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Grant, Michael G. K. "Factors affecting the mechanical properties of blast furnace coke." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26702.
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The influence of coking conditions, with respect to position in a commercial coke-oven, on the mechanical behaviour of blast furnace coke has been studied. This involved the determination of density, porosity, the characterization of microstructure and assessing the influence of all three on the compressive strength of coke. The plastic flow properties were also investigated at temperatures greater than 1000°C.
Three coke batches, originating in a 5m commercial coke-oven at three different positions with respect to height (0.8m, 3.3m and 5m below the coal line), along with three coke batches produced in a 460mm test-oven, were supplied by Energy, Mines and Resources (CANMET) in Ottawa. A warf coke batch was also provided as a control sample. Several hundred core-drilled specimens (≃1.3cm diameter and 1.3cm length) were produced from the seven coke batches. The bulk density of each cylindrical coke specimen was determined. Also, a detailed microstructural analysis, using a Leitz Image Analyzer, of the flat faces of the coke cylinders was performed to quantitatively characterize the pore and cell wall size, and the pore geometry. The compressive strength of each coke cylinder was determined both at ambient temperature and at 1400°C. In addition, the plastic flow behaviour of the commercially produced coke batches was studied. Results indicate that the coke product bulk density was affected by the coke-oven pressure (static load). Studies of the test-oven coke batches revealed that coke bulk density increased with higher oven pressure. Furthermore, the pore size was found to be larger for cokes produced at lower oven pressures. The cell wall size did not appear to be affected by coke-oven pressure. The bulk density of the commercially produced samples increased with depth below the coal line. This was attributed to a higher temperature and static load that existed at the bottom of the battery. The pore size was larger in cokes extracted from higher regions. No correlation of cell wall size with depth below the coal line was found. However, an oven size effect on the pore and wall size was noticed. Both the pore and wall size was smaller in the test-oven coke batches.
The compressive strength of coke was higher in batches subjected to higher coke-oven pressures. Similarly,' the compressive strength of commercial coke batches was higher for coke batches extracted from regions near the sole of the coke-oven, than that for coke batches extracted from higher regions. It was concluded that high oven pressures resulted in cokes exhibiting a lower porosity and small pores which had the combined effect of producing stronger coke. Coke strength was generally shown to be higher at 1400°C than at room temperature. The test-oven cokes were always stronger than cokes produced in the 5m commercial coke-oven. Constant load tests revealed that coke exhibited plastic flow behaviour at temperatures above 1000°C. The time dependent strain data was described using an interactive-double-Kelvin element visco-elastic model.Applied Science, Faculty of
Materials Engineering, Department of
Graduate
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Cochrane, R. F. "Energy conservation in the zinc-lead blast furnace." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383056.
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SIQUEIRA, ELIS REGINA LIMA. "NATURAL GAS SIMULATION INJECTED FOR TUYERES OF BLAST FURNACES STEEL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25322@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O alto forno é um reator metalúrgico cujo objetivo consiste na produção de ferro-gusa. O consumo de combustível/redutor no processo de redução de minério de ferro em altos fornos, representa mais de 50 por cento do custo do gusa. No sentido de aumentar a produtividade e reduzir o consumo de combustível/redutor são empregadas técnicas de injeção de combustíveis auxiliares pelas ventaneiras dos altos fornos. A combustão de gás natural (GN) injetado nas ventaneiras produz grande quantidade de hidrogênio, esse gás é melhor redutor se comparado ao monóxido de carbono, pois ele possui velocidade de reação maior com os óxidos de ferro e, além disso, a geração de CO2 no processo de redução é diminuída quando comparado ao uso do carvão pulverizado (PCI), que é atualmente o material de injeção mais usado no Brasil. Este trabalho propõe a simulação da combustão de GN injetado pelas ventaneiras de um alto forno, utilizando o software CHEMKIN. As simulações provenientes deste software são amplamente utilizadas para otimização da combustão, sendo possível explorar rapidamente o impacto das variáveis de projeto sobre o desempenho do processo. Os resultados provenientes dessa simulação computacional em condições típicas de alto forno permitiram a previsão da temperatura de chama adiabática e a quantificação dos gases redutores de óxidos de ferro: H2 e CO. A partir da variação dos parâmetros de processo foi possível obter resultados úteis para a tomada de decisão, visando controlar e otimizar o processo.
The blast furnace is a metallurgical reactor whose goal is to produce pig iron. The fuel / reductant in the reduction of iron ore in the blast furnace process, represents more than 50 percent of the cost of the iron. In order to increase the productivity of the blast furnace and reduce fuel consumption / reducer injection techniques are employed by tuyeres of materials that act as fuel / reducer. The combustion of natural gas injected into the tuyeres produces large amounts of hydrogen, which replaces part of the carbon monoxide as reducing gas in the tank. The hydrogen gas is better compared to the reductant carbon monoxide, because it has reaction rate with the iron oxides and, moreover, the CO2 generation in the process of reduction is decreased when compared to the use of pulverized coal (PCI), which is currently the material most commonly used injection by tuyeres in Brazil. This paper proposes the simulation of combustion of natural gas injected into the tuyeres of a blast furnace, using the CHEMKIN software package. Simulations from this software are widely used for optimization of combustion, which can quickly explore the impact of design variables on the performance of the process, using accurate models of chemical kinetics. The computer simulation results from the combustion of natural gas at typical conditions of blast furnaces allowed the prediction of the adiabatic flame temperature and the reaching of the reducing gases of iron oxides: H2 and CO. From the variation of process parameters was possible to obtain useful results in order to control and optimize the process.
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Dong, Xuefeng Materials Science & Engineering Faculty of Science UNSW. "Modelling of gas-powder-liquid-solid multiphase flow in a blast furnace." Awarded by:University of New South Wales. School of Materials Science and Engineering, 2004. http://handle.unsw.edu.au/1959.4/20808.
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The ironmaking blast furnace (BF) is a complex reaction vessel involving counter-, coand/ or cross-current flows of gas, powder, liquid, and solids. However, the interactions of these multiphase flows have not been completely understood. The objective of this thesis is to develop a suitable model to simulate the powder flow and accumulation in packed beds and then extend it to numerically investigate the multiphase flow in the furnace. Gas-powder flow in a slot type packed bed has been experimentally studied in order to understand the flow and accumulation behaviour of powder in systems like an ironmaking blast furnace. A variety of variables including gas flowrate, powder flowrate and packing properties have been taken into consideration. It is found that a clear and stable accumulation region can form in the low gas-powder velocity zone at the bottom of the bed. The accumulation region is stable and shows strong hysteresis. The distribution of softening-melting layers in the blast furnace known as the cohesive zone (CZ) is modelled by inserting solid blocks into the bed. The results indicate that the inverse-V cohesive zone shape leads to low powder accumulation within the CZ and at the corner of the bed. A mathematical model is proposed to describe gas-powder flow in a bed packed with particles. The model is the same as the two fluid model developed on the basis of the space-averaged theorem in terms of the governing equations but extended to consider the interactions between gas, powder and packed particles, as well as the static and dynamic holdups of powder. In particular, a method is proposed to determine the boundary between dynamic and stagnant zones with respect to powder phase, i.e. the profile of the powder accumulation zone. The validity of numerical modelling is examined by comparing the predicted and measured distributions of powder flow and accumulation under various flow conditions. With high PCI rate operations, a large quantity of unburned coal/char fines flow together with the gas into the blast furnace. Under some operating conditions, the holdup of fines results in deterioration of furnace permeability and lower production efficiency. Therefore, the proposed model is applied to simulate the powder (unburnt coal/char) flow and accumulation inside the blast furnace when operating with different cohesive zone (CZ) shapes. The results indicate that powder is likely to accumulate at the lower part of W-shaped CZs and the upper part of V- and inverse V-shaped CZs. In addition, for the same CZ shape, a thick cohesive layer can lead to a large pressure drop while the resistance of narrow cohesive layers to gas-powder flow is found to be relatively small. Gas-powder flow in moving beds of solid particles has been numerically investigated, under conditions related to the ironmaking blast furnace and high rate pulverized coal injection. A new correlation, which is formulated to describe static powder holdup in a moving packed bed, is incorporated into the previous mathematical model and applied to a description of gas-powder flow in a blast furnace. Compared with the results of fixed beds, the results show that the solids descent due to the consumption of ore, coke and unburnt char in various regions, together with the non-uniform structural distribution, significantly affects powder flow and accumulation in a blast furnace. Finally, liquid flow is simulated through force balance approach and numerical results are compared with the different liquid inlet distribution under the iron-making blast furnace conditions with gas flow. The results show that the effect of inlet distribution on liquid flow is significant in the upper part of coke region in BF and possible loading and dry zone can be numerically identified. Then, this part of work is incorporated to the developed gas-powder-solid modelling system to investigate the influence of liquid phase on other phases flow in the blast furnace although heat transfer and chemistry are not considered in the model.
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Chen, Matthew Lidong Materials Science & Engineering Faculty of Science UNSW. "Multiphase flow in packed beds with special reference to ironmaking blast furnace." Awarded by:University of New South Wales. Materials Science & Engineering, 2008. http://handle.unsw.edu.au/1959.4/41354.
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Multi-phase flows can be found in a range of processes in vanous industries. Ironrnaking blast furnace is one of the typical examples. With high pulverized coal injection rates, complete combustion within the raceway of blast furnace becomes difficult, giving rise to a large amount of powder flow together with gases into the furnace. Thus, the performance of a modern blast furnace with high PCI strongly depends on the characteristics of a multiphase system which involves gas, powder, and liquid superimposed on the motion of solid particles. For this multiphase flow system, the solid (coke, sinter/pellets, etc) movement and liquids (hot metal and slag) and powders (unbumt coal and coke ash) accumulation in the lower region of the furnace are believed to play an important role. This thesis presents an experimental study focus on quantifying the hydrodynamics of gas-powder and gas-powder-liquid flows through packed beds with special reference to blast furnace. The effects of process variables including fluid flowrate and some material properties on powder hold-up, pressure gradient and phase interaction are examined. An experimental study of the hydrodynamics of gas-powder flow in packed beds has been carried out. Glass powder and spherical/non-spherical particles are used to simulate pulverized coal and coke particle respectively. It is found that solid motion, powder flowrate and particle spericity affect powder hold-up and pressure gradient significantly. New correlations are proposed for static and dynamic powder hold-ups to account for these effects based on experimental results. A hydrodynamic model is proposed for gas-powder flow in packed beds with spherical and non-spherical particles. Incorporation these correlations and porosity function into the existed Fanning and Ergun equations, the pressure gradients in fixed and moving beds can be reasonably estimated. The gas-powder-liquid flow through the moving beds is studied. The effects of fluid variables and some material properties on total powder hold-up and pressure gradients have been examined experimentally within the so-called operational regime. The normal and non-wetting treated glass beads, glass powder and water or mixture of water and glycerin are used to simulate coke, pulverized coal and hot metal/slag in a blast furnace. The results indicates that steady-state gas-powder-liquid flow in moving packed beds can be achieved under certain flow conditions since particle motion gives main contribution while it provides a higher bed porosity, enhances powder and liquid flow and removes the accumulation of the powder. The fluid variables and liquid viscosity significantly affect the total powder hold-up and hence pressure gradient but the wettability does not. Based on the experimental results, new correlations for powder hold-up and pressure gradient are proposed for blast furnace modelling in terms of dimensionless number of flowrates for different phases. Incorporation of these correlations and the existed empirical correlations of phase interactions, a hydrodynamic model is proposed to quantify the interaction force between liquid and powder. The results show that this force plays an important role for stable gas-powder-liquid flow in moving beds though it is ignored by most of the previous researchers.
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Pipatmanomai, Suneerat. "Investigation of coal behaviour under conditions simulating injection into blast furnaces." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289829.
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Van, der Vyver W. F. (Wilhelmina Fredrika). "Evaluation of the REAS test for blast furnace charge materials." Diss., University of Pretoria, 1998. http://hdl.handle.net/2263/30402.
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During the past two decades many efforts have been made to increase the control of blast furnace conditions to ensure a homogeneous product. The dissections on blast furnaces by various iron and steel companies in Japan in the early 70s provided valuable information on the high temperature properties of charging material. Standard tests (ISO) to determine ore, sinter and pellet qualities only provide information of up to 1100°C . By using the REAS apparatus - a high temperature reduction vessel that simulates the blast furnace process from stockline to melting - the high temperature properties of burden materials have been investigated. The REAS process not only provides an insight into the reactions occurring during the softening and melting process but a range of indices with which to judge the blast furnace performance. Since 1993 new developments started and a test method for Iscor blast furnaces was specifically developed. Although certain indices have been established, uncertainties around the melting mechanisms still existed. These uncertainties include: • Why does the maximum pressure over the sample bed vary extensively between different samples? • Why does a temperature decrease occur only in certain samples and what determines the extent of the temperature decrease? • Which low melting phase forms that causes the initial rise in pressure drop over the sample bed? Four tests were performed on a mixture of Sishen and Thabazimbi ore to determine the phase changes in the test sample. During the reduction of the iron ore, five distinct phases are present. Above 1200°C two liquid phases, an alkali rich phase and a liquid phase with a fayalite composition is present. The rest of the iron reports at different stages in various forms of metallic iron and wustite. Small amounts of a high melting oxide phase, hercynite, also occurs. Softening of the sample is said to occur when the ΔP over the sample bed increases by more than 200 mm H2O. For the specific tests evaluated, this occurred at 1200°C. At this temperature, the liquid with a fayalite composition as well as the alkali rich liquid are present. The formation of the low melting fayalite phase with a high viscosity appears to cause the sudden rise in ΔP. A temperature arrest occurs at the same time supporting the suggestion that liquid formation is responsible for the pressure increase. The results indicate that the mechanisms responsible for the observed pressure drop (decreased gas permeability) and dripping may well be different from those given in the literature. The literature mechanisms emphasise the importance of the amount of FeO available to act as flux for the silica which is present as gangue; hence a greater degree of (indirect) reduction below the melting point of fayalite gives poorer fluxing of silica since less FeO is available. However, the charge materials considered in this study appear to be of substantially higher grade than those used in the previous work. For this reason, there does not appear to be any shortage of FeO to act as flux. This abundance of FeO, and the observation that the peak in pressure drop is not associated with any great change in the amount of liquid, together imply that the literature mechanism regarding changes in the amount and composition of the liquid (i.e. becoming more Si02-rich and viscous as the FeO is reduced) cannot explain the pressure fluctuations observed here. Rather, the increase in pressure appears to be a joint effect of liquid being present (giving the first increase in pressure) and compaction of the sample. Loss of voidage in the sample by this substantial amount of compaction appears the likely cause of the pressure increase. The subsequent decrease in the pressure drop is probably associated with lower viscosity as the sample temperature increases. The importance of compaction means that the amount of indirect reduction does playa role in the development of the pressure drop, but not for the reasons cited in the literature. Pure iron is more malleable than the oxides, and reduction gives a porous iron structure which is more easily compacted. F or both these reasons, the metallic product of indirect reduction favours compaction (and hence the pressure increase). The sharp increase in reduction rate close to the peak pressure presumably results from better contact between the remaining iron oxide (in the fayalite-based liquid, and wustite) with the coke reductant, so favouring direct reduction; this increased reduction (endothermic because of the Boudouard reaction) results in one of the noticeable temperature arrests on the sample temperature curve. The correspondence between the temperature arrests and the changes within the sample do imply that these arrests can be used to gain some information on the reduction mechanisms. However, the reliability of the temperature arrests as indicators of the state of the sample and the reaction conditions within the sample must be tested by further work.Dissertation (MSc (Metallurgy))--University of Pretoria, 1998.
Materials Science and Metallurgical Engineering
unrestricted
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Schlesinger, Mark E. "LEAD OXIDE SOLUBILITY IN LEAD BLAST-FURNACE SLAGS (ACTIVITY, THERMODYNAMICS)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/291261.
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Sun, Stanley Shuye. "A study of kinetics and mechanisms of iron ore reduction in ore/coal composites." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ30115.pdf.
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Zhou, Zongyan Materials Science & Engineering Faculty of Science UNSW. "Mathematical modelling of gas-solid flow and thermal behaviour in an ironmaking blast furnace." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/35214.
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The ironmaking blast furnace (BF) remains the most significant and important process for the production of liquid iron. For the achievement of stable furnace operation and good performance, mathematical modellings at different levels increasingly become a powerful tool in developing better understanding of this multiphase flow system, in particular the gas-solid flow. This thesis represents an effort in this area. A simplified and continuum-based mathematical model is proposed and tested to predict the BF gas-solid flow at a macroscopic level. The results show that the simple model is able to predict the general features of the solid flow, including the effects of gas and solid flowrates, and materials properties. The simplified model can be readily implemented in a full process model that needs to have a quick response to change for the purpose of control and optimization. To overcome the difficulties encountered in continuum modelling, i.e. determination of constitutive correlations, and particularly the description of the stagnant zone when related to BF, a discrete model based on the coupling approach of discrete element method (DEM) and computational fluid dynamics (CFD) is then employed to investigate the gas-solid flow in a model BF at a microscopic level. The results confirm the effects of variables such as gas flow rate, solid flow rate, particle properties, and model types. More importantly, such an approach can generate abundant microscopic information such as flow structure (particle velocity, porosity, coordination number) and force structure, which are of paramount importance to elucidate the gas-solid flow mechanisms, and develop a more comprehensive understanding of BF gas-solid flow, such as the formation mechanism of the stagnant zone. Further, the transient gas-solid flow phenomena, together with the considerations of cohesive zones and hearth liquid, can be predicted. Further, in order to develop understanding of thermal behaviour and elucidate the heat transfer mechanisms occurring in particle-fluid flow system, a new model is proposed by extending the DEM-CFD, and then tested in gas fluidization. The model considers the three heat transfer modes, and demonstrates its ability in investigating the heat transfer mechanisms, and offers an effective method to elucidate the mechanisms governing the heat transfer in particle-fluid systems at a particle scale. It is recommended to apply to the study of BF thermal behaviour.
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Shen, Yansong Materials Science & Engineering Faculty of Science UNSW. "Mathematical modelling of the flow and combustion of pulverized coal injected in ironmaking blast furnace." Awarded by:University of New South Wales. Materials Science & Engineering, 2008. http://handle.unsw.edu.au/1959.4/41108.
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Pulverized coal injection (PCI) technology is widely practised in blast furnace ironmaking due to economic, operational and environmental benefits. High burnout of pulverized coal in the tuyere and raceway is required for high PCI rate operation. A comprehensive review reveals that although there have been a variety of PCI models, there is still an evident need for a more realistic model for PCI operation in blast furnace. Aiming to build a comprehensive PCI model of a full-scale blast furnace, this thesis presents a series of three-dimensional mathematical models, in terms of model development, validation and application, in a sequence from a pilot-scale to a full-scale, from a simple to complicated geometry, from a coal only system to a coupled coal/coke system. Firstly a three-dimensional model of pulverized coal combustion is developed and applied to a pilot-scale PCI test rig. This model is validated against the measurements from two pilot-scale test rigs in terms of gas species composition and coal burnout. The gas-solid flow and coal combustion are simulated and analysed. The results indicate that the model is able to describe the evolutions of coal particles and provide detailed gas species distributions. It is also sensitive to various parameters and hence robust in examining various blast furnace operations. This model is then extended to examine the combustion of coal blends. The coal blend model is also validated against the experimental results for a range of coal blends conditions. The overall performance of a coal blend and the individual behaviours of its component coals are analysed. More importantly, the synergistic effect of coal blending on overall burnout is examined and the underlying mechanisms are explored. It is indicated that such synergistic effect can be optimized by adjusting the blending fraction, so as to compensate for the decreased burnout under high coal rate operation. The model provides an effective tool for the optimum design of coal blends. As a scale-up phase, the coal combustion model is applied to the blowpipe-tuyereraceway region of a full-scale blast furnace, where the raceway is simplified as a tube with a slight expansion. The in-furnace phenomena are simulated and analysed, focusing on the main coal plume. The effect of cooling gas conditions on combustion behaviours is investigated. Among the three types of cooling gas (methane, air, and oxygen), oxygen gives the highest coal burnout. Finally, a three-dimensional integrated mathematical model of pulverized coaVcoke combustion is developed. The model is applied to the blowpipe-tuyere-raceway-coke bed region of a full-scale blast furnace, which features a complicated raceway geometry and coke bed properties. The model is validated against the measurements in terms of coal burnout from a test rig and gas composition from a blast furnace, respectively. The model gives a comprehensive full-scale picture of the flow and thermo-chemical characteristics of PCI process. The typical operational parameters are then examined in terms of coal burnout and gas composition. It is indicated that the final burnout along the tuyere axis is insensitive to some operational parameters. The average burnout over the raceway surface can better represent the amount of unburnt coal particles entering the surrounding coke bed and it is also found to be more sensitive to the changes of most parameters. In addition, the underlying mechanisms of coal combustion are obtained. The coal burnout strongly depends on both oxygen availability and residence time. The existence of recirculation region gives a more realistic coal particle residence time and burnout. Compared with the fore-mentioned two models, this model is considered as a more comprehensive model of PCI operation for understanding the infurnace behaviours and provides more reliable information for the design of operational parameters.
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Kalcioglu, Ali Ferdi 1960. "Distribution of antimony between carbon-saturated iron and blast furnace slags." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277129.
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Understanding the effects of the process parameters on the distribution behaviour of antimony between metal and slag in the iron blast furnace is critical to develop a universal method of controlling temper embrittlement in commercially pure low alloy steels.
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Bradley, Frederick Joseph. "Thermal shock resistance parameters for the industrial lining problem." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25568.
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A two-dimensional constant heating rate thermoelastic model has been used to develop design and selection criteria for refractory components of linings of high-temperature furnaces and process vessels. The criteria are in the form of resistance to fracture initiation and resistance to damage parameters which account for the influence of thermal and mechanical properties, geometry, and temperature range, while distinguishing between the heating and cooling cases. The resistance to fracture initiation parameter ɸs is the maximum rate at which a shape can be heated or cooled through a specified temperature range without causing fracture. The damage resistance parameter Rd is expressed as the ratio of surface energy per unit area to the elastic strain energy available for crack propagation. Both parameters can be quickly estimated for arbitrary conditions with the aid of tabulated solutions for the maximum principal tensile stress and total strain energy
Thermoelastic analyses were used to interpret published results of a variety of thermal shock experiments. Thermal conditions associated with water quenching, radiative furnace heating, gas burners, and controlled heating were simulated using appropriate analytical solutions. Finite element analysis was used to compute maximum principal tensile stresses and elastic strain energy. A simple procedure was developed to invert the stress solution and thereby determine the instant of fracture. Good agreement between thermoelastic predictions and published experimental results with regard to strength retained versus thermal shock relationships, location of fracture, and safe heating rates provided justification for a thermoelastic approach to the thermal shock.Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate
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Tungtrongpairoj, Jennarong [Verfasser]. "Contribution to Estimate the Multiphase Streaming Flow in the Dripping Zone of Blast Furnaces / Jennarong Tungtrongpairoj." Aachen : Shaker, 2019. http://d-nb.info/1188551930/34.
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GIGLIO, ANDRE MALICIA. "QUALITY PREVISION MODEL OF METALLURGICAL COKE TO BE USED ON BLAST FURNACES USING A COKE TEST FACILITY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=29703@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
É bem conhecido o alto peso que o coque representa no custo final do ferro-gusa, além do que, as suas propriedades estão intimamente ligadas à performance dos altos-fornos. Portanto, buscar uma qualidade do coque compatível com as necessidades do alto-forno e com o menor custo possível, se transforma em uma tarefa difícil senão se dispuser de ferramentas que permitam uma correta seleção de carvões e testes prévios em fornos pilotos. Dentre as propriedades utilizadas pelos altofornistas para qualificar o coque, se destacam a CSR - resistência mecânica após reação com CO2, e a CRI - índice de reatividade, por serem, respectivamente, uma medida direta da reação de Boudouard - solution loss, e da associação desta com a resistência do coque. Com isso se torna possível prever o consumo desta matéria prima nos altos fornos e, devido a sua grande influência nos custos da operação, mensurar seu impacto na economicidade do processo. A unidade de coqueificação do processo heat recovery da ThyssenKrupp Companhia Siderúrgica do Atlântico - TKCSA, possuindo uma concepção diferente do tradicional by product coking process, utiliza um forno piloto próprio, especificamente projetado pela empresa, com o qual se procura simular as condições operacionais das unidades de coqueificação. Entretanto, essa unidade de coqueificação ainda carecia de um estudo experimental especifico capaz de permitir uma análise comparativa confiável entre o coque produzido e o das baterias industriais. O objetivo principal desta dissertação foi desenvolver um modelo de previsão da CSR -resistência mecânica do coque após reação com CO2, e do CRI através da coqueificação de misturas de carvões, obtidas por diferentes metodologias, em no forno escala piloto e sua comparação estatística com os dados obtidos em escala industrial na ThyssenKrupp Companhia Siderúrgica do Atlântico - TKCSA. O modelo de previsão para o CSR quando obtido através de escala piloto se mostrou bastante aderente aos dados obtidos em escala industrial. Portanto, os procedimentos utilizados e este modelo desenvolvido mostraram-se adequados, e podendo assim ser usados como ferramenta para auxiliar na seleção e compra de carvões.
It is well known that coke has a major importance on the final cost of the Hot Metal and besides this fact its properties are closely connected with the performance of blast furnaces. Therefore, seeking a type of coke compatible with the blast furnace technical requirements and at the lowest possible price may become a hard challenge if neither a prediction tool is available to accomplish a correct selection of coals nor previous test were made on coke test facility. Among the properties used by the Blast Furnace specialists to qualify the coke, it can be highlighted CRI - Coke Reaction Index and CSR - Coke Strength after Reaction with CO2, because they represent a direct measure of the Boudouard reaction – solution loss, and its association with the coke strength, respectively. Based on them it is possible to predict the consumption of this raw material in the Blast Furnaces and, due to its high influence on the operational costs, measure its impact on the overall process economy. The Coke Plant unit at thyssenkrupp Companhia Siderurgica do Atlantico - TKCSA follows the coking process known as heat recovery and its concepts differ from the traditional one, by product. This unit uses its own coke test facility, specifically designed by the company s experts to simulate the operational conditions at the coke plant industrial furnaces. However, the coke test facility still required further specific experimental study capable of making a reliable comparison analysis between the cokes produced in it with the one from the industrial coke batteries. The main goal of this dissertation is to develop model to predict the CRI - Coke Reaction Index and CSR - Coke Strength after Reaction with CO2, through the coking process of coal blends, generated by different methodologies, charged on the coke test facility statistically compared with the ones from the industrial Coke plant at thyssenkrupp Companhia Siderúrgica do Atlântico - TKCSA. The prediction of CSR represented when generated through the coke test facility showed good adherence with the values obtained with the industrial scale. Therefore, the current procedures used on the developed model has proved to be adequate and may be used as a predicting tool to help the purchase of coals.
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Chapman, Michael Wallace. "Insoluble oxide product formation and its effect on coke dissolution in liquid iron." School of Mechanical, Materials and Mechatronic Engineering - Faculty of Engineering, 2009. http://ro.uow.edu.au/theses/3039.
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A significant body of work exists around coke dissolution into liquid iron, however there are key aspects of this important reaction that are not well described. This study was focused on gaining the answers to the questions “How does the coke mineral matter behave during coke dissolution?” and “Can the effects of sulphur and oxide layer formation on the dissolution rate be separated and quantified?”. Issues that must be addressed if the understanding of the kinetics of this reaction is to be advanced and coke's use in the blast furnace further optimised.To this end, a detailed investigation was conducted examining the influence of coke mineral matter on coke (carbon) dissolution into liquid iron. This project was focused on the mineral matter layer that forms at the coke/iron interface and how the presence of this layer affects the kinetics of carbon dissolution from the coke into the liquid iron. A range of experimental techniques were used to identify and characterise the mineral layer as it formed at the coke/iron interface and to assess the layers influence on the carbon dissolution kinetics.Carbon dissolution experiments, utilising a carburiser cover technique, were carried out where carbon and sulphur transfer to an iron-carbon melt was measured over time at temperatures of 1450°C, 1500°C and 1550°C. This technique allowed fundamental data on the dissolution rate constant to be calculated, and the effects of temperature, melt sulphur and different carbonaceous materials to be explored.Development of the mineral layer at the coke/iron interface as a function of both time and temperature was studied utilising a quenched carbon dissolution technique that was developed during the project. This technique had the additional benefit of allowing the composition of the melt to be determined for a larger range of elements than the dissolution experiments. The quenched carbon dissolution experiments complemented the carbon dissolution experiments and allowed direct comparisons between the dissolution behaviour measured in the dissolution experiments and the composition and morphology of the mineral layer observed in the quenched samples.The dissolution studies were further complemented by sessile drop measurements of the wetting behaviour of iron on the mineral phases that were identified in the mineral layer present at the coke/iron interface, thermodynamic modelling utilising the MTDATA software package and a conceptual model of the interfacial mineral layer.A mineral layer was observed to have formed at the coke/iron interface during coke dissolution into liquid iron at experimental temperatures ranging from 1450°C to 1550°C. The mineral layer was solid at these temperatures and persistent at the interface. The amount of mineral matter present in the mineral layer was observed to be increasing with increased reaction time. The composition and structure of the mineral layer changed with both experimental time and temperature. The composition of the mineral layer was principally composed of oxides of aluminium and calcium, present as various calcium aluminates and calcium sulphides. Initially the mineral layer was a loose agglomeration of particles of which a majority were alumina particles. As the dissolution reaction proceeded, the loose agglomeration of particles was replaced by an open acicular layer that was predominantly the calcium aluminate CaO.6Al2O3 (CA6). As the dissolution reaction continued further, the calcium aluminates became increasingly richer in calcium oxide, with the predominate phase present in the mineral layer progressing through the calcium aluminates phases CA6 to CaO.2Al2O3 (CA2) and onto CaO.Al2O3 (CA). The apparent calcium enrichment of the mineral layer was observed to occur more rapidly as the experimental temperature increased. Accompanying the compositional changes in the mineral layer, the morphology of the mineral layer was also observed to change. The mineral layer was formed as an initial loose agglomeration of alumina particles, changing to an open acicular structure consisting of CA6/CA2 before being converted to a dense layer as the dissolution reaction proceeded and the composition of the mineral layer changed to CA and calcium sulphide (CaS) appeared at the interface.It was found that the formation of the calcium sulphide layer was preceded by the formation of the calcium aluminate layer. Only after the calcium aluminate layer had experienced progressive calcium enrichment and the CA and CA2 phases had formed did the CaS phase appear at the iron interface. Thermodynamic analysis of the experimental results confirmed that the formation of the calcium enriched calcium aluminates, CA2 and CA, were a necessary requirement to stabilise the calcium sulphide layer for the coke composition studied.The kinetics of carbon dissolution from the coke to the liquid iron were observed to be dependent on the structure of the interfacial mineral layer. This dependence was manifest as two stage behaviour in the first order mass transfer plots. The initial stage, characterised by rapid carbon dissolution, was observed while the mineral layer was developing or had the open acicular structure of the CA6/CA2 layer. The second stage was characterised by a significant reduction in the rate of carbon dissolution. The onset of the second stage was coincident with the change in the composition of the mineral layer from CA6/CA2 to CA2/CA and the associated densification of the mineral layer. In stating that the nature of the mineral layer affects the dissolution kinetics, a change in the reaction control mechanism is implied. This represents a change in the coke dissolution kinetics from simple mass transfer control to a mixed control regime where both mass transfer and the mineral (product) layer are active.In an attempt to overcome the problems associated with the heterogeneity of coke a coke analogue was developed. In the coke analogue the composition and dispersion of the carbonaceous and mineral matter (oxides) are controlled and the porosity is fixed. When single phase calcium aluminates were introduced into the coke analogues, calcium enrichment of the resulting calcium aluminate mineral layer was observed. The observed carbon dissolution kinetics were dependant on the structure of the interfacial calcium aluminate layer. Consistent with the coke dissolution studies, the calcium aluminate layer formed at the coke analogue iron interface during carbon dissolution was at least in part rate controlling the carbon dissolution reaction for the coke analogues studied.Utilising the sessile drop experimental technique the wettability with liquid ironcarbon-sulphur alloys of the predominate phases that were observed in the mineral layer were measured. It was observed that the contact angle decreased as the proportion of lime (CaO) in the calcium aluminate increased. Further it was observed that while the presence of sulphur in the melt increased the contact angle for the alumina and CA6 substrates, on the CA2 and CA substrates the contact angle was decreased. The improvement in the wetting of the CA2 and CA substrates with sulphur was attributed to the formation of CaS at the substrate/droplet interface.This study has produced new fundamental data on the growth and development of the mineral layer and the wettability of the predominate calcium aluminates observed in the mineral layer. These detailed studies have illuminated the changing nature of the layer in terms of both composition and morphology and found that the kinetics of carbon dissolution from the coke to the liquid iron were dependant on the structure of the interfacial mineral layer.
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ROCCA, HECTOR C. C. "Determinacao de vazamentos em placas de refrigeracao de altos fornos." reponame:Repositório Institucional do IPEN, 1994. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10406.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Singh, Maneesh. "Studies on the cement-bonded briquettes of iron and steel plant by-products as burden material for blast furnaces /." Luleå, 2003. http://epubl.luth.se/1402-1544/2002/50.
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McCarthy, Fiona Materials Science & Engineering Faculty of Science UNSW. "Interfacial phenomena and dissolution of carbon from chars into liquid iron during pulverised coal injection in a blast furnace." Awarded by:University of New South Wales. School of Materials Science and Engineering, 2005. http://handle.unsw.edu.au/1959.4/20797.
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As carbon dissolution rates have been determined for a few chars only, a systematic and comprehensive study was undertaken in this project on the dissolution behaviour of carbon from non-graphitic materials into liquid iron. In addition to measuring the kinetics of carbon dissolution from a number of coal chars into liquid iron as a function of parent coal and coal ash composition, the influence of chemical reactions between solute/solid carbon and ash oxides was also investigated. These studies were supplemented with investigations on one metallurgical coke for the sake of comparison. The wettability of coal chars and coke with liquid iron at 1550 degrees C was measured as a function of time. Being essentially non-wetting, only a marginal improvement in contact angles was observed with time. The accumulation of alumina at the interface was detected for all materials and was seen to increase with time in all cases. Calcium and sulphur also appeared to preferentially accumulate at the interface, concentrating at levels in excess of those expected from the ash composition alone. Despite the high levels of silica in the ash initially, very little silica was detected in the interfacial region, implying ongoing silica reduction reactions. A small amount of silicon was however detected in the iron droplets, indicating silica reduction with solute carbon. It was identified that the reduction reactions can also consume solute carbon in the liquid iron. As this is occurring simultaneously with carbon dissolution into liquid iron, the interdependency of silica reduction and carbon dissolution could potentially limit the observed carbon dissolution rate. A theoretical model was developed for estimating the interfacial contact area between chars and liquid iron. Wettability was found to have a very significant effect on the area of contact. A two-step behaviour was observed in the carbon dissolution of two chars and coke. Slow rates of carbon dissolution in stage II were attributed to very high levels of interfacial blockage by reaction products leading to much reduced areas of contact between carbonaceous material and liquid iron. The first order dissolution rate constants for four chars/coke and the observed trend in first order dissolution rate constants were calculated. These dissolution results compare well with the previously measured dissolution rate constants. The trends in dissolution can be adequately explained on the basis of carbon structure, silica reduction, sulphur concentration in the metal and ash impurities.
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Gray, Stuart. "Groundwater remediation using a coal washery discard permeable reactive wall." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20061017.133840/index.html.
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Massucato, Carlos Jose. "Utilização de escoria de alto-forno a carvão vegetal como adição no concreto." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258498.
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Orientador: Vladimir Antonio PaulonDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: Este estudo teve como objetivo principal avaliar propriedades oriundas da adição de escória de alto-forno à carvão vegetal, do concreto no estado fresco e endurecido, produzido com cimentos que já utilizam em sua composição a escória de alto-forno. Com a determinação da quantidade de escória de alto-forno pelo método de dissolução seletiva, foi possível adicionar escória de alto-forno no concreto até os limites estabelecidos na especificação do cimento de alto-forno (CPIII) pela NBR 5735 (ABNT, 1991) e conhecer o efeito na resistência mecânica, módulo de elasticidade, abatimento, incorporação de ar, tempo de pega e exsudação, em traços de concreto sem adição e com adição de escória de alto-forno à carvão vegetal e à coque. As indústrias de cimento utilizam, em sua maioria, escórias provenientes dos altos-fornos à coque. Entretanto, o tratamento adequado nas escórias de alto-forno à carvão vegetal pode ampliar o consumo deste produto como adição mineral diretamente nas centrais de concreto, com a vantagem de ser uma fonte renovável de energia e eliminar este resíduo que se acumula nas usinas siderúrgicas. O estudo comprovou que, a utilização da escória de alto-forno à carvão vegetal como adição, não provoca alterações nas propriedades do concreto no estado fresco, em comparação com a escória de alto-forno à coque. A resistência à compressão com adição da escória de alto-forno à carvão vegetal aumentou em até 5% em idades superiores a 60 dias em comparação com o concreto sem adição de escória
Abstract: This study had the main purpose to evaluate properties of fresh and hardened concrete in with slag addition of blast furnace from charcoal in concrete produced with cements that already use in its composition the blast furnace slag. With the determination of the amount of slag of blast furnace by the selective method of dissolution, it was possible to add slag of blast furnace in concrete up to the limits established by NBR 5735 (ABNT, 1991) and to know the effect in concrete resistance, modulus of elasticity, slump test, air entrained concrete, setting of the cement and bleeding, in the mix proportions of concrete with and without slag addition of blast furnace from charcoal and coke. The cement industries use in its majority slag from coke deriving from blast furnace. However, the suitable treatment in slag of blast furnace from charcoal can extend the consumption of this product as mineral addition directly in the concrete plant, with the advantage of being a renewable source of energy and to eliminate this residue that accumulates in the siderurgical plants. The study proved that the use of the slag of blast furnace from charcoal as addition in concrete presented the same properties of fresh concrete compared with the slag of blast furnace with coke. The compressive strength increased in 5% at superior ages at 60th day in comparison without slag addition
Mestrado
Edificações
Mestre em Engenharia Civil
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Scholey, Kenneth Erwin. "Heat tranfser and crack formation in water-cooled zinc fuming furnace jackets." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30078.
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In the zinc slag fuming process, zinc is extracted from lead blast furnace slag by reduction with a coal/air mixture injected into the slag through submerged tuyeres. The furnace is constructed of water-cooled jackets to contain the molten bath and freeze a protective slag layer. The slag layer greatly reduces vessel wear caused by the corrosive and violently agitated bath. However, the jackets are known to develop cracks in the working face panel that initiate on the slag face and propagate towards the water cavity. If the cracks reach the water cavity explosions may result should the molten slag come into contact with the water.
In this study an analysis of heat transfer in the jacket has been carried out using in-plant measurements and mathematical modelling. The working face of a water jacket was instrumented with thermocouples and positioned in a fuming furnace at the Trail smelter of Cominco Ltd. Measurements revealed the presence of large thermal transients or temperature "spikes" in the panel approximately 20 cm above the tuyeres. The transients were observed during charging and tapping of the furnace and are likely associated with slag fall-off due to surface wave action and gas injection effects when the bath level is low. Temperatures at the mid-thickness were seen to rise by as much as 180 °C above the steady-state level. Under these conditions large compressive stresses are produced in the panel that are sufficient to cause yielding. Over time, the transients lead to low-cycle fatigue of the working face panel with crack formation initiating at pre-existing surface flaws.
A mathematical modelling analysis of the transient freezing phenomena has been carried out using the finite element method. The results indicate that the temperature spikes are associated with the sudden removal of patches of slag and molten slag
coming into direct contact with the jacket. The temperature spikes are large enough to generate compressive stresses that cause yielding of the material in the exposed area. In order to reduce the damage caused by the removal of the slag shell an increased number of anchoring studs should be used in critical areas and a higher water circulation velocity should be employed to increase the size of the frozen slag layer and its strength.Applied Science, Faculty of
Materials Engineering, Department of
Graduate
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Myrstener, Erik. "Environmental impacts of early metallurgy in Moshyttan : A study of one of Europe's oldest blast furnaces, using three lakes records in Nora bergslag." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-64733.
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The aim of this study was to assess the environmental effects of Moshyttan, one of the earliest known blast furnaces in Europe (ca. 11th century). The study was based on the analysis of three lake records in the immediate surroundings of the smelter. Fickeln lies directly downstream and is the main recipient of waterborne pollution. Mosjökälla lies directly upstream and served as the main water reservoir for the water-powered bellows. Kramptjärnen lies 1 km to the NW in a separate catchment and acts as a reference. The data includes 31 elements analyzed by X-ray fluorescence spectroscopy (XRF), organic content inferred from loss on ignition (LOI), biogenic silica (BSi) modeled from Fourier-transform infrared spectroscopy (FT-IRS) for all lakes and diatom counts for Fickeln. Two other studies provided dating of slag from the smelter and pollen- and geochemical data from Fickeln. The results show that the metallurgy and associated activities (e.g. agriculture, forest grazing and charcoal production) led to eutrophication and alkalization in Fickeln. This is indicated by the diatom community that in the background is dominated by benthic genera indicative of oligotrophy and dystrophy (Frustilia, Brachisyra and Eunotia) that during the active smelter phase is replaced by pelagic genera indicative of eutrophy (Aulacoseira and Asterionella). BSi also decreases after smelter establishment, which speculatively could indicate an overall decrease in diatom production. At the same time, a suite of elements commonly associated with iron processing (Fe, Pb and Zn) increase in the sediment.
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Mendes, Wanderley. "Analise quantitativa da composição de escorias siderurgicas pelo metodo de espectroscopia e difração de raios-X." [s.n.], 1992. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264851.
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Orientador: Carlos Kenichi SuzukiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: A indústria siderúrgica é historicamente um setor que produz impactos ambientais inerentes ao seus processos de produção. Anualmente são gerados 135 milhões de toneladas de escórias para uma produção de 700 milhões de toneladas de aço. As novas regulamentações dos órgãos ambientais têm motivado a pesquisa em busca de novas aplicações destes resíduos. Atualmente, as escórias tem sua aplicação na indústria de cimento Portland e vidros, na pavimentação de estradas, revestimentos acústicos e térmicos, neutralizante de solos, mas há necessidade de novas aplicações das escórias devido ao montante gerado pelas usinas. Neste contexto, a caracterização física, química e de impactos ambientais das escórias se faz necessária, visando uma nova aplicação tecnólogica, tendo em vista que as suas propriedades físicas e químicas estão diretamente relacionadas as suas estruturas. Com o objetivo de determinar a composição química e determinação estrutural, métodos analíticos foram aplicados em escórias de alto forno (AF) e conversores LD (CLD) utilizando-se das técnicas de espectroscopia de fluorescência (FRX) e difração de raios-X (DRX). O presente trabalho foi desenvolvido em duas etapas: (1) a determinação e quantificação química das escórias por FRX; (2) caracterização estrutural das fases presentes e quantificação da fase mervinita cristalina Ca2Mg(SiO4h que se fez presente em todas as amostras analisadas de escórias de alto forno. Foram utilizadas duas metodologias nas escórias analisadas por FRX: métodos de parâmetros fundamentais (PF) e análise semi-quantitativa (SQ), onde as diferenças nas concentrações foram significativas, justificadas pela maior acuracidade nas medições realizadas pelo PF, haja visto uma maior interação númerica e utilização de curvas de sensitividade para a análise. Também verificamos a presença de impurezas que não foram detectadas no SQ e observadas no PF, tais como: P, N, V, Cr. Com os resultados obtidos na análise por DRX observamos os diferentes graus de cristalização/amorfo; a caracterização de fases presentes, mesmo quando se encontravam em baixas porcentagens nas amostras, além da quantificação da fase mervinita utilizando-se do método de padrão interno
Abstract: Steel plants are historicalIy associated with environrnental impacts because of their manufacture processoIn that process, there are generations of 135 million tons of slag from 700 million tons of steel produced. The new regulations of environrnental agencies have stimulated research of new uses for the generated wastes. Nowadays, slag is re-used in Portland cement plants, glass manufacture, paving highways, acoustic and thermal insulating, and soil neutralization. Despite those applications, the slag generation is large enough to demand new innovative technologies. In this context, it is necessary to accomplish physical and chemical characterization of slag to extend knowledge of its structure and properties. Analytical methods for chemical and structural determination of slag were applied in blast furnace slag (AL) and steel converter unit slag (CLD) by using X-ray Fluorescence Spectroscopy (FRX) and X-ray Diffraction (DRX). The present research was carried out in two stages: (1) determination of chemical elements presents in slag followed by quantitative analysis of these elements (by FRX); (2) structural characterization followed by quantitative determination of merwinite crystalline phase [CazMg(SiO4)z]present in alI analyzed samples. There were used two methods for FRX characterization of slag: Fundamental Parameter (PF) and Semi-Quantitative Analysis (SQ). Those methodologies were divergence in the results, maybe due to the higher accuracy with PF methodology that utilizes more interactions and sensibility curves in the optimization processoAIso in PF method, there were observed presence of impurities that were not detected in SQ method such as: P, Nb, V, Cr, Y. The DRX analysis showed several stages of crystalline/amorphous structures, determination of crystalline phases even in low concentration and quantification of merwinitic phase by using internal standard method in DRX analysis
Mestrado
Materiais e Processos de Fabricação
Mestre em Engenharia Mecânica
25
Both, Christian. "Entwicklung eines Verfahrens zur Beurteilung des Schädigungszustandes von Schrägaufzugseilen an Hochöfen mittels magnetinduktiver Streuflußmessung - Development of a system for the evaluation of skip steel cables of blast furnaces using electromagnetic testing." Gerhard-Mercator-Universitaet Duisburg, 2001. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-05252001-115538/.
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Based on the problem of a total evaluation of skip steel cables of blast furnaces two computer aided procedures for the analysis of the measured data of electromagnetic steel cable testing are developed. The first procedure is useful to detect inner and outer broken wires and simulates the analysis of a skilled inspector by a pattern classification algorithm using fuzzy-logic. Like an inspector this system has to be trained. This is implemented with the help of a genetic algorithm. The second procedure is helpful serves as evaluation of accumulated inner faults of steel cables. Therefore two characteristic values describing the inner condition are determined by frequency analysis of the measured data. - Ausgehend von der Problemstellung einer umfassenden Beurteilung des Schädigungszustandes von Schrägaufzugseilen an Hochöfen werden zwei rechnergestützte Auswerteverfahren für die magnetinduktive Streuflußprüfung von Drahtseilen entwickelt. Das erste Verfahren dient der Erkennung innerer und äußerer Drahtbrüche und bildet die Auswertemethodik eines erfahrenen Inspekteurs in einem Musterklassifikator basierend auf Fuzzy-Logic nach. Den Erfahrungsprozeß des Inspekteurs vollzieht das Verfahren durch eine Optimierung mittels genetischen Algorithmus anhand realer Meßdaten nach. Das zweite Verfahren dient der Abschätzung des inneren Schädigungszustandes eines Drahtseiles hervorgerufen durch Schadenshäufungen. Dazu erfolgt die Berechnung zweier charakteristischer Kennwerte aus eine Frequenzanalyse der aufgezeichneten Meßdaten.
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Medeiros, Fernando Tadeu Pereira de. "Desenvolvimento de um modelo de predição de condições operacionais de altos-fornos siderugicos com base em redes neurais artificiais." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267679.
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Orientadores: Ana Maria Frattini Fileti, Andre Pitasse da CunhaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Este trabalho descreve o desenvolvimento de um modelo capaz de prever as condições operacionais do processo de redução de minério de ferro em alto-forno a partir de características das matérias-primas e da composição da carga e do sopro, fornecendo aos operadores e engenheiros de processo, uma ferramenta de planejamento e de análise de desempenho da operação. A motivação para este trabalho deveu-se à constatação de que existe uma deficiência de modelos capazes de identificar cotidianamente os fatores críticos na operação dos altos-fornos siderúrgicos. Os modelos encontrados são excessivamente simples para preverem condições futuras de processo ou são demasiadamente complexos para o uso operacional diário ou no pJanejamento estratégico da produção. Os altos-fornos e os conversores de aço são as unidades centrais de uma usina siderúrgica integrada. O primeiro obtém o ferro primário a partir dos óxidos contidos nos minérios e o segundo refina e ajusta a composição química do metal produzindo o aço. O modelo desenvolvido e aplicado tem natureza híbrida, combinando algoritmos simuladores baseados em balanços de massa e energia com variável grau de desvio estequiométrico e térmico. O valor de cada indicador de desvio é previsto por uma rede neural cujas variáveis de entrada quantificam características das matérias-primas e condições de sopro e carga do alto-forno. A aplicação industrial do modelo comprovou sua capacidade de prever as condições do processo e sua aplicação resultou em aumento da produtividade média do processo e menor consumo específico de redutores, decorrentes da melhor efetividade das ações operacionais. Além disso, o modelo, associado a um módulo de balanço do setor primário da usina, vem sendo aplicado na simulação de alternativas de padrões operacionais, atividade fundamental para o planejamento estratégico do negócio
Abstract: This work describes the development of a model capable of evaluating and predicting iron ore reduction process in blast-furnaces based on raw materiais characteristics as well as burden and blast composition. It provides a planning and analysing toll to operators and process engineers. The motivation for this development resides on the lack of this kind of model in the ironmaking industry. The many models found are either toa simple and not capable of predicting raw materiais parameters effects on the furnace performance or toa complexo The latter are useful in technology potential identifications but not in the daily work or ordinary operation planning. Blast-furnaces and oxygen converters are the core units in a integrated steel works. The former one produces primary iron from oxides bared by iron ores and the latter one refines molten iron into steel, adjusting its chemical compositiono The developed and applied model is hybrid in nature, combining simulating algorithms based on mass and energy balances with variable lack of fitnesso The value of each lack-of-fitness index is estimated by a neural model in which the input quantify burden materiais characteristics as well as blow and charging conditions. The model has shown its predicting capacity during its industrial application, which lead to higher average productivity and lower specific fuel consumption are expected following better operation action and process planning efficiency. In addition, the model is now being associated to a plant mass balance module to asses alternative operation pattern simulation for the hole company which is a fundamental activity in strategic business planning
Doutorado
Sistemas de Processos Quimicos e Informatica
Doutor em Engenharia Química
27
Shankar, Amitabh. "Studies on High Alumina Blast Furnace Slags." Doctoral thesis, Stockholm : Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4431.
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Sexton, Dane. "Coal agglomeration in blast furnace injection coals." Thesis, Cardiff University, 2019. http://orca.cf.ac.uk/119742/.
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In order to reduce expensive coke usage, blast furnace operators inject coal to replace a portion of the coke. However, the use of some injection coals can result in blast furnace instability and lowered permeability. This thesis is concerned with the injection of coal under entrained flow, high heating rate (104-106 °C/s) blast furnace conditions, namely the possibility of coal particle agglomeration via the use of caking coals. Methods of mitigating agglomeration via blending and pre-oxidation are tested, whilst the resultant performance implications of agglomerated coal chars are considered and analysed. A drop tube furnace (DTF) was used to experimentally test coal injection under conditions that are applicable to the blast furnace 'hot blast' region. Relatable DTF parameters include an operating temperature of 1100°C, and heating rate of 104 °C/s. Four industrial injection coals with varying volatile matter and caking properties were tested at both granulated and pulverised particle size specifications. It was found that coals defined as 'caking coals' showed consistent agglomeration during DTF injection, a potentially problematic effect regarding blast furnace injection. Agglomeration percentages (as defined by sieve classification) for the industrially problematic MV4 coal were 11% and 23% for the granulated and pulverised samples respectively. Blending of whole coals was effective in reducing the amount of agglomerated material in the char, as was sample pre-oxidation prior to injection. Regarding performance, agglomerated chars had greater combustion performance and gasification reactivity than the non-agglomerated samples. With agglomeration shown to be present under high heating rate conditions at temperatures akin to the blast furnace hot blast, it is concluded that agglomeration is a possibility during blast furnace injection. However, due to differing feed systems between the DTF and blast furnace, the precise form and extent of agglomeration in the blast furnace remains uncertain. Based on char combustion and gasification analysis, chars characterised by fine agglomerated material are not likely to be problematic for blast furnace operators relative to 'standard' injection coals.
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Leimalm, Ulrika. "Interaction between pellet properties and blast furnace operation." Doctoral thesis, Luleå : Luleå University of Technology, 2010. http://pure.ltu.se/ws/fbspretrieve/3541696.
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Oberlink, Anne Elizabeth. "NON-PORTLAND CEMENT ACTIVATION OF BLAST FURNACE SLAG." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/25.
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The purpose of this project was to produce a “greener” cement from granulated ground blast furnace slag (GGBS) using non-Portland cement activation. By eventually developing “greener” cement, the ultimate goal of this research project would be to reduce the amount of Portland cement used in concrete, therefore reducing the amount of carbon dioxide emitted into the atmosphere during cement production.
This research studies the behavior of mineral binders that do not contain Portland cement but instead comprise GGBS activated by calcium compounds or fluidized bed combustion (FBC) bottom ash. The information described in this paper was collected from experiments including calorimetry, which is a measure of the release of heat from a particular reaction, the determination of activation energy of cement hydration, mechanical strength determination, and pH measurement and identification of crystalline phases using X-ray diffraction (XRD).
The results indicated that it is possible to produce alkali-activated binders with incorporated slag, and bottom ash, which have mechanical properties similar to ordinary Portland cement (OPC). It was determined that the binder systems can incorporate up to 40% bottom ash without any major influence on binder quality. These are positive results in the search for “greener cement”.
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Rhodes, Emma. "Flow control of a blast furnace tuyère." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400232.
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Zuo, Guangqing. "Improving the performance of the blast furnace ironmaking process /." Luleå, 2000. http://epubl.luth.se/1402-1544/2000/24/index.html.
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Leimalm, Ulrika. "Pellet reduction properties under different blast furnace operating conditions." Licentiate thesis, Luleå : Luleå tekniska universitet/Tillämpad kemi och geovetenskapProcessmetallurgi, 2006. http://epubl.ltu.se/1402-1757/2006/67/LTU-LIC-0667-SE.pdf.
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Obasohan, E. "Study of steelmaking reactions of blast furnace hot-metal." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/12288/.
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Means of utilising low quality high phosphorus ores and coals is the focus of much research within the steelmaking industry due to the high cost and decreasing availability of premium quality raw materials. Practices such as double converter practice are used in some steel plants to drive HM phosphorus levels down to low levels, but even then costs and time constraints are associated with such practice. To tackle this issue, a HM dephosphorisation pre-treatment process was proposed by Tata Steel R&D featuring the refinement of desulphurised HM droplets. To determine the feasibility of dephosphorisation reaction occurring within the HM droplets as it descended down the reactor, kinetic experiments were conducted using a purpose built levitation melting furnace featuring electromagnetic coils for melting the sample. Experiments conducted included free fall and stationary levitation kinetic experiments where oxidising gas mixture and/or slag-making material was introduced into the reaction system and quenched samples were analysed for change in composition and surface morphology. Results indicated whilst no dephosphorisation took place within the short fall time (~0.32 seconds) or during the extended reaction time (60 seconds), liquid surface oxides formed as oxidation of carbon, silicon, manganese and iron occurred. Shifted focus onto analysing the composition and growth of the surface oxides with respect to parameters such as droplet size and gas phase oxygen content showed that such factors had limited effect on oxide growth and composition. Whilst lime was unable to flux into the liquid oxide, low liquidus basic synthetic slag was able to but with no change in HM phosphorus levels. HM silicon and manganese content were however significantly lowered in the presence of the basic slag indicating mass transfer of these elements from the metal to the slag. Whilst the significance of the experimental results is that the suggestion of extensive dephosphorisation occurring during the fall of desulphurised HM droplets within the pre-treatment process has been disproved, the study improves understanding of droplet steelmaking reactions as well as offering a new experimental technique not previously available to Tata Steel for investigating reactivity or surface properties of metal droplets.
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Edmundson, J. T. "Energy savings by co-distribution of basic oxygen furnace gas with blast furnace gas." Thesis, Swansea University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636767.
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Cameron, David Bruce. "Dynamic data reconciliation in the context of an equation-oriented flowsheet simulator." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359394.
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Sarson, Stuart C. "Investigations in the copper-lead system." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239160.
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Chan, Brenda Kit Ching. "Reaction of potassium with carbons." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316091.
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Bean, Ian James Materials Science & Engineering Faculty of Science UNSW. "Blast furnace hearth drainage improvement of the residual - flowout correlation." Publisher:University of New South Wales. Materials Science & Engineering, 2008. http://handle.unsw.edu.au/1959.4/41490.
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Experimental cold modelling of hearth drainage was performed at Bluescope Steel Research Laboratories to understand the impact of variable drainage rate on slag removal. These drainage studies were designed to simulate real operational aspects such as: continuous casting, variable tapping rate and inflow liquid distribution. During the analysis of these drainage experiments it was demonstrated that the residual-flowout correlation in use since the 1970??s may possibly be incomplete or inaccurate. The removal of slag from the blast furnace hearth is the greater concern of the two liquids produced in the iron making process. In the 1970??s operational difficulties arose when large volumes of residual slag remained in the furnace after casting. This prompted research related to the flow of viscous liquids through uniformly packed beds providing fundamental insight on the most effective means of removal of slag from the blast furnace hearth. The core subject of this study, the residual-flowout correlation developed by Fukutake and Okabe that is used to predict cast duration and liquid accumulation in the blast furnace hearth is discussed in detail. The residual-flowout correlation is examined for four different sets of conditions based on constant or increasing slag drainage, with and without liquid dripping. The outcome of this study will improve our understanding of the residual-flowout relationship and develop it further, so that drainage conditions whether for constant or increasing drainage rates, with or without dripping, will hold using the one general Fl equation.
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Hellberg, Per. "A Model of Gas Injection into a Blast Furnace Tuyere /." Stockholm : Department of Materials Science and Engineering, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-525.
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Hilding, Tobias. "Evolution of coke properties while descending through a blast furnace." Licentiate thesis, Luleå, 2005. http://epubl.luth.se/1402-1757/2005/19.
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Ge, Angela X. (Angela Xiaoyun) 1977. "A neural network approach to the modeling of blast furnace." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80642.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 65-69).
by Angela X. Ge.
M.Eng.
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Vereš, Ján, Štefan Jakabský, and Vladimír Šepelák. "Chemical, physical, morphological and structural characterization of blast furnace sludge." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-188184.
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Vereš, Ján, Štefan Jakabský, and Vladimír Šepelák. "Chemical, physical, morphological and structural characterization of blast furnace sludge." Diffusion fundamentals 12 (2010) 88, 2010. https://ul.qucosa.de/id/qucosa%3A13909.
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Jampani, Megha. "Increased Use of Natural Gas in Blast Furnace Iron-Making." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/851.
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Steelmaking is a highly carbon intensive process. Most of the CO2 emissions in steelmaking are from the blast furnace. Coke has been the major reductant used in a blast furnace since 1750. The recent boom in the US energy outputs due to shale rock formations has motivated the need to look at natural gas as a partial replacement for coke in a blast furnace. During the course of this project, the impact of higher natural gas utilization has been studied in detail. Theoretical models suggesting the injection of natural gas as a viable method to replace coke partially have been used. These theoretical claims have then been tested experimentally and the results have been discussed. The experimental work described includes reduction of hematite to wüstite, followed by the study of interaction of natural gas with a bed of iron pellets replicating the wüstite reserve zone of a blast furnace. Furthermore, the reforming of methane over metallic iron pellets was investigated and these reactions were tested under blast furnace conditions. Mass and energy balance calculations, along with experimental results were used to support the proposed shaft injection of natural gas.
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McQueen, Mark. "Heat recovery from molten blast furnace slag in a fluidized bed." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ55918.pdf.
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Boltz, Daniel Edward. "Early performance of concrete pavement containing ground granulated blast furnace slag." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176839817.
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Banks, Bradley S. (Bradley Scott) 1974. "Neural network based modeling and data mining of blast furnace operations." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/44600.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 55-57).
Industrial production processes have traditionally been predicted using models whose structure is determined from domain specific knowledge. Steel production is an ex.ample of such a process, where conventional modeling techniques are based on knowledge of the materials and reactions involved. These models have several shortcomings, including the impossibility of constructing precise models, the inability to adapt to changing conditions, and the high cost of development. Because of these limitations, there is growing interest in applying methods which take a data driven approach to modeling these processes. One such method, the Artificial Neural Network (ANN), has been successfully used in many areas. ANNs offer a data driven approach which has potential to produce a more accurate, flexible model in less time and at a lower cost. This model can then be used for simulation, prediction, and control. A case study application of using ANNs to model the production of pig iron, an intermediate step in producing steel, is presented. Two qualitatively different aspects of pig iron production, hot metal temperature and hot metal silicon content, were modeled. Early results indicated the importance of preprocessing the raw data in order to make network learning easier. Modeling efforts focused on the most well known neural network architecture, a feed forward network trained with the back propagation learning algorithm. A neural network software package, NNRUN, was developed to automate the search for the best neural network for a given dataset. The combination of preprocessing and modeling with NNRUN produced models which yielded significantly more accurate predictions than traditional modeling methods.
by Bradley S. Banks.
M.Eng.
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Dhond, Anjali 1977. "Application of neural network techniques for modeling of blast furnace parameters." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/17490.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaves 93-96).
This thesis discusses the predictions of various output variables in a blast furnace. It compares the ability of multi-layer perceptron neural networks for prediction with other blast furnace prediction techniques. The output variables: Hot Metal Temperature, Silicon Content, Slag Basicity, RDI, and +10 are all modeled using the MLP networks. Different solutions are proposed for preprocessing the original data and finding the most relevant input variables. The NNRUN software is used to find the best MLP neural network. Finally, methods to control the output variables in the blast furnace are examined and a derivative-based sensitivity analysis is discussed.
by Anjali Dhond.
M.Eng.
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Lundgren, Maria. "Blast furnace coke properties and the influence on off-gas dust." Licentiate thesis, Luleå tekniska universitet, Industriell miljö- och processteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18007.
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In blast furnace ironmaking, efforts are made to decrease the coke consumption mainly by increasing the pulverized coal injection rate. This will cause changes in in-furnace reduction conditions, burden distribution and demands on raw material strength, etc. In order to maintain stable operation and minimize material losses through the off-gas, it is important to understand fines generation and behaviour in the blast furnace. The strength and reactivity of coke at high temperature, measured by the Coke Strength after Reaction (CSR) and Coke Reactivity Index (CRI), have been studied. Mechanisms of disintegration were evaluated using basket samples charged into the LKAB Experimental Blast Furnace (EBF) prior to quenching and dissection. Coke charged into basket samples was analysed with CSR/CRI tests and compared with treated coke from the blast furnace. Results from tumbling tests, chemical analyses of coarse and fine material, as well as Light Optical Microscope (LOM) studies of original and treated coke have been combined and evaluated. The results indicate a correlation between the ash composition and CSR values. Differences in the texture of the coke were determined with LOM, and a change in the coke texture during the CSR/CRI test conditions was found. The results suggest that the main reaction between coke and CO2 during the solution loss reaction took place in isotropic areas, which was especially pronounced in coke with a low CSR. Signs of degradation were apparent throughout the coke pieces that have undergone CSR/CRI testing, but were less observable in coke reacted in the blast furnace. The results indicate that the solution loss reaction was generally limited by the chemical reaction rate in the CSR/CRI test, while in the blast furnace the reaction is limited by the diffusion rate. Coke degradation is therefore mostly restricted to the coke surface in the blast furnace. At a later EBF campaign, off-gas dust and shaft fines were sampled during operation with different iron-bearing materials. EBF process data were used to evaluate the relationship between off-gas dust amounts and furnace conditions. Characterization was focused on fines from coke, iron-bearing materials and slag formers. The graphitization degree (Lc value) of coke taken out of the EBF shaft and coke in flue dust was determined in order to trace the fines generation position. The results showed that flue dust, mainly <0.5 mm, was mechanically formed and created in the same manner for all investigated samples. Carbon-containing particles dominated in the fractions >0.075 mm and consisted mainly of coke particles originating from the shaft. Solution loss in the shaft had a negligible effect on coke degradation and the coke particles which ended up in the flue dust were mainly derived from abrasion at low temperatures. Sludge consisted mainly of chemically formed spherical particles <1μm formed in the blast furnace high-temperature area and then precipitated from the ascending gas as the temperature decreased. The amount of alkali and SiO2 in sludge increased with higher pulverized coal injection rates and flame temperatures, which confirmed that submicron spherical particles in sludge originated from the high-temperature area around the raceway. Theoretical critical particle diameters of materials, which could be blown out with the off-gas, were estimated. Flow conditions in the top of the shaft as well as the properties of fine particles in terms of size and density are important when outflow of mechanical dust, such as flue dust, is concerned. Low off-gas temperatures, and thus lower off-gas velocities, are desirable for blast furnace operation with low amounts of flue dust.Godkänd; 2010; 20100504 (lunmar); LICENTIATSEMINARIUM Ämnesområde: Processmetallurgi/Process Metallurgy Examinator: Professor Bo Björkman, Luleå tekniska universitet Diskutant: Docent Bo Lindblom, LKAB Tid: Tisdag den 8 juni 2010 kl 13.00 Plats: F531, Luleå tekniska universitet