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Rahman, Muhammad Mahfuzur Materials Science & Engineering Faculty of Science UNSW. "Fundamental investigation of slag/carbon interactions in electric arc furnace steelmaking process." Awarded By:University of New South Wales. Materials Science & Engineering, 2010. http://handle.unsw.edu.au/1959.4/44798.
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This work investigates the interactions of carbonaceous materials (metallurgical coke, natural graphite and HDPE/coke blends) with three EAF slags [FeO: 24% to 32%]. Experiments were conducted using the sessile drop technique (1500??C-1600??C) with off-gases (CO, CO2) measured using an IR analyzer; the wetting behaviour was determined from contact angle measurements. Estimation of slag foaming behaviour was determined from the droplet volume changes calculated using specialized software. At 1550??C, all slags were non-wetting with coke due to increased surface tension due to sulphur. At 1550??C, slag 1 was initially non-wetting on natural graphite due to gas entrapment in the slag droplet; the wetting improved after that. Other slags showed comparatively better wetting. At 1600??C, all slags were non-wetting with coke. Slags showed a shift from non-wetting to wetting behaviour with natural graphite. Slag/coke reactions produced high off-gases levels causing extensive FeO reduction; gas entrapment in the slag was poor (small volume droplets). Slag/natural graphite interactions revealed both slow gas generation rates and FeO reduction, and excellent gas entrapment (higher droplet volumes) with minor changes in slag properties due to low ash levels. The iron oxide reduction rates were determined to be 1.54x10-5 and 4.2x10-6 mol.cm-2/sec (Slag 1, 1550??C) for metallurgical coke and natural graphite respectively. Slag interactions with coke/HDPE blends showed increasing off-gas levels with increasing HDPE levels. Blend#3 produced the highest off-gas levels, extensive FeO reduction and displayed significantly higher slag foaming and better wetting compared to coke. Our line on trends compared well for slag/carbon interactions and resulted in deceased specific energy consumption and carbon usage and increased productivity. These findings have enhanced the possibility of utilizing polymeric wastes in blends with coke in EAF steelmaking for slag/carbon interactions.
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Kumar, Harjinder. "Laboratory evaluation of electric arc furnace slag as a potential wetland substrate." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18690.
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Phosphorus (P) is considered as the controlling element in the proliferation of eutrophication in water bodies. Constructed wetlands are accepted as the most appropriate treatment technology for removal of nutrients, including phosphorus from agricultural drainage waters. As most of P removal in constructed wetlands is through precipitation and abiotic sorption, introduction of suitable substrate can enhance the P removal efficiency of the system. Slag has immense capacity for P sorption however its composition and ability as a wetland substrate varies from locale to locale. A study divided into bench and pilot scale was undertaken to evaluate the efficiency of a locally available electric arc furnace slag (EAFS). The pilot scale study was used to validate the findings of bench scale together with conducting additional investigations. In bench scale study EAFS was found to have high efficiency (nearly 100%) in P removal. Amount of P removed increased by increasing the contact time between the P solution and the slag. Where mechanical shaking appreciably enhanced the P-removal efficiency (90 %) in 3 hour, aeration resulted in (97-99%) phosphorus removal in a much reduced contact time of one hour for all P concentrations used (0.3, 3.0, 6.0 mg/L). Adsorption capacity of 1457 mg/kg was ascertained for this slag. In the pilot scale study higher P removal was recorded in residence time treatments of five and ten hour but, the rate of removal was slower than what was observed in case of one and two hour residence time. The EAFS when subjected to application of a high concentration of P solution over 72 hour period depicted a gradual decrease in the P removal efficiency, falling from 85% to 53% at the end of experiment. It was also established that EAFS can be regenerated to 70% of its original P-sorption capacity by putting it to a resting period of 3 weeks.Le phosphore est considéré comme l'élément nutritif déterminant dans le foisonnement par eutrophisation des eaux. Les marais artificiels sont reconnus comme la technologie la plus appropriée pour enlever les éléments nutritifs, tel le phosphore, des eaux usées agricoles. Comme la majorité de l'enlèvement du P dans les marais artificiels est le résultat de précipitation et de sorption abiotique, l'introduction d'un matériel approprié pourrait améliorer l'efficacité d'enlèvement de P du système. Quoi que les scories ait une immense capacité de sorption du P, leur composition et applicabilité comme matériel de marais filtrant varie toutefois de lieu en lieu. Une étude visant à évaluer l'efficacité de scories de four électrique à arc (SFEA), disponibles localement, à ces fins, fut entreprise à l'échelle de banc d'essai, ainsi qu'à l'échelle préindustrielle. A cette dernière échelle l'étude servit à valider les résultats de l'étude à l'échelle de banc d'essai, ainsi qu'a compléter d'autres expériences. A l'échelle du banc d'essai, la SFEA montra un efficacité d'enlèvement du P très élevée (près de 100%). La quantité de P enlevée augmenta de concert avec la durée de contact entre la solution contenant le P et les scories. Pour toutes les concentrations de P étudiés (0.3, 3.0, et 6.0 mg/L), une agitation mécanique améliora notamment l'efficacité d'enlèvement du P (90% en 3 hr), tandis que l'introduction d'une aération eu pour résultat un enlèvement quasi-total (97-99%) du P dans un temps de contact beaucoup plus court (1 hr). Une capacité d'adsorption de 1400 mg/kg fut déterminé pour ces scories. Lors de l'étude à l'échelle préindustrielle, des temps de séjour plus longs (5 et 10 h) augmentèrent l'enlèvement du P, mais le taux d'augmentation de l'enlèvement du P fut significativement plus élevé lors des premières (1, 2 h) heures de séjour. Lorsque soumises à une application d'une solution
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Bird, Simon. "Investigations of Electric Arc Furnace Slag Filters: Phosphorus Treatment Performance, Removal Mechanisms and Material Reuse." ScholarWorks @ UVM, 2009. http://scholarworks.uvm.edu/graddis/24.
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Around the world, the eutrophication of freshwater lakes and streams by the excess loading of phosphorus (P) has become one of the most important water quality issues. In Vermont, P pollution from urban and agricultural non-point sources has led to severe blooms of toxic cyanobacteria in Lake Champlain, and the degradation of the lake’s value as a drinking water source and its recreation potential. Electric arc furnace (EAF) steel slag has been identified as an effective material for use as a filter media for the removal of P from both point and non-point sources of pollution. In order to further assess the feasibility of this technology for use in Vermont, several investigations were carried out starting in the winter of 2006. Three objectives for research were identified: 1) to construct 2 EAF steel slag filters in-series at the Constructed Wetlands Research Center (CWRC) and investigate their efficiency in P, TSS and metals reduction from dairy waste water in a cold climate; 2) investigate the potential for reuse of P saturated EAF steel slag as a soil amendment and plant fertilizer by testing bioavailability of sorbed P and quantities of P released to surface runoff; 3) To elucidate the principal mechanisms responsible for the removal of P in EAF slag filters when used for the treatment of dairy effluent. The results indicated that 2 EAF steel slag filters constructed in-series are an effective method to increase the treatment efficiency and longevity of a filter system. Additionally, parameters for the concentrations of total suspended solids (TSS) and biological oxygen demand (BOD) were developed, both important factors for design of filter systems. In greenhouse trials, Medicago sativa plants achieved greater above ground biomass growth with P fertilization by triple super phosphate (TSP) than EAF steel slag at the shorter growth period (5 weeks). However, by the end of the longer growth period (10 weeks) except at the highest amendment rate, the plants treated with EAF steel slag had a higher growth rate than the TSP, suggesting that EAF steel slag is an effective slow release P source. Using a rain simulator, the amount of P lost to surface runoff from both a saturated and a semi-saturated EAF steel slag was found to be negligible, and except for total P in the saturated slag, to be below 1 mg L-1. Voltammetric analysis and geochemical modeling were used to identify possible mechanisms for the removal of P from waste effluent. The Ca mineral hydroxyapaptite and the Fe(II) mineral vivianite were both shown to be likely mechanisms given the chemical conditions in EAF steel slag filters. This research represents the first investigation of cold weather performance of EAF steel slag filters for the treatment of dairy parlor and milk house waste effluent. Additionally, it was also the first research on the bioavailability of P sorbed to EAF steel slag, and of the possibility of its reuse as a soil amendment, and of the mechanisms involved in P removal from dairy waste effluent.
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Muntasser, Tarek Ziad. "Properties and durability of slag based cement concrete in the Mediterranean environment." Thesis, University of Surrey, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247994.
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VAZ, GUILHERME DEMBERG. "QUANTIFICATION OF METALLIC IRON LOSSES IN ELECTRIC ARC FURNACE SLAGS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18624@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROA metalurgia é a ciência que estuda os diversos meios para a transformação dos metais em materiais úteis à sociedade. A metalurgia do ferro representa a maior fatia da aplicação dos metais. Por ser tão representativa é chamada de Siderurgia. Dentre as diversas rotas para a transformação do ferro em aço, as usinas semi-integradas apresentam um forte apelo ecológico, pois utilizam a sucata, oriunda da reciclagem de ferro, e o ferro gusa como matérias-primas para a fusão no Forno Elétrico a Arco. Naturalmente, em todo processo industrial há a geração de resíduos e, neste caso, o principal é a escória, composta de óxidos formados e adicionados ao longo da fusão. Seus principais constituintes são: CaO, SiO2, FeO, MnO, MgO, Al2O3 e P2O5. No entanto, ainda há a presença de Ferro Metálico, um fato indesejável, pois atua negativamente no rendimento metálico e, consequentemente, aumenta o custo do aço. Toda escória gerada é beneficiada com o intuito de recuperar a parte metálica. Este material beneficiado retorna para as usinas como sucata metálica, contendo teores definidos de ferro metálico. O teor de ferro presente na sucata recuperada é avaliado pelas empresas processadoras de escória de maneira indireta por um ensaio de densidade específica. Havia dúvidas se a sucata recuperada da escória do forno apresentava teores de ferro que justificasse seu emprego como matéria-prima ferrosa. Assim sendo, foi proposta uma rota de processamento capaz de mensurar o teor de ferro presente e permitir a comparação com os teores obtidos com o ensaio de densidade. Os resultados mostram que i) é possível calcular o impacto no rendimento, ii) que as sucatas recuperadas apresentam valores inferiores ao esperado, iii) que a equação de densidade superestima o teor de ferro e iv) que modificações propostas nos coeficientes da equação vigente melhoram seu grau de assertividade. Estes resultados foram comprovados em 3 plantas siderúrgicas.
Metallurgy is the science that studies the various processes for the transformation of metals into society useful materials. The iron metallurgy represents the largest body of the metals application, hence it is called Steel industry. Among the various routes for the transformation of iron into steel, semiintegrated plants have a strong ecological appeal due to their extensive use of scrap, derived from the recycling of iron, and pig iron as raw materials for the Electric Arc Furnace. Of course, industrial processes generate waste. The major waste of the Electric Arc Furnace is the slag, a mixture of oxides produced during the process, containing CaO, SiO2, FeO, MnO, MgO, Al2O3 e P2O5. However, there is also the presence of metallic iron, a fact undesirable, because it acts negatively on the metallic yield and therefore increases the cost of steel. All slag generated is processed in order to recover the metallic iron. The slag beneficiation returns to the mills a material containing defined levels of iron. The content of recovered iron is assessed by slag processing companies indirectly by a specific gravity test. There have been doubts whether the recovered scrap iron content justify its use as raw ferrous materials. Therefore, it is proposed a processing route capable of measuring the amount of iron present in the recovered scrap. The measured iron content is also compared with the levels obtained from the test density. The results show that i) it is possible to calculate the impact on iron yield, ii) the recovered iron content is lower than expected, iii) the density equation overestimates the amount of iron and iv) a correction is proposed to improve the assertiveness of the density equation. Three steel plants confirmed the results from this research.
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Lindholm, Linda. "Inhibition of phosphorus release from sediments of Lake Erhai through argon oxygen decarburisation slag (AOD) and electric arc furnace slag (EAF) capping." Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199181.
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The effects of eutrophication in lakes and the open seas has been largely the result of phosphorus (P) that accumulate in the sediment. Eutrophication occurs mainly in the waters in densely populated coastal areas and agricultural dominated areas and occurs when an excess of nutrients reach the soil and water. In situ capping is a proven method to inhibit P and is the method used in this study. A capping is placed on the polluted sediment surface to physically isolate it and reduce the release of P and prevent resuspension, i.e. suspension of already precipitated P. The possibility of inhibiting P by using sediment capping and the reactive filter materials (sorbents) argon oxygen decarburisation (AOD) slag in particle size fractions 0-0.5 mm and 2-8 mm and electric arc furnace (EAF) slag in particle size fraction 1-2.36 mm, have been investigated. Soluble reactive phosphorus (SRP), also called orthophosphates, were the main species of P investigated in this study. A total of three studies were conducted in Lake Erhai in Dali China, during April 2016. One pre-study was conducted at ten different sites in the lake, which aimed to find the most P polluted site. This site was chosen for the main study. The main study aimed to investigate if the aforementioned sorbents managed to absorb orthophosphates after contact with lake sediment for seven days. The post-study was conducted to see if the sorbents themselves released any orthophosphates into the water. The water samples were tested for pH, conductivity and dissolved oxygen (DO) before and after contact with lake sediment. The slag materials and lake sediment were studied with inductively coupled plasma (ICP) spectroscopy and X-ray diffraction (XRD) to detect elements and compounds. Obtained results showed that the AOD slag (0-0.5 mm) could absorb 96% of the orthophosphates. However, both the AOD slag (2-8 mm) and EAF slag (1-2.36 mm) showed an increase of orthophosphates in the water after contact with lake sediment. The XRD analysis showed contents of silica (Si) and calcium (Ca) compounds in all of the slag materials, which was expected due to the configuration of these materials. The ICP analysis showed that 2% P was absorbed by the EAF (1-2.36 mm) slag, but there were no absorption by the AOD (0-0.5 mm) or AOD (2-8 mm) slag. The conclusion from this study is that AOD slag (0-0.5 mm) can be used successfully in P remediation projects because it absorbs 96% of the orthophosphates. The results are consistent with previous results from (Zuo et al., 2015) and (Renman et al., 2013).
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Aula, M. (Matti). "Optical emission from electric arc furnaces." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526210926.
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Abstract The main cause of temperature and composition fluctuations in the electric arc furnace (EAF) process is the scrap used as a raw material. Process conditions in EAF can vary significantly from heat to heat because there is no accurate information of scrap composition. Due to harsh process conditions, there are currently few sensors available for direct on-line measurement of the EAF process. In this work new information about stainless steelmaking EAF process conditions is sought with optical emission spectrum measurement. The measurement system relies on transportation of the light emitted from the measured furnace to a remotely situated spectrometer. Analysing the slag composition from the arc emission spectrum was tested in the laboratory and on a pilot scale. The laboratory measurements indicate that changes in the amount of CrOx and MnO in the slag have the highest impact on optical emission spectra. The pilot scale measurements show that the Cr2O3 content of the slag can be measured from the arc emission spectrum using suitable reference lines with an average absolute error of 0.62 %-points and a standard deviation of 0.49 %-points. The results from measurements at Outokumpu Stainless Oy, Tornio Works, indicate that measurement of the optical emission spectrum from industrial EAF is feasible in a practical sense, and can be used in analysing of EAF atmosphere, scrap melting and slag surface. Furthermore, the results of industrial measurements indicate that the atoms in the arc plasma mainly originate from the slag. The measurement of scrap melting could be potentially used in EAF control in optimization of arc voltages and second scrap bucket charging. The potential use of slag CrOx measurements is in optimization of reductant additions as well as defining the further processing of EAF slagTiivistelmä Valokaariuunien ohjaus on perinteisesti ollut uunioperaattorin käsissä. Valokaaariuuniprosessin on-line mittaukseen on olevassa vähän menetelmiä johtuen uunin hyvin haastavaista olosuhteista. Tässä työssä on tutkittu optiseen emissiospektroskopiaan perustuvaa menetelmää uuden jatkuva-aikaisen tiedon tuottamisessa valokaariuuniprosessista. Mittausjärjestelmä perustuu valon keräämiseen mitattavasta uunista valokuidun avulla, joka johtaa valon analysoitavaksi etäälle prosessista sijoitettuun spektrometriin. Mittauksia suoritettiin laboratorio-, pilot- ja tehdas-mittakaavassa. Valokaariuunin kuonan koostumuksen analysointia testattiin laboratorio- ja pilot-mittakaavan uuneilla. Laboratoriomittaukset osoittivat että kuonan komponenteista CrOx ja MnO ja vaikuttavat eniten mitattuun emissiospektriin. Pilot-mittakaavan kokeissa havaittiin, että kuonan Cr2O3-pitoisuutta voidaan mitata valokaaren emissiospektristä 0,62 %-yksikön keskimääräisellä absoluuttisella virheellä ja 0,49 %-yksikkön hajonnalla. Teollisella valokaariuunilla suoritetuista mittauksista havaittiin että optisen emissiospektrin mittaus voidaan suorittaa ilman ylitsepääsemättömiä teknisiä esteitä. Mittauksen tuloksia voidaan puolestaan käyttää kaasufaasin reaktioiden, romun sulamisen ja kuonapinnan ominaisuuksien arvioinnissa. Valokaaren emissiospektrin analyysi osoitti, että valokaaren plasman komponentit ovat pääosin peräisin kuonasta, joka mahdollistaa kuonan koostumuksen arvioinnin valokaaren emissiospektrin perusteella. Romun sulamisen mittausta voidaan prosessinohjauksessa käyttää jänniteportaiden ja toisen korin panostuksen optimointiin. Kuonan kromipitoisuuden mittaamista voidaan puolestaan käyttää pelkistinaineiden lisäyksen optimointiin ja kuonan jatkokäsittelyn valintaan
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Puthucode, Rahul. "Neutralization of acidic wastewaters with the use of landfilled Electric Arc Furnace (EAF) high-alloyed stainless-steel slag : An upscale trial of the NEUTRALSYRA project." Thesis, KTH, Materialvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-258901.
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The landfilling of slag obtained from the high alloyed Electric Arc Furnace (EAF) steel making process, constitutes an environmental treat for society as well as an economical problem for the companies producing it, due to the costs related to waste management practices. Conventional methods of slag recycling are abundantly used among the steelmaking business, but due to their particular physical properties, high- alloyed EAF slags cannot be properly valorized. Moreover, the pickling process that high-alloyed EAF steels undergo to, generates acidic wastewaters, that need to be collected and neutralized, before they can be recirculated into the natural water streams. For such a task, steel mills currently utilize slaked lime (a Ca rich mineral) to raise the pH and to remove any metal particles dissolved into the wastewaters. Slag contains high amount of Ca; therefore, it has already been tested as a slaked lime replacement. In fact, previous studies conducted at the Material Science and Engineering department at KTH Royal Institute of Technology showed, on a laboratory scale, that slag has the potential to replace lime for the neutralization and purification of the acidic wastewaters. This Master’s thesis project aims at upscaling the volumes of wastewaters to be tested, about 70 to 90 folds of the one from previous research, bridging the gap between laboratory tests and the industrial scale. The thesis is divided into three tranches, a first part where a water-salt solution conductivity trials were carried out, to model the behavior or slag dispersion in the acidic wastewaters. After the results obtained from the conductivity trials, neutralization trials with slag and the lime product currently in use by the company, were carried out at the neutralization plant in Outokumpu Stainless, Avesta (Sweden). The neutralization trials were carried out with 70 and 90 liters of acidic wastewaters and in order to perform the trials on site, the slag sample was dried and later sieved to a particle size of less than 350μm. Moreover, data was analyzed and compared to previous studies in order to have a clearer understanding regarding the neutralization efficiency of the slag, especially whether or not the technology would had worked on upscaled volumes. Additionally, the project checked if it was possible to find a generalized relationship between the mass of slag and volume of wastewaters required for the neutralization process. Slag demonstrated to be able to buffer the pH to the target values of 9, while also showing an almost linear trend compared to previous studies. The reaction progress between slag, lime, and the acidic wastewaters was also analyzed.Deponering av slagg som erhållits från den höglegerade ljusbågsugn (EAF) stålframställningsprocessen utgör en miljömässig behandling för samhället och ettekonomiskt problem för de företag som producerar den på grund av kostnaderna för avfallshantering. Konventionella metoder för återvinning av slagg används i storutsträckning bland stålindustrin, men på grund av deras speciella fysiska egenskaper kan höglegerade EAF-slaggen inte värderas ordentligt. Dessutom produceras sura avloppsvatten av betningsprocessen som höglegerade EAF-stål genomgår som sedan måste samlas in och neutraliseras innan de kan återcirkuleras i det naturliga vattnet. För en sådan uppgift använder stålfabriker för närvarande släckt kalk (ett Ca-rikt mineral) för att höja pH-värdet och för att avlägsna alla metallpartiklar som löses upp i avloppsvattnet. Slaggen innehåller hög mängd Ca och därför har den testats som en ersättning till släckt kalk. Tidigare studier utförda vid avdelningen materialvetenskap och teknik vid Kungliga Tekniska Högskola visade på laboratorieskala att slagg har potential att ersätta kalk för neutralisering och rening av sura avloppsvatten. Detta examensarbete syftar till att skala upp volymerna av avloppsvattnet som ska testas till cirka 70–90 gånger av den från tidigare forskning, och därav fylla ut bryggan mellan laboratorietester och industriell skala. Avhandlingen är uppdelad i tre delar, Första delen innehåller försök på ledningsförmåga i en vatten-saltlösning som genomfördes för att modellera beteende eller slaggspridning i sura avloppsvatten. Efter de resultat som erhållits från konduktivitetsmätningarna genomfördes neutraliseringsförsök med slagg och kalk som för närvarande används av företaget vid neutraliseringsanläggningen i Outokumpu Stainless, Avesta (Sverige). Neutraliseringsförsöken genomfördes med 70 och 90 liter sura avloppsvatten och för att utföra experimenten på plats torkades slagg provet och siktades senare till en partikelstorlek på mindre än 350 μm. Dessutom analyserades data och jämfördes med tidigare studier för att få en tydligare förståelse för slaggens neutraliseringseffektivitet, särskilt huruvida tekniken skulle ha fungerat på större volymer, och även om det också var möjligt att hitta ett generaliserat samband mellan mängden slagg och volym avloppsvatten som krävs för neutraliseringsprocessen. Slagget visade sig kunna buffra pH till målvärdena 9, samtidigt som den visade en nästan linjär trend jämfört med tidigare studier. Reaktionsförloppet mellan slaggkalk och de sura avloppsvattnen analyserades också.
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Huss, Joar. "Optimizing the slag system for phosphorus removal in a DRI-based EAF-process using the dictionary attack method." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229743.
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Abstract Carbon emissions pose a serious threat to the continued survival of this planet. All sectors of society must, therefore, lower their emissions, this includes the steel industry. The production of steel is based on iron ore reduction by carbon. In an attempt to relieve the steel industry from its inherent fossil dependence an initiative called HYBRIT has been started. It aims to supplant carbon reduction with hydrogen reduction. Currently, there is no economically viable industrial production of steel that uses fossil-free hydrogen as reduction agent. In order to create economic viability for such a process work has to be conducted to innovate and optimize. This study aims to be a part of that optimization process by creating a tool for optimizing the slag system with regards to phosphorus removal. 26843 slag compositions were evaluated using modules written in “Matlab” combined with “Thermo-Calc”. 1583 possible slag compositions were found to be suitable for phosphorus removal. These compositions were then optimized after slag weight in order to minimize slag associated cost. The compositions were tested against two theoretical raw materials with varying initial phosphorus content 250 ppm and 125 ppm. It was found that the initial phosphorus concentration of the raw material has a substantial impact not only on the slag costs but also the slag praxis that should be used.
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Nascimento, Kamila Ângela Leal do. "Utilização de escória proveniente da reciclagem do aço em concreto de cimento Portland." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-09042008-152040/.
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A redução no volume de resíduos produzidos, industriais e agrícolas, vem se tornando uma exigência constante em todos os processos de produção. A falta de espaço físico para a disposição destes resíduos, a contaminação ambiental causada por eles, além da necessidade de preservação dos recursos naturais não-renováveis e da diminuição do consumo de energia e emissão de poluentes, tornam a reciclagem e a reutilização dos resíduos uma alternativa bastante atraente. A construção civil apresenta-se como um setor bastante apto à utilização de técnicas de reaproveitamento de resíduos, provenientes das mais diversas indústrias. Além de todos os benefícios ambientais, este reaproveitamento, pela construção civil, pode gerar recursos financeiros, bem como, possibilita a melhora das características de alguns materiais de construção, e pode diminuir o custo de construção, fator importante, quando se avalia o déficit de habitacional existente no Brasil. Neste trabalho, desenvolveu-se um estudo baseado no aproveitamento de escória de aciaria elétrica, resíduo gerado a partir da reciclagem do aço, empregada como agregado para concreto de cimento Portland, em substituição total ou parcial dos materiais convencionais. Os resultados obtidos apontaram para a viabilidade de utilização deste resíduo como agregado.The reduction on the volume of produced wastes, from industries or agriculture, is becoming a current demand in all production processes. The lack of space to dispose these wastes, the environment contamination caused by them, besides the necessity to preserve the non-renewable natural resources, to reduce energy consumption and greenhouse gas emission , are making wastes recycling and reutilization an interesting alternative. The civil construction presents itself as a field quite able to utilize techniques to reuse wastes from different industries. Besides all the environmental benefits, this reuse by the civil construction can create new profits, as well as, the improvement of the characteristics of some construction materials and it can also decrease the costs of the construction, which is a major factor, considering the Brazilian habitation deficit. In the present work a study was developed based on the reutilization of the electric arc furnace slag, a metallurgic waste from the steel recycling process, employed as an aggregate to the concrete of Portland cement, totally or partially replacing the conventional materials. The obtained results indicate this waste reutilization viability.
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Allen, Dana J. "Evaluating Alternative Technologies And Monitoring Methods For Water Quality In A Field Setting; Research On Effects On Phosphorous And Solids Removal From Cheese Factory Wash Water And Stormwater Runoff Treatment." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/694.
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Lake Champlain is a major economic driver for Vermont's tourism economy, as well as a primary source of drinking water for many of the state's residents but nutrient pollution represents a potential threat to ecosystem health and economic well-being. From December 2011 to December 2012 a field trial of an EAF steel slag filter was assessed for its feasibility in treating wastewater originating from Swan Valley Cheese (SVC), in Swanton, VT. The study focuses on a period of the filter's operation from May 4 to October 10, 2012. The plant generates approximately 20,000 gallons per day of high P concentration wash water which is treated in an open aerated lagoon. The filter treated effluent from this lagoon. The major goals of this research were to conduct a field trial of an EAF steel slag filter to evaluate its effect on total P (TP), dissolved reactive P (DRP), and total suspended solids (TSS). Research was also conducted on pH reduction for filter effluent.
Results indicate that the filter removed 95.83% of TP, 96.65% of DRP, and 52.25% of TSS. Average pH effluent was measured at 10.12 ±1.55.
Additionally, a field study was conducted on sampling two unlined bioretention systems treating urban stormwater runoff. Methods used are presented and methodological considerations for future studies are presented to guide researchers in more effective and efficient methods for obtaining influent and effluent samples from bioretention systems that are not necessarily designed for sampling.
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Prigent, Stephane. "Optimisation du traitement de l'azote et du phosphore des eaux usées domestiques adapté aux filtres plantés de roseaux." Phd thesis, Ecole des Mines de Nantes, 2012. http://tel.archives-ouvertes.fr/tel-00809593.
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Le rejet des nutriments (phosphates et nitrates) issues des eaux usées domestiques entraînent la dégradation des écosystèmes (74 % du territoire français concerné en 2006). Compte tenu de la situation, l'Etat français a promulgué la Loi sur l'Eau et les Milieux Aquatiques le 30décembre 2006 qui vise à atteindre le " bon état écologique des eaux et des milieux aquatiques " d'ici 2015. Cette notion bien que difficilement intégrable a généré des normes plus strictes pour les stations d'épuration en termes de rejet de nutriments vers le milieu récepteur (jusque 15 mg NTOT.L-1 et 2 mg PTOT.L-1). Depuis la fin des années 1990, la technologie des filtres plantés de roseaux (FPR) est de plus en plus employée(> 2500 unités en 2012) pour le traitement des eaux usées domestiques des petites collectivités inférieures à 2000 Equivalent-Habitants. Cependant, des limites de traitement existent sur les concentrations résiduelles en azote (rejet de 70-80 mg NTOT.L-1) et en phosphore (rejet> 10 mg PTOT.L-1), en vue de répondre à la réglementation future. Ce travail a eu pour objectif de mettre en oeuvre des améliorations telles que la recirculation sur un étage de traitement pour le traitement de l'azote d'une part et l'emploi de matériaux réactifs pour piéger le phosphore d'autre part. La démarche scientifique expérimentale déployée a consisté à suivre des pilotes sur site réel et en laboratoire pendant 2 années. Le suivi des performances épuratoires et hydrauliques a été réalisé au cours du temps. Pour l'azote, 2 FPR (2,5 m²) garnis de schiste expansé (Mayennite®) ont été alimentés en effluent brut. L'effet de la hauteur de saturation en eau dans la partie drainante ainsi que l'effet de la recirculation ont été étudiés. Les résultats obtenus ont montré : une couche saturée à 38 % (rapporté à la hauteur totale) et un ratio de recirculation de 100 % permettent une meilleure élimination de la matière particulaire-carbonée (Arrêté du22 juin 2007) et de l'azote (< 20 mg NTK.L-1 ; < 45 mgNTOT.L-1). Deux laitiers de four à arc électrique ont été sélectionnés pour le traitement du phosphore. Ceux-ci ont été mis en œuvre dans 5 colonnes (6 L) en laboratoire alimentées en effluent synthétique en phosphore puis secondaire et dans 4 filtres réactifs pilote (0,3 m² ; 34 L) à flux horizontal sous surfacique alimentés en effluent secondaire. Il ressort de ces expériences: (i) des disparités existent entre les deux échelles en termes de performances (< 2 mg P.L-1 pendant 20 mois en colonne et variation saisonnière des performances en pilote) et mécanismes épuratoires (adsorption/précipitation P-Caen colonne ; P-Ca + P-Fe en pilote), (ii) l'augmentation de la température (> 15 °C) et/ou du temps de séjour (48h et plus) améliore la cinétique d'élimination du phosphore à échelle pilote et (iii) l'implantation d'un filtre réactif garni de laitier de four à arc électrique est limité par le degré de traitement souhaité et la distance du futur chantier (coût du transport).
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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.
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Bergstedt, Edwin, Johan Földhazy, and Alexander Lundstjälk. "Vibration Analysis on AC Electric Arc Furnace." Thesis, KTH, Materialvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173354.
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A computerized Fast Fourier Transform system has been used to analyse vibration measurements sampled from a 100-ton electric arc furnace. It has been the hypothesis that patterns in the vibration data would correlate to specific events in the electric arc furnace during the melting process. The theory was that the vibration patterns would be most powerful in multiples of 50 Hz, as the electric arcs operate with a frequency of 50 Hz. It was concluded that the multiples of 50 Hz were dominant. Investigation was made regarding how the amount of scrap affects the amplitude in the vibrations after a defined amount of energy input. It was confirmed that the intensity of the vibrations decreased with increasing mass and basket volume. Another discovery was the M-shaped pattern at the beginning of the melting process. This pattern was statistically analysed. It was found that 71 % of the 41 charges showed an M-shaped correlation. The appearance of this M-shape was analysed regarding power usage, and steel-type. It was concluded that the steel type affected the appearance of the M-shape. The occurrence of flat-bath was also investigated. The theory was that the vibration data would be fairly constant with the occurrence of flat-bath. It was discovered that the vibration data experienced a somewhat constant behaviour towards the end of the melting process in approximately 57 % of the 41 charges. Difficulties were encountered regarding detection of patterns, and correlating them to specific conditions, due to the many parameters that affect the vibration measurements from charge to charge. It was concluded that vibration analysis are unlikely to be used as an absolute way to foresee every event in the electric arc furnace during each charge. But can rather serve as a statistical tool, upon which decisions of how the melting process should be conducted could be based on.
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Banda, Wezi. "Pyrometallurgical recovery of cobalt from waste reverbaratory furnace slag by DC plasma-ARC furnace technology." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52425.
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Thesis (MScEng.)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: Slag cleaning has become a common practice at many smelters in the nonferrous industry to maximize recovery of valuable metals. However, during the carbothermic reduction of nonferrous slag to recover cobalt, in particular, iron is recovered predominantly. High iron levels present a problem for the subsequent treatment of the alloy as it may increase the solids loading to the filter and lead to increased reagent consumption during leaching. Finding an appropriate slag modifier that would selectively improve the recovery of cobalt against that of iron to the metallic alloy can solve this problem. In the present study the effects of lime (CaO), rutile (Ti02), and fluorspar (CaF2) on the recovery of cobalt from waste nonferrous slag have been investigated under reducing conditions at 1500°C. The selective recovery of cobalt compared to the recovery of iron at different levels of flux additions is discussed in this study, to show the selectivity of these fluxes. It is also shown in the study that the recovery of cobalt does not only depend on the oxygen partial pressure and temperature but on the slag composition as well. The slags used in the experiments were a) synthetic slag prepared from chemically pure reagents and its composition was derived from that of the industrial nonferrous slag composition typical of reverbaratory furnace and b) actual slag obtained from an old slag dump situated on the Zambian Copperbelt region. The investigation has shown that Ti02 addition leads to the most selective cobalt recoveries in all cases. On the other hand, both CaO and CaF2 lead to higher overall cobalt recoveries. The effect of Ti02 on the slag chemistry leads to the formation of iron titanate compounds in the slag unlike CaO, which displaces "FeO" from the fayalitic slag and thus increases the activity of FeO in the molten slag, which in tum affects the iron recoveries to the alloy product. CaF2 on the other hand, affects the fluidity of the slag leading to improved recoveries by improved settling of metals through the slag to the alloy product. A 44V/I100A DC-plasma arc furnace was used to reduce slag to recover cobalt at about 13.5kV A power input. The major part of the study was conducted in a tube furnace and the findings were applied to the extraction of cobalt from slag using the plasma-arc furnace. It was found that the synthetic slag experiments could be used as a guide to understand the behaviour of cobalt during the carbothermic recovery of cobalt from silica saturated fayalitic slags. Cobalt recoveries were higher in the DC furnace than the corresponding reduction experiments carried out in the tube furnace. However, significant amounts of silicon and carbon were detected in the metallic alloy product of the DC plasma-arc furnace.
AFRIKAANSE OPSOMMING: Slak suiwering is besig om standaard praktyk te word by vele smelters om die herwinning van waardevolle metale uit slak te maksimeer. Tydens die karbotermiese reduksie van slakke vanaf kopersmelters om kobalt te herwin, word beduidende hoeveelhede yster ook herwin. Hoë ystervlakke in die herwinde legering veroorsaak probleme met die stroom-af verwerking van die legering aangesien dit lei tot verhoogde reagensgebruik tydens loging en 'n verhoogde vastestof las of die filterstelsel. Die identifisering van 'n geskikte slak modifiseerder, wat die selektiwiteit van herwinning van kobalt relatief tot yster verhoog, sal hierdie probleem verminder. In hierdie tesis word die rol van kalk (CaO), rutiel (Ti02) en vloeispaat (CaF2) toevoeging tot die selektiewe herwinning van kobalt uit afvalslakke ondersoek. Die karbotermiese reduksie van die slak vind by 1500 °C plaas. Dit word getoon dat bo-en-behalwe die suurstofpotensiaal en die bedryfstemperatuur, die slakchemie 'n beduidende rol speel. Die slakke gebruik in hierdie studie is: a) 'n sintetiese slak gemaak van chemies-suiwer rou-materiale (waarvan die samestelling afgelei is van die samestelling van tipiese reverbereeroond slakke), en b) monsters van die ware slak verkry vanaf 'n slakhoop van die Zambiese Kopergordel. Die studie het getoon dat Ti02 toevoeging gelei het tot die hoogste selektiwiteit in alle gevalle. Daarteenoor het CaF2 en CaO gelei tot hoër algehele herwinnings van kobalt. Ti02 toevoeging lei tot die vorming van ystertitanaat komplekse in die slak, teenoor CaO wat die "FeO" uit die fajaliet struktuur verplaas en die aktiwiteit van FeO in die slak verhoog en dus gevolglik herwinning van yster tot die legering beïnvloed. CaF2 verhoog egter die vloeibaarheid van die slak wat lei tot verhoogde herwinning deurdat die legering druppels makliker uitsak deur die slak. 'n 44VIII OOAGelykstroom-plasmaboogoond is gebruik om die kobalt te herwin uit die slak teen ongeveer 13.5 kVA Die grootste gedeelte van die studie is gedoen in 'n buisoond en die bevindings was dan toegepas op die ekstraksie van kobalt uit slak in die plasmaboogoond. Dit was gevind dat die sintetiese slak eksperimente gebruik kan word as 'n voorlopige gids om die gedrag van kobalt in silika-versadigde slakke tydens karbotermiese reduksie te verstaan. Kobalt herwinnings was oor die algemeen hoër il) die plasmaboogoond as vir die ooreenstemmende reaksies in die buisoond. Daar het egter beduidende hoeveelhede silikon en koolstof In die legering opgelos tydens die plasmaboogoond eksperimente.
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Ramírez, Marco Aurelio (Ramírez-Argáez) 1970. "Mathematical modeling of D.C. electric arc furnace operations." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/8847.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2000.Vita.
Includes bibliographical references (leaves 236-240).
A fundamental study of the Direct Current Electric Arc Furnace (DC-EAF) for steel-making has been carried out through the development of a rigorous mathematical model. The mathematical representation involves the simultaneous solution of Maxwell's equations for the electromagnetic fields, and the turbulent fluid flow and heat transfer equations. In solving the arc and bath regions it was assumed ( and justified) that the arc-bath interactions are dominated by the behavior of the arc. In contrast to previous modeling investigations, this work relaxes some critical assumptions and provides a more realistic and comprehensive representation of the system. This work also examines and compares the relative merits of alternative electromagnetic and turbulence formulations, and addresses the role of induced currents and compressibility effects in the representation of the arc. Furthermore, due allowance was made to represent and analyze the effect of gas injection, the presence of a slag layer in the bath and changes in anode configuration at the bottom of the reactor. Because of a lack of experimental information on actual or pilot plant DC-EAF systems, different aspects of the model were validated using several sources of experimental data reported in the literature for related systems. These included measurements on welding arcs, laboratory scale high-intensity carbon arcs, electromagnetically driven metallic systems, and ladle metallurgy physical models. It was found that, in general, the agreement between measurements and predictions was good. A detailed analysis was carried out to examine the effect of process parameters (e.g., arc current, arc length, bath dimensions, anode arrangements, etc) on the behavior of the furnace (e.g., heat transfer to the bath, heating efficiency, mixing times in the bath, etc). Predictions from the arc model show that all the arc characteristics are strongly coupled and that the arc physics is governed by the expansion of the arc. From a parametric study it was found that when the arc region (defined by the 10,000 K isotherm) is plotted in dimensionless form, a universal shape for the arc can be defined, regardless of the values of arc current or arc length. This universality was restricted to the range of conditions analyzed in this thesis, to arcs struck between graphite cathodes in air, and does not include the jet impingement region on the bath surface. This common arc expansion behavior suggested the universal nature of other arc characteristics. Universal maps of temperature, magnetic: flux density, and axial velocity are also reported in terms of simple analytical expressions. The practical effects of the two main process parameters of the arc region,. i.e. the arc current and the arc length, were analyzed. It was found that increasing the arc length significantly increases the arc resistance and, consequently, the arc power, although this behavior reached asymptotic values at larger arc lengths. Increasing the arc current, however, does not affect the arc voltage. Thus, it is found that increasing the arc power increases the amount of energy transferred into the bath, but the heat transfer efficiency decreases. Therefore, the shorter the arc the more efficient is the heat transfer to the bath. It is also recognized that heat transfer from the arc to the bath is controlled by convection, although radiation can become an important mechanism, especially for large arc lengths. Results of the bath model indicate that, in the absence of inert gas stirring and with no slag present in the system, electromagnetic body forces dominate and are responsible for the fluid flow patterns in the system. The effects of the arc determine the distributions of temperature and other mixing characteristics in the bath. The bath model was used to evaluate the effect of the main process parameters and design variables on mixing, refractory wear, temperature stratification, and heat transfer efficiency. An increase in the arc length is detrimental to mixing but increases the rate of heating in the melt as a result of the increased arc power. Increasing arc current improves mixing and the heat transferred to the bath, but is likely to be detrimental to the life of the bottom refractory. The results also suggest that high furnace aspect ratios (taller and thinner arc furnaces) are highly recommended because an increase in the aspect ratio increases mixing, prevents refractory wear, and promotes arc heating efficiency. The arc configuration in the furnace can be changed to control fluid flow patterns in the bath to meet specific needs, such as better mixing, or to prevent refractory wear. The presence of a top layer of slag reduces mixing and increases overall liquid temperatures. Injection of gases through the bottom in eccentric operations generates complex flow patterns that improve mixing in regions away from the symmetry axis. It is the author's belief that this model is a useful tool for process analysis in the DC-EAF. It has the capability to address many issues of current and future concern and represents one component of a fundamental approach to the optimization of DC-EAF operations.
by Marco Aurelio Ramírez.
Ph.D.
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MacRosty, Richard Swartz Christopher L. E. "Modelling, optimization and control of an electric arc furnace." *McMaster only, 2005.
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D'Souza, Neil S. "Thermal remediation of stainless steel electric arc furnace (EAF) dust." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30239.
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Along with the essential importance of the metallurgical sector, one must recognise that it is also one of the largest sources of environmental pollution. In particular, the problem of electric arc furnace (EAF) dusts is of a growing concern due to the increase in popularity of EAF steelmaking. This dust is classified as a hazardous product due to the elevated content of toxic metals (e.g., Cr).Studies on the properties of EAF dusts are sparse. Experiments were performed in order to determine the chemical and physical characteristics of the dust. It was determined that EAF dust is constituted of randomly distributed agglomerations of homogeneously nucleated particles and entrained particles. The main elements present within the particular dust were iron and chromium, the latter due to the fact that the dust used was formed within a stainless steel mini-mill. The main phases present within the dust were Fe2O3/Fe 3O4 and Cr2O3.
Thermal remediation experiments were then carried out in a computer controlled thermogravimetric system. The parameters studied during the tests included temperature, residence time and heating rate. In addition, the behaviour of the EAF dust during remediation was studied; in terms of weight and volume loss, gas evolution, particle morphology and resulting leachability of the treated product. Furthermore, it was observed that at temperatures greater than 1200°C metal leachability decreased significantly due to a decrease in toxic metal concentration within the treated product and the formation of a resistant, dense, plate-like morphology. At 1600°C, no toxic metals leached out of the remediated EAF dust and volume reduction was significant, resulting in a product that would be safe and more economical to landfill.
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Best, Timothy Edward. "The reduction of electric arc furnace dust in carbon monoxide." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ36003.pdf.
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D'Souza, Neil S. "Thermal remediation of stainless steel electric arc furnace (EAF) dust." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0031/MQ64215.pdf.
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DENG, LEI. "Investigation of Electric Arc Furnace Chemical Reactions and stirring effect." Thesis, KTH, Materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109248.
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Chemical energy plays a big role in the process of modern Electric Arc Furnace (EAF). The objective of this study is to compare the results of chemical reaction enthalpies calculated by four different methods. In general, the “PERRY-NIST-JANAF method” is used to calculate the chemical energies. However, this method heavily depend on heat capacities of the substances which have to be deduced from “Perry’s Chemical Engineers’ Handbook” and “NIST-JANAF Thermochemical Tables”, even the calculation process is complicated. Then, some other methods are introduced: Total enthalpy method, HT (High Temperature) enthalpy method and Atomic energy method. In this thesis, the above four methods have been used to calculate the enthalpies of chemical reactions in EAF process. Both of “Total enthalpy method” and “HT enthalpy method” are not complicated, but some basic data are not available. The calculation for chemical reaction enthalpies cannot be completely made by these two methods. “Atomic energy method” is more complicated than “Total enthalpy method” and “HT enthalpy method”, even almost all data are available, but some results of these methods are far from those of the other three methods’. The results show that values of enthalpies obtained by “PERRY-NIST-JANAF method” are more reasonable, though the calculation process is more complicated. In this study, it is also discussed two influencing factors on EAF process: electric power and electromagnetic stirring (EMS).
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Snell, Jared James. "Improved modeling and optimal control of an electric arc furnace." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/741.
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This thesis centers around an electric arc furnace (EAF) at a steel mini-mill in Wilton, IA. First, the thesis replicates previous optimization attempts. Next, the modeling is greatly altered to produce a much improved steel-melting model. Then, a new optimal control system is created and used to reduce energy and fuel costs over the melting process. Finally, results are presented. This thesis shows that when the new optimal control is simulated, the system shows significant energy and fuel savings.
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Stewart, Timothy Glen. "The characterization and separation of electric arc steelmaking furnace flue dust." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/10094.
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Xia, Dan Kui. "Recovery of zinc from zinc ferrite and electric arc furnace dust." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq38338.pdf.
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Coetzee, Lodewicus Charl. "Robust model predictive control of an electric arc furnace refining process." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08212007-145804.
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Barnett, Catherine Grace. "The development of a construction material using electric arc furnace dust." Thesis, Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/80038.
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During the 1970s, the United States passed a series of laws regulating the handling and disposal of hazardous material. The new rules drastically increased the cost of processing toxic wastes. Consequently, many producers began investigating methods that would render toxic material non-hazardous. one solution developed was cement encapsulation, a process that incorporates toxic material into a cement matrix, thus solidifying the waste and reducing the potential for the migration of toxins into the environment. This process can be used to prepare a waste for disposal or can be used to develop a construction material, thus mitigating costs further. This solution was selected by Roanoke Electric Steel as a possible way to dispose of electric arc furnace dust, a by-product which contains a variety of heavy metals which are classified as hazardous by the United States Environmental Protection Agency.
In this study, the furnace dust was incorporated into mortar as a portion of the fine aggregate. By including a chelating agent and a stabilizing agent, mortar was developed which meets the requirements of ASTM C150 with respect to strength and time of setting. The optimum mixture has a 28 day strength of 4500 psi and passed the EP Toxicity test, as required by the Environmental Protection Agency before a material can be delisted. To further validate the use of furnace dust in masonry products, the mortar was evaluated for its dimensional stability, both physical and chemical, and for its freezing and thawing durability characteristics.Master of Science
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Jarnerud, Tova. "Construction and initial testing of a LABORATORY SCALE ELECTRIC ARC FURNACE." Thesis, KTH, Materialvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215013.
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This work aims to describe the designing and construction of a 10 kg laboratory scale Electric Arc Furnace equipped with a system for measurement of electrical parameters. The EAF is used in a research project where the aim is to develop a new online measurement system for an optimized steel production with respect to a low energy consumption and resource efficiency. The laboratory scale is the first step in the project and will be followed by pilot testing and industrial testing, if the results are successful. In order to calculate how much energy that is fed into the system, the power and voltage were measured. To simplify the system at this initial stage with regard to energy and heat losses, the system is limited to treating pre-melted metal. This report provides some theoretical background for not only EAF´s, but also induction furnaces. This is due to that an induction furnace is used to melt the steel before the laboratory scale EAF is used. This report will give some advice based on the experience gained in this study. Furthermore, list important things to consider while working with this kind of equipment. Also, a system that manages to scale voltage and current signals to more easy handled magnitude is presented. The overall conclusion is that it was possible to construct an experimental setup, which can be used to perform on-line measurements from an electric arc furnace operated with steel and slag.Det här arbetet beskriver designen och konstruktionen av en ljusbågsugn i labbskala, för 10 kg stål, som är utrustad med ett mätsystem för elektriska parametrar. Den här ljusbågsugnen används i ett forskningsprojekt som ska utveckla ett nytt uppkopplat mätsystem för optimerad stålproduktion med avseende på energi- och resurseffektivitet. Experiment i labbskala är det första steget i det här projektet, som efterföljs av tester i pilotskala och sedan industriell skala, om resultaten är bra. För att kunna räkna ut hur mycket energi som matas in i systemet så mättes ström och spänning. För att förenkla systemet i ett initialt skede med avseende på energi- och värmeförluster så begränsas systemet till att behandla redan smält metall. Den här rapporten tillhandahåller teoretisk bakgrund om inte bara ljusbågsugnar, utan även induktionsugnar eftersom att en induktionsugn används för att smälta stålet innan den labbskaliga ljusbågsugnen används. Den här rapporten ger råd av erfarenhet från den här studien. Vidare listas viktiga saker att ta hänsyn till när man jobbar med sådan här utrustning. Ett system som skalar upp och ner signalstyrka vid ström- och spänningsmätningar till mer hanterbara storlekar presenteras. Den övergripande slutsatsen är att det var möjligt att konstruera en försöksutrustning som kan användas till mätningar i ett uppkopplat system i en ljusbågsugn som körs med stål och slagg.
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Arzpeyma, Niloofar. "Modeling of electric arc furnaces (EAF) with electromagnetic stirring." Thesis, KTH, Materialvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-43906.
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The influence of electromagnetic stirring in an electric arc furnace (EAF) has been studied. Using numerical modeling the effect of electromagnetic stirring on the thermal stratification and fluid flow has been investigated. The finite element method (FEM) software was used to compute the electromagnetic forces, and the fluid flow and heat and mass transfer equations were solved using a finite volume method (FVM) software. The results show that electromagnetic stirring has a significant effect on temperature homogenization and mixing efficiency in the bath. The important part of this study was calculation of heat transfer coefficient. The results show, electromagnetic stirring improves the heat transfer from the melt to scrap which is dependent on the stirring direction and force magnitudes.
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Wang, Weifeng. "Cost optimization of scrap when making steel with an electric arc furnace." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110703.
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In steel production, an electric arc furnace (EAF) is most commonly used to melt raw material in order to produce liquid steel. Scrap is the main raw material which differs in regard to the content of iron and of some chemical elements. The price of scrap depends on these attributes. In order to obtain the desired quality and quantity, each melting bath unit of steel has either its own material constraints or the constraints for electric arc furnace such as the capacity of EAF. In addition, the availability and transportation of scrap are also restricted because they need space. The research in this thesis is to create an optimization model which minimizes the cost of raw material and charges the EAF efficiently while meeting the constraints of the scrap recipe and scrap transportation system. This problem is a combinational optimization problem and the model is developed based on linear programming theory. The running speed of the model is reasonably guaranteed by properly designing the combinatorial structure with branch and bound rules and heuristics. Finally, a software is created by representing the model in the spreadsheet, which can be used in real, everyday production. Simulation results show significant improvement compared to the strategy applied today at ArcelorMittal(Contrecoeur, Quebec): the cost of scrap steel is reduced by 2 to 6% and the time of charging buckets is 2 to 10 minutes faster.Dans la production d'acier, four à arc électrique (FEA) est la technologie la plus couramment utilisée pour faire fondre les matières premières afin de obtenir de l'acier liquide. La ferraille est la matière première principale dont les types se diffèrent selon le contenu de fer et d'autres éléments chimiques. Le prix de la ferraille dépend de ces attributs. Afin d'obtenir la qualité et la quantité souhaitées, chaque unité bain de fusion de l'acier a subi à ses propres contraintes matérielles ou des contraintes liées au four à arc électrique, telles que la capacité du FEA. En outre, la disponibilité et la capacité à transporter de la ferraille sont également limitées, en raison d'espace limité. L'objectif dans cette thèse est de créer un modèle d'optimisation qui minimise le coût des matières premières et charge le FEA efficacement afin de satisfaire des contraintes de la recette de ferraille et de transport de ferraille. Le modèle est développé sur la base de théorie de la programmation linéaire. La vitesse de l'exécution du modèle est raisonnablement garantie par une bonne conception de la structure combinatoire avec les règles de 'branch and bound' et heuristiques. Enfin, un logiciel qui applique le modèle est créé. Celui-ci peut être utilisé dans la production réelle quotidienne. Les résultats des simulations montrent une amélioration significative par rapport aux pratiques actuelles de planification de production appliquée aujourd'hui dans ArcelorMittal (Contrecoeur, Quebec): le coût de la ferraille est réduite de 2 à 6 pour cent et le temps de godets de charge est de 2 à 10 minutes plus vite.
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Ljungqvist, Pär. "Evaluaton of sound-, current, and vibrations measurements in the Electric Arc Furnace." Thesis, KTH, Materialvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-160542.
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The aim of this report was to investigate new methods for measuring the condition of the scrap in the electric arc furnace. This was done by evaluating three different methods theoretically and chooses two of them for test in the electric arc furnace in Avesta. Due to lack of time and equipment only Total harmonic distortion (THD) measurements was used. The results show that THD reaches low values during refining. This suggests that all the scrap is melted and the arcs are stable.
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SANTOS, FELIPE SOMBRA DOS. "CHARACTERIZATION AND CHEMICAL PROCESSING, USING CHLORINE AGENTS, OF ELECTRIC ARC FURNACE DUST." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35488@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Este trabalho aborda um estudo alternativo voltado para o tratamento de um resíduo industrial gerado durante a fabricação de aço nos fornos elétricos, através do uso reagentes cloretantes. O resíduo analisado quantitativamente apresenta os seguintes resultados em relação aos seus principais constituintes: 29 por cento de Fe e 16 por cento Zn. Tem-se como principal objetivo uma recuperação do zinco contido e o simultâneo enriquecimento do resíduo em Fe2O3, que permitiria, então, o reaproveitamento do resíduo pela indústria e a conseqüente diminuição do impacto ambiental. Foram utilizados diversos métodos de análise de caracterização, tais como difração de raios-X, microscopia eletrônica de varredura, difração e fluorescência de raios-X e espectroscopia de massa (ICPMS). Observou-se que o zinco encontra-se presente na amostra na forma de ferrita de zinco (franklinita). As análises prévias dos clássicos diagramas energia livre de Gibbs versus T em variadas opções de tratamentos químicos indicaram que algumas ustulações, tais como aquelas com Cl2 e CaCl2, seriam capazes de viabilizar a remoção seletiva do zinco, enriquecendo assim o resíduo em ferro, a fim de que possa ser usado novamente na alimentação do forno. Os resultados experimentais da ustulação com cloreto de cálcio confirmaram tal possibilidade ao mostrar que quando a reação é conduzida a 1100 graus Celsius durante 30 minutos com um excesso de 40 por cento de reagentes, o teor de ferro no resíduo aumenta ligeiramente (com remoção de 21 por cento), enquanto o teor de zinco decresce de 16 por cento para 1 por cento (remoção de 94 por cento), sugerindo estudos complementares onde a seletividade fosse otimizada.
This work is related to an alternative chemical treatment of an electric furnace dust. The residue containing 29 percent of Fe and 16 percent of Zn, most of it in a zinc ferrite (ZnFeO4) structure, was submitted to chlorine containing reagents. The main idea was to separate the zinc from the iron through a selective chloride formation of the former followed by its volatilization. In this case, the residue, without the zinc presence, could be reused in the industrial plant, minimizing the environmental impact. Some characterization analyze methods was used as Xray diffraction, scanning electronic microscopy, diffraction and X-ray fluorescence and mass spectroscopy (ICP-MS). The zinc observed in the sample was present as zinc ferrite (franklinite). Preliminary thermodynamics studies have shown that chlorine and calcium chloride roasting could act selectively on the residue, then producing the volatile zinc chloride and leaving behind the iron oxide. Experimental work has proved that possibility showing that when the reaction happened at 1100 degrees Celsius, with 40 percent the reagents excess, for 30 minutes, the iron content increase slowly (with 21 percent removed) while that the zinc conten decrease the 16 to 1 percent (94 percent removed), proposing complementaries studies to optimize the selectivity.
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De, Colle Mattia. "Topological Data Analysis to improve the predictive model of an Electric Arc Furnace." Thesis, KTH, Materialvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-201744.
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Data mining, and in particular topological data analysis (TDA), had proven to be successful inabstracting insights from big arrays of data. This thesis utilizes the TDA software AyasdiTM inorder to improve the accuracy of the energy model of an Electric Arc Furnace (EAF), pinpointingthe causes of a wrong calculation of the steel temperature. Almost 50% of the charges analyzedpresented an underestimation of temperature, while under 30% an overestimation.First a dataset was created by filtering the data obtained by the company. After an initialscreening, around 700 charges built the dataset, each one characterized by 104 parameters. Thedataset was subsequently used to create a topological network through the TDA software. Bycomparing the distribution of each parameter with the distribution of the wrong temperatureestimation, it was possible to identify which parameters provided a biased trend. In particular, itwas found that an overestimation of temperature was caused by an underestimation of themelting energy of materials not having through a melting test. It was also found a possible biasedtrend in some distribution of parameters like %O in steel and slag weight, which it is believedare all connected together. Despite not finding a global solution for the reasons behind theunderestimation of temperature, it is believed that a different settings more focused around thematerials used as scrap mix can highlight more on that subject. In conclusion TDA proved itselfefficient as a problem solving technique in the steel industry.
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Janjua, Rizwan Ahmed. "Optimisation of electric arc furnace dust recycling and zinc recovery by scrap de-zincing." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2009. http://nbn-resolving.de/urn:nbn:de:bsz:105-1759549.
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A considerable rise in the Electric Arc Furnace steelmaking has taken place in the EU during the last decade. As a result, the amount of steelmaking dust has increased as well. This dust is recycled in order to recover the valuable amount of zinc present in it. In contrast to the increase in dust generation, the capacity of recycling sites has not changed accordingly and there are growing concerns over this imbalance. In the present thesis, logistics and resource allocation of dust recycling in the EU are analysed. Data collected through a questionnaire survey was used to formulate the transportation model of linear programming. The results of the model highlight the location of gaps in recycling capacity and its uneven geographical distribution. The state of the recycling can be improved by research in scrap de-zincing; a process that can recover most of the zinc prior to steelmaking thereby lowering the total amount of dust. To this effect experiments were conducted using electro-galvanized scrap samples in order to study the kinetics of zinc evaporation. Various parameters such as the flow rate of carrier gas, scrap heating rate, packed bed voidage, permeability, and specific surface area were studied with a view of a possible scale-up of the process. The results show that there is a potential of integrating the de-zincing step into high temperature scrap pre-heating processes using shaft type systems that utilize off-gases of steelmaking and auxiliary burners.
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Lobel, Jonathan. "The direct recycling of dust generated in the electric arc furnace stainless steelmaking process /." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33335.
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This research investigates the possibility of recovering the metallic content of the dust generated by stainless steelmaking operations in the Electric Arc Furnace (EAF) at ATLAS Stainless Steels by recycling it to the EAF. The physical and chemical properties of the dust were determined. The pelletization of dust-carbon fines was optimized in order to obtain strong pellets capable of carbothermic self-reduction. The high temperature behavior of dust-carbon pellets was investigated in a Thermogravimetric Analyzer (TGA) coupled with a Fourier-Transform Infrared Spectrometer (FTIR). The mechanisms involved in metal recovery were identified. The feasibility of direct recycling was verified by testing pellets in a scaled-down simulation of the EAF process. As a result of this research practical recommendations concerning the application of the direct recycling process at ATLAS were formulated.
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Kournetas, Nicholas George. "The use of oxygen to decrease electrical energy usage in the electric arc furnace." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0003/MQ34148.pdf.
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Cubukcuoglu, Beste. "Performance assessment of alternative binders for the solidification/stabilisation of electric arc furnace dust." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.581794.
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The aim of this study is to evaluate the potential of using solidification/stabilisation (S/S) for the treatment of electric arc furnace dust (EAFD) and examine the effects of using a variety of industrial by-products, i.e., pulverised fuel ash (PFA), hydrated lime (hlime), steel slag and low-grade magnesium oxide (LGMgO) as cement replacements. LGMgO, steel slag and PFA with 0%, 40% and 70% EAFD additions met the Waste Acceptance Criteria (WAC) requirements with respect to unconfined compressive strength (UCS), initial and final setting times and consistency results. The acid neutralisation capacity (ANC) results showed that PFA and steel slag do not have as high buffering capacity as LGMgO and hlime when exposed to acid attacks. The pH level •• »:' was reduced to 5 when 10 meq/g acid was added into both LGMgO and hlime-blended mixtures. ' The monolithic leaching test results showed that the fixation of the heavy metals was hardly possible in almost all the mixtures studied. The granular leaching tests yielded very good results with no metals leaching except for Mo. Mo fixation was achieved only for CEMI-hlime and CEMI-LGMgO 1:2:40 mix ratios at 28 days', and for CEMI-LGMgO 1:4:40 and CEMI-slag 1:4:70 mix ratios at both 7 and 28 days' curing age. Depletion-controlled release was observed throughout most ofthe testing (intervals 1-7) and was the dominant leaching mechanism for LGMgO, PFA, slag, hlime and CEMI blended samples. X-ray Diffraction (XRD) analyses showed that EAFD is mainly composed of zincite (ZnO), franklinite (ZnFe204) and magnetite (Fe304)' Scanning Electron Microscopy (SEM) analysis confirmed the presence of zincite, a compound known to hinder strength development. The XRD results of LGMgO and waste blended products at 28 days' curing age indicated the presence of zincite. Overall, this study demonstrated that the optimum combinations where S/S of EAFD was successful were for CEMI-LGMgO 1:4:40 and CEMI-slag 1:4:70 mix ratios.
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Li, Jianghua Provatas Nikolas. "Kinetics of steel scrap melting in liquid steel bath in an electric arc furnace." *McMaster only, 2007.
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Chen, Chieh-Li, and 陳劼立. "Carbonation of Electric Arc Furnace Slag for Cement Replacement." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/72825895120581982691.
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碩士國立臺灣大學
環境工程學研究所
103
In this study, an integrated process of waste-to-resource technology was developed. Carbon dioxide (CO2) sequestration using the accelerated carbonation of electric arc furnace (EAF) slag under various operational conditions in a high-gravity rotating packed bed (RPB) was investigated. Moreover, wastewater neutralization and product utilization were investigated as well. The performance of CO2 capture by EAFS were evaluated under various levels of reaction time, reaction temperature, rotational speed and liquid-to-solid ratio. The samples of reacted slurry were analyzed quantitatively and qualitatively by using thermogravimetric analysis (TGA) and X-ray diffraction (XRD), respectively. Furthermore, the morphology and microstructure of samples were also examined using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Furthermore, utilization of electric arc furnace (EAF) slag as cement replacing materials for Portland cement has been examined. Both fresh and carbonated EAF slag were blended in the cement with the percentages of 5, 10, 15 and 20% replacements of Ordinary Portland Cement (OPC) were tested for compressive strength. According to ATSM C109 regulation, the cement mortars were tested at 3, 7 and 28 days of curing age with the 50 mm x 50 mm x50 mm molds. The physico-chemical characteristics and structure of the hardened cement mortars were studied. In addition, the performance of EAF slag as a filler in the OPC-EAF slag mortars was examined.
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Lin, Yung-yu, and 林湧昱. "Composite Geopolymer Produced by Using Electric-arc Furnace Reductive Slag." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/11369635307014151202.
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碩士國立中央大學
土木工程研究所
100
Electric arc furnace reductive slag contains the characteristics of silicon, aluminum, calcium is a multi-type calcium aluminum silicate materials, Si4+, Al3+, Ca2+ in an alkaline solution can be isolated, and the mutual bond formation of Si-O-Si and CSH gel the coexistence composite geopolymer. In this paper, the electric-arc furnace reductive slag produced composite geopolymer mortar specimens for physical and chemical performance and micro explore analysis, and the use of slag to replace the amount of reductive slag to improve the insufficient strength and shrinkage Analysis and Discussion. The results showed that the strength analysis found that the higher the fineness of grind of reductive slag, the compressive strength has the best range, and mortar specimens curing temperature to improve the compressive strength increases, and the performance of mortar mixing time, the compressive strength increased with the mixing time increase with, but the strength increase of the result is not significant. Slag to replace reductive slag in terms of compressive strength, the slag replaced by the increase in the compressive strength increase, but the setting time decreases. Microscopic analysis of reductive slag produced composite geopolymer mortar specimens in 8%(by Na2O) of Ca2+ into the cut-off point; To the purely reductive slag in the drying shrinkage test, 8%(by Na2O) cut-off point, Drying shrinkage of more than 8%(by Na2O) percent less than 8%(by Na2O) below the CSH gel was reduced by Ca2+ with AlO4 reaction.; Slag to replace reductive slag, the drying shrinkage with the slag to replace the amount of increase is reduced.
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Mon, Hnin-Hnin, and 黃慶慶. "Feasibility study of concrete made with electric arc furnace slag." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/78535243205733258294.
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碩士國立中央大學
土木工程研究所
96
Several studies indicate that alkali-activated slag cements and concretes present high mechanical strength and good performance in chemical attack. However waterglass-activated slag mortars and concretes show significantly higher shrinkage and shorter setting time than ordinary Portland cement. This study aims at reducing shrinkage and averting the rapid setting by partly replacing blast furnace slag in alkali-activated electric arc furnace reductive slag concrete. Also, concrete mix composition for alkali-activated electric-arc furnace reductive slag cement concrete with compressive strength of 140 kgf/cm2 to 210 kgf/cm2 at the age of 28 days are developed. The dosage of alkaline activator was reduced form 7% to 4% (by Na2O) and modulus was reduced from 1.75 to 0.75 when the replacement of blast furnace slag was up to 50% of electric-arc furnace reductive slag. When the dosage of alkaline activator decrease, the setting time increase and longer than ordinary Portland cement. The drying shrinkage was been reduced and the compressive strength of the concrete was found to be over 210 kgf/cm2 at 28 days.
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Lin, Yo-Hung, and 林友煌. "Rapid Detection of Electric Arc Furnace Slag in Fine Aggregate." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/16497197815627452668.
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碩士國立中興大學
土木工程學系所
104
Because the lacks of environmental awareness in Taiwan, domestic waste disposal were almost buried under ground, it can also be funded in steel industry wastes. Under erosion after heavy rain, the steel industry waste material of Electric Arc Furnace (EAF) slag from underground may mix into the natural aggregates. In addition, the aggregate manufacturers would mix the EAF slag into the fine aggregates due to cost down. The EAF slag disadvantages the quality of fine aggregates. When the concrete mixes these kinds of imperfect goods, not only the appearance of the structure will be damaged but also be facing a huge penalty. This research is aimed to investigate the fast detected method of EAF slag that mixed in fine aggregates. Three methods were checked in this study, includes pH test, magnetic test and the digital electronic magnifier distinguished. When the fine aggregate arrives at the plant, fast detected before the concrete batching can easily find out whether the fine aggregates were unsuitable. On the other hand, through a fast mortar expansion test and compression test of mortar specimens, the mortar deterioration caused by the expansion of slag was observed. The result shows that the critical value of the pH of natural aggregates in Taiwan is 9.5 and the critical weight ratio of magnetic test is 1%. Fast detected method was not proper to be carried out on import aggregate of China due to the high level of alkalinity and metallic content. This research establishes a series of photos to help distinguish the source of fine aggregate. With a SOP method of this study suggested, the quality affected of fine aggregates caused by EAF slag can be easily tested within 3 hours, ensuring the quality control of fine aggregates.
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Chen, Lee, and 陳立. "Utilization of Electric arc Furnace Oxidizing Slag as Concrete aggregates." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/18879892087165374798.
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博士國立中央大學
土木工程研究所
91
Electrical arc furnace oxidizing slag is the by-product produced by the steelmaking plants from using recycled iron. The growing demand for steel has resulted in significant increase in the production of electrical arc furnace slag. Also, disposal of the slag has become more costly to the steelmaking industry due to stringent environmental regulations. Therefore, interest in this slag as a substitute for conventional construction material has increased considerably in recent years. The utilization of the slag not only solves a waste disposal problem but also provides an economic construction material. This study assesses those properties of electrical arc furnace slag that are likely to affect its use as a replacement for conventional aggregate in making concrete. After crushing and screening processes, electric arc furnace oxidizing slag was evaluated, in the laboratory, for the potential as an alternative of aggregate in making concrete. Tests included complete chemical analysis and physical properties, Mineral composition, expansion test, environmental influence test, Toxicity characteristic leaching procedure, alkali aggregate reaction, concrete mix design and strength development, Microstructure analysis and test pavement build. ………. The economic potential of the utilization of slag as construction materials demand more versatile applications of this by-product. This study demonstrated that the incorporation of slag in concrete is feasible. More areas in construction related applications of electric arc furnace slag are yet to be developed.
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Shu, Yu-Chia, and 許育加. "A Study of Electric Arc Furnace Slag on the Pervious Concrete." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/81280100952115028906.
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碩士國立臺灣海洋大學
河海工程學系
95
Because of global warming, lack of land in Taiwan and over-development using waterproof pavement, the ecological system is deteriorated and the water resource circulation and air quality become worse. These factors result in the hot-island effect. In this study, making pervious concrete by slag-aggregate is studied. The parameters considered include different aggregate, aggregate size, paste amount and water/cement ratio. Mechanical properties, connected void ratio, permeability coefficient and soundness test were investigated. According to the data and capital analysis, the suitability of using slag as aggregates to make pervious concrete is evaluated. By selecting a better mix with sufficient strength and good permeability, the filling ratios of paste with respect to the initial void volume with 93%, 96% and 99% were studied to see if it increasing paste the pervious concrete can achieve its best performance. The results indicated using slag as aggregate can make pervious concrete with satisfactory water permeability even when the past/initial void volume ratio reached 99%. The trends and results matched previous study. For example, the compressive strength, splitting tensile strength and flexural strength all increases as the paste amount increases. In addition, they all decrease as the aggregate size increases. The water permeability coefficient and connected void ratio become higher when the aggregate size becomes bigger, and become lower when paste amount is higher. In addition, it was found that for higher w/c ratio mix, using chemical admixture can increase the viscosity of paste such that the vertical flowing phenomenon can be avoided.
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TSAI, CHIU-SHENG, and 蔡秋生. "Study on Reutilization of Slag from EAF (Electric Arc Furnace) Steel." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/93606643242566528836.
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碩士朝陽科技大學
環境工程與管理系
105
The environmental concepts on people have been improved in recent years. The reuse of waste, such as reuse of slag was carried out. Therefore, this research main discuss about reuse of slag. Then propose the correct management measures to industry. This research report be able to increase cognition and safety of slag industry. The people worried about the slag expansion with water. This reason cause safety problems when using. If the slag via stability test that has environmental protection and energy saving features. This study case was Cheng Sheng Environmental Protection Co., Ltd. There are three reasons for the instability of the ballast: 1. unstable composition; 2. high pH of slag; 3. particle size influences. When obtain the safety slag have been 3 steps. First step was raw material classification. Second step was stability. Third step was select products (quality control). This study evaluation the process program and product quality of slag in the Cheng Sheng Co. The application were concrete building materials. Therefore, slag was classify that about crude and fine. Using the slag to make permeable brick and brick. At permeable brick part testing result as follows: 1. Compressive strength (kgf/cm2) were 653, 447 and 210 when cement and slag ratio were 0:1, 7:3, 1:1, respectively. 2. Permeability coefficient (cm/sec) were 32.76×10-2, 8.15×10-2 and 7.54×10-2 when cement and slag ratio were 0:1, 7:3, 1:1, respectively. The other experiment at brick part testing result as follows: 1. Compressive strength (kgf/cm2) were 1245 and 1055 when cement and slag ratio were 0:1 and 1:1, respectively. 2. Water absorption (%) were 6.6 and 6.2 when cement and slag ratio were 0:1 and 1:1, respectively. The testing results all standards compliant in accordance with CNS14995 and CNS13295 regulations. Therefore, the results prove the slag have hard and wear characteristics. When the product could be selectivity in classification management. The slag could create safety use by people.
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Shyng, Jin-Chyr, and 刑金池. "Utilization of the Electric Arc Furnace Oxidizing Slag as Microstructure Materials." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/28227947589546559960.
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碩士國立臺北科技大學
材料及資源工程系碩士班
92
The iron and steel demand is increasing in the past few years due to the recovery of the international steel industry, increasing demand in mainland China and domestic high-speed railway project, therefore, the amount of slag produced along with steel metallurgical process is also increased. In the past, slag was treated as waste and was either dumped or buried at the waste yard, and thus, result in environmental problems. Because the limitations such as available land, high population and lack of resources if the EAF slag can be reutilized based upon its characteristics, not only the overall metallurgical cost and energy consumption can be reduced, the social-economical benefit can also be increased. The purpose of this research is to explore the possibility to convert EAF oxidized slag into microstructure material that possess good mechanical property using powder sintering process. Base on chemical analysis data collected, it was found that the EAF oxidized slag is mainly composed with Si, Al, Fe, Ca, Mg, etc. After crushing, screening and grinding processes, the slag was shaped in mold under pressure and then sintered into microstructure material. The microstructure material manufactured is expected to be used in ceramics, construction materials and related industries. The experiments conducted in this research include raw material analysis, hardness test, compression test, bending test and chemical corrosion resistance test and the test results were compared with those obtained from natural dimension stone. According to test results obtained, the microstructure material produced using high temperature sintering process possess good mechanical strength and chemical corrosion resistance properties and can be used as industrial construction and ceramics materials to achieve environmental protection and resource reutilization purposes.
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Wu, Ming-Cherng, and 吳銘誠. "Recycling Study of Electric Arc Furnace Slag of Stainless Steel Plant." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/91465101372082803496.
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碩士國立高雄第一科技大學
環境與安全衛生工程所
91
The purpose of this study is to explore the feasibility of recycling stainless steel EAF slag as a resource. The valuable contents of oxidized slag of stainless steel EAF are mainly the stainless steel slag iron and steel drops, which accounted for about 14﹪of oxidized slag. Since they are with magnetism, they can be magnetically selected in mechanical and physical methods for remelting. After removing stainless steel slag iron and steel drops, the oxidized slag is a brittle material and its TCLP and pH values are under the determining standard of hazardous waste and may be regarded as general industrial waste. The micro-structure is smooth and free of pore, and is different from the porous carbon steel water-quenched slag. The breaking test results indicated the bearable load of oxidized slag is as high as 3,947 kg/kg of slag that shows their higher pressure and abrasion resisting properties. The ICP and EDS analysis confirmed that he stainless steel oxidized slag is mainly comprised of CaO、SiO2 and Cr2O3, and is similar to the composition of Portland cement. Therefore, it may be used as admixture to cement. In the aggregate durability test, the specific gravity of oxidized slag（3.29） is higher than the standard of river sand （2.5） and water content （0.93﹪） is far lower than the standard of river sand （3.0﹪）. The solved silicon (Sc) of the oxidized slag is 2.23mmol/L, smaller than the 10mmol/L of the river sand. The alkali reaction consumption (Rc) of the oxidized slag is 950mmol/L, higher than the 700mmol/L of the standard of river sand. The solved silicon (Sc) and alkali reaction consumption (Rc) are both harmless, i.e. the quantity of reaction between SiO2 and alkali is insufficient to damage the strength of concrete. The test for sieve soundness of analysis of aggregate durability indicated the loss rate is 9.96%, and the fine aggregate tolerable loss rate is within 12% range, which confirms to durability test standards. After breaking oxidized slag, screened, grounded to substitute raw and fine aggregate, then mixed with cement paste in different ratio. The compression strength test after curing indicated that the test piece with 5% oxidized slag of raw aggregate has the pressure resistance strength confirming to ASTM C109 standard. In fine aggregate, in the same water/cement ratio, mixed with oxidized slag, the compression strength of the test piece is better than the conventional mixing with standard sand. Conclusion drawing from the above, it is found that the oxidized slag is an artificial mineral and may be used to replace natural size gradation raw material after treatment.
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Li, Da-Ching, and 李大慶. "The chemical and physical characteristics of electric arc furnace oxidizing slag mortar." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/31683444621569317093.
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碩士國防大學中正理工學院
軍事工程研究所
90
Electric arc furnace oxidizing slag which is produced as a by-product from the steel-making process is utilized as concrete aggregate. In recent years, however, improvements in the electric steel making process have been carried out, and the possibility of applications of the slag has been increased. This paper discussed the chemical and physical characteristics for mortar of electric arc furnace oxidizing slag. Compressive strength, flexural strength, and shrinkage tests were carried out. Ages of the tests were 3, 7, 14, 28, 56, 90 and 180 days. Three specimens were tested for each age. Specimens of experiment were cured in 23℃ 100％RH, 50℃ 80％RH, and sulfate solution. Four different fine aggregate replacements were used: 0% slag (control), 25% slag, 50% slag, and 100% slag. The microstructural development of the slag mortar was studied with X-ray diffraction and scanning electron microscope. Specimens were cured in 23℃, 100％RH conditions. Ages of the tests were 1,3, 7, 14, 28, 56, and 90 days. The results indicated that specimens were cured in 23℃and 100％RH conditions which compressive strength and flexural strength of slag mortar were increasing by the increased ages. After 90 days, the strength development of the slag mortar became slower. More fine aggregate replacements, higher strength of slag mortar were.
48
Lin, Ting-Yi, and 林庭亦. "The Application of Electric Arc Furnace Reduction Slag to High Performance Concrete." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/13364943562746956272.
Full textAbstract:
碩士國立臺灣科技大學
營建工程系
91
In order to protect the living environment on earth, the International Environmental Protection Institutions have become more demanding about the environment since 2000. Besides, the pollution of ozonosphere and the greenhouse effect of the atmospheric layer have worsened the damage of ultraviolet and impact of global warming resulting in worldwide climate change. Therefore, ISO 14000, the quality assurance and environmental management standard, will be the main pursuit of the businesses. Regarding the concrete, to produce 1 kg cement will exhaust 1 m3 CO2. Because cement is energy- consuming and air- polluted material, how to reduce the use of cement has a great meaning to environment. Additional concern of earth ecology is to recycle the discarded materials. According to the official documents, the reduction slag of electric arc furnace, produced during the process of steel smelting, not only has similar chemical property as cement and blast furnace slag but also contains resembling property as Pozzolana material. Hence it acts well as the binding material in concrete. This research is focused on stainless steel slag and carbon steel slag produced in the process of steel smelting during the reduction period of electric arc furnace, and adapts the ecology- concerned Densified Mixture Design Algorithm, concrete design law, to measure the fresh and hardened property, analyze the change of the microstructure, and evaluate the possibility the application to high performance concrete. Results show that the high performance concrete which substitute partial cement to reduction slag are high liquid; the slump can reach more than 230mm and the slump flow will be within 500~700mm.The compressive strength can meet the requirement of design strength at the age of 28 days. Also, the pulse velocity can surpass 4000 m/s, and the category of concrete resistivity is higher than 20kΩ-cm. The measure of MIP porosity decreases as water to binder ratio lowers and the age increase. It is not only with high liquidity and high strength as high performance concrete but also durability. Accordingly, the reduction slag will have similar effects as the blast furnace slag powder applied to high performance concrete.
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Hung, Yan-Liang, and 洪延良. "A Study of Electric Arc Furnace Slag Concrete on the Pervious Pavement." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/87141406264949532496.
Full textAbstract:
碩士國立臺灣海洋大學
河海工程學系
97
As the public pays much attention on the issue of global warming, the environmental destruction caused by the production process of the civil engineering industry makes civil engineers consider how to mitigate the global warming problem on the basis of functionality, safety, and durability and to achieve the purpose of preserving natural resources at the same time. Pervious pavement, which has features of ventilation, temperature adjustment, and water permeation, has been viewed as one of the measures to mitigate the global warming problem. Consequently, using electric arc furnace to make pervious slag concrete is studied. The parameters used in the study include aggregate type, aggregate size, past void volume ratio and water-cement ratio, compressive strenght, connected void ratio, permeability coefficient, suspended solid test, and obstruct ratio were investigated. According to the experiment data, the basic features of electric arc furnace slag concrete and the feasibility of application of electric arc furnace slag concrete on pervious pavement are evaluated. The results indicated the electric arc furnace slag concrete has better mechanical properties and water permeability than other comparable nature aggregate. The compressive strength increases as the paste amount increases but decreases as the aggregate size increases. In addition, electric arc furnace slag concrete on the pervious pavement has better performance at suspending solid and obstruct ratio than other nature aggregate. The result of examining the water passing through the pervious pavement showed the quality of the water was not changed because of the cover by cement and the transient period of passing water.
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林志杰. "Utilization of electric arc furnace oxidizing slag in controlled low strength materials." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/93506607069572949679.
Full textAbstract:
碩士淡江大學
土木工程學系
92
This study was focused on the feasibility of utilization of electric arc furnace oxidizing slag in controlled low strength materials (CLSM). Electric arc furnace oxidizing slag was added as fine aggregate replacement to make normal CLSM and high early strength CLSM, respectively. Effects of water/cement ratio and replacement percentage of slag on CLSM’s engineering properties were examined according to the specifications of the Ministry of the Interior and the Taipei Municipal Government. For application in normal CLSM water/cement ratios were set at 1.5, 1.7 and 2.0 and replacement percentages were set at 0%, 25%, 50% and 100%. For application in high early strength CLSM water/cement ratios were set at 0.7, 0.8 and 0.9 and replacement percentages were set at 0%, 25%, 50% and 100%. Based on the results of this study major findings were summarized as follows： 1.Workability was decreased with increasing electric arc furnace oxidizing slag proportion for both normal CLSM and high early strength CLSM. 2.Utilization of electric arc furnace oxidizing slag in controlled low strength materials resulted in increasd unit weight and decreased air content of CLSM. 3.Utilization of electric arc furnace oxidizing slag in high early strength CLSM resulted in delayed initial setting time. 4.Compressive strength was increased with increasing of electric arc furnace oxidizing slag proportion for both normal CLSM and high early strength CLSM. 5.For application in normal CLSM when water/cement ratio is between 1.5 and 2.0 the replacement percentage of slag can be up to 100%. For high early strength CLSM when water/cement ratio is between 0.7 and 0.8 the replacement percentage of slag can be up to 50%. 6.The results of this study showed that the material’s cost was decreased with the utilization of electric arc furnace oxidizing slag in CLSM. Keywords：Electric Arc Furnace Oxidizing Slag, Controlled Low Strength Materials, CLSM