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1
Nassyrov, Dmitri. "Slag solidification modeling." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119538.
Testo completoAbstract (sommario):
Two models able to predict Time-Temperature-Transformation (TTT) diagrams for liquid oxides and oxyfluorides have been developed. One on the basis of the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation and the other – using Classical Nucleation Theory (CNT). The most recent FactSage database was used for calculating the thermodynamic properties of the liquid and solid phases. The model based on the JMAK equation provided much better agreement with experimental data than the CNT model. The model developed in this study was used to successfully predict TTT diagrams for binary, ternary and multicomponent oxide slags containing no more than 50 wt% SiO2 and for some of the oxyfluoride slags.<br>Deux modèles capables de prédire les diagrammes temps-température-transformation (TTT) pour des oxydes et oxyfluorures liquides ont été développés. Un des modèles est basé sur l'équation de Johnson-Mehl-Avrami-Kolmogorov (JMAK), et l'autre – utilisant la théorie classique de la nucléation (TCN). La base de données la plus récente a été utilisée pour calculer les propriétés thermodynamiques des phases liquides et solides. Le modèle basé sur l'équation JMAK a démontré un accordement avec les données expérimentales bien meilleur que la TCN. Le modèle développé dans cette étude peut être utilisé pour prédire des diagrammes TTT pour les oxydes contenant pas plus que 50 % massique de SiO2 et pour quelques oxyfluorures.
2
Sulasalmi, P. (Petri). "Modelling of slag emulsification and slag reduction in CAS-OB process." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526214160.
Testo completoAbstract (sommario):
Abstract Composition Adjustment by Sealed argon bubbling – Oxygen Blowing (CAS-OB) process is a ladle treatment process that was developed for chemical heating and alloying of steel. The main stages of the process are heating, (possible) alloying and reduction of slag. The CAS-OB process aims for homogenization and control of the composition and temperature of steel. In this dissertation, a mathematical reaction model was developed for the slag reduction stage of the CAS-OB process. Slag reduction is carried out by applying vigorous bottom stirring from porous plugs at the bottom of the ladle. Due to the bottom stirring a circular steel flow is induced which disrupts top slag layer and due to shear stress at the steel-slag interface small slag droplets are detached. This induces an immense increase in the interfacial area between steel and slag which provides favourable conditions for the reduction reactions. In order to model reduction reactions, a sub-model for describing the interfacial area was needed. For this the slag droplet formation was studied using computational fluid dynamics (CFD) and based on these studies, a sub-model for droplet formation was developed. The model for the reduction stage of the CAS-OB process takes into account not only the reaction during the reduction but also the heat transfer between the phases, ladle and surroundings. The reduction stage model was validated using validation data obtained from the CAS-OB station of the SSAB Raahe steel plant in Finland. It was concluded that the model was able to predict steel and slag compositions as well as the steel temperature very well<br>Tiivistelmä CAS-OB -prosessi on sulametallurgiassa käytettävä senkkakäsittelyprosessi, joka on kehitetty teräksen kemialliseen lämmittäseen ja seostukseen. CAS-OB-prosessin pääprosessivaiheet ovat lämmitysvaihe, mahdollinen seostusvaihe ja kuonan pelkistysvaihe. CAS-OB -prosessilla tavoitellaan teräksen koostumuksen homogenisointiin ja lämpötilan kontrollointiin. Tässä tutkimuksessa kehitettiin matemaattinen reaktiomalli CAS-OB -prosessin kuonan pelkistysvaiheen kuvaamiseen. Kuonan pelkistys tapahtuu senkan pohjassa olevien huuhtelutiilien avulla suoritettavan voimakkaan kaasuhuuhtelun avulla. Pohjahuuhtelu aiheuttaa kiertävän teräsvirtauksen senkassa. Teräsvirtaus irrottaa teräksen päällä olevasta kuonakerroksesta pisaroita ja kuonan ja teräksen välinen reaktiopinta-ala kasvaa voimakkaasti. Tämä tarjoaa suotuisat olosuhteet pelkistysreaktiolle senkassa. Pelkistysreaktioiden mallintamiseksi tässä työssä kehitettiin CFD-simulaatioiden avulla alimalli, jonka avulla voidaan kuvata teräksen ja kuonan välisen pinta-alan suuruutta. Pelkistysvaiheen mallissa huomioidaan reaktioiden lisäksi myös systeemissä tapahtuva lämmösiirto. Pelkistysmalli validoitiin mittausdatalla, joka hankittiin SSAB Raahen terässulaton CAS-OB -asemalla järjestetyssä validointikampanjassa. Tutkimuksessa havaittiin, että malli kykenee hyvin ennustamaan teräksen ja kuonan koostumuksen sekä teräksen lämpötilan
3
Muhmood, Luckman. "Investigations of thermophysical properties of slags with focus on slag-metal interface." Doctoral thesis, KTH, Materialens processvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-26611.
Testo completoAbstract (sommario):
The objective of this research work was to develop a methodology for experimentally estimating the interfacial properties at slag-metal interfaces. From previous experiments carried out in the division, it was decided to use surface active elements like sulfur or oxygen to trace any motion at the interface. For this purpose the following experimental investigations were carried out. Firstly the density of slag was estimated using the Archimedes Principle and the Sessile Drop technique. The density of the slag would give the molten slag height required for the surface active element to travel before reaching the slag-metal interface. Diffusivity measurements were uniquely designed in order to estimate the sulfur diffusion through slag media. It was for the first time that the chemical diffusivity was estimated from the concentration in the metal phase. Experiments carried out validated the models developed earlier. The density and diffusivity value of sulfur in the slag was used to accurately capture the time for sulfur to reach the slag-metal interface. The oscillations were identified by calculating the contact angle variations and the interfacial velocity was estimated from the change in the surface area of the liquid iron drop. The interfacial tension was estimated from the contact angles and the interfacial dilatational modulus was calculated. Based on cold model experiments using water as well as mercury, an equation of the dependence of the interfacial shear viscosity on the interfacial velocity and interfacial tension was established. This paved way for the estimation of the interfacial shear viscosity at the slag-metal interface. The present study is expected to have a strong impact on refining reactions in pyometallurgical industries where slag/metal interfaces play an important role. From a fundamental view point, this provides a deeper insight into interfacial phenomena and presents an experimental technique to quantify the same.<br>QC 20101130
4
Isaksson, Jenny. "Slag Cleaning of a Reduced Iron Silicate Slag by Settling : Influence of Process Parameters and Slag Modification on Copper Content." Licentiate thesis, Luleå tekniska universitet, Mineralteknik och metallurgi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84798.
Testo completoAbstract (sommario):
During the pyrometallurgical extraction of copper, a significant part of the copper is lost with discard slag, which decreases profits, overall copper recovery, and efficiency of raw material usage. Smelting furnace slag usually has a copper content that is close to or higher than that of copper ores. The investigation of copper losses to slag is thus a task of practical significance, as the ore grades are depleting. Slag cleaning, e.g., a settling furnace, can reduce copper losses to slag as the mechanically suspended copper-containing droplets separate from slag under the action of gravity and can hence be recovered. An industrial trial was conducted in an electric settling furnace with slag originating from an electric smelting furnace and processed in a zinc fuming furnace. The trial was conducted to increase the understanding of copper losses to slag and how the process parameters temperature and settling time influence the slag copper content. The obtained slag samples were also evaluated to gain better insights as to the settling mechanism and, if any, factors that hinder the copper phases from settling. Slag modification with CaO was also evaluated to investigate how the modification influences the settling of copper phases and, thus, the final slag copper content. Samples collected during the industrial trial were the basis for the evaluation in the current work. The samples came from batches with varying temperatures, settling times, and CaO content collected at four different sample positions. Instrumental techniques, including XRF, FAAS, ICP-SFMS, and SEM-EDS, were used to analyze the chemical compositions of the samples and the appearance of copper and associated phases. The results indicated that the copper content of outgoing slag increased with increasing temperature in the evaluated interval. The copper content was also concluded to be more strongly affected by the temperature compared to the settling time. Regulating the temperature to the lower temperature interval in the settling furnace could thus decrease the final slag copper content. During the slag characterization, it was found that suspended copper-containing phases were hindered from settling, due to the attachment to solid phases and gas bubbles in the slag. By controlling and minimizing the presence of the bottom buildup and thus solid phases in the slag, the copper content can be decreased. The results indicated that the CaO slag modification decreased the final slag copper content, and can thus be used as a modifier for increased settling.
5
Wang, Shao-Dong. "Alkaline activation of slag." Thesis, Imperial College London, 1995. http://hdl.handle.net/10044/1/7767.
Testo completo
6
Ng, Ka Wing 1965. "Skimming of fluid slag." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33340.
Testo completoAbstract (sommario):
A 1/12 scale tank was constructed to physically simulate the metallurgical skimming process in order to gain a better insight of the skimming of fluid slag from copper anode furnaces. 1-decanol and water were used to represent the slag and the underlying liquid metal respectively. It was observed that slag skimming was comprised of two steps, a transportation step to carry slag to the skimming lip, and a removal step to move the slag across the lip. The efficiency of the transportation by bath surface circulation was strongly affected by the method of creation of the surface movement. Submerged gas injection failed to carry slag to the lip effectively because of the uncontrollable circulation pattern generated on the bath surface. On the other hand, three impinging gas jets in glancing contact with the bath surface were able to carry slag to the lip effectively. The Re of the jets (I.D. 0.01m) inclined 50° to the horizontal was 6100. The jet configuration was two of the jets were placed close and parallel to the rear wall of the model and faced each other. The third jet was parallel to the model short axis and was directed at the skimming mouth. With the same amount of time, 70% of the slag originally charged to the tank was skimmed with the assistance from the impinging gas jets in comparison to 20% when no jet was used. Detailed analysis of the skimming process revealed that the underlying liquid bath level continuously decreased as the slag was skimmed and resulted in continuous reduction of the skimming rate. In order to compensate the reduction of skimming rate due to bath level reduction, a control strategy was proposed for rotating the furnace continuously to maximize the skimming effectively.
7
Berryman, Eleanor. "Carbonation of steel slag." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110434.
Testo completoAbstract (sommario):
Iron and steel production is a rapidly growing industry with global outputs increasing 65% over the last ten years (World Steel Association, 2012). Unfortunately, it is also the largest industrial source of atmospheric CO2, accounting for a quarter of the CO2 emissions from industrial sources (International Energy Agency (IEA), 2007).Mineral carbonation provides a robust method for permanent sequestration of CO2 that is environmentally inert. Larnite (Ca2SiO4), the major constituent of steel slag, reacts readily with aqueous CO2 (Santos et al., 2009). Consequently, its carbonation offers an important opportunity to reduce CO2 emissions at source. A potential added benefit is that this treatment may render steel slag suitable for recycling. This study investigates the impact of temperature, fluid flux and reaction gradient on the dissolution and carbonation of steel slag, and is part of a larger study designed to determine the conditions under which conversion of larnite, and other calcium silicates, to calcite is optimized. Experiments were conducted on 2 – 3 mm diameter steel slag grains supplied by Tata Steel RD&T. A CO2-H2O mixture was pumped through a steel flow-through reactor containing these grains. For a given experiment, temperature was fixed at a value between 120°C and 200°C, pressure was 250 bar, and the fluid flux was fixed at 0.8 mL/cm2min or 6 mL/cm2min. Reactions were also carried out in a batch reactor at 180°C and 250 bar, corresponding to a condition of zero flux. The duration of experiments ranged from 3 to 7 days. The CO2-H2O fluid reacted with the steel slag grains to form phosphorus-bearing Ca-carbonate phases. At high fluid flux, 6 mL/cm2min, these phases dissolved at the edges of slag grains, leaving behind a porous rind of aluminum and iron oxides. Increasing temperature increased the rate of this reaction. At low fluid flux, 0.8 mL/cm2min, the extent of carbonation was increased. At the edge of grains, instead of being transformed to porous rinds, primary Ca minerals were replaced by phosphorus-bearing Ca-carbonate phases. As a result of the greater length of reactor used in these experiments, a reaction gradient was observed along which the fluid remained supersaturated with respect to the calcium carbonate, coating the surfaces of the slag grains. Steel slag exposed to the CO2-H2O fluid in the batch reactor was less carbonated; incongruent dissolution of the slag followed by surface coating of the grains by calcium carbonate inhibited further interaction of the slag with the fluid, limiting the extent of possible carbonation.The results of this study show that carbonation of steel slag by aqueous CO2 is feasible using relatively large grains, and that it can be optimised by varying fluid flux. Experiments of the type described above will contribute to the eventual global reduction of industrial CO2 emissions.<br>L'industrie du fer et de l'acier est en pleine croissance et sa production mondiale a augmenté de 65% au cours des dix dernières années (World Steel Association, 2012). Malheureusement, elle est également responsable d'un quart des émissions industrielles de CO2 ce qui en fait la plus importante source industrielle de CO2 atmosphérique (International Energy Agency (IEA), 2007).La carbonatation minérale fournit une méthode robuste pour la séquestration permanente du CO2 sous une forme écologiquement inerte. La larnite (Ca2SiO4), constituant principal des scories d'acier, réagit aisément avec le CO2 aqueux (Santos et al., 2009). Par conséquent, sa carbonatation offre une importante occasion de réduire à la source les émissions de CO2. Un avantage potentiel supplémentaire de ce traitement est de rendre les scories d'acier convenables pour le recyclage. Cette étude examine l'impact de la température, le flux molaire surfacique du fluide carbonaté, et d'un gradient de réaction sur la dissolution et la carbonatation des scories d'acier. Elle s'inscrit dans une étude plus large visant à déterminer les conditions optimisant la conversion de la larnite, et d'autres silicates de calcium, à la calcite.Des expériences ont été menées sur des grains de scories d'acier d'un diamètre de 2 à 3 mm fournis par Tata Steel RD&T. Un mélange de CO2-H2O a été pompé à travers un réacteur continu contenant ces grains et maintenu à une température entre 120°C et 200°C, une pression de 250 bar et à des flux molaires surfaciques de 0.8 à 6 mmol/cm2min. Chaque expérience a duré de 3 à 7 jours. Le fluide CO2-H2O a réagi avec les grains de scories d'acier et a formé des minéraux de carbonate de calcium contenant du phosphore. À flux molaire surfacique élevé, soit 6 mL/cm2min, ces phases sont dissoutes aux bords des grains, laissant place à une bordure poreuse d'oxydes d'aluminum et de fer. Une augmentation de la température a augmenté la vitesse de cette réaction. A valeur intermédaire de flux molaire surfacique, 0.8 mL/cm2min, le degré de carbonatation a augmenté. Au lieu laisser des bordures poreuses d'oxydes, les minéraux de calcium primaires en marge des grains ont plutôt été remplacés par des phases de calcium carbonate contenant du phosphore. En plus, l'usage d'un réacteur plus long a créé un gradient de réaction et maintenu la supersaturation du fluide relative au carbonate de calcium qui a enrobé les grains. Les scories d'acier exposées au fluide dans un réacteur discontinu (sans flux de fluide) ont été moins carbonatées; la dissolution non-congruente de la scorie a pris place suivie par l'enrobage des grains de scories par le carbonate, et ce dernier a réduit la surface de réaction de la scorie avec le fluide.Les résultats de cette étude démontrent que la carbonatation par le CO2 aqueux des scories d'acier à granulométrie relativement grossière est possible et qu'elle peut être optimisée en variant le flux molaire surfacique du fluide. Les expériences de ce type contribueront à la réduction éventuelle des émissions industrielles globales de CO2.
8
Ekengård, Johan. "Aspects on slag/metal equilibrium calculations and metal droplet characteristics in ladle slags." Licentiate thesis, KTH, Materials Science and Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1788.
Testo completoAbstract (sommario):
<p>In the present work the mixing between the metal and slagphase during the ladle refining process from tapping from theelectric arc furnace to casting in two different Swedish steelplants has been studied.</p><p>Three slag models and the sulphur-oxygen equilibrium betweenslag and steel was used together with the dilute solution modelfor the liquid steel phase to predict the equilibrium oxygenactivity in steel bulk and metal droplets in top slag inequilibrium with the top slag. The predicted oxygen activitieswere compared with measured oxygen activities from the steelbulk. The results show significant discrepancies between thecalculated and measured oxygen activities and the reasons forthe differences are discussed.</p><p>Metal droplet distribution in slag samples have also beendetermined using classification according to the Swedishstandard SS111116. It was found that most metal droplets arefound in the slag samples taken before vacuum degassing. Thetotal area between steel droplets and slag has been determinedto be 3 to 14 times larger than the projected flat interfacearea between top slag and steel. The effect of slag viscosityand reactions between steel and slag on the metal dropletformation in slags is also discussed.</p><p>The chemical composition of the metal droplets in the topslag was determined and possible reactions taking place betweenthe steel droplets and the slag was studied. Differencesbetween steel droplet compositions and the bulk steelcomposition are discussed. The results show significantdifferences between steel droplet and bulk steelcomposition.</p><p><b>Key words:</b>oxygen activity, metal droplets, sulphur,slag, ladle, refining, distribution.</p>
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Johnston, Murray. "Thermodynamics of selenium and tellurium in molten metallurgical slags and alloys." University of Western Australia. School of Biomedical, Biomolecular and Chemical Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0064.
Testo completoAbstract (sommario):
There are a number of impurity elements present in sulphide ores that can have a deleterious effect on the properties of the final copper metal product. In this thesis, an equilibrium distribution technique was used to determine the thermodynamic behaviour of selenium and tellurium in molten slags used in copper production. Calcium ferrite based slags and copper or silver alloy were equilibrated in magnesia crucibles at temperatures of 1200 to 1400 °C and oxygen partial pressures of 10-11 to 10-0.68 atm. Under conditions typical of those employed during copper converting, the minor elements were found to enter the slag as negatively charged species. The partitioning of selenium and tellurium to the slag was greatest at high temperature, low oxygen partial pressure and at highest concentration of basic oxide (CaO or BaO). The experimentally derived data were combined with published information to calculate the selenide and telluride capacities of the slag, and also to generate fundamental thermodynamic activity data for selenium and tellurium in the slag phase. It was found that the activity coefficients of selenium and tellurium were independent of their concentration in the slag over the range studied, but were strongly dependent on the temperature, slag chemistry and oxidation state of the slag. Experiments were also designed and carried out to determine what effect the presence of iron oxide and its oxidation state has on the behaviour of selenium in the slag. A series of experiments involving iron oxide additions to a calcium aluminate slag was conducted under increasingly oxidising conditions to assess the effect of total iron on the selenide capacity as the dominant oxidation state of iron in the slag changed. It was shown that at a constant ratio of CaO:Al2O3, the selenide capacity increased with total iron in the slag. However, the effect on the selenide capacity did not appear any more significant as the Fe3+:Fe2+ ratio changed in a particular direction. 4 Another series of experiments was carried out with iron calcium silicate slags to determine the stability of phases within the slag, and how this affected the equilibrium distribution and activity coefficient of selenium in the slag. A number of solid phases were identified and their composition determined by scanning electron microscopy, energy dispersive spectroscopy and electron microprobe analysis. The composition and minor element content of the remaining liquid was calculated using a thermodynamic model. From this it was found that the capacity of the liquid slag has a region of independence against slag chemistry, before increasing strongly with increasing lime content to the calcium ferrite composition. Some of the implications of this work are discussed with reference to the practicality of adjusting the process variables in a large-scale industrial process for the purpose of managing minor element content of the molten phases. Considerations include the effect on copper recovery and rate of wear of furnace refractory materials.
10
Gautier, Annaig. "Luminescence dating of archaeometallurgical slag." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326805.
Testo completo
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Adediran, A. (Adeolu). "Alkali activation of fayalite slag." Master's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201709062801.
Testo completoAbstract (sommario):
In this thesis, alkali activation of fayalite slag was investigated. The slag utilized is a waste by product from nickel production, the activation of which resulted in the formation of a geopolymer binder of acceptable properties. The need for a reduction in overall waste output as well as the cementitious properties exhibited by this slag motivated this study.
The literature section of this research provides an insight on the previous work in the area of geopolymerization, the source materials used, the activators employed as well as the properties exhibited by various geopolymer products. The experimental section reports the particle size distribution and particle size optimization as well as geopolymer synthesis. The size reduction was carried out by milling for a required time while the particle size optimization and mix design was done with “Elkem Material Mixture Analyser (EMMA).
The milling reduced the particle size of fayalite slag to 10.08 µm after 3 hours which is sufficient fineness for most geopolymer precursors. Different mix compositions were activated with potassium silicate and sodium hydroxide at varying mass ratio with the one activated with 50:50 mass ratio of NaOH /K₂SiO₃ had the highest mechanical strength. The workability and setting time were good for the mixtures with liquid to solid ratio from 0.1–0.2. Compressive strength test were carried out on various mix compositions and the result shows the maximum compressive strength of 16.5 MPa was achieved at room temperature after 28 days. The water absorption was very low (5%). It was also noticed that the strength after water absorption was higher than the unconfined compressive strength due to subjection of slag geopolymer to elevated temperature before water absorption.
The alkali activation of fayalite slag has shown promising properties which could further be improved for better mechanical performance.
12
Hosan, Md Anwar. "Durability Properties of High Volume Slag and Slag-Fly Ash Blended Concrete Containing Nano materials." Thesis, Curtin University, 2020. http://hdl.handle.net/20.500.11937/83225.
Testo completoAbstract (sommario):
This research investigated the effect of the addition of a small amount of nano silica and nano calcium carbonate on the compressive strengths and durability properties of high volume slag (HVS) and high volume slag-fly ash (HVS-FA) blended concretes. The results showed that low-carbon concretes containing 70% blast furnace slag or 70% slag-fly blended materials with superior strengths and durability can be achievable by adding only 1% nano calcium carbonate and 2-3% nano silica.
13
Whittaker, Mark James. "The impact of slag composition on the microstructure of composite slag cements exposed to sulfate attack." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/9307/.
Testo completoAbstract (sommario):
The work presented here focuses on the impact of slag composition on the resistance of slag composite cements exposed to sulfates. Such composite systems can be an effective way to provide better sulfate resistance of the binder. However, the differing composition and hydration kinetics between slag and cement results in a change in the phases present and their quantities, the effect of which is often overlooked when assessing their sulfate resistance. Rather, the composition of the slag is typically considered. Compared to cement, slags are richer in Si, Al and Mg, but poorer in Ca. Blended with cement, they hydrate much more slowly to produce comparable hydrates including a C-S-H phase deficient in calcium plus a hydrotalcite-like phase. Furthermore, aluminium from slag can promote the formation of other aluminate hydrates. The changes in microstructure and ultimately performance is then dependent on the composition of the slag. The aim of the work was to determine how slag composition affected the performance of slag cements in sulfate rich environments by means of the developed microstructure. A first hydration study was carried out to follow how slag composition affected microstructural developments by comparing a neat (control) cement with several slag blends curing in idealised lab conditions. Subsequently, the same samples were exposed to a 3g.L-1 Na2SO4 solution. By comparing hydration in controlled conditions and in aggressive media in parallel, analysing only the degraded zone in the latter case, the role of slag composition on phase assemblage and composition and, ultimately, on sulfate resistance was highlighted All the slag blended systems showed great resistance to sulfate attack during the testing period. This can be attributed to several changes in the microstructure in slag blended systems including (i) a lowering of the calcium content of the C-S-H phase which led to (ii) an increase in the amount of alumina bound to a possibly water rich silicate hydrate, (iii) a greater amount of a hydrotalcite phase varying in alumina content and (iv) a diluted calcium hydroxide content. Furthermore, monosulfate had formed in the slag blended systems during attack whereas ettringite had only formed in a neat system. This implies an availability of alumina from the slag keeping the $/Al of the pore solution low favouring monosulfate formation. Lastly, the role of calcium and ettringite stability was tentatively probed at.
14
Persson, Mikael. "Investigations of Slag Properties and Reactions." Doctoral thesis, Stockholm : Materialvetenskap, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4378.
Testo completo
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Ahmed, Yousif Hummaida. "Toxic waste treatment by slag cements." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336560.
Testo completo
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Al-Otaibi, Saud. "Performance of alkali-activated slag concrete." Thesis, University of Sheffield, 2003. http://etheses.whiterose.ac.uk/3453/.
Testo completoAbstract (sommario):
The environmental concerns related to the production of cement in terms of the energy consumption and the emission of CO2 lead to the search for more environmentally viable alternatives to cement. One of those alternative materials is alkali-activated slag (AAS) where ground granulated blast furnace slag is used not as a partial replacement to cement but as the sole binder in the production of concrete. The performance of alkali-activated slag concrete with sodium silicate (water glass) as an activator was studied. The scope of the work covered seven mixes: a normal strength OPC control mix, a blended OPC/Slag mix of similar compressive strength but of lower water to binder ratio, a second OPC control mix of a water to binder ratio similar to that of the OPC/Slag mix, and four alkali-activated slag mixes of the same binder content and the same water to binder ratio as those of the second OPC mix. The AAS mixes were prepared with slag as the sole binder, activated with water glass at two dosages, 4% and 6% Na2O (by weight of slag). Two types of water glass were used, one in a solution form and the other in a solid granules form. The two forms of the activator used were also of different silicate modulus (Ms); 1.65 for the solution form and 1.0 for the granule form. Different curing regimes were used including normal water curing, air dry curing and accelerated autoclave heat curing. The fresh concrete properties studied were setting time, workability and air content. The engineering properties studied were compressive strength, splitting tensile strength, flexural strength, dynamic modulus of elasticity and ultrasonic pulse velocity and drying shrinkage. The durability potential of alkali-activated stag concrete was investigated by testing for oxygen permeability, chloride penetration resistance, porosity, carbonation, and alkali-silica reaction. The hydration of alkali-activated slag was studied using x-ray diffraction and thermogravimetry techniques. Alkali-activated slag concrete was found to achieve good workability which was, comparable to that of OPC and OPCfslag concrete. The increase of the Na2O dosage resulted in a lower workability and the activator with higher silicate modulus exhibited lower workability. AAS concrete however, sets rapidly if not controlled by the addition of lime. The main hydration products in the AAS systems were C-S-H (I) and hydrotalcite as observed in the XRD patterns with autoclaving resulting in the formation of a more crystalline C-S-H gel and the possible formation of xonotlite. The mechanical properties of AAS concrete are highly influenced by the activator's silicate modulus and the Na2O dosage where strength was found to be higher with the higher modulus and dosage. The AAS concrete is very sensitive to curing and dry curing resulted in a reduction in strength for AAS concrete much more than that for OPC concrete. Accelerated curing (autoclave) increased the initial gain of strength in AAS concrete but eventually gave results close to those of water curing. Using a waterglass activator with Ms = 1.65 and 6% Na2O resulted in the highest drying shrinkage where as it is lower when the dosage is less and the modulus is lower. Autoclave curing of AAS concrete reduces the drying shrinkage as it causes the formation of more crystalline products of hydration. The increase of the Na2O dosage in AAS concrete, where the activator has an M. = 1.0, results in a decrease in porosity, but in the case of the AAS concrete, with the activator having Ms = 1.65, the porosity increases with the increase of the Na20 dosage. Dry curing increases the porosity of all the concrete mixes. The porosity test results are influenced by the sample preconditioning prior to testing. The alkali-silica test results show that replacing 60% OPC by slag reduces the expansion of concrete prisms containing reactive aggregates. They also indicate that AAS concrete has low susceptibility to ASR expansion because of stronger binding of alkalis in the hydration products. The carbonation test results show that OPCIslag concrete undergoes higher carbonation than OPC concrete with the same w/c ratio. AAS concrete with low compressive strength around 40 MPa has higher carbonation compared to OPC concrete of the same grade while the carbonation is lower with higher strength.
17
Oladipupo, Adebisi Oladimeji. "Slag detachability from submerged arc welds." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14953.
Testo completoAbstract (sommario):
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1987.<br>MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.<br>Bibliography: leaves 78-80.<br>by Adebisi Oladimeji Oladipupo.<br>Sc.D.
18
Stadler, S. A. C. (Susanna Aletta Carolina). "An experimental study of slag foaming." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52669.
Testo completoAbstract (sommario):
Thesis (MScEng)--University of Stellenbosch, 2002.<br>ENGLISH ABSTRACT: Slag foaming occurs in several pyrometallurgical processes. These processes include
steelmaking in basic oxygen steelmaking furnaces and electric arc furnaces (EAF) as well
as various non-ferrous operations like sulphide smelting/converting and base metal slag
cleaning. Although slag foaming in steelmaking processes has been extensively researched,
little attention has been given to slag foaming in non-ferrous operations. Slag foaming
phenomena are complex because often the system consists of three or more phases.
The objectives of this study is to review the published work on slag foaming, to obtain
through physical modelling an understanding of the principles governing foaming and to
investigate slag foaming phenomena through pyrometallurgical experiments.
To obtain these objectives, experiments were carried out with aqueous mixtures at different
column sizes, different pore sizes for gas injection and varying liquid depths, and also for
high temperature metallurgical slags with varying composition and at different
temperatures. Through gas injection, foaming conditions were simulated and the
equilibrium foam height was measured for different gas velocities.
The following conclusions were drawn:
1. For physical modelling of slag foaming in 3-phase systems the average foam index
increases with increasing amounts of solids present in the system. The effect of
additional solids in the system is independent of the system geometry.
2. The following conclusions were reached by determining coefficients for an
empirical dimensional model fitted to aqueous mixtures: Higher liquid density leads
to lower foam index values. The influence of the liquid viscosity is dependent on
the system investigated and may have a positive or negative result on foaming. The empirical model should only be applied to the property range and geometric set-up
for which it was derived, as coefficients may vary greatly for different systems.
3. Influence of solid precipitates on slag foaming can be summarised by noting that
small amounts of magnetite stabilise slag foaming, while precipitates of
wollastonite and anorthite decreased foaming. The influence of solid precipitates is
thought to be related to the density, morphology and degree of surface activity of
the solid precipitates.
4. The foam index decreases with increasing basicity due to the lowering of the slag
viscosity. This continues until the precipitation of solids starts and the foam index
once again increases.
5. For increasing "FeO" concentration the foam index will decrease due to lower
viscosity, but higher surface tension depression may lead to increased foam index
values at high "FeO" concentrations.
6. Higher foam index values were obtained for slags with lower densities. The
_1
empirical relationship observed is L IX: P 3 .
7. Higher foam index values were obtained for slags with higher viscosity. The
empirical relationship observed is L IX: f1 .
8. Higher foam index values were obtained for slags with lower surface tensions. The
empirical relationship observed is L IX: U-I.
9. Models derived for the foaming of basic steelmaking slags does not satisfactorily
describe the foaming behaviour of acidic slags.
10. The physical properties of the slag influence the foam stabilisation mechanism.<br>AFRIKAANSE OPSOMMING: Slak skuiming kom in verskeie pirometallurgiese prosesse voor. Hierdie prosesse sluit die
maak van staal in basiese staalmaakoonde en elektriese boogoonde in, sowel as verskeie
nie-yster prosesse soos sulfied smelting/omsetting en die skoonmaak van basis metaal
slakke. Alhoewel slak skuiming in staalmaak slakke reeds intensief nagevors is, is min
aandag gegee aan slak skuiming in nie-yster prosesse. Slak skuiming verskynsels is
kompleks, want dikwels betaan die sisteem uit drie of meer fases.
Die doelwitte van hierdie studie is om werk wat reeds oor slakskuiming gepubliseer is te
hersien, om deur fisiese modellering 'n begrip van die prinsiepe waarop skuiming berus te
bekom en om slak skuiming verskynsels na te vors deur piromettallurgiese eksperimente te
beplan en uit te voer.
Ten einde hierdie doelwitte te bereik, is eksperimente uitgevoer met water mengsels in
verskillende kolom groottes, verskillende porie groottes vir gas inspuiting en by
verskillende vloeistof hoogtes, en ook vir hoë temperatuur metallurgiese slakke met
variërende samestelling en by verskillende temperature. Skuimingskondisies is deur gas
inspuiting gesimuleer en die ewewig skuimhoogte is gemeet by verskillende gas snelhede.
Die volgende gevolgtrekkings is bereik:
1. Tydens fisiese (koue) modellering van slak skuiming in 3-fase sisteme styg die
gemiddelde skuim indeks met toenemende hoeveelhede vastestof in die sisteem. Die
uitwerking van addisionele vastestof in die sisteem is onafhanklik van die sisteem
geometrie.
2. Die volgende gevolgtrekkings is gemaak deur die koëffisiente vir 'n empiriese
dimensionale model te pas op waterige mengsels. Hoër vloeistof digtheid lei na laer
skuim indeks waardes. Die invloed van die vloeistof viskositeit is afhanklik van die
sisteem ondersoek en mag 'n positiewe of 'n negatiewe resultaat op skuiming hê.
Die empiriese model moet slegs toegepas word op die eienskap omvang en geometriese opstelling waarvoor dit bepaal is, omdat koëffisiënte grootliks kan
varieer vir verskillende sisteme.
3. Die invloed van vastestof partikels op slak skuiming kan opgesom word deur die
waarneming dat klein hoeveelhede magnetiet slakskuiming stabiliseer terwyl
neerslag van wollastoniet en anhortiet skuiming verminder. Die invloed van
vastestof neerslag hou vermoedelik verband met die digtheid, vorm en graad van
oppervlak aktiviteit van die vastestof partikels.
4. Die skuim indeks verminder met toenemende basisiteit as gevolg van die afname in
die slak viskositeit. Dit geld tot die neerslag van vastestof begin en die skuim indeks
weereens toeneem.
5. Vir toenemende 'FeO' konsentrasie sal die skuim indeks afneem as gevolg van laer
viskositeit, maar hoër oppervlakspanning onderdrukking kan lei na hoër skuim
indeks waardes by hoër 'FeO' konsentrasies.
6. Hoër skuim indeks waardes is verkry vir slakke met laer digthede. Die empiriese
_1
verhouding is bepaal as L cx: p 3 .
7. Hoër skuim indeks waardes is verkry vir slakke met hoër viskositeit. Die empiriese
verhouding is bepaal as L cx: Jl .
8. Hoër skuim indeks waardes is verkry vir slakke met laer oppervlakspannings. Die
empiriese verhouding is bepaal as L cx: 0--1
•
9. Modelle afgelei vir die skuiming van basiese staalmaak slakke beskryf nie die
skuimings gedrag van suur slakke bevredigend nie.
10. Die fisiese eienskappe van die slak beïnvloed die skuim stabiliseerings meganisme.
19
Allertz, Carl. "Sulfur and nitrogen in ladle slag." Doctoral thesis, KTH, Mikro-modellering, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-182981.
Testo completoAbstract (sommario):
The present work deals with some aspects of slags related to secondary metallurgy in the steelmaking process. More specifically the focus is given to sulfur and nitrogen in ladle slags. Even though slags have been fairly well-researched in the past, the available data for these elements in typical ladle slag compositions is rather scarce. In some cases the available data is in discordance. There are also inconsistencies between the literature data and what is commonly observed in the industrial processes. Sulfide capacities were measured at steelmaking temperatures, 1823–1873 K, in ladle slags. The data was found to be in reasonable agreement with the industrial process norms. The sulfide capacity was found to increase with the basic oxides CaO and MgO; and decrease with the acidic components Al2O3 and SiO2. The sulfide capacity was also found to increase with temperature. The dependence of sulfide capacity on the oxygen partial pressure, for slags containing multivalent elements, was investigated experimentally at 1873 K with a slag containing vanadium oxide. A strong dependence of oxygen partial pressure was observed. The sulfide capacity increase by more than two orders of magnitude when the oxygen partial pressure was increased from 4.6×10-16 atm to 9.7×10-10 atm. The nitrogen solubility and the effect of carbon was investigated in typical ladle slags and the CaO–MgO–SiO2 system at 1873 K. Carbon increases the nitrogen solubility substantially. In the absence of carbon, the nitrogen solubility is extremely low. Low concentrations of cyanide was detected in the carbon saturated slag. This was much lower than the total nitrogen content and formation of cyanide cannot explain the large increase. The possibility of removing sulfur with oxidation from used ladle slag was investigated experimentally at 1373–1673 K. The sulfur removal of mostly solid slag was found to be a slow process, and would not suitable for industrial practice. At 1673 K the slag was mostly liquid and more than 85% of the sulfur was removed after 60 min of oxidation in pure oxygen atmosphere.<br><p>QC 20160229</p>
20
Ogirigbo, Okiemute Roland. "Influence of slag composition and temperature on the hydration and performance of slag blends in chloride environments." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13383/.
Testo completoAbstract (sommario):
The use of GGBS as supplement for cements has been shown to improve the long-term strength and durability properties of concrete. In practice, while the chemical composition of GGBS from a single plant may be constant, due to the varying sources from which GGBS is obtained the chemical composition from plant to plant may vary. The wide variability in the use of GGBS as a SCM in different climates, coupled with differences in chemical composition, is bound to have impact on the performance of slag blends. This study investigated the combined influence of difference in slag composition and temperature on the performance of slag blends. Performance was evaluated in terms of strength and transport properties. Paste samples were characterised by calorimetry, TGA, XRD and SEM to follow hydration and microstructural development. Mortar samples were used to follow strength development and transport properties. All tests were carried out at temperatures of 20 and 38°C. Curing at 38°C accelerated the early hydration, but not the later hydration. This led to higher early strengths and lower later strengths, and was attributed to the coarsening of the pore structure caused by the high temperature curing. Except at the early ages at 20°C, both slag blends showed better strength performance than the reference cement. The slag blends also showed better transport properties than the reference cement, especially at 38°C, and this was attributed to their finer pore structure and higher chloride binding capacity. Of the two slags studied, the more reactive slag (slag 1) had better performance, especially at 38°C. Performance of the slag blends at 20°C was influenced mainly by the length of curing, and by the difference in chemical composition at 38°C.
21
Talefirouz, Davood. "Use Of Granulated Blast Furnace Slag, Steel Slag And Fly Ash In Cement-bentonite Slurry Wall Construction." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615432/index.pdf.
Testo completoAbstract (sommario):
Slurry walls have been widely used for more than 25 years to control the migration of contaminants in the subsurface. In the USA, vertical barriers are mostly constructed of soil-bentonite using the slurry trench method of construction. In this method, sodium bentonite is mixed with water to form a viscous slurry that is pumped into a trench during excavation to maintain the trench stability. The stable trench is then backfilled with a mixture of soil and slurry having a consistency of high slump concrete. These barriers have been designed primarily for low permeability, generally less than 10&minus<br>9 m/s. Some investigations have pointed toward improved performance using admixtures that would provide low permeability. In this study, Soma thermal power plant fly ash, granulated blast furnace slag, lime, and steel slag are used as admixture to improve the performance of slurry walls. Permeability, compressive strength, slump, compressibility properties of the mixtures were found and checked for the minimum requirements. According to the findings of this study, granulated blast furnace slag (GGBS), fly ash and steel slag can be used at certain percentages and curing periods as additive in cement-bentonite barrier wall construction. Permeability of specimens having fly ash decreases by increasing fly ash content. Mixtures having 50 % of GGBS type I with 5 % of lime and 9% bentonite content gave acceptable results in 28 days of curing time. Specimens including 50 % of GGBS type II with 5 % of lime and 9% bentonite content gave the higher permeability value in 28 days of curing time with respect to GGBS type I. In addition, most of the mixtures prepared by steel slag gave the acceptable permeability values in 28 days of curing period. Unconfined compressive strength of all mixtures increase by increasing curing time. Cc, Cr, Cv, kcon values were found from consolidation test results. Permeability values found from consolidation tests are 10 times to 100 times higher than flexible wall k results for the same effective stress of 150 kPa. Generally, mv values are decreasing with increasing curing time. As mv decreases, D increases.
22
Cockcroft, Steven Lee. "High-pressure coal injection in the zinc slag fuming process." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26687.
Testo completoAbstract (sommario):
Zinc slag fuming is a kinetically controlled process based on the direct reduction of slag by entrained coal. The kinetics of the process are governed primarily by two factors:
(1) the fraction of coal entrained in the slag, and
(2) the rate of ferrous iron oxidation.
A series of high-pressure coal injection trials have been completed at Cominco's lead smelter in Trail, British Columbia in order to facilitate increased coal entrainment. Fuming rates were increased substantially and over-all efficiencies were improved. These results are in direct contradiction to the
predictions of models based on equilibrium.
The kinetics based mathematical model of the zinc slag - fuming process originally developed by Richards and Brimacombe¹a has been modified to include the reduction and removal of lead from the furnace. A lead “prill” - slag
reaction model has been formulated to account for the behaviour of liquid metallic lead. Analyses of the trial data with the
modified model indicates that significant improvements in entrainment were achieved with high-pressure coal injection.<br>Applied Science, Faculty of<br>Mining Engineering, Keevil Institute of<br>Graduate
23
Bjerke, Helene. "Removal of boron from silicon by slag treatment and by evaporation of boron from slag in hydrogen atmosphere." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19341.
Testo completoAbstract (sommario):
Background and objective: Removal of boron is one of the main challenges in the purification of metallurgical grade silicon (MG-Si) for solar cells and a simple low cost method is therefore needed. Boron removal by slag treatment is today regarded as the most promising method, but the efficiency of the refining method is relatively low. Slag refining as a method for boron removal can be improved by optimization of the slag composition by changing the components and/or the composition of the slag. Another method for improving the slag refining efficiency is to remove boron containing species from the slag by evaporation. The aim of this work is to study the refining properties of the Al2O3-MgO-SiO2 slag and the CaO-SiO2-TiO2 slag, respectively. Furthermore, the possibility of evaporating boron from a CaO-SiO2 slag when refined in a hydrogen containing atmosphere will be investigated. Methods: In all, 12 experiments were performed at 1600&#730;C for determination of the distribution- and mass transfer coefficient of boron in the Al2O3-MgO-SiO2 and CaO-SiO2-TiO2 slag, respectively. In the study of boron evaporation from CaO-SiO2 slag in hydrogen atmosphere 14 experiments were performed. Boron evaporation was investigated in the temperature range 1500-1600&#730;C, the refining time was 0-6 hours and the slag/silicon mass ratio was varied between 0.25 and 1.5. Results: The distribution- and mass transfer coefficient of boron in the Al2O3-MgO-SiO2 (29%-23%-48%) slag was found to be 1.9 and 2.3x10-6 m/s, respectively. The amount of TiO2 in the CaO-SiO2-TiO2 slag was found to rapidly decrease due to reduction of TiO2 by Si. The distribution- and mass transfer coefficients found for the system were therefore not the same as for the original system. A decrease in the boron content in the slag was observed with increasing refining time in a hydrogen atmosphere at 1600&#730;C. This indicated that boron evaporated from the system, but the evaporation rate was found to be low. Temperature was not found to significantly influence the evaporation rate of boron in the temperature range 1500-1600&#730;C. When varying the slag/silicon mass ratio, a considerable increase in the refining efficiency compared to conventional slag refining was observed for the lower slag/silicon mass ratios. The effect diminished for the higher slag/silicon mass ratios. Conclusion: The kinetic and thermodynamic properties of the Al2O3-MgO-SiO2 slag evaluated in this thesis were shown to be in the same range as comparable slags in previous studies. In the CaO-SiO2-TiO2 slag most of the TiO2 was reduced during the refining process which makes it difficult to use this compound as a part of a slag for refining of silicon. When slag refining was performed in a hydrogen atmosphere the refining efficiency compared to conventional slag refining was shown to increase.
24
El-Rassi, Kamal Philippe. "Electric furnace slag reduction, AC versus DC." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0003/MQ45617.pdf.
Testo completo
25
Tan, Chee Keong. "The monitoring of near burner slag formation." Thesis, University of South Wales, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289169.
Testo completo
26
Pobokina, Elena. "Usage of converter slag in blast-cupola." Thesis, Вид-во СумДУ, 2006. http://essuir.sumdu.edu.ua/handle/123456789/11792.
Testo completo
27
Kombathula, Sushanth. "Sequestration of carbon dioxide in steel slag." Thesis, KTH, Materialvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280716.
Testo completoAbstract (sommario):
Although Iron and steel industry is essential for the development of society, the industry is responsible for a large portion of CO2 emissions. The industry also produces by-products like metallurgical slag in orders of million tons. The slag is alkaline in nature and rich in Ca and Mg oxides. Upon use the oxide interact with atmospheric CO2 and form carbonates, making them unstable. Storing CO2 in the slag would make it more stable, enhances its life cycle and promotes further usage in various applications. CO2 sequestration can be done through carbonation of steel slag. Carbonation of slag can be achieved through direct and indirect carbonation. Direct carbonation is performed either in a gaseous or an aqueous state in a single step. Indirect carbonation involves multiple steps as it activates the Ca/Mg ions in the slag before they interact with CO2. For an industrial process the direct route would be more viable as it involves lesser steps, easier to scale up. Since there are no solvents to activate the Ca/ Mg the cost involved is also less. This thesis focuses on developing an industrial process to sequester CO2 in metallurgical slag. Sequestration through a combination of gaseous and aqueous has been attempted while studying the effect of carbonation time, carbonation temperature and shape of slag used. Carbonation of the slag is performed using CO2 and steam. The results show that carbonation yield increases with carbonation time and decreases with increase in temperature. The effect of the shape of slag used for carbonation was studied by performing carbonation test in a slag pellet. Diffusion plays a significant role in carbonation process. Powdered slag showed higher carbonation yield compared to the pellet. CO2 uptake as high as 53g of CO2/kg of slag at 200 oC for 6 hr has been achieved. The results indicate the possibility for an industrial carbonation process.<br>Även om järn- och stålindustrin är avgörande för samhällets utveckling, är industrin ansvarigför en stor del av koldioxidutsläppen. Industrin producerar också biprodukter som metallurgisk slagg i order på miljoner ton. Slaggen är alkalisk till sin natur och rik på Ca- och Mg-oxider. Vid användning interagerar oxiden med atmosfärisk CO2 och bildar karbonater, vilket gör dem instabila. Att lagra koldioxid i slaggen skulle göra den mer stabil, förbättra livscykeln och främja ytterligare användning i olika applikationer. CO2-bindning kan göras genom kolsyrning av stålslagg. Kolsyrning av slagg kan uppnås genom direkt och indirekt karbonatisering. Direkt karbonatisering utförs antingen i ett gasformigt eller vattenhaltigt tillstånd i ett enda steg. Indirekt kolsyrning involverar flera steg eftersom den aktiverar Ca/Mg-jonerna i slaggen innan de interagerar med CO2. För en industriell process skulle den direkta vägen vara mer livskraftig eftersom den innebär mindre steg, lättare att skala upp. Eftersom det inte finns några lösningsmedel för att aktivera Ca/Mg är kostnaden också mindre. Denna avhandling fokuserar på att utveckla en industriell process för att binda koldioxid i metallurgisk slagg. Sekvestrering genom en kombination av gasformig och vattenhaltig har försökt under undersökning av effekten av kolsyratid, kolsyratemperatur och form av den använda slaggen. Kolsyringen av slaggen utförs med CO2 och ånga. Resultaten visar att karbonatiseringsutbytet ökar med kolsyratiden och minskar med temperaturökningen. Effekten av formen på slagg som användes för karbonatisering studerades genom att utföra karbonatiseringstest i en slaggpellet. Diffusion spelar en viktig roll i karbonatiseringsprocessen. Pulveriserad slagg visade högre karbonatiseringsutbyte jämfört med pelleten. CO2-upptag så högt som 53 g CO2/kg slagg vid 200 oC under 6 timmar har uppnåtts. Resultaten indikerar möjligheten för en industriell karbonatiseringsprocess.
28
Ndula, Bungu Peter. "Fluidised-bed chlorination of oxidised titania slag." Diss., University of Pretoria, 2004. http://hdl.handle.net/2263/29501.
Testo completoAbstract (sommario):
Please read the abstract in the section, 00front of this document<br>Dissertation (MSc (Metallurgy))--University of Pretoria, 2004.<br>Materials Science and Metallurgical Engineering<br>MSc<br>unrestricted
29
Skagerkvist, Mio. "Adsorption of anionic elements to steel slag." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-71048.
Testo completoAbstract (sommario):
Steel slag is a by-product from steel production and has potential to act as a sorbent for several contaminants. Contaminated water is a global problem and cheap and simple remediation solutions are often sought. The potentials are many to use an industrial residue for water purification purposes e.g. low cost. The absorption efficiency was evaluated for two different steel slags further divided into two grain sizes, <0.9 mm and 0.9-2 mm. Laboratory experiments was conducted for three anionic elements; bromine, chromate and molybdate. Controlled parameters were; time, sorbent amount and sorbate concentration. The sorption was primarily dependent on the grain size and the smaller grain size had a higher sorption of all three tested anionic species. Unfortunately the results are partially affected by the release of the tested elements from the sorbent itself.
30
Jelkina, Albertsson Galina. "Investigations of Stabilization of Cr in Spinel Phase in Chromium-Containing Slags." Licentiate thesis, KTH, Materialens processvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-50709.
Testo completoAbstract (sommario):
The influence of basicity, heat treatment as well as different oxygen partial pressures on the phase relationships in the CaO-MgO-SiO2-Cr2O3 slags was studied with a view to control the precipitation of Cr-spinel in the slag phase. The equilibrium phases in CaO-MgO-SiO2-Cr2O3 slag system in the range on 1673-1873 K have been investigated under low oxygen partial pressure as well as in as air atmosphere. In low oxygen partial pressure experiments, a suitable mixture of CO and CO2 was used to control the oxygen partial pressure. The oxygen partial pressure was kept at 10-4 Pa. The Cr2O3 and MgO contents in the slag were fixed to be 6 and 8wt% respectively. The basicity (CaO/ SiO2) of the slag was varied in the range 1.0-2.0. Gas/slag equilibrium technique was adopted to synthesize the slag at a suitable temperature above the liquidus point. One heat treatment procedure is that the samples were heated to and soaked at 1873 K for 24h in order to achieve the equilibrium state and subsequently quenched in water. The other is that the samples were heated to and soaked at 1873 K for 24h, then slow cooled to 1673 K and soaked at this temperature for additional 24h in order to achieve the equilibrium state at lower temperature before quenching in water. The chromium distribution and phase compositions in the quenched slag were studied using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction techniques (XRD). FACTsage software was used for the phase equilibrium calculations. The experimental results obtained from the present work are compared with the calculation results from FACTsage software as well as with results from samples directly quenched after soaking at 1873K. It is found that the spinel formation at 1873 K in air atmosphere is favored in the slag basicity range of 1.0 to 1.6. The size of spinel crystals increased drastically after slow cooling followed by annealing compared to samples being quenched after soaking at 1873 K. The amount of foreign elements dissolved in the spinel phase, and matrix phases decreased after slow cooling followed by annealing at lower temperature, resulting in purer phases with less defects. It was found that the amount of foreign elements in the spinel phase, and other phases decreased after soaking at very low PO2. The size of the spinel crystals was found to be larger in samples with low basicity. Spinel phase precipitation has improved in the samples with higher basicities compared to the results obtained in air.<br>QC 20111208
31
Feng, Qiu Ling. "Chemical and microstructural investigations on slag hydration products." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 1989. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59672.
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Tshilombo, Kabamba Ghislain. "Oxygen activity measurements in simulated converted matte." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-05152007-110604.
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33
Kondratiev, Alex. "Development of viscosity models for multiphase slag system /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18306.pdf.
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34
Corell, Linda, and Erika Larsson. "Nya 3:12-reglerna - ett slag i luften?" Thesis, Karlstad University, Faculty of Economic Sciences, Communication and IT, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-335.
Testo completoAbstract (sommario):
<p>Från och med årsskiftet 2006 gäller nya beskattningsregler för fåmansföretagare. Reglerna började reformeras för några år sedan och har under utredningens gång diskuterats häftigt. Många företagare har tyckt att de förbisetts av lagstiftaren i de nya 3:12-reglerna då många av deras förmåner tagits bort.</p><p>Syftet med vår undersökning var att ta reda på om förändringen av 3:12-reglerna medfört en förbättring eller försämring för företagen. Det undersöktes med utgångspunkt i företagens storlek, resultat och sammansättning av delägare. För att få så mycket verklighetsanknytning som möjligt genomfördes beräkningar på tre verkliga företag. Tanken med jämförelsen var att se hur dessa påverkades av förändringen. För att få ytterligare underlag för våra slutsatser intervjuades två revisorer och representanter från Skatteverket samt Svenskt näringsliv.</p><p>Kopplat till beteendevetenskapen har vi analyserat vilka effekter förändringen av 3:12-reglerna har fått för företagarna. Vi har kommit fram till att ägarens privatekonomi påverkas olika beroende på hur företagets situation ser ut. Företagets situation påverkas av en rad faktorer, bland annat av dess mål och strategi.</p><p>Vår undersökning visar att vinstgivande företag med höga lönekostnader där ägarna uppfyller spärreglerna är att ses som vinnare. Likaså är mindre företag vinnare då de nu har möjlighet till kapitalbeskattning genom att använda den nytillkomna schablonregeln. De företag som missgynnas av de nya 3:12-reglerna är de som tidigare kunde använda sig av löneunderlaget men som nu inte når upp till den höjda spärregeln.</p><p>Vi anser att reglerna i de flesta avseenden blivit bättre med tanke på den nytillkomna schablonregeln.</p>
35
Strandkvist, Ida. "A Dissolution Study of Common Ferrous Slag Minerals." Licentiate thesis, Luleå tekniska universitet, Mineralteknik och metallurgi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-60227.
Testo completoAbstract (sommario):
Slag is a vital part of metal production since it removes impurities from the metal. As slag is continuously produced, the options are either to dispose slag in landfill or acknowledge slag as a product. Slag can be used in many different applications, ranging from fertilizer to construction material; in some cases, the properties of slag make it a superior alternative to virgin stone materials. The properties and thereby the field of application is determined by the mineralogical composition of the slag. Slag is considered an environmentally friendly material as long as the leaching of certain elements stay below specified thresholds, for leaching of chromium the limit is at 0.5 mg/kg for slag to be considered inert material. The most common leaching approach is to compare leaching analyses from slag samples to deduce which elements and/or phases contribute or prevent leaching of specific elements. With this method each slag need to be investigated separately and the result may only apply for that specific slag type. In this thesis the approach is different: individual minerals are synthesized and dissolved separately at various pH to accurately assess their dissolution capabilities. By studying the dissolution of individual minerals the leaching of any type of slag with known mineralogical composition can be anticipated. Slag leaching can then be tailored, for example, chromium leaching can be eliminated if all chromium containing phases are removed or not capable of dissolving. In this thesis the dissolution of akermanite, β- and γ-dicalciumsilicate, merwinte, monticellite, pseudowollastonite and magnesiowüstite with varying FeO/MgO ratios are studied. Leaching tests of magnesiowüstite with 4 wt% Cr2O3 were also included. The dissolution of each mineral is calculated by the acid addition required to maintain a constant pH with 50 mg of mineral in 100 ml water. As expected, the dissolution decreases as pH increases, with exception of the dicalcium silicates which dissolved completely at pH 4 to 10. The dissolution of the minerals is largely connected to the elemental composition. In the silica based minerals a high Ca ratio promotes dissolution while a high Si ratio impedes the dissolution rate. Both dissolution and chromium leaching of magnesiowüstite depends on the FeO content, with increasing FeO content the dissolution and leaching decreases, magnesiowüstite with at least 60 wt% FeO does not dissolve at pH 10. None of the magnesiowüstite compositions were close to the chromium leaching limit of inert material, 0.5 mg/kg, as the highest leaching sample, with 52 wt% FeO, leached 0.069 mg/kg.
36
Lee, Seung Hwan. "Phosphorus removal mechanisms in soil and slag media." University of Technology, Sydney. Faculty of Engineering, 1995. http://hdl.handle.net/2100/356.
Testo completoAbstract (sommario):
Excessive phosphorus (P) is one of the major pollutants in natural water that are responsible for algal blooms and eutrophication. P removal by soil and slag is an attractive solution if the P sorption capacity of soil or slag is significant. To design an efficient land treatment facility, basic information on the behaviour of P in the media-water environment is required. In this study, detailed experiments were conducted to study P removal under static and dynamic conditions, and mathematical models were developed to describe these processes. The kinetic studies on P sorption onto a sandy loam soil from North Sydney, Australia, and dust and cake waste products from the BHP steel industry revealed that P sorption is a slow process. More than 90% of the P was adsorbed within 70, 12 and 60 hours in a mixing system for soil, dust and cake respectively while it was within 240, 24 and 120 hours respectively in a static (no stirring) system. Dust adsorbed P the most, compared to the other adsorbents (220-225 times and 4-5 times of the sorptivity of soil and cake respectively). P sorption in the batch experiments was described better by an equation using the Langmuir isotherm than one using the Freundlich isotherm. The kinetics of P sorption were satisfactorily explained by a static, physical, non-equilibrium sorption model (SPNSM). The pH of the P solution played a critical role in the extent of removal and the removal mechanisms of P. Removal was at a minimum at pH 2. The effect of pH on P removal varied depending on the type of adsorbents and the initial P concentration. The dominant removal mechanism of P at pH<8 was physical sorption, while it was chemical precipitation at pH>10. Batch flocculation experiments revealed that the P removal efficiency increased with an increase of adsorbent dose, flocculation (contact) time and mixing rate. P sorption is affected by the presence of NH4 which competes for available sites on the adsorbents. The amount of P adsorbed by dust and cake in the presence of NH4 was less than that in a single solute system. The reduction percentage of P for dust ranged from 33 to 57%. Detailed column experiments conducted with soil, dust and cake as media indicated that dust and cake have much higher sorption capacities than soil. The solid phase P concentrations on dust and cake calculated from batch experimental isotherm constants are substantially higher than those estimated.
37
Swinnerton, Mark. "The influence of slag evolution on BOF dephosphorisation." School of Mechanical, Materials & Mechatronic Engineering - Faculty of Engineering, 2005. http://ro.uow.edu.au/theses/282.
Testo completoAbstract (sommario):
A study has been conducted to examine the influence of slag evolution on BOF dephosphorisation. An experimental technique was developed where slag/metal emulsion samples were obtained from the BOF during processing. The observed evolution of slag composition was consistent with many previous studies, where in the first half of the blow slags high in (%SiO2) and low in (%FeO) are generated. During the second half of the oxygen blow, (FeO) generation and lime dissolution improve the slag basicity and contribute to the transfer of phosphorus from metal to slag. Poor levels of phosphorus removal during the centre region of the blow were found to coincide with a minimum in the (%FeO) composition. By the end of blow, 70% of the mass of phosphorus in the furnace is present in the slag, and the extent of phosphorus removal is proportional to the slag basicity and the (%FeO) concentration in the slag. By utilizing mass balance calculations to estimate the mass of slag in the furnace, it was shown that at tap, approximately 30% of lime and 50% of magnesia remain undissolved in a liquid slag saturated in both components. It was concluded that the mass of lime added to the furnace could be reduced without influencing the dissolved concentration of (%CaO), and therefore without deteriorating the extent of dephosphorisation.
38
Chen, Wei. "Hydration of slag cement theory, modeling and application /." Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57703.
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39
Kjellqvist, Lina. "Studies of Steel/Slag Equilibria using Computational Thermodynamics." Licentiate thesis, Stockholm Stockholm : Materialvetenskap, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3914.
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40
Holloway, Mark. "Corrosion of steel reinforcement in slag-based concrete." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365811.
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41
Oberlink, Anne Elizabeth. "NON-PORTLAND CEMENT ACTIVATION OF BLAST FURNACE SLAG." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/25.
Testo completoAbstract (sommario):
The purpose of this project was to produce a “greener” cement from granulated ground blast furnace slag (GGBS) using non-Portland cement activation. By eventually developing “greener” cement, the ultimate goal of this research project would be to reduce the amount of Portland cement used in concrete, therefore reducing the amount of carbon dioxide emitted into the atmosphere during cement production.
This research studies the behavior of mineral binders that do not contain Portland cement but instead comprise GGBS activated by calcium compounds or fluidized bed combustion (FBC) bottom ash. The information described in this paper was collected from experiments including calorimetry, which is a measure of the release of heat from a particular reaction, the determination of activation energy of cement hydration, mechanical strength determination, and pH measurement and identification of crystalline phases using X-ray diffraction (XRD).
The results indicated that it is possible to produce alkali-activated binders with incorporated slag, and bottom ash, which have mechanical properties similar to ordinary Portland cement (OPC). It was determined that the binder systems can incorporate up to 40% bottom ash without any major influence on binder quality. These are positive results in the search for “greener cement”.
42
Sadatgol, Seyedhani. "Upgrading of Landfill Gas with Household Waste Slag." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170724.
Testo completoAbstract (sommario):
Modern landfills produce landfill gas, LFG, on a smaller scale and with limited content of degradable organic materials in the waste. The waste deposit in the Sofielund landfill began in 2005 and the final coverage is not yet commenced. The landfill waste must contain up to 10% decomposable organic materials at most. In a previous experiment on Sofielund landfill in summer 2011, the measurements from four sample wells showed the landfill gas consisted of up to 45% Methane and about 17000 ppm of Hydrogen sulfide, and the rest was only carbon dioxide. During the earlier experiment in 2011 and during 2012 the smell of H2S got offensive periodically and apart from that, concentrations above 1000 ppm are toxic. Previous research, Bottom ash for biogas upgrading, BABIU, shows that bottom ash from municipal solid waste incinerator (MSWI) can effectively reduce CO2 and H2S contents of landfill gas. Bottom ash from MSWI can be utilized in upgrading landfill gas and reduce odor problems of landfills with high H2S production. In this study, an area of 15m x 12m was covered with weathered slag from bottom ash with thickness of about 30cm, to examine how this layer can reduce the concentrations of H2S and CO2. Gas samples were taken from depths of 10cm and 15cm below the surface of bottom ash. There were also samples taken from around the slag-covered area. The surface was laid out 5 days before the first measurement was performed. The experiment was carried out for 20 days, 5, 7, 11, 13, 18 and 20 days after establishment of the surface with bottom ash. The intensity of emissions in different parts of the landfill varied from time to time, due to compacting and changing the permeability of the surface, and it shows that LFG flow in the Sofielund is near the lowest limit of it. Considering the results from the tests in 2011 in deep wells, the recent measurements done in this study showed low contents of LFGs. The highest contents of LFGs in the measurements belong to a pipe, which was found in the waste area of the landfill. Those highest contents of LFG were 15.1% methane, 12.1% carbon dioxide, 0.4% oxygen and the hydrogen sulfide did not exceed 2 ppm. This shows that in deeper depths concentrations of LFG is higher than that of the surface and 10cm below the surface. In the slag covered area CO2 content increased day by day from the first day of the measurement to the last day due to carbonation of the slag and its role in CO2 sequestration. According to the recent measurement, it can be suggested to cover the landfill with a layer of slag as a construction material, to minimize the LFG emissions and the bad smell from H2S. Therefore it can eliminate direct emissions of LFG to the atmosphere by diffusion through the slag layer. This diffusion allows adsorption of CO2 and oxidation of H2S.
43
Ekengård, Johan. "Slag/Metal Metallurgy in Iron and Steel Melts." Doctoral thesis, KTH, Tillämpad processmetallurgi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187228.
Testo completoAbstract (sommario):
In this work, the metal and slag phase mixing in three steps of a ladle refining operation of steel melts and for an oxygen balance during cooling of cast iron melts have been studied at two Swedish steel plants and at two Swedish cast iron foundries, respectively. In order to predict the oxygen activity in the steel bulk in equilibrium with the top slag as well as in metal droplets in the top slag in equilibrium with the top slag, three slag models were used. In addition, the assumptions of a sulphur-oxygen equilibrium between steel and slag and the dilute solution model for the liquid steel phase were utilized in the calculations. Measured oxygen activities in steel bulk, which varied between 3.5-6 ppm, were compared to predicted oxygen activities. The differences between the predicted and measured oxygen activities were found to be significant (0-500%) and the reasons for the differences are discussed in the thesis. Slag samples have been evaluated to determine the distribution of the metal droplets. The results show that the relatively largest numbers of metal droplets are present in the slag samples taken before vacuum degassing. Also, the projected interfacial area between steel bulk and top slag has been compared to the interfacial area between the metal droplets and slag. The results show that the droplet-slag interfacial area is 3 to 14 times larger than the flat projected interfacial area between the steel and top slag. Furthermore, the effect of the reactions between top slag and steel and the slag viscosity on the metal droplet formation is discussed. The results show significant differences between the steel bulk and steel droplet compositions and the reasons for the differences are discussed in the thesis. The oxygen activity in different cast irons was studied. Plant trials were performed at three occasions for lamellar, compacted and nodular iron melts. The results show that at temperatures close to the liquidus temperature the oxygen activities were 0.03-0.1 ppm for LGI, around 0.02 ppm for CGI, and 0.001ppm for SGI. In addition, it was found that as the oxygen activities increased with time after an Mg treatment, the ability to form a compact graphite or a nodular graphite in Mg-treated iron melts was decreased. Also, extrapolated oxygen activity differences up to 0.07 ppm were found for different hypoeutectic iron compositions for lamellar graphite iron at the liquidus temperature. Overall, the observed differences in the dissolved oxygen levels were believed to influence how graphite particles are incorporated into the austenite matrix and how the graphite morphology will be in the cast product.<br><p>QC 20160518</p>
44
HUANG, JIA-YU, and 黃家裕. "Concrete made with portland / slag cements and slag aggregate." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/40357362301117682869.
Testo completo
45
Cengizler, Hakan. "Thermodynamic activity of MnO in manganese slags and slag-metal equilibria." Thesis, 2015. http://hdl.handle.net/10539/16928.
Testo completo
46
Chung-HoTsai and 蔡宗和. "Alkali-activated Slag Binders with BOF Slag and Fly Ash." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/86526443069730108431.
Testo completo
47
Liu, Yiing-Thsang, and 劉穎蒼. "The Usability of Water-Quenched BF Slag Slag Substituing Offshore Sand." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/16870118576598208557.
Testo completoAbstract (sommario):
碩士<br>國立交通大學<br>土木工程學系<br>84<br>To conform usability of water-quenched BF slag substitution
offshore sand,the effect on concrete by water-quenched BF slag,
which produced by China Steel Corp.,in different percentage of
substitute was inve-stigate. Under the conditions of 3 different
fineness modulous of offshore sand,5 different slag
substitutes,1 slump and 4 different water-cement ratios,
properties such as workability,compressive strength,tensile
strength,durability,diffusibility,elapsing time,agg-regation,
etc., of concrete composed of different substitutes of water-
quenched BF slag were compared.The particles of water-quenched
BF slag are mostly in globular shape and with good flowability.
The workability then can be enhanced and the consumption of
water can be reduced as the ratio of substitution increased.
However,the bleeding and segregation also become more prominent
when the ratio of substitution increased due to its high
specific gravity. Therefore,the best ratio of substitution is
around 40% to 55%. The substitution may be reasonably reduced if
the fineness modulous of offshore sand can be enhanced.The
results of this study showed that the compressive strength of
all concrete composed of water-quenched BF slag in different
substitution were better than that of concrete composed of
offshore sand. The change of tensile strength and water
tightness are similar to that of compressive strength.As the
substitution increased,the durability was enhanc-ed,the
shrinkage lessened,and the time of aggregation delayed.
48
"Kinetics of Alkaline Activation of Slag and Fly ash-Slag Systems." Master's thesis, 2012. http://hdl.handle.net/2286/R.I.15972.
Testo completoAbstract (sommario):
abstract: Alkali-activated aluminosilicates, commonly known as "geopolymers", are being increasingly studied as a potential replacement for Portland cement. These binders use an alkaline activator, typically alkali silicates, alkali hydroxides or a combination of both along with a silica-and-alumina rich material, such as fly ash or slag, to form a final product with properties comparable to or better than those of ordinary Portland cement. The kinetics of alkali activation is highly dependent on the chemical composition of the binder material and the activator concentration. The influence of binder composition (slag, fly ash or both), different levels of alkalinity, expressed using the ratios of Na2O-to-binders (n) and activator SiO2-to-Na2O ratios (Ms), on the early age behavior in sodium silicate solution (waterglass) activated fly ash-slag blended systems is discussed in this thesis. Optimal binder composition and the n values are selected based on the setting times. Higher activator alkalinity (n value) is required when the amount of slag in the fly ash-slag blended mixtures is reduced. Isothermal calorimetry is performed to evaluate the early age hydration process and to understand the reaction kinetics of the alkali activated systems. The differences in the calorimetric signatures between waterglass activated slag and fly ash-slag blends facilitate an understanding of the impact of the binder composition on the reaction rates. Kinetic modeling is used to quantify the differences in reaction kinetics using the Exponential as well as the Knudsen method. The influence of temperature on the reaction kinetics of activated slag and fly ash-slag blends based on the hydration parameters are discussed. Very high compressive strengths can be obtained both at early ages as well as later ages (more than 70 MPa) with waterglass activated slag mortars. Compressive strength decreases with the increase in the fly ash content. A qualitative evidence of leaching is presented through the electrical conductivity changes in the saturating solution. The impact of leaching and the strength loss is found to be generally higher for the mixtures made using a higher activator Ms and a higher n value. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) is used to obtain information about the reaction products.<br>Dissertation/Thesis<br>M.S. Civil Engineering 2012
49
Logeshwari, J. "Characterization of Different Slags for Bulk Geotechnical Applications." Thesis, 2017. http://etd.iisc.ac.in/handle/2005/3627.
Testo completoAbstract (sommario):
Generation of wastes in the form of liquid, solid or gas is inevitable in any industry.Industrial Solid Waste is the waste that is generated from an industrial or manufacturing process and includes the waste generated from non-manufacturing activities as well.Most of these wastes fall under the category of Ashes, Slagsor Sludges. For the present work, three types of secondary lead slag, two types of granulated blast furnace slag (GBS) or iron slag and four types of steel slags were procured and studied.An elaborate study on various characteristics of the slags has been performed. Based on the results, all the possible applications for the individual slags are considered. The performance of the secondary lead slag as an embankment material was analyzed. The slope stability for various conditionswas analyzed using Geo5 and experimentally determined strength parameters. It was found that the material can be used safely for embankment constructions.The CBR values were very good in the range for both GBS and steel slag,thus repeated load triaxial test are done to determine the resilient modulus. k1-k3model was adopted and the regression coefficients were determined. Based on the results the pavement design is done using KENPAVE software. An exercise has been performed to determine the quantity of the conventional material that could be saved, considering the type and size of the pavement. For the aggregate sized steel slag, the tests were done to find the suitability of the material for various applications like, as railway ballast, concrete aggregate, gabion and rip rap stones. And the tests result shows the material to be suitable for these applications and is expected to perform well. Study on morphological parameters reveals that the size and gradation of any material plays an important role in its mechanical behavior, however in the case of slags, this could be tailor made by using appropriate crushers, as per the requirements.
50
Logeshwari, J. "Characterization of Different Slags for Bulk Geotechnical Applications." Thesis, 2017. http://etd.iisc.ernet.in/2005/3627.
Testo completoAbstract (sommario):
Generation of wastes in the form of liquid, solid or gas is inevitable in any industry.Industrial Solid Waste is the waste that is generated from an industrial or manufacturing process and includes the waste generated from non-manufacturing activities as well.Most of these wastes fall under the category of Ashes, Slagsor Sludges. For the present work, three types of secondary lead slag, two types of granulated blast furnace slag (GBS) or iron slag and four types of steel slags were procured and studied.An elaborate study on various characteristics of the slags has been performed. Based on the results, all the possible applications for the individual slags are considered. The performance of the secondary lead slag as an embankment material was analyzed. The slope stability for various conditionswas analyzed using Geo5 and experimentally determined strength parameters. It was found that the material can be used safely for embankment constructions.The CBR values were very good in the range for both GBS and steel slag,thus repeated load triaxial test are done to determine the resilient modulus. k1-k3model was adopted and the regression coefficients were determined. Based on the results the pavement design is done using KENPAVE software. An exercise has been performed to determine the quantity of the conventional material that could be saved, considering the type and size of the pavement. For the aggregate sized steel slag, the tests were done to find the suitability of the material for various applications like, as railway ballast, concrete aggregate, gabion and rip rap stones. And the tests result shows the material to be suitable for these applications and is expected to perform well. Study on morphological parameters reveals that the size and gradation of any material plays an important role in its mechanical behavior, however in the case of slags, this could be tailor made by using appropriate crushers, as per the requirements.