found in unpolluted soils. The average concentrations of water soluble Cr (Ⅵ) in top soils under slag heap and in the vicinity of slag heap are 176.9 times and 52.7 times higher than that in the uncontaminated soils, respectively. However, water soluble Cr (Ⅵ) contents in soils near sewer channel are all low and the values are close to that in the uncontaminated soils. Although water soluble Cr (Ⅵ) content in soil profiles decreases with soil depths, it in soils under slag heap maintains a high level even at a depth of 100-150 cm. The results imply that the transportation of Cr (Ⅵ) can result in a potential risk of groundwater system in this area.

  9. Use of copper slag in the manufacture of Portland cement

    Directory of Open Access Journals (Sweden)

    Aquilar Elguézabal, A.

    2006-03-01

    Full Text Available Given its chemical and mineralogical characteristics, copper slag, a solid industrial by-product, may serve as a partial substitute for silica and hematite in raw mixes used to manufacture Portland cement clinker. The benefits of such substitution include lower production costs and energy savings. The effect of slag-containing raw mixes on the reactivity of the CaO-Si02-Al203-Fe203 system was studied at three temperatures (1,350, 1,400 and 1,450ºC. Four mixes were used: M-1 and M-2 prepared with conventional prime materials and M-3 and M-4, in which ignimbrite and hematite were substituted for slag. In M-3 the slag replaced 45.54% of the ignimbrite and 100% of the hematite, and in M-4 100% of the mineral iron. The samples were clinkerized at 1,350, 1,400 and 1,450ºC. At 1,400ºC, clinker M-3 was found to have 10.7% less free lime than M-1, while the level in M-4 it was 15.93% lower than in M-2. The presence of the main clinker phases was confirmed by X-ray diffraction, which also showed that adding slag during c/inker manufacture slightly improves raw mix burnability without generating new unwanted phases. Consequently, recovery in cement kilns would appear to be an economically and environmentally feasible alternative to coprocessing such waste, although the industrial use of slag depends on its heavy metal content.En acuerdo con las características químicas y mineralógicas de la escoria de cobre, este residuo sólido industrial puede ser utilizado en el proceso de fabricación de clínker Portland como sustituto parcial de los minerales de sílice y hematita en la formación de mezclas crudas cuyos beneficios serían: disminución de los costos de producción de mezclas crudas y del consumo calorífico. El efecto de la adición de la escoria en las mezclas crudas sobre la reactividad del sistema CaO-Si02-Al203-Fe20 3 se estudió en tres niveles de temperatura (1.350, 1.400 Y 1.450ºC. Se trabajó con cuatro mezclas crudas, M-1 y M

  10. The thermodynamic behavior of sulfur in BaO-BaF2 slags

    Science.gov (United States)

    Rachev, Ivan P.; Tsukihashi, Fumitaka; Sano, Nobuo

    1991-06-01

    A gas-slag-metal equilibration technique was used to determine the sulfide capacity of the BaO-BaF2 system at 1473 and 1573 K. The dependence of carbonate capacity on the slag composition was also measured at these temperatures. It was found that the BaO-BaF2 system has the highest sulfide capacities among the fluxes which are of metallurgical interest. The dependence of sulfide and carbonate capacities on the partial pressure of O2 and CO2 was also investigated. The partial pressure of CO2 proved to have a strong effect on these values at the investigated temperatures. The influence of temperature on the sulfide and carbonate capacities was studied in the temperature range between 1423 and 1623 K. The data for sulfide and carbonate capacities were correlated in order to check if the carbonate capacity can be used as a measure of basicity of slags. It was found that the carbonate capacity can be used as a representative measure of the slag basicity at low contents of BaO and at temperatures higher than 1623 K when the carbonate dissolution into the slag is low and the ratio of the activity coefficient of a sulfide ion to that of a carbonate ion is independent of slag composition.

  11. Studies on use of Copper Slag as Replacement Material for River Sand in Building Constructions

    Science.gov (United States)

    Madheswaran, C. K.; Ambily, P. S.; Dattatreya, J. K.; Rajamane, N. P.

    2014-09-01

    This work focuses on the use of copper slag, as a partial replacement of sand for use in cement concrete and building construction. Cement mortar mixtures prepared with fine aggregate made up of different proportions of copper slag and sand were tested for use as masonry mortars and plastering. Three masonry wall panels of dimensions 1 × 1 m were plastered. The studies showed that although copper slag based mortar is suitable for plastering, with the increase in copper slag content, the wastage due to material rebounding from the plastered surfaces increases. It is therefore suggested that the copper slag can be used for plastering of floorings and horizontal up to 50 % by mass of the fine aggregate, and for vertical surfaces, such as, brick/block walls it can be used up to 25 %. In this study on concrete mixtures were prepared with two water cement ratios and different proportions of copper slag ranging from 0 % (for the control mix) to 100 % of fine aggregate. The Concrete mixes were evaluated for workability, density, and compressive strength.

  12. Remediation of TCE-contaminated groundwater using acid/BOF slag enhanced chemical oxidation.

    Science.gov (United States)

    Tsai, T T; Kao, C M; Wang, J Y

    2011-04-01

    The objective of this study was to evaluate the potential of applying acid/H(2)O(2)/basic oxygen furnace slag (BOF slag) and acid/S(2)O(8)(2-)/BOF slag systems to enhance the chemical oxidation of trichloroethylene (TCE)-contaminated groundwater. Results from the bench-scale study indicate that TCE oxidation via the Fenton-like oxidation process can be enhanced with the addition of BOF slag at low pH (pH=2-5.2) and neutral (pH=7.1) conditions. Because the BOF slag has iron abundant properties (14% of FeO and 6% of Fe(2)O(3)), it can be sustainably reused for the supplement of iron minerals during the Fenton-like or persulfate oxidation processes. Results indicate that higher TCE removal efficiency (84%) was obtained with the addition of inorganic acid for the activation of Fenton-like reaction compared with the experiments with organic acids addition (with efficiency of 10-15% lower) (BOF slag=10gL(-1); initial pH=5.2). This could be due to the fact that organic acids would compete with TCE for available oxidants. Results also indicate that the pH value had a linear correlation with the observed first-order decay constant of TCE, and thus, lower pH caused a higher TCE oxidation rate.

  13. Methods for Improving Volume Stability of Steel Slag as Fine Aggregate

    Institute of Scientific and Technical Information of China (English)

    LUN Yunxia; ZilOU Mingkai; CAI Xiao; XU Fang

    2008-01-01

    Suitable methods for enhancing the volume stability of steel slag utilized as fine aggregate were determined. The effects of steam treatment at 100 ℃ and autoclave treatment under 2.0 Mpa on the soundness of steel slag sand were investigated by means of powder ratio, linear expansion, compressive and flexural strength. DTA, EDX, XRD and ethylene glycol methods were employed to analyze both the treated slags and susceptible expansion grains. Experimental results indicate that powder ratio, content of free lime and rate of linear expansion can express the improvement in volume stability of different treated methods. Steam treatment process cannot ultimately prevent specimens from cracking and decrease of strength, but mortar made from autoclave treated slag keeps integration subjected to hot water of 80 ℃ until 28 d and its strength do not show significant decrement. The hydration of over-burn free lime and periclase phase are the main cause for the disintegration or crack of untreated and steam treated steel slag's specimens. Autoclave treatment process is more effective than steam treatment process on enhancement of volume stability of steel slag.

  14. The composition and temperature dependence of the sulfide capacity of metallurgical slags

    Science.gov (United States)

    Sosinsky, Nd. J.; Sommerville, I. D.

    1986-06-01

    The concept of optical basicity and its applicability as a means of correlating the available data on the sulfide capacity of metallurgical slags has been reviewed. An excellent correlation based on very extensive data at 1500 °C, which was discussed in a previous paper, is combined with good correlations based on considerably less data at 1550 °C and 1650 °C to quantify the effect of temperature on the sulfide capacity of slags. The combined effects of slag composition and temperature have been expressed in the equation, log C s = [(22690 - 54640A)/7] + 43.6A - 25.2. Use of this equation permits the calculation of the sulfide capacity of a slag at any temperature between 1400 °C and 1700 °C simply from a knowledge of its chemical composition, and can be employed for virtually any oxide slag of interest in the field of iron and steelmaking. This, in turn, permits calculation of the equilibrium distribution of sulfur between this slag and iron or steel, provided that the oxygen potential is known or can be calculated from the degree of deoxidation applied.

  15. Effect of copper slag recovery on hydrometallurgical cut-off grades considering environmental aspects

    Institute of Scientific and Technical Information of China (English)

    AFSHIN AKBARI; ESMAEIL RAHIMI

    2016-01-01

    Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value (NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.

  16. Bioleaching of metals from steel slag by Acidithiobacillus thiooxidans culture supernatant.

    Science.gov (United States)

    Hocheng, Hong; Su, Cheer; Jadhav, Umesh U

    2014-12-01

    The generation of 300–500 kg of slag per ton of the steel produced is a formidable amount of solid waste available for treatment. They usually contain considerable quantities of valuable metals. In this sense, they may become either important secondary resource if processed in eco-friendly manner for secured supply of contained metals or potential pollutants, if not treated properly. It is possible to recover metals from steel slag by applying bioleaching process. Electric arc furnace (EAF) slag sample was used for bioleaching of metals. In the present study, before bioleaching experiment water washing of an EAF slag was carried out. This reduced slag pH from 11.2 to 8.3. Culture supernatants of Acidithiobacillus thiooxidans (At. thiooxidans), Acidithiobacillus ferrooxidans (At. ferrooxidans), and Aspergillus niger (A. niger) were used for metal solubilization. At. thiooxidans culture supernatant containing 0.016 M sulfuric acid was found most effective for bioleaching of metals from an EAF slag. Maximum metal extraction was found for Mg (28%), while it was least for Mo (0.1%) in six days. Repeated bioleaching cycles increased metal recovery from 28% to 75%, from 14% to 60% and from 11% to 27%, for Mg, Zn and Cu respectively.

  17. Thermodynamic Properties of Lead Oxide in a Mixture of Stainless Steelmaking and Nonferrous Smelting Slags

    Science.gov (United States)

    Maruoka, Nobuhiro; Ueda, Shigeru; Shibata, Hiroyuki; Yamaguchi, Katsunori; Kitamura, Shin-ya

    2012-06-01

    In our previous paper, a slag modification process involving the mixing of stainless steelmaking and nonferrous smelting slags was proposed for preventing the disintegration of the stainless steelmaking slag. In order to use this method, the behavior of heavy metals especially PbO contained in the nonferrous slag has to be assessed. In the present study, the activity coefficient of PbO in CaO-SiO2-FetO-Al2O3-MgO and CaO-SiO2-FetO slags saturated with iron was measured at 1673 K. The results showed that the activity coefficient of PbO increased with basicity and had a maximum value when the basicity was approximately 1.0. The equilibrium PbO content in the modified slag had a minimum value that corresponded to a mixing ratio of 0.6. The trend was similar to the change in the removal ratio of PbO observed in the previous study. Therefore, the change in the oxygen potential and the change in the activity coefficient of PbO can be considered the cause of this trend.

  18. Evaluation and Characterization of Plasma Sprayed Cu Slag-Al Composite Coatings on Metal Substrates

    Directory of Open Access Journals (Sweden)

    S. Mantry

    2013-01-01

    Full Text Available Copper slag is a waste product obtained during matte smelting and refining of copper. The present work explores the coating potential of copper slag by plasma spraying. This work shows that copper slag is eminently coatable. An attempt has been made in the present investigation to use the composites coatings of copper slag and Al powder in suitable combination on aluminium and mild steel substrates in order to improve the surface properties of these ductile metal-alloy substrates. When premixed with Al powder, the coating exhibits higher interfacial adhesion as compared to pure copper slag coatings. Maximum adhesion strengths of about 23 MPa and 21 MPa are recorded for the coatings of copper slag with 15 wt% of Al on aluminium and mild steel substrates, respectively. The input power to the plasma torch is found to affect the coating deposition efficiency and morphology of the coatings. It also suggests value addition of an industrial waste.

  19. Synthesis and Characterization of Titanium Slag from Ilmenite by Thermal Plasma Processing

    Science.gov (United States)

    Samal, Sneha

    2016-09-01

    Titanium rich slag has emerged as a raw material for alternative titanium source. Ilmenite contains 42-50% TiO2 as the mineralogical composition depending on the geographical resources. Application of titanium in paper, plastic, pigment and other various industries is increasing day by day. Due to the scarcity of natural raw mineral rutile (TiO2), ilmenite is considered as precursor for the extraction of TiO2. Ilmenite is reduced at the initial stage for the conversion of complex iron oxide into simpler form. Therefore, pre-reduction of ilmenite concentrate is essential to minimize the energy consumption during thermal plasma process. Thermal plasma processing of ilmenite for the production of titania rich slag is considered to be the direct route to meet the current demand of industrial needs of titanium. Titania rich slag contains 70-80% TiO2 as the major component with some other minor impurities, like oxide phases of Si, Al, Cr, Mg, Mn, Ca, etc. Usually titanium is present in tetravalent forms with globular metallic iron in the slag. Titania rich slag undergoes leaching for the removal of iron and transforming the slag into synthetic rutile having 85-95% of TiO2.

  20. LATS refining ladle slag modifying with CaO-CaF2

    Institute of Scientific and Technical Information of China (English)

    Hongming Wang; Guirong Li; Zhongming Ren; Bo Li; Xuejun Zhang; Guomin Shi

    2007-01-01

    To reduce the slag sticking onto the snorkel of the ladle during the ladle alloying treatment station (LATS) process, CaO-CaF2 (the mass ratio of CaO/CaF2 is 1:1) was employed as the modifier of the LATS refining ladle slag. The effect of CaO-CaF2 on the melting point, viscosity, and desulfurizing capability of the ladle slag was investigated. The melting point of the unmodified ladle slag is 1439°C. When adding 20wt% CaO-CaF2, the melting point is decreased to 1327°C. At 1500°C, the viscosity of the unmodified ladle slag is 6.5 Pa·s, which can be decreased lower than 2 Pa·s by adding more than 10wt% CaO-CaF2. The experimental results of desulfurization of the melts show that the desulfurizing power of the ladle slag can be enhanced by adding CaO-CaF2.

  1. Effects of Steel Slag Powder on Workability and Durability of Concrete

    Institute of Scientific and Technical Information of China (English)

    GUO Xiaolu; SHI Huisheng; WU Kai

    2014-01-01

    The workability and durability of a type of sustainable concrete made with steel slag powder were investigated. The hydrated products of cement paste with ground granulated blast furnace slag (GGBFS) alone or with a combined admixture of GGBFS-steel slag powder were investigated by X-ray diffraction (XRD). Furthermore, the mechanism of chemically activated steel slag powder was also studied. The experimental results showed that when steel slag powder was added to concrete, the slumps through the same time were lower. The initial and final setting times were slightly retarded. The dry shrinkages were lower, and the abrasion resistance was better. The chemically activated steel slag powder could improve compressive strengths, resistance to chloride permeation and water permeation, as well as carbonization resistance. XRD patterns indicated that the activators enhanced the formation of calcium silicate hydrate(C-S-H) gel and ettringite (AFt). This research contributes to sustainable disposal of wastes and has the potential to provide several important environmental benefits.

  2. Steel Slag and Shredded Tires as Media for Blind Inlets to Improve Water Quality

    Science.gov (United States)

    Gonzalez, J. M.; Smith, D. R.; Livingston, S.

    2015-12-01

    Off-site transport of contaminants through surface runoff affects water quality. Blind inlets are proven conservation practices for reducing surface runoff, and consequently reducing nutrient loadings from small agricultural closed depressions to water bodies. Gravel is the most widely used blind inlet media to reduce flow, but not to sorb contaminants from the water. Readily available byproducts, such as steel slag and shredded tires, could be used as alternative media in blind inlets to sorb nutrients and pesticides from surface runoff. Sorption isotherms were performed to investigate the sorption capabilities of steel slag and shredded tires for phosphate and atrazine in electrolyte background solutions containing either 10 mM CaCl2 or KCl. Results of this research demonstrated that phosphate and atrazine were irreversibly sorbed by the steel slag and shredded tires. The steel slag increased the pH solution increased about 4 pH units after the sorption step; while the pH of the solution with shredded tires remained the same. Desorption of the phosphate and atrazine was low from the steel slag and shredded tires, respectively. Thus, the above results suggest that the steel slag and shredded tires can potentially be used as media to sorb phosphate and atrazine, respectively.

  3. [Removal of metal ions Cu2+, Cd+ and Pb+ from solutions by sorption on slag].

    Science.gov (United States)

    Chen, Xiao; Hou, Wen-hua; Wang, Qun-hui

    2009-10-15

    Batch experiments were carried out to investigate the adsorption kinetics and thermodynamic characteristics of heavy metal ions Cu2+, Cd2+ and Pb2+ on the electric are furnace (EAF) slag from Baoshan Steel Factory. Several kinds of techniques including XRD analysis, BET specific surface analysis and SEM/EDS analysis were employed to determine the physico-chemical and surface characteristics of slag. Results indicated that the adsorption rate of heavy metal ions on the EAF slag was relatively high, and the sorption rate followed the order Cd2+ > Pb2+ > Cu2+. The adsorption kinetics obeyed first-order kinetics model (R2 > 0.99). Adsorption isotherm experiment showed that adsorption isotherm of heavy metal ions on slag fitted Langmuir model, and the maximum adsorption capacity of Cu2+, Cd2+ and Pb2+ was 0.101, 0.058 and 0.120 mmol x g(-1), respectively. The adsorption of heavy metal ions on slag was a spontaneous reaction (deltaG0 0). The effect of enthopy was the main driving force of the spontaneous adsorption reaction. The analysis results of SEM/EDS revealed the changes of surface morphology and chemical proportion before and after adsorption. Due to low-cost and high-efficiency, electric are furnace slag showed great potential for the treatment of heavy metal polluted wastewaters.

  4. Maximum availability and mineralogical control of chromium released from AOD slag.

    Science.gov (United States)

    Li, Junguo; Liu, Bao; Zeng, Yanan; Wang, Ziming; Gao, Zhiyuan

    2017-03-01

    AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database. The leaching tests indicated that the leaching availability of chromium was slight and mainly consisted of trivalent chromium. Aging of AOD slag under the atmosphere can oxidize trivalent chromium to hexavalent chromium, which could be leached out by rainwater. According to the simulation, the chromium concentration in leachates was controlled by the freely soluble pseudo-binary phases in the pH = 7.0 leaching process and controlled by the Cr2O3 phase in the pH = 4.0 leaching process. Chromium concentrations were underestimated when the controlling phases were determined to be FeCr2O4 and MgCr2O4. Facilitating the generation of the insoluble spinel-like phases during the cooling and disposal process of the molten slag could be an effective approach to decreasing the leaching concentration of chromium and its environmental risk.

  5. An Overview of Use of Linz-Donawitz (LD Steel Slag in Agriculture

    Directory of Open Access Journals (Sweden)

    Sasmita Chand

    2015-12-01

    Full Text Available Slag generated from basic oxygen furnace (BOF or Linz-Donawitz (LD converter is one of the recyclable wastes in integrated steel plants. This paper deals with the present and possible use of LD slag in agriculture. At present, the amount of slag deposited in storage yard, leading to the occupation of farm land and serious pollution to the environment. Improving the slag utilization is an important way to resolve these problems. The physical and chemical characteristics of steel slag were analyzed and then the research progress of steel slag utilization in agriculture as fertilizer introduced. Due to increasing awareness of the environment, disposal, reuse of wastes without harming the environment has became a prime concern for the industry. The local availability of non conventional sources of plant nutrients and soil conditioners plays a vital role because of the non availability and higher price of environmental fertilizers. Therefore, this waste can be utilized for enhancing yield as well as solving the disposal problem and improve the environment.

  6. Basic Oxygen Furnace Slag as a Liming Agent for Paddy and Upland Field Soils

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choong Il [Pohang Research Institute of Industrial Science and Technology, Pohang(Korea)

    1998-03-31

    Basic oxygen furnace (BOF) slag, a by-product of the iron and steelmaking industry produced in large quantities in Korea, poses a substantial disposal challenge. The BOF slag used in this study was 1/3 CaCO{sub 3} in total neutralizing power and application of 7-8 Mgha{sup -1} was needed to bring soil pH to 6.5 from pH 5.0-5.5 in silty clay or clay loam soil contained about 10% organic matter. A field assay was conducted to study whether BOF slag could be used as a dolomitic liming agent for agricultural soils. Four slag rates (0, 4, 8, 12 Mgha{sup -1})were investigated for their effect on soil properties, mineral concentrations in leaf tissues of rice and soybean, and yield of the crops. Slag application at 8 Mgha{sup -1} rate in paddy field increased pH, Ca, Mg, P, Si and Fe content in soil and rice yield by 4.3-14.2% depending on the soil type. In upland field the 8 Mgha{sup -1} rate increased pH, Ca and Fe content in soil and soybean yield by 36.6%. Thus, BOF slag appears to be a useful liming material for correcting soil acidity on both paddy and upland field soils and for increasing Ca, Mg, P, Si, and Fe concentration in plants. (author). 27 refs., 7 tabs.

  7. Slagging characteristics of molten coal ash on silicon-aluminum combustion liners of boiler

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to study the slagging characteristics of boiler combustion liners during pulverized coal stream combustion,the slag samples on the surface of combustion liner were investigated by X-ray diffractometry,scan electron microscopy and energy dispersive X-ray analysis,and the transformation characteristics of the compositions and crystal phases were studied.The results show that the size of slag granules decreases as the slagging temperature increases;the crystallinity of coal ash I reduces to about 48.6% when the temperature is increased up to 1 350 ℃,and that of the coal ash Ⅱ reduces to about 65% when the temperature is increased up to 1 500 ℃;the encroachment of molten coal ash to the combustion liner is strengthened.At the same time,the diffusion and the segregation of the compositions in combustion liners have selectivity,which is in favor of enhancing the content of crystal phases,weakening the conglutination among molten slag compositions and combustion liner,and avoiding yielding big clinkers.But the diffusion of the compositions in combustion liners increases the porosity and decreases the mechanical intensity of combustion liner,and makes the slag encroachment to the liner become more serious.

  8. Adsorption Study of Electric Arc Furnace Slag for the Removal of Manganese from Solution

    Directory of Open Access Journals (Sweden)

    C. L. Beh

    2010-01-01

    Full Text Available Problem statement: Steel making slag from Electric Arc Furnace (EAF is an abundant by-product in Malaysia steel making industry. It has potential to be used for heavy metal removal from contaminated water or waste water. Approach: The aim of this study was to investigate the characteristic and behavior of manganese removal by using EAF slag for efficient metal removal. The removal characteristics of manganese were investigated in term of sorption kinetics and isotherm. The batch adsorption kinetics and isotherm studies were carried out at 28°C and ten grams of EAF slag was added into 1 L manganese solution of various concentrations of 10, 25, 50, 75, 100 and 120 mg L-1. All these different mixtures were stirred and sampled at various desired times and centrifuged. The supernatant solutions were then collected for chemical analysis. Results: It was found that the EAF slag adsorption kinetics can be described well by the pseudo-2nd order kinetic model with fairly high correlation coefficients. The adsorption process obeyed the Langmuir isotherm model and the maximum uptake of the manganese from the solution is 2.31 mg L-1 g-1 of EAF slag used. Conclusion: From the study, it was concluded that the EAF slag can be an efficient adsorbent to remove manganese from both the solution and waste water.

  9. Fully automated (operational) modal analysis

    Science.gov (United States)

    Reynders, Edwin; Houbrechts, Jeroen; De Roeck, Guido

    2012-05-01

    Modal parameter estimation requires a lot of user interaction, especially when parametric system identification methods are used and the modes are selected in a stabilization diagram. In this paper, a fully automated, generally applicable three-stage clustering approach is developed for interpreting such a diagram. It does not require any user-specified parameter or threshold value, and it can be used in an experimental, operational, and combined vibration testing context and with any parametric system identification algorithm. The three stages of the algorithm correspond to the three stages in a manual analysis: setting stabilization thresholds for clearing out the diagram, detecting columns of stable modes, and selecting a representative mode from each column. An extensive validation study illustrates the accuracy and robustness of this automation strategy.

  10. Singularities in fully developed turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Shivamoggi, Bhimsen K., E-mail: bhimsen.shivamoggi@ucf.edu

    2015-09-18

    Phenomenological arguments are used to explore finite-time singularity (FTS) development in different physical fully-developed turbulence (FDT) situations. Effects of spatial intermittency and fluid compressibility in three-dimensional (3D) FDT and the role of the divorticity amplification mechanism in two-dimensional (2D) FDT and quasi-geostrophic FDT and the advection–diffusion mechanism in magnetohydrodynamic turbulence are considered to provide physical insights into the FTS development in variant cascade physics situations. The quasi-geostrophic FDT results connect with the 2D FDT results in the barotropic limit while they connect with 3D FDT results in the baroclinic limit and hence apparently provide a bridge between 2D and 3D. - Highlights: • Finite-time singularity development in turbulence situations is phenomenologically explored. • Spatial intermittency and compressibility effects are investigated. • Quasi-geostrophic turbulence is shown to provide a bridge between two-dimensional and three-dimensional cases.

  11. Analyzing the Technology of Using Ash and Slag Waste from Thermal Power Plants in the Production of Building Ceramics

    Science.gov (United States)

    Malchik, A. G.; Litovkin, S. V.; Rodionov, P. V.; Kozik, V. V.; Gaydamak, M. A.

    2016-04-01

    The work describes the problem of impounding and storing ash and slag waste at coal thermal power plants in Russia. Recovery and recycling of ash and slag waste are analyzed. Activity of radionuclides, the chemical composition and particle sizes of ash and slag waste were determined; the acidity index, the basicity and the class of material were defined. The technology for making ceramic products with the addition of ash and slag waste was proposed. The dependencies relative to the percentage of ash and slag waste and the optimal parameters for baking were established. The obtained materials were tested for physical and mechanical properties, namely for water absorption, thermal conductivity and compression strength. Based on the findings, future prospects for use of ash and slag waste were identified.

  12. Effect of Physicochemical Properties of Slag and Flux on the Removal Rate of Oxide Inclusion from Molten Steel

    Science.gov (United States)

    Park, Jun Seok; Park, Joo Hyun

    2016-12-01

    The slag-metal reaction experiments were carried out using a high-frequency induction furnace to confirm the effect of slag composition on the removal rate of inclusions in molten steel through the CaO-based slags. The apparent rate constant of oxygen removal ( k O) was obtained as a function of slag composition. It increased with increasing basicity, and the content of MgO and CaF2, whereas it decreased by increasing the content of Al2O3 in the slag. The removal rate of inclusions was strongly affected not only by the driving force of the chemical dissolution but also by the viscosity of the slags and fluxes.

  13. Distribution Behavior of Aluminum and Titanium Between Nickel-Based Alloys and Molten Slags in the Electro Slag Remelting (ESR) Process

    Science.gov (United States)

    Yang, Jun Gil; Park, Joo Hyun

    2017-08-01

    The equilibrium reaction between Ni alloys and CaO-Al2O3-CaF2-TiO2 system electroslag remelting (ESR) slags was investigated in the temperature range of 1773 K to 1873 K (1500 °C to 1600 °C) at p(O2) = 10-16 atm in order to obtain the optimized composition of the slags for producing Ni alloys with various Al and Ti ratios. In addition, the temperature dependence of the reaction equilibria between the ESR slags and Ni alloys was also evaluated. The stable ionic species of titanium in the ESR slag under the present experimental conditions was experimentally confirmed to be mainly Ti4+ ( i.e., TiO2) by X-ray photoelectron spectroscopy analysis of the quenched samples. The activity-composition relationship of TiO2 and Al2O3 in the ESR slag was determined as a function of the Al/Ti ratio of the alloys and the CaF2 content of the slags in conjunction with the activity ratio of Al to Ti in the alloys calculated from the FactSageTM 7.0 software. The temperature dependence of the activity-composition relationship of TiO2 and Al2O3 in the slag showed good linear correlations, and the equilibrium content ratio of TiO2 to Al2O3 at a fixed activity ratio increased with increasing temperature, which was expected based on the standard enthalpy change of the reaction. Thus, higher amounts of TiO2 should be added at higher operation temperatures in the ESR process. A 120 kg scale pilot ESR test (2000 A and 16 V) was performed to produce a commercial grade Ni-based superalloy based on the activity-composition relationship of the slag components obtained in the present study. Consequently, the contents of Al and Ti in the solidified ESR ingot were nearly the same as that of the original electrode throughout the entire length (280 mm) after the ESR process.

  14. Evaluation of electric arc furnace-processed steel slag for dermal corrosion, irritation, and sensitization from dermal contact.

    Science.gov (United States)

    Suh, Mina; Troese, Matthew J; Hall, Debra A; Yasso, Blair; Yzenas, John J; Proctor, Debora M

    2014-12-01

    Electric arc furnace (EAF) steel slag is alkaline (pH of ~11-12) and contains metals, most notably chromium and nickel, and thus has potential to cause dermal irritation and sensitization at sufficient dose. Dermal contact with EAF slag occurs in many occupational and environmental settings because it is used widely in construction and other industrial sectors for various applications including asphaltic paving, road bases, construction fill, and as feed for cement kilns construction. However, no published study has characterized the potential for dermal effects associated with EAF slag. To assess dermal irritation, corrosion and sensitizing potential of EAF slag, in vitro and in vivo dermal toxicity assays were conducted based on the Organisation for Economic Co-operation and Development (OECD) guidelines. In vitro dermal corrosion and irritation testing (OECD 431 and 439) of EAF slag was conducted using the reconstructed human epidermal (RHE) tissue model. In vivo dermal toxicity and delayed contact sensitization testing (OECD 404 and 406) were conducted in rabbits and guinea pigs, respectively. EAF slag was not corrosive and not irritating in any tests. The results of the delayed contact dermal sensitization test indicate that EAF slag is not a dermal sensitizer. These findings are supported by the observation that metals in EAF slag occur as oxides of low solubility with leachates that are well below toxicity characteristic leaching procedure (TCLP) limits. Based on these results and in accordance to the OECD guidelines, EAF slag is not considered a dermal sensitizer, corrosive or irritant.

  15. Basicity for blast furnace-type slag containing B2O3 and high MgO

    Institute of Scientific and Technical Information of China (English)

    黄振奇; 蔡亚旻; 朱文非; 杨祖磐

    2003-01-01

    There is quite abundant resource of ludwigite ore in Liaoning Province of China. Content of MgO in the slag of pyrometallurgical separation of boron from iron is much higher than that in the ordinary slags. Through the equilibrium partition ratio of sulfur LS between the metal and the slag in an atmosphere of CO-N2, the acidic coefficients for B2O3 and the basic coefficients for MgO were estimated. The basic formulae were given for the blast furnace-type slag containing B2O3 and high MgO.

  16. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  17. Recycling of Malaysia's electric arc furnace (EAF) slag waste into heavy-duty green ceramic tile.

    Science.gov (United States)

    Teo, Pao-Ter; Anasyida, Abu Seman; Basu, Projjal; Nurulakmal, Mohd Sharif

    2014-12-01

    Recently, various solid wastes from industry such as glass waste, fly ash, sewage sludge and slag have been recycled into various value-added products such as ceramic tile. The conventional solutions of dumping the wastes in landfills or incineration, including in Malaysia are getting obsolete as the annual huge amount of the solid wastes would boost-up disposal cost and may cause permanent damage to the flora and fauna. This recent waste recycling approach is much better and greener as it can resolve problems associated with over-limit storage of industrial wastes and reduce exploration of natural resources for ceramic tile to continuously sustain the nature. Therefore, in this project, an attempt was made to recycle electric arc furnace (EAF) slag waste, obtained from Malaysia's steel making industry, into ceramic tile via conventional powder compaction method. The research work was divided into two stages. The first stage was to evaluate the suitability of EAF slag in ceramic tile by varying weight percentage of EAF slag (40 wt.%, 50 wt.% and 60 wt.%) and ball clay (40 wt.%, 50 wt.% and 60 wt.%), with no addition of silica and potash feldspar. In the second stage, the weight percentage of EAF slag was fixed at 40 wt.% and the percentage of ball clay (30 wt.% and 40 wt.%), feldspar (10 wt.% and 20 wt.%) and silica (10 wt.% and 20 wt.%) added was varied accordingly. Results obtained show that as weight percentage of EAF slag increased up to 60 wt.%, the percentage of apparent porosity and water absorption also rose, with a reduction in tile flexural strength and increased porosity. On the other hand, limiting the weight percentage of EAF slag to 40 wt.% while increasing the weight percentage of ball clay led to a higher total percentage of anorthite and wollastonite minerals, resulting in higher flexural strength. It was found that introduction of silica and feldspar further improved the flexural strength due to optimization of densification process. The highest

  18. Restaurant No. 1 fully renovated

    CERN Multimedia

    2007-01-01

    The Restaurant No. 1 team. After several months of patience and goodwill on the part of our clients, we are delighted to announce that the major renovation work which began in September 2006 has now been completed. From 21 May 2007 we look forward to welcoming you to a completely renovated restaurant area designed with you in mind. The restaurant team wishes to thank all its clients for their patience and loyalty. Particular attention has been paid in the new design to creating a spacious serving area and providing a wider choice of dishes. The new restaurant area has been designed as an open-plan space to enable you to view all the dishes before making your selection and to move around freely from one food access point to another. It comprises user-friendly areas that fully comply with hygiene standards. From now on you will be able to pick and choose to your heart's content. We invite you to try out wok cooking or some other speciality. Or select a pizza or a plate of pasta with a choice of two sauces fr...

  19. Temporal dissolution of potentially toxic elements from silver smelting slag by synthetic environmental solutions.

    Science.gov (United States)

    Ash, Christopher; Borůvka, Luboš; Tejnecký, Václav; Šebek, Ondřej; Nikodem, Antonín; Drábek, Ondřej

    2013-11-15

    Waste slag which is created during precious metal smelting contains high levels of potentially toxic elements (PTE) which can be mobilised from unconfined deposits into the local environment. This paper examines the extractability of selected PTE (Pb, Zn, Cd, Mn) from slag samples by synthetic solutions designed to replicate those in the environment. Extracting agents were used to replicate potential leaching scenarios which are analogous to natural chemical weathering. Slag was submersed in a rainwater simulation solution (RSS), weak citric acid solution (representing rhizosphere secretions) and control solutions (deionised water) for a one month period with solution analyses made at intervals of 1, 24, 168 and 720 h. In 1 mM citric acid, dissolution of Cd and Zn showed little change with time, although for Zn the initial dissolution was considerable. Lead in citric acid was characterized by overall poor extractability. Mn solubility increased until an equilibrium state occurred within 24 h. The solubility of studied metals in citric acid can be characterized by a short time to equilibrium. RSS proved to be an effective solvent that, unlike citric acid solution, extracted increasing concentrations of Cd, Mn and Zn with time. Solubility of Pb in RSS was again very low. When taken as a proportion of a single 2 M HNO3 extraction which was applied to slag samples, Cd was the element most readily leached into RSS and control samples. In both studied solvents, slag heterogeneity is prominent in the case of Cd and Zn solubility. Contact time with solvent appears to be an important variable for the release of PTE from slag into solution. The purpose of this study was to provide insight into the environmental chemical dissolution of PTE from slag, which causes their enrichment in surrounding soils and surface waters.

  20. Utilization of lightweight materials made from coal gasification slags. Quarterly report, March 1995--May 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Integrated-gasification combined-cycle (IGCC) technology is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, this process generates large amounts of solid waste, consisting of vitrified ash (slag) along with some unconverted carbon, which is disposed of as solid waste. In previous projects, Praxis investigated the utilization of {open_quotes}as-generated{close_quotes} slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for {open_quotes}as-generated{close_quotes} slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag could be made into a lightweight material by controlled heating in a kiln at temperatures between 1400 and 1700{degrees}F. These results indicated the potential for using such materials as substitutes for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis with funding from the Electric Power Research Institute (EPRI), Illinois Clean Coal Institute (ICCI), and internal resources. The major objectives of the subject project, funded by DOE`s Morgantown Energy Technology Center (METC), are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for various applications.

  1. Steel slag carbonation in a flow-through reactor system: the role of fluid-flux.

    Science.gov (United States)

    Berryman, Eleanor J; Williams-Jones, Anthony E; Migdisov, Artashes A

    2015-01-01

    Steel production is currently the largest industrial source of atmospheric CO2. As annual steel production continues to grow, the need for effective methods of reducing its carbon footprint increases correspondingly. The carbonation of the calcium-bearing phases in steel slag generated during basic oxygen furnace (BOF) steel production, in particular its major constituent, larnite {Ca2SiO4}, which is a structural analogue of olivine {(MgFe)2SiO4}, the main mineral subjected to natural carbonation in peridotites, offers the potential to offset some of these emissions. However, the controls on the nature and efficiency of steel slag carbonation are yet to be completely understood. Experiments were conducted exposing steel slag grains to a CO2-H2O mixture in both batch and flow-through reactors to investigate the impact of temperature, fluid flux, and reaction gradient on the dissolution and carbonation of steel slag. The results of these experiments show that dissolution and carbonation of BOF steel slag are more efficient in a flow-through reactor than in the batch reactors used in most previous studies. Moreover, they show that fluid flux needs to be optimized in addition to grain size, pressure, and temperature, in order to maximize the efficiency of carbonation. Based on these results, a two-stage reactor consisting of a high and a low fluid-flux chamber is proposed for CO2 sequestration by steel slag carbonation, allowing dissolution of the slag and precipitation of calcium carbonate to occur within a single flow-through system.

  2. Effects of Temperature, Oxygen Partial Pressure, and Materials Selection on Slag Infiltration into Porous Refractories for Entrained-Flow Gasifiers

    Science.gov (United States)

    Kaneko, Tetsuya Kenneth

    The penetration rate of molten mineral contents (slag) from spent carbonaceous feedstock into porous ceramic-oxide refractory linings is a critical parameter in determining the lifecycle of integrated gasification combined cycle energy production plants. Refractory linings that withstand longer operation without interruption are desirable because they can mitigate consumable and maintenance costs. Although refractory degradation has been extensively studied for many other high-temperature industrial processes, this work focuses on the mechanisms that are unique to entrained-flow gasification systems. The use of unique feedstock mixtures, temperatures from 1450 °C to 1600 °C, and oxygen partial pressures from 10-7 atm to 10-9 atm pose engineering challenges in designing an optimal refractory material. Experimentation, characterization, and modeling show that gasifier slag infiltration into porous refractory is determined by interactions between the slag and the refractory that either form a physical barrier that impedes fluid flow or induce an increased fluid viscosity that decelerates the velocity of the fluid body. The viscosity of the slag is modified by the thermal profile of the refractory along the penetration direction as well as reactions between the slag and refractory that alter the chemistry, and thereby the thermo-physical properties of the fluid. Infiltration experiments reveal that the temperature gradient inherently present along the refractory lining limits penetration. A refractory in near-isothermal conditions demonstrates deeper slag penetration as compared to one that experiences a steeper thermal profile. The decrease in the local temperatures of the slag as it travels deeper into the refractory increases the viscosity of the fluid, which in turn slows the infiltration velocity of fluid body into the pores of the refractory microstructure. With feedstock mixtures that exhibit high iron-oxide concentrations, a transition-metal-oxide, the oxygen

  3. Dusts, scale, slags, sludges... Not wastes, but sources of profits

    Science.gov (United States)

    Koros, Peter J.

    2003-12-01

    Historically, the steel industry has focused on the need for and the many benefits of recycling steel that is discarded either in its own or in its customers’ manufacturing processes, as well as in recovery and reuse of steel scrap that arises after the product has served its intended purpose. In fact, modern steelmaking relies on the use of recycled iron units for at least half of its production. The other side of the story is the fate of the non-steel by-products (e.g., oxide dusts, sludges, scales, slags, spent refractories and the contained “low grade” energy units that are generated as natural adjuncts to iron and steelmaking processes). These valuable by-products often are classified as “wastes” and are discarded to landfills, at significant cost, although in reality they offer significant potential for cost savings or profit if reintroduced into the industrial arena via well planned programs. Examples of such instances will be presented, including energy credit issues, in the hope of pointing the way for future expansion of benefits from these opportunities. Preparing for a challenge and honor such as the Howe Memorial Lecture, one has to stand in awe of the accomplishments of the predecessor we honor in this forum. He worked in the early days of our industry without the benefits of the many technological improvements he and his successors brought to play as the years went by. John Stubbles, in his Howe Memorial Lecture in 1997,[1] presented a masterful and entertaining biography of Howe and his very active and prolific life. Perhaps the most telling quotation he attributed to Howe is very pertinent to the topic we will address presently: “Metallurgy lives by profit, not logic,” to which I would like to add a comment that bears on the topic of this lecture from the 1991 Howe lecturer, my friend and mentor Bill Dennis, “Where there is muck, there is money.” There are numerous examples of “one hand washes the other” in this business; that

  4. Improved Refractories for Slagging Gasifiers in IGCC Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, Cynthia P.; Kwong, Kyei-Sing; Bennett, James P.; Chinn, Richard E.

    2003-04-24

    The gasification of coal and other carbon-containing fuels provides the opportunity to produce energy more efficiently, and with significantly less environmental impact, than more-conventional combustion-based processes. In addition, the synthesis gas that is the product of the gasification process offers the option of ''polygeneration,'' i.e., the production of alternative products instead of power should it be economically favorable to do so. Because of these advantages, gasification is viewed as one of the key processes in the U.S. Department of Energy's Vision 21 power system. However, issues with both the reliability and the economics of gasifier operation will have to be resolved before gasification will be widely adopted by the power industry. Central to both enhanced reliability and economics is the development of materials with longer service lives in gasifier systems that can provide extended periods of continuous, trouble-free gasifier operation. The focus of the Advanced Refractories for Gasification project at the Albany Research Center is to develop improved refractory materials capable of withstanding the harsh, high-temperature environment created by the gasification reaction, and includes both the refractory lining that protects and insulates the slagging gasifier, as well as the thermocouple assemblies that are utilized to monitor gasifier operating temperatures. Current generation refractory liners in slagging gasifiers are typically replaced every four to 18 months, at costs ranging up to $2,000,000, depending upon the size of the gasification vessel. Compounding materials and installation costs are the lost-opportunity costs for the time that the gasifier is off-line for the refractory exchange. Current generation thermocouple devices rarely survive the gasifier start-up process, leaving the operator with no real means of temperature measurement during routine operation. Reliable, efficient, and economical gasifier

  5. The fully Mobile City Government Project (MCity)

    DEFF Research Database (Denmark)

    Scholl, Hans; Fidel, Raya; Mai, Jens Erik

    2006-01-01

    The Fully Mobile City Government Project, also known as MCity, is an interdisciplinary research project on the premises, requirements, and effects of fully mobile, wirelessly connected applications (FWMC). The project will develop an analytical framework for interpreting the interaction...

  6. A Laboratory Study of the Treatability of Synthetic Stormwater Under Varying Conditions Using Electric Arc Furnace Steel Slag

    Directory of Open Access Journals (Sweden)

    Nnaemeka C. Okochi

    2012-03-01

    Full Text Available The investigation of electric arc furnace (EAF steel slag as a viable add-on technology to existing stormwater systems for the removal of dissolved phosphorus (P was extended to explore the effects of varying environmental and treatment system conditions. Parameters such as stormwater composition, P concentration, metal concentration, pH, temperature, slag mass and slag particle size were varied. Observations relating to the method of P removal via EAF slag were also carefully considered to explain removal mechanisms involved. Results demonstrated that, although physisorption contributed to P reduction, it was not the key P removal mechanism. Instead, precipitation was observed to be a key removal pathway as evidenced by the correlation between the loss of iron (Fe from slag and the amount of P removed from solution. The reduced removal of P by slag in a copper-dominant stormwater solution was attributed to the formation of a stable complex formed by the interaction of copper with the slag via the ion-exchange surface model. The stability of this complex inhibits the loss of Fe from the EAF slag and, consequently, P removal by means of precipitation. In terms of the effect of changing environmental and treatment system conditions on the P removal process, stormwater composition, P concentration, metal concentration, pH, temperature, slag mass and slag particle size were found to significantly influence the effectiveness of EAF slag in removing P from a given stormwater system. It was also established that a number of combinations of these factors influence P uptake differently.

  7. The pH-dependent leaching behavior of slags from various stages of a copper smelting process: Environmental implications.

    Science.gov (United States)

    Jarošíková, Alice; Ettler, Vojtěch; Mihaljevič, Martin; Kříbek, Bohdan; Mapani, Ben

    2017-02-01

    The leaching behaviors of primary copper (Cu) slags originating from Ausmelt, reverbatory, and converter furnaces operating under a single technological process were compared to a residual slag tailing obtained by slag re-processing via flotation and metal recovery. The EN 12457-2 leaching test, used for assessment of the hazardous properties, was followed by the CEN/TS 14997 pH-static leaching test (pH range 3-12). Both leaching experiments were coupled with a mineralogical investigation of the primary and secondary phases as well as geochemical modeling. Metals (Cd, Cu, Pb, Zn) exhibit the highest leaching at low pH. Under acidic conditions (pH 3-6), Ausmelt slag and slag tailing exhibited higher metal leaching compared to other slag types. Very low leaching of metals (far below EU limits for non-hazardous waste) was observed at natural pH (7.9-9.0) for all the studied slag samples. In contrast, relatively high leaching of As was observed over the entire pH range, especially for Ausmelt slag (exceeding the EU limit for hazardous waste by 1.7×). However, geochemical modeling and scanning electron microscopy indicated that formation of stable Ca-Cu-Pb arsenates and the binding of As to newly formed Fe (oxyhydr)oxides play an important role in efficient As immobilization at the slag-water interface. In contrast, no controls were predicted for Sb, whose leaching was almost pH-independent. Nevertheless Sb leached concentrations at natural pH were below EU limit for hazardous waste. Re-processing of primary Cu slags for metal recovery, and subsequent co-disposal of the resulting slag tailing with dolomite-rich mine tailing and local laterite is suitable for stabilizing the remaining contaminants (except Sb) and limiting their leaching into the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Characterization of the lead smelter slag in Santo Amaro, Bahia, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Lima, L.R.P. de, E-mail: lelo@ufba.br [Department of Materials Science and Technology, Federal University of Bahia, C.P. 6974, Salvador, BA 41810-971 (Brazil); Bernardez, L.A. [Ingenium Consultoria em Engenharia Ltda (Brazil)

    2011-05-30

    For 33 years, a primary lead smelter operated in Santo Amaro (Brazil). Since the 1970s, large amounts of Pb and Cd have been widely documented in the blood and hair of people living near the smelter. The plant closed down in 1993, and several years later, the Pb levels in the blood of children under 4 years of age living near the smelter were high, where the disposed lead slag was suspected to be the main source of this contamination. The objective of this study is to elucidate the source of the Pb contamination and any other potentially toxic contamination, focusing on the characterization of the slag. The samples used for this characterization study were taken from the slag heaps. The results of the chemical analysis showed that the major constituents of the slag, in decreasing order of wt%, were the following: Fe{sub 2}O{sub 3} (28.10), CaO (23.11), SiO{sub 2} (21.39), ZnO (9.47), MgO (5.44), PbO (4.06), Al{sub 2}O{sub 3} (3.56), C (2.26), MnO (1.44), Na{sub 2}O (0.27), S (0.37), K{sub 2}O (0.26), and TiO{sub 2} (0.25). The Cd content of the slag was 57.3 mg/kg, which is relatively low. The X-ray diffraction and the electron probe microanalyzer X-ray mapping indicated that the major phases in the slag were wuestite, olivine, kirschsteinite, and franklinite. Only spheroidal metallic Pb was found in the slag. The leaching study showed that the slag was stable at a pH greater than 2.8, and only in an extremely acidic environment was the solubilization of the Pb enhanced significantly. The solubilization of Zn was very limited in the acidic and alkaline environments. These results can be explained by the limited leachability of the metallic Pb and Zn-bearing compounds. The leaching study used TCLP, SPLP, and SWEP and indicated that the lead slag was stable in weak acidic environments for short contact times.

  9. Life Cycle Assessment of Internal Recycling Options of Steel Slag in Chinese Iron and Steel Industry%Life Cycle Assessment of Internal Recycling Options of Steel Slag in Chinese Iron and Steel Industry

    Institute of Scientific and Technical Information of China (English)

    CHEN Bo; YANG Jian-xin; OUYANG Zhi-yun

    2011-01-01

    The internal recycling process of BOF slag which is one of the huge solid wastes from iron and steel indus try was emphasized. Based on the four scenarios of different internal recycling strategies for BOF slag, life cycle assessment (LCA) as a valuable t

  10. Mechanism of Mineral Phase Reconstruction for Improving the Beneficiation of Copper and Iron from Copper Slag

    Science.gov (United States)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jan; Zhang, Feng

    2016-09-01

    To maximize the recovery of iron and copper from copper slag, the modification process by adding a compound additive (a mixture of hematite, pyrite and manganous oxide) and optimizing the cooling of the slag was studied. The phase reconstruction mechanism of the slag modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that the synergy between the burnt lime and the compound additive promotes the generation of target minerals, such as magnetite and copper matte. In addition, the multifunctional compound additive is able to improve the fluidity of the molten slag, which facilitates the coalescence and growth of fine particles of the target minerals. As a result, the percentage of iron distributed in the form of magnetite increased from 32.9% to 65.1%, and that of the copper exiting in the form of metallic copper and copper sulfide simultaneously increased from 80.0% to 90.3%. Meanwhile, the grains of the target minerals in the modified slag grew markedly to a mean size of over 50 μm after slow cooling. Ultimately, the beneficiation efficiency of copper and iron was improved because of the ease with which the target minerals could be liberated.

  11. Sulfide capacity of CaO-CaF2-SiO2 slags

    Science.gov (United States)

    Susaki, Katsujiro; Maeda, Masafumi; Sano, Nobuo

    1990-02-01

    The sulfide capacity C S 2- = (pct S2-) · ( P O 2/ P S 2)1/2) of CaO-CaF2-SiO2 slags saturated with CaO, 3CaO · SiO2 or 2CaOSiO2 was determined at 1200 °C, 1250 °C, 1300 °C, and 1350 °C by equilibrating molten slag, molten silver, and CO-CO2 gas mixtures. Higher sulfide capacities were obtained for CaO-saturated slags. A drastic decrease was observed in those values when the ratio pct CaO/pct SiO2 is less than 2. The sulfur partition between carbon-saturated iron melts and presently investigated slags was calculated by using the sulfide capacities obtained and the activity coefficient of sulfur in carbon-saturated iron, which was also experimentally determined. For slags saturated with CaO, partitions of sulfur as high as 10,000 were obtained at 1300 °C and 1350 °C. Correlations between the sulfide capacity and other basicity indexes such as carbonate capacity and theoretical optical basicity were also discussed.

  12. Removal of contaminants in leachate from landfill by waste steel scrap and converter slag.

    Science.gov (United States)

    Oh, Byung-Taek; Lee, Jai-Young; Yoon, Jeyong

    2007-08-01

    This study may be the first investigation to be performed into the potential benefits of recycling industrial waste in controlling contaminants in leachate. Batch reactors were used to evaluate the efficacy of waste steel scrap and converter slag to treat mixed contaminants using mimic leachate solution. The waste steel scrap was prepared through pre-treatment by an acid-washed step, which retained both zero-valent iron site and iron oxide site. Extensive trichloroethene (TCE) removal (95%) occurred by acid-washed steel scrap within 48 h. In addition, dehalogenation (Cl(-) production) was observed to be above 7.5% of the added TCE on a molar basis for 48 h. The waste steel scrap also removed tetrachloroethylene (PCE) through the dehalogenation process although to a lesser extent than TCE. Heavy metals (Cr, Mn, Cu, Zn, As, Cd, and Pb) were extensively removed by both acid-washed steel scrap and converter slag through the adsorption process. Among salt ions (NH (4)(+) , NO (3)(-) , and PO (4)(3-) ), PO (4)(3-) was removed by both waste steel scrap (100% within 8 h) and converter slag (100% within 20 min), whereas NO (3)(-) and NH (4)(+ ) were removed by waste steel scrap (100% within 7 days) and converter slag (up to 50% within 4 days) respectively. This work suggests that permeable reactive barriers (PRBs) with waste steel scrap and converter slag might be an effective approach to intercepting mixed contaminants in leachate from landfill.

  13. Rheological Characterization of Warm-Modified Asphalt Mastics Containing Electric Arc Furnace Steel Slags

    Directory of Open Access Journals (Sweden)

    M. Pasetto

    2016-01-01

    Full Text Available The environmental sustainability of road materials and technologies plays a key role in pavement engineering. In this sense, the use of Warm Mix Asphalt (WMA, that is, a modified asphalt concrete that can be produced and applied at lower temperature, is considered an effective solution leading to environmental and operational benefits. The environmental sustainability of WMA can be further enhanced with the inclusion of steel slag in partial substitution of natural aggregates. Nevertheless, such innovative material applied at lower temperatures containing warm additives and steel slag should be able to guarantee at least the same performance of traditional hot mix asphalts, thus assuring acceptable mechanical properties and durability. Therefore, the purpose of this study is to investigate the rheological behaviour of bituminous mastics obtained combining a warm-modified binder and a filler (material passing to 0.063 mm coming from electric arc furnace steel slag. To evaluate the influence of both warm additive and steel slag, a plain binder and limestone filler were also used for comparison purposes. Complex modulus and permanent deformation resistance of bitumens and mastics were assessed using a dynamic shear rheometer. Experimental results showed that steel slag warm mastics assure enhanced performance demonstrating promising applicability.

  14. Deformation Pattern of Nickel Slag Bonding on the Development of Concrete Construction

    Science.gov (United States)

    Sujiono, E. H.; Husain, H.; Mulyadi, M.; Samnur, S.; Arsyad, M.

    2017-05-01

    This paper presents an experimental work to study the deformation and compressive strength on Portland cement concrete with nickel slag aggregate. The amount of nickel slag varied were towards the total mass of coarse aggregate are 0%, 20%, 40%, 60%, 80%, and 100%, respectively. Each variation of the samples was made with a dimension of 15 cm X 15 cm X 15 cm, and then through the curing process. After 28 days, the sample was checked using mechanical testing conducted to investigate the compressive strength. The surface of the concrete fracture after mechanical testing process shows that the bonding between the matrix of Portland cement and nickel slag is a very strong. The bonding has connected very well. Therefore, when the force was given, then the fractions of nickel slag aggregate will hold the connectivity until to the maximum of the pressure force value before the materials are a damaged. The maximum of pressure force caused by the cracks will follow the fracture pattern of the concrete materials. This indicates that the bonding between matrix Portland cement and nickel slag has become the key factor in construction high-quality concrete.

  15. Production of brown and black pigments by using flotation waste from copper slag.

    Science.gov (United States)

    Ozel, Emel; Turan, Servet; Coruh, Semra; Ergun, Osman Nuri

    2006-04-01

    One of the major problems in copper-producing countries is the treatment of the large amount of copper slag or copper flotation waste generated from copper slag which contains significant amounts of heavy metals such as Cu, Zn, Pb and Co. Dumping or disposal of such large quantities of flotation waste from copper slag causes environmental and space problems. In this study, the treatment of flotation waste from copper slag by a thermal method and its use as an iron source in the production of inorganic brown and black pigments that are used in the ceramic industry were investigated. The pigments were produced by calcining different amounts of flotation waste and chromite, Cr2O3, ZnO and CoO mixtures. The pigments obtained were added to transparent ceramic glazes and porcelainized tile bodies. Their colours were defined by L*a*b* measurements with a spectrophotometer. The results showed that flotation waste from copper slag could be used as an iron source to produce brown and black pigments in both ceramic body and glazes.

  16. Model of phosphorus precipitation and crystal formation in electric arc furnace steel slag filters.

    Science.gov (United States)

    Claveau-Mallet, Dominique; Wallace, Scott; Comeau, Yves

    2012-02-07

    The objective of this study was to develop a phosphorus retention mechanisms model based on precipitation and crystallization in electric arc furnace slag filters. Three slag columns were fed during 30 to 630 days with a reconstituted mining effluent at different void hydraulic retention times. Precipitates formed in columns were characterized by X-ray diffraction and transmission electronic microscopy. The proposed model is expressed in the following steps: (1) the rate limiting dissolution of slag is represented by the dissolution of CaO, (2) a high pH in the slag filter results in phosphorus precipitation and crystal growth, (3) crystal retention takes place by filtration, settling and growth densification, (4) the decrease in available reaction volume is caused by crystal and other particulate matter accumulation (and decrease in available reaction time), and (5) the pH decreases in the filter over time if the reaction time is too low (which results in a reduced removal efficiency). Crystal organization in a slag filter determines its phosphorus retention capacity. Supersaturation and water velocity affect crystal organization. A compact crystal organization enhances the phosphorus retention capacity of the filter. A new approach to define filter performance is proposed: saturation retention capacity is expressed in units of mg P/mL voids.

  17. Phosphorus removal by steel slag filters: modeling dissolution and precipitation kinetics to predict longevity.

    Science.gov (United States)

    Claveau-Mallet, Dominique; Courcelles, Benoît; Comeau, Yves

    2014-07-01

    This article presents an original numerical model suitable for longevity prediction of alkaline steel slag filters used for phosphorus removal. The model includes kinetic rates for slag dissolution, hydroxyapatite and monetite precipitation and for the transformation of monetite into hydroxyapatite. The model includes equations for slag exhaustion. Short-term batch tests using slag and continuous pH monitoring were conducted. The model parameters were calibrated on these batch tests and experimental results were correctly reproduced. The model was then transposed to long-term continuous flow simulations using the software PHREEQC. Column simulations were run to test the effect of influent P concentration, influent inorganic C concentration and void hydraulic retention time on filter longevity and P retention capacity. High influent concentration of P and inorganic C, and low hydraulic retention time of voids reduced the filter longevity. The model provided realistic P breakthrough at the column outlet. Results were comparable to previous column experiments with the same slag regarding longevity and P retention capacity. A filter design methodology based on a simple batch test and numerical simulations is proposed.

  18. Effect of Additives on Melting Point of LATS Refining Ladle Slag

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-ming; LI Gui-rong; DING Zhen-tao; DAI Qi-xun; LI Bo

    2007-01-01

    To avoid slag sticking on the ladle immersion cover during the LATS refining and alloying process, the effect of Al2O3 on the melting point of the ladle slag was studied and the additives including CaF2, B2O3, Li2O, and CaO were used to decrease the melting point of the ladle slag. The melting point was measured using the hemisphere method. The results show that the addition of Al2O3 to the ladle slag increases the melting point. The fluxing action is not remarkable if only CaF2 or CaO is used as the additive. The fluxing action of the composite additive obtained by the mixing of CaO and CaF2 in the mass proportion of wCaO∶wCaF2=2∶1 is preferred. The fluxing action of B2O3 is also notable. When the B2O3 content in mass percent is in the range from 2% to 10%, the corresponding melting point is 1 380 ℃ to 1 290 ℃. The fluxing action of Li2O is the most remarkable. When the Li2O content is up to 5%, the melting point of the slag is lower than 1 300 ℃.

  19. Chloride-Ion Penetrability and Mechanical Analysis of High Strength Concrete with Copper Slag

    Directory of Open Access Journals (Sweden)

    Savaş Erdem

    2014-05-01

    Full Text Available The use of waste materials and industrial by-products in high-strength concrete could increase the sustainability of the construction industry. In this study, the potential of using copper slag as coarse aggregate in high-strength concrete was experimentally investigated. The effects of replacing gravel coarse aggregate by copper slag particles on the compressive strength, chloride ion- migration, water permeability and impact resistance of high-strength concretes were evaluated. Incorporating copper slag coarse particles resulted in a compressive strength increase of about 14 % on average partly due to the low Ca/Si ratio through the interface area of this concrete (more homogenous internal structure as confirmed by the energy dispersive X-ray micro chemical analysis. It was also found that the copper slag high-strength concrete provided better ductility and had much greater load carrying capacity compared to gravel high-strength concrete under dynamic conditions. Finally, it was observed that in comparison to the high strength concrete with slag, the chloride migration coefficient from non-steady state migration was approximately 30 % greater in the gravel high-strength concrete.

  20. EFFECTS OF BLAST-FURNACE SLAG ON NATURAL POZZOLAN-BASED GEOPOLYMER CEMENT

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    MAHSHAD YAZDANIPOUR

    2011-03-01

    Full Text Available A number of geopolymer cement mixes were designed and produced by alkali-activation of a pumice-type natural pozzolan. Effects of blast-furnace slag on basic engineering properties of the mixes were studied. Different engineering properties of the mixes such as setting times and 28-day compressive strength were studied at different amounts of blast-furnace slag, sodium oxide content, and water-to-cement ratio. The mix comprising of 5 wt.% blast-furnace slag and 8 wt.% Na2O with a water-to-dry binder ratio of 0.30 exhibits the highest 28-day compressive strength, i.e. 36 MPa. Mixes containing 5 wt.% of ground granulated blast furnace slag showed the least efflorescence or best soundness. Laboratory techniques of X-ray diffractometry (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM were utilized for characterizing a number of mixes and studying their molecular and micro-structure. Investigations done by scanning electron microscopy confirm that smaller blast-furnace slag particles react totally while the larger ones react partially with alkaline activators and contribute to the formation of a composite microstructure.