Os cimentos de escória apresentam boas possibilidades de mercado, especialmente em aplicações em que o cimento Portland não possa ser utilizado ou onde o seu uso provoque uma elevação dos custos. A confecção de matrizes para fibras sensíveis aos álcalis e a produção de cimentos com baixo calor de hidratação são exemplos. Neste trabalho, a escória foi ativada com silicato de sódio e cal hidratada. O ativador foi formulado de maneira a proporcionar teores de Na2O de 2,5% e 5%, SiO2 de 0% a 14,8% e Ca(OH)2 de 0%, 2,5% e 5%. O aumento dos teores de Na2O e de SiO2, dentro de determinados limites, propicia um notável crescimento da resistência à compressão. Este crescimento da resistência está associado a uma diminuição da porosidade, para um mesmo fator/água aglomerante. Certamente a diminuição da porosidade é devida a um menor grau de organização cristalina dos produtos hidratados, decorrente do aumento da velocidade de precipitação de hidratados e de gel de N-C-S-H. A adição de Ca(OH)2 diminui a velocidade de perda da trabalhabilidade. Os cimentos de escória ativada com silicatos de sódio podem apresentar resistência à compressão de até 100 MPa, superior à dos cimentos Portland, com calor de hidratação da mesma ordem de grandeza. A velocidade de carbonatação destes cimentos é equivalente a dos cimentos Portland de mesma resistência. No entanto, estes cimentos apresentam maior retração hidráulica. / Binders based on ground granulated blast furnace slag (BFS) are suitable for the building industry, mainly if the use of Portland cement is expensive or may cause problems, such as: alkali sensitive fibre-reinforced cement and concretes and low heat-hydration concretes. BFS is activated by sodium silicates and hydrated lime. The compound\'s proportions are: Na2O - 2.5 and 5.0%; SiO2 from 0 to 14.8%; CaOH2 - 0, 2.5 and 5%. The increase of Na2O and SiO2 amounts allows a considerable improvement of binder strength, with values up to 100 MPa. This increase of the strength is related to the decrease of the porosity for a constant water-binder ratio. The porosity is affected certainly by the reduction of the degree of cristalynity of the hydrated compounds, due to the increase of the speed of precipitation of the hydrates or the N-C-S-H gel. It is possible to obtain BFS binders stronger than the Portland cement, with similar hydration heat. The carbonation rate of these new binders is equivalent to those of Portland cement specimens with similar strength. However these BFS binders have higher drying shrinkage.

"Heat treating is the controlled heating and cooling of a material to achieve certain mechanical properties, such as hardness, strength and the reduction of residual stresses. Many heat treating processes require the precise control of temperature over the heating cycle. Typically, the energy used for process heating accounts for 2% to 15% of the total production cost. The objective of this work is to develop a comprehensive furnace model by improving the current Computerized Heat Treatment Planning System (CHT) based furnace model to accurately simulate the thermal profile of load inside the furnace. The research methodology was based on both experimental work and theoretical developments including modeling different types of heat treat furnaces. More than 50 experimental validations through case studies using the current CHT model were conducted in 11 manufacturing locations to identify the specific problems in the current model. An enhanced furnace model based on Knowledge Data Discovery (KDD) technique and neural network is developed and validated. The new model takes into account the real time furnace parameters determined from the experimental data and accounts for furnace deterioration and some of the complex gradients and heating patterns that exist inside the furnace that is difficult to model. "

Resumo: Esta dissertação analisou a viabilidade técnica de gaseificação de lama de alto de alto forno da ArcelorMittal Tubarão para produção de gás visando uma utilização interna. A gaseificação foi conduzida através de simulação em modelo de equilíbrio químico TCW - Termochemical Information and Equlibrium Calculation. Foram simuladas 3 misturas para gaseificação: a) 100% carvão metalúrgico de alto volátil (base das misturas), b) de lama de alto forno com 85% de carvão metalúrgico alto volátil e c) de lama de alto forno com 75% de carvão metalúrgico alto volátil. Os dois parâmetros principais que definiram a viabilidade técnica de gaseificação de lama de alto forno foram poder calorífico inferior - PCI e faixas de trabalho temperaturas no reator. O PCI do gás foi calculado a partir das frações molares de H2 e CO contidas no gás obtidos nas misturas simuladas / Abstract: This dissertation analyzed the technical viability of blast furnace slurry gasification with the objective of using the obtained gas at ArcelorMittal Tubarão. The process was simulated using an equilibrium program, the TCW - Termochemical Information and Equilibrium Calculation. Three mixtures were considered for gasification: a) 100% high volatile metallurgical coal (the base of the mixtures), b) 15% slurry and 85% coal, and c) 25% slurry and 25% coal. The two main parameters that defined the technical viability of the blast furnace slurry were the mixture Low Heat Value (LHV) and the temperature ranges for work in the gasification reactor. The LHV was calculated from the molar fractions of H2 and CO in the gas obtained in the simulation / Orientador: João Andrade de Carvalho Junior / Coorientador: Sergio Leite Lopes / Banca: Luiz Roberto Carrocci / Mestre

<p>Södra Cell Mörrum is one of the five paper pulp plants that are included in Södra Cell, and the paper pulp that is produced here is not only sold to Swedish paper mills. Most of the paper pulp is exported to different countries in Europe. In the manufacturing process the plant needs different kind of process water and there are guideline values for how much copper, iron and sodium this water is allowed to contain. Analyzes of this water is in the current situation done with an atomic absorption spectrometric instrument (AAS-instrument) with a flame.</p><p> </p><p>Measurements done with flame-AAS of samples that have concentrations near the guideline values for copper, iron and sodium, are not reliable. The reason for not being reliable is that the quantitation limits of these metals are higher than the limit values. An alternative method that should give more reliable values is to analyze with an AAS- instrument with a graphite furnace. The purpose of this project was to perform a method validation of the graphite furnace of the AAS-instrument in the analysis of Cu, Fe and Na. The focus of the project was to find the detection limits for each metal, study the variation and to see if it is possible to analyze these water samples with this technique.</p><p> </p><p>The concentrations of the calibration solutions is between 1-10 µg/l for Na, 5-25 µg/l for Cu and 2-20 µg/l for Fe.The detection limits for all metals were slightly below 1 µg/l and during the present circumstances in the laboratory; it would be difficult to get even lower detection limits. There are improvements that can be done to get to the even lower detection limits. The results from this work show that the variation in each sampling cup is very small but if you look at different sampling cups the variation could be large if the cups are not treated in the right way. Further validation analyzes like variation in between days needs to be done.<strong> </strong></p><p>It is possible to analyze these low concentrations of copper, iron and sodium in the water samples with the AAS- graphite furnace, but it is difficult because there are many factors that affect the results. Examples of such factors are the environment where the instrument is placed in the laboratory and the human factor. Further analyzes needs to be done to get a better view of how these factors affect the result.</p>

Vegetable oils have been researched as alternative source of energy for many years because they have proven themselves as efficient fuel sources for diesel engines when used in the form of biodiesel, vegetable oil–diesel blends, vegetable oil-water-diesel blends and mixtures thereof. However, very few studies involving the use of emulsified low grade alcohols in straight vegetable oils, as fuels for combustion have been published. Even, the published literature involves the use of emulsified fuels only for compression ignition diesel engines. Through this project, an attempt has been made to suggest the use of alcohol-in-vegetable oil emulsions (AVOE) as an alternate fuel in stationary burners like electric utility boiler producing steam for electricity generation and more dynamic systems like diesel engines. The main goal of this study is to understand the effect of the combustion of different methanol-in-canola oil emulsions, swirl angle and equivalence ratio on the emission levels of NOx, unburned hydrocarbons (UHC), CO and CO2. The 30 kW furnace facility available at Coal and Biomass Energy Laboratory at Texas A & M University was modified using a twin fluid atomizer, a swirler and a new liquid fuel injection system. The swirler blades were positioned at 60° and 51° angles (with respect to vertical axis) in order to achieve swirl numbers of 1.40 and 1.0, respectively. The three different fuels studied were, pure canola oil, 89-9 emulsion [9 percent methanol – in – 89 percent canola oil emulsion with 2 percent surfactant (w/w)] and 85-12.5 emulsion [12.5 percent methanol – in – 85 percent canola oil (w/w) emulsion with 2.5 percent surfactant]. All the combustion experiments were conducted for a constant heat output of 72,750 kJ/hr. One of the major findings of this research work was the influence of fuel type and swirl number on emission levels. Both the emulsions produced lower NOx, unburned (UHC) hydrocarbon and CO emissions than pure canola oil at both swirl numbers and all equivalence ratios. The emulsions also showed higher burned fraction values than pure oil and produced more CO2. Comparing the performance of only the two emulsions, it was seen that the percentage amount of methanol added to the blend had a definite positive impact on the combustion products of the fuel. The higher the percentage of methanol in the emulsions, the lesser the NOx, UHC and CO emissions. Of all the three fuels, 85-12.5 emulsion produced the least emissions. The vorticity imparted to the secondary air by the swirler also affected the emission levels. Increased vorticity at higher swirl number led to proper mixing of air and fuel which minimized emission levels at SN = 1.4. The effect of equivalence ratio on NO_x formation requires a more detailed analysis especially with regards to the mechanism which produces nitrogen oxides during the combustion of the studied fuels.

The blast furnace is still the dominant form of iron production, but over the years, direct reduction methods have increased due to a number of reasons. Overall, iron production methods have optimal requirements with respect to the feed materials especially iron ore. In this study, tests were carried out on Muko iron ore from Uganda to analyse its suitability to meet the feed requirements of today's dominant iron production methods. More specifically, the Tumbler, Abrasion, and Shatter Indices of the ore were determined. In addition, porosity, thermoanalysis, and reducibility tests were performed. Overall, the Muko ore was found to have good mechanical properties exemplified with tumble and shatter index data &gt;89.0 wt% and &lt;2.5 wt%, respectively. Furthermore, its reducibility at 0.87%/min is within the acceptable range as a natural material feed for blast furnace and direct reduction furnaces. Also, the energy requirement for heating the ore to 1100°C was found to be higher in the samples containing a wider size range of irregular grains and the largest contaminations. In summary, it is concluded that the Muko iron ore has good physical and metallurgical properties to serve as a natural material for the blast furnace and direct reduction furnaces. / <p>QC 20130531</p> / Sustainable Technology Development in the Lake Victoria Region

In order to keep a high level and to stay competitive in the world market in the future, it is important for the Swedish steel industry to improve their efficiencies continuously and to reduce the energy consumption. In order to realize these goals, the Swedish steel association Jernkotoret was found and by their initiative Triple Steelix was found in 2006 in Berglanden, a significant area for the steel industry. In 2009, the Clean Production Centre was found in Hofors in order to build a cluster of local steel manufacturers, factories and companies. One of those companies is Gästrike Härdverkstad, a small steal heat treatment industry with six employees and about 700.000 tons treated materials every year. The aim for this thesis is to suggest solutions for recovering waste heat and lowering the total energy consumption in furnaces for heat treatment in the case of Gästrike Härdverkstad. Some limitations were necessary to complete the analysis and to come to conclusions. The yearly treated material and energy prices were assumed to be constant and the yearly power consumption was estimated by an extrapolation of a one to five days measurement. Gästrike Härdverkstad is located in Uhrfors, the southern part of Åshammar, a village with 727 inhabitants. There are not any buildings with a possibility to supply heat and there is no district heating in the surroundings. The company has a power consumption of 1.40 GWh/year, of which 65.7% is consumed by the 12 main furnaces. The rest is used by eight seldom used furnaces, devices and auxiliary machines of the support process like fans, pumps, compressor, office heating, and some other. The efficiencies of the main furnaces are between 10% and 20%.The estimated energy consumption of the space heating is about 27 MWh/year, which completely can be covered by the material coolant and the combustion heat of the exhaust gases from the hardening furnaces. Since there are 10 different types of furnaces with different duties and efficiencies, the preheating furnace was taken as an example and compared with a new furnace. According to the needs of Gästrike Härdverkstad, the furnace VAW 60/100-650°C from the company Vötsch was chosen at the cost of 248,827 SEK. The payback time depends on the efficiency. With an efficiency of 40% the payback time would be about 13 years, see Figure 20. After the annealing and ageing, the finished products are cooled down in the building hall by the ambient air. In future, the possibility of preheating the material with the heat of the finished products should be considered. With an efficiency of 30.87%, one preheating furnace could bereplaced, and taken a payback time of 5 years into account; the price of the construction would be allowed to be up to 253,200 SEK.

The archaeological and technical questions about ancient glass have lead to various research activities such as identification and sourcing raw materials used in the glass production, investigation of the ways in which colors can be modified according to furnace atmosphere and times of firing. Considering research areas and publications it can be suggested that compositional studies of well-dated samples of ancient glass have disclosed useful information concerning raw materials characteristics and production technology. Within this context, aim of this study was to determine the composition and technology of some 13th century Seljuk period window glasses from Alanya Castle archaeological site. During the excavations at the area called Vaulted Galleria in Alanya Castle many glass pieces in different sizes and colors had been found. In this study 10 samples were examined. Elemental analysis of the samples have been made using two different methods / X-Ray Fluorescence Spectroscopy (XRF) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) to determine major, minor and some trace elements. The XRF and ICP-OES data reflect the typical composition of a soda-lime-silica glass with the average values of / 12.9% (Na2O): 7.7% (CaO): and 65.5% (SiO2). Samples were grouped by color as green, blue and purple. Color producing elements are Fe, Mn, Cu and Co. Most of the samples had shown casting character as production technique.

This investigates the voltage flicker problem of a large steel plant and presents the mitigation strategy by applying the static var compensator (SVC) and cogenerator. The fluctuation of real power and reactive power consumption by an arc furnace has been measured and recorded during the steel production process. The dynamic load model of the A/C arc furnace is derived based on the actual field data and has been included in the computer simulation by the CYME software package for load flow analysis. The block diagrams of SVC controller and the excitation system of cogenerators are considered to solve the response of reactive power compensation according to the voltage fluctuation of the control bus. To maintain the electric service reliability of arc furnace when an external utility fault occurs, the tie line tripping and load shedding is implemented to prevent the tripping of cogenerator after system disturbance. It is found that the dynamic load behavior of arc furnace in the isolated industrial power system can be well compensated by the cogenerator with adaptive control of exciter and governor to generate proper reactive power and real power according to the fluctuation of bus voltage and system frequency respectively.

Thanks to the booming of China and eastern Europe demanding, the world steel annual production soaring from 0.75 billion tons in 1990 to 1.239 billion tons in 2006, the percentage of top 10 steel company is 28.43% of the world production and it is a history record. It looks like raw material industrial like steel makers are shinning. Nevertheless, due to merge of the steel industry and final product customer of local market were shifting to the China market, threaten are increasing. Therefore, to find out how China Steel gains more competition through her resource integration becomes main reason of this research. In Blast Furnace steel making, the co-relationship between upstream and downstream is highly cohesive, China Steel has started to set up her Process computer system since 1979. The main function of the Process computer is to receive production order from ERP system and download the receipt to the low level controller through its built in model; During production, the Process computer also track the material from semi-product to the final product, A Quality evaluation system in every Process computer system also helping the production supervisor to make sure the quality of the outlet. To leverage the thirty years Process computer know-how becomes main search of this essay. Through survey of Dragon steel¡BChung-Hung Info Steel and Inform-Champ corporation to study their current status of the system¡Borganization and requirement, list all the demanding and possible solution as an information base, then use RBV to analysis these demanding. This research will based on the process computer know-how center of the CSC Process control computer shop to establish a new process to contribute the following ¡§Rent¡¨ in CSC group: (1). To readjust the data flow of CSC Process control computer shop based on the competition acknowledge survey of all the team members in this shop. (2) To support Chung-Hung Steel for his revamping and new process control computer system. (3) To support Dragon steel to establish his own maintenance system and to handle the new project of the Dragon Steel to minimize the project organization manpower. (4) To establish a common platform of spare parts and an integrated purchasing system to minimize the stock of spare parts and to meet the economic scale on purchasing. (5) To establish a model research center in China steel as a CSC Group model ware. (6) To assist ICSC to set-up his total solution capability of process computer technology