Foram tomadas amostras de aço líquido referentes a três grupos de aço, a saber: (I) aços baixo-carbono (0,02 %C 0,08), acalmados ao alumínio; (II) aços peritéticos (0,09 %C 0,15), acalmados ao alumínio e silício; (III) aços ultrabaixo carbono ( C<35 ppm), acalmados ao alumínio.Os aços foram produzidos em aciaria do tipo LD e foram, a seguir, tratados em equipamentos de refino secundário, adequados a cada um dos casos.As amostras forma colhidas no distribuidor de uma máquina de lingotamento contínuo de placas, segundo critério que minimiza a possibilidade da ocorrência de interferências que pudessem mascarar o resultado do tratamento de refino secundário tais como re-oxidação do aço e coleta simultânea de escória. As amostras foram submetidas à análise de inclusões utilizando-se técnicas de microscopia óptica, microscopia eletrônica e micro-análise. Foi possível caracterizar as inclusões presentes em cada tipo de aço segundo a morfologia, o tamanho, a quantidade e a composição química. / Non-metallic inclusions in liquid samples of (I) low-carbon aluminium killed steel (0,02wpct C 0,08wpct), (II) peritetic aluminium and silicon killed steel (0,09wpct C 0,15wpct); (III) extra-low-carbon, aluminium killed steel (C<35 ppm) were taken from the tundish distributor of a continuous casting caster for steel plates according to a procedure that minimizes re-oxidation of steel and/or pick up of liquid slag. The samples were inspected through the following microstructural techniques: optical microscopy, electronic microscopy, and electron microprobe. Were possible to feature present inclusion in each kind of steel according to morphology, size, amout and chemical composition.

Alkaline industrial wastes are considered potential resources for the mitigation of CO2 emissions by simultaneously capturing and sequestering CO2 through mineralization. Mineralization safely and permanently stores CO2 through its reaction with alkaline earth metals. Apart from natural formations, these elements can also be found in a variety of abundantly available industrial wastes that have high reactivity with CO2, and that are generated close to the emission point-sources. Apparently, it is the applicability and marketability of the carbonated products that define to a great extent the efficiency and viability of the particular process as a point source CO2 mitigation measure. This project investigates the valorization of iron- and steel-making slags through methods incorporating the carbonation of the material, in order to achieve the sequestration of sufficient amounts of CO2 in parallel with the formation of valuable and marketable products. Iron- and steel-manufacturing slags were selected as the most suitable industrial byproducts for the purposes of this research, due to their high production amounts and notable carbonation capacities. The same criteria (production amount and carbonation capacity) were also used for the selection of the iron- and steel-making slag types that are more suitable to the scope of this work. Specifically for the determination of the slag types with the most promising carbonation capacities, the maximum carbonation conversions resulting from recent publications related to the influence of process parameters on the conversion extent of iron- and steel-manufacturing slags, were directly compared to each other using a new index, the Carbonation Weathering Rate, which normalizes the results based on particle size and reaction duration. Among the several iron- and steel-manufacturing slags, basic oxygen furnace (BOF) and blast furnace (BF) slags were found to combine both high production volumes and significant affinity to carbonation. In the context of this research, two different procedures aiming to the formation of value added materials with satisfactory CO2 uptakes were investigated as potential BF and BOF slags valorization methods. In them, carbonation was combined either with granulation and alkali activation (BOF slag), or with hydrothermal conversion (BF slag). Both treatments seemed to be effective and returned encouraging results by managing to store sufficient amounts of CO2 and generating materials with promising qualities. In particular, the performance of the granulation-carbonation of BOF slag as a method leading to the production of secondary aggregates and the sequestration of notable amounts of CO2 in a solid and stable form, was evaluated in this work. For comparison purposes, the material was also subjected to single granulation tests under ambient conditions. In an effort to improve the mechanical properties of the finally synthesized products, apart from water, a mixture of sodium hydroxide and sodium silicate was also tested as a binding agent in both of the employed processes. According to the results, the granules produced after the alkali activation of the material were characterized by remarkably greater particle sizes (from 1 to 5 mm) compared to that of the as received material (0.2 mm), and by enhanced mechanical properties, which in some cases appeared to be adequate for their use as aggregates in construction applications. The maximum CO2 uptake was 40 g CO2/kg of slag and it was achieved after 60 minutes of the combined treatment of alkali activated BOF slag. Regarding the environmental behavior of the synthesized granules, increased levels of Cr and V leaching were noticed from the granules generated by the combination of granulation-carbonation with alkali activation. Nevertheless, the combination of granulation with alkali activation or that of granulation with carbonation were found not to worsen, if not to improve, the leaching behaviour of the granules with regards to the untreated BOF slag. The formation of a zeolitic material with notable heavy metal adsorption capacity, through the hydrothermal conversion of the solid residues resulting from the calcium- extraction stage of the indirect carbonation of BF slag, was also investigated in this project. To this end, calcium was selectively extracted from the slag by leaching, using acetic acid of specific concentration (2 M) as the extraction agent. The residual solids resulting from the filtration of the generated slurry were subsequently subjected to hydrothermal conversion in caustic solution of two different compositions (NaOH of 0.5 M and 2 M). Due to the presence of calcium acetate in the composition of the solid residues, as a result of their inadequate washing, only the hydrothermal conversion attempted using the sodium hydroxide solution of higher concentration (2 M) managed to turn the amorphous slag into a crystalline material, mainly composed by a zeolitic mineral phase (detected by XRD), namely, analcime (NaAlSi2O6·H2O), and tobermorite (Ca5(OH)2Si6O16·4H2O). Finally, the heavy metal adsorption capacity of the particular material was assessed using Ni2+ as the metal for investigation. Three different adsorption models were used for the characterization of the adsorption process, namely Langmuir, Freundlich and Temkin models. Langmuir and Temkin isotherms were found to better describe the process, compared to Freundlich model. Based on the ability of the particular material to adsorb Ni2+ as reported from batch adsorption experiments and ICP-OES analysis, and the maximum monolayer adsorption capacity (Q0 = 11.51 mg/g) as determined by the Langmuir model, the finally synthesized product can potentially be used in wastewater treatment or environmental remediation applications.

A escória de aciaria LD é um coproduto originado do refino do ferro gusa em aço e da metalurgia secundária, sendo gerado, em média, uma quantidade de aproximadamente 120 kg/t de aço produzido. Assim como as escórias de alto-forno, que são utilizadas como matéria-prima para a fabricação do cimento, as escórias de aciaria LD, após beneficiamento (chamadas de agregados siderúrgicos), possuem diversas aplicações, tais como: artigos de concreto, diques marítimos, tratamentos de efluentes, lastro ferroviário, base e sub-base para pavimentos de rodovia, corretivo de solos, entre outros. Entretanto, este material possui compostos (CaO e MgO quando livres, Fe0, FeO e mCaO.nSiO2) que sofrem reações quando exposto ao ambiente, provocando expansão e desintegração dos materiais onde é aplicado, sendo necessária a estocagem em pátios para cura ou envelhecimento e consequente minimização da expansão. Atingido um determinado tempo de envelhecimento, o agregado é avaliado sob o ponto de vista do potencial de expansão para que, a partir dos resultados obtidos, seja ainda mantido sob cura ou destinado à sua aplicação. Os métodos mais comuns que avaliam a expansão de escórias de aciaria são o PTM-130/78, JIS A 5015/92 e o ASTM D4792/00. No Brasil, atualmente, o ensaio PTM-130 é o mais utilizado pelo Departamento de Estradas de Rodagem, entretanto o método leva 14 dias para obtenção dos resultados, que em geral são pouco detalhados sobre o comportamento da escória. Desta forma, o presente trabalho buscou correlacionar o método de avaliação do potencial de expansão volumétrica da escória de aciaria LD com a concentração de determinados compostos, quantificados através da difratometria de raios X em pós e o método de Rietveld, respectivamente. Buscou-se, também, compreender a influência dos diferentes compostos sobre a expansibilidade. / BOF slag is a byproduct originated from the hot metal refining to steel and its subsequent types of secondary metallurgy processes, being generated, on average, an amount about 120 kg/t of steel. Similar to blast furnace slag which is used as raw material for the manufacturing of cement, BOF slag, after treatment (so-called of steel slag aggregates), has many applications such as: concrete components, marine docks, effluent treatment, ballast, road and highways base, correction of soil, among others. However, BOF slag is composed by chemical products (such as free CaO and MgO, Fe0, FeO and mCaO.nSiO2) which suffer expansive reactions when exposed to the atmosphere, causing expansion and disintegration of the materials where it is applied. Therefore, it is required some temporary storage for curing or aging to minimize the volumetric instability that is evaluated trough the potential of expansion. Depending on the volumetric expansion results, steel slag aggregates may be approved or disapproved according to a specified limit that will allow to be used or not. The most common methods to evaluate the expansion of BOF slags are the PTM-130/78, JIS A 5015/92 and ASTM D4792:2013. In Brazil, PTM-130 test is currently the most used by the department of highways. This method spends 14 days to obtain the result that generally shows few details about the behavior. Thus, the present study has the purpose of correlating the traditional method of evaluation with the one of X-ray diffraction in powders associated to the Rietveld Method. Another goal is to understand the influence of different compounds on expansion.

Foram tomadas amostras de aço líquido referentes a três grupos de aço, a saber: (I) aços baixo-carbono (0,02 %C 0,08), acalmados ao alumínio; (II) aços peritéticos (0,09 %C 0,15), acalmados ao alumínio e silício; (III) aços ultrabaixo carbono ( C<35 ppm), acalmados ao alumínio.Os aços foram produzidos em aciaria do tipo LD e foram, a seguir, tratados em equipamentos de refino secundário, adequados a cada um dos casos.As amostras forma colhidas no distribuidor de uma máquina de lingotamento contínuo de placas, segundo critério que minimiza a possibilidade da ocorrência de interferências que pudessem mascarar o resultado do tratamento de refino secundário tais como re-oxidação do aço e coleta simultânea de escória. As amostras foram submetidas à análise de inclusões utilizando-se técnicas de microscopia óptica, microscopia eletrônica e micro-análise. Foi possível caracterizar as inclusões presentes em cada tipo de aço segundo a morfologia, o tamanho, a quantidade e a composição química. / Non-metallic inclusions in liquid samples of (I) low-carbon aluminium killed steel (0,02wpct C 0,08wpct), (II) peritetic aluminium and silicon killed steel (0,09wpct C 0,15wpct); (III) extra-low-carbon, aluminium killed steel (C<35 ppm) were taken from the tundish distributor of a continuous casting caster for steel plates according to a procedure that minimizes re-oxidation of steel and/or pick up of liquid slag. The samples were inspected through the following microstructural techniques: optical microscopy, electronic microscopy, and electron microprobe. Were possible to feature present inclusion in each kind of steel according to morphology, size, amout and chemical composition.

A escória de aciaria LD é um coproduto originado do refino do ferro gusa em aço e da metalurgia secundária, sendo gerado, em média, uma quantidade de aproximadamente 120 kg/t de aço produzido. Assim como as escórias de alto-forno, que são utilizadas como matéria-prima para a fabricação do cimento, as escórias de aciaria LD, após beneficiamento (chamadas de agregados siderúrgicos), possuem diversas aplicações, tais como: artigos de concreto, diques marítimos, tratamentos de efluentes, lastro ferroviário, base e sub-base para pavimentos de rodovia, corretivo de solos, entre outros. Entretanto, este material possui compostos (CaO e MgO quando livres, Fe0, FeO e mCaO.nSiO2) que sofrem reações quando exposto ao ambiente, provocando expansão e desintegração dos materiais onde é aplicado, sendo necessária a estocagem em pátios para cura ou envelhecimento e consequente minimização da expansão. Atingido um determinado tempo de envelhecimento, o agregado é avaliado sob o ponto de vista do potencial de expansão para que, a partir dos resultados obtidos, seja ainda mantido sob cura ou destinado à sua aplicação. Os métodos mais comuns que avaliam a expansão de escórias de aciaria são o PTM-130/78, JIS A 5015/92 e o ASTM D4792/00. No Brasil, atualmente, o ensaio PTM-130 é o mais utilizado pelo Departamento de Estradas de Rodagem, entretanto o método leva 14 dias para obtenção dos resultados, que em geral são pouco detalhados sobre o comportamento da escória. Desta forma, o presente trabalho buscou correlacionar o método de avaliação do potencial de expansão volumétrica da escória de aciaria LD com a concentração de determinados compostos, quantificados através da difratometria de raios X em pós e o método de Rietveld, respectivamente. Buscou-se, também, compreender a influência dos diferentes compostos sobre a expansibilidade. / BOF slag is a byproduct originated from the hot metal refining to steel and its subsequent types of secondary metallurgy processes, being generated, on average, an amount about 120 kg/t of steel. Similar to blast furnace slag which is used as raw material for the manufacturing of cement, BOF slag, after treatment (so-called of steel slag aggregates), has many applications such as: concrete components, marine docks, effluent treatment, ballast, road and highways base, correction of soil, among others. However, BOF slag is composed by chemical products (such as free CaO and MgO, Fe0, FeO and mCaO.nSiO2) which suffer expansive reactions when exposed to the atmosphere, causing expansion and disintegration of the materials where it is applied. Therefore, it is required some temporary storage for curing or aging to minimize the volumetric instability that is evaluated trough the potential of expansion. Depending on the volumetric expansion results, steel slag aggregates may be approved or disapproved according to a specified limit that will allow to be used or not. The most common methods to evaluate the expansion of BOF slags are the PTM-130/78, JIS A 5015/92 and ASTM D4792:2013. In Brazil, PTM-130 test is currently the most used by the department of highways. This method spends 14 days to obtain the result that generally shows few details about the behavior. Thus, the present study has the purpose of correlating the traditional method of evaluation with the one of X-ray diffraction in powders associated to the Rietveld Method. Another goal is to understand the influence of different compounds on expansion.

Stålindustrin är kraftigt energi och utsläppsintensiv och står för upp till cirka 7% av de globala 𝐶𝑂2-utsläppen. Den huvudsakliga utsläppskällan utgörs av masugnsprocessen där järnmalm reduceras till råjärn med hjälp av fossilt kol i den malmbaserade processvägen. Flera tidigare studier har visat att den mest effektiva metoden för att minska industrins utsläpp av 𝐶𝑂2 och därmed bidrag till klimatförändringar är att öka andelen skrot i kolfärskningsprocessen för att på så sätt minska behovet av råjärn.  Syftet med studien var att undersöka möjligheterna att minska stålindustrins utsläpp av 𝐶𝑂2 genom en ökad andel skrot i kolfärskningsprocessen. Rapporten delades upp i två delar, inledningsvis en litteraturstudie som ge en bild över vilka metoder som finns tillgängliga samt vilken potentiell effekt dessa har. Den andra delen baserades på analyser av produktionsdata från SSAB Oxelösund. Tillsammans med resultatet från litteraturstudien användes analyserna för att ta reda på hur mycket råstålets 𝐶𝑂2-avtryck skulle kunna minskas med användning av metoder relevanta för det specifika stålverkets förutsättningar, förbättringsområden och framtida planer.  Parametrarna som undersöktes utgjordes av effekt på skrotinsmältning samt övriga utmaningar och fördelar kopplat till industrins klimatpåverkan. Resultatet från litteraturstudien visade att det fanns ett flertal effektiva metoder för att öka skrotinsmältningskapaciteten i kolfärskningsprocessen och att dessa vid kombinerad användning har en addidativ effekt och har potential att höja skrotinsmältningen avsevärt. Effekten av dessa är dock till stor del beroende på utgångspunkt och produktionsspecifika förutsättningar och måste undersökas vidare genom exempelvis industriförsök.  Eftersom stålverket ställer om produktionen till 2026 kan inte några större investeringar för att minska utsläppen från den äldre produktionen anses vara motiverbar både gällande utsläpp av 𝐶𝑂2 och investeringskostnad. Analyserna av produktionsdata tillsammans med resultatet från litteraturstudierna visade att det fanns flera förbättringsområden och rimliga metoder för stålverket att öka sin skrotinsmältning med syfte att minska utsläppen av 𝐶𝑂2. Genom implementering av dessa metoder som skulle skrotinsmältningen kunna ökas med 2,3 % vilket skulle resultera i en relativ minskning av råstålets 𝐶𝑂2-avtryck med 2,8%.

Le présent manuscrit de thèse présente l'étude de différents phénomènes dans un convertisseur d?acier, grâce au développement de deux modèles distincts. Le premier modèle décrit la cavité produite à la surface libre du bain de métal par l'impact du jet d'oxygène supersonique. Il est basé sur le découpage du domaine de calcul en deux régions. Les effets de compressibilité du gaz sont pris en compte uniquement dans la région du jet où la vitesse est élevée, alors que partout ailleurs, le gaz est considéré comme incompressible. La méthode Volume Of Fluid (VOF) est utilisée pour suivre la déformation de la surface libre du bain. Les résultats de simulations sont présentés pour des systèmes bi- et triphasés et comparés à des données expérimentales obtenues dans diverses maquettes froides. L'influence sur la taille et la forme de la cavité de différents paramètres (parmi lesquels les conditions aux limites en sortie de la lance d'injection, le schéma d'advection de la méthode VOF et le modèle de turbulence) est étudiée. Le modèle est ensuite utilisé pour simuler l'interaction entre un jet supersonique d'oxygène et la surface libre d'un bain d'acier liquide dans un convertisseur de taille pilote. Le second modèle se focalise sur l'écoulement du gaz, le transfert de chaleur et la réaction de postcombustion dans la phase gazeuse au-dessus du bain de métal. Il utilise l'algorithme Simple Chemical Reaction Scheme pour décrire le transport des espèces chimiques, et prend en compte l'absorption d'oxygène dans le bain et les transferts thermiques par rayonnement. Les prédictions numériques sont en assez bon accord avec les mesures recueillies dans une expérience de laboratoire et dans un four à l'échelle pilote / The present thesis treats different phenomena taking place in a steelmaking converter through the development of two separate models. The first model describes the cavity produced at the free surface of the metal bath by the high speed impinging oxygen jet. It is based on a zonal approach, where gas compressibility effects are taken into account only in the high velocity jet region while elsewhere the gas is treated as incompressible. The Volume Of Fluid (VOF) method is employed to follow the deformation of the bath free surface. Calculations are presented for two- and three-phase systems and compared against experimental data obtained in various cold model experiments. The influence on the size and shape of the cavity of various parameters (including the jet inlet boundary conditions, the VOF advection scheme and the turbulence modelling) is studied. Next, the model is used to simulate the interaction of a supersonic oxygen jet with the surface of a liquid steel bath in a pilot-scale converter. The second model concentrates on fluid flow, heat transfer and the post-combustion reaction in the gas phase above the metal bath. It uses the Simple Chemical Reaction Scheme approach to describe the transport of the chemical species and takes into account the consumption of oxygen by the bath and thermal radiative transfer. The numerical predictions are in reasonable agreement with measurements collected in a laboratory experiment and in a pilot-scale furnace

This thesis presents a novel Dynamic Gesture Language Recognition (DGLR) system for human-robot and inter-robot communication. We developed and implemented an experimental setup consisting of a humanoid robot/android able to recognize and execute in real time all the arm gestures of the Dynamic Gesture Language (DGL) in similar way as humans do. Our DGLR system comprises two main subsystems: an image processing (IP) module and a linguistic recognition system (LRS) module. The IP module enables recognizing individual DGL gestures. In this module, we use the bag-of-features (BOFs) and a local part model approach for dynamic gesture recognition from images. Dynamic gesture classification is conducted using the BOFs and nonlinear support-vector-machine (SVM) methods. The multiscale local part model preserves the temporal context. The IP module was tested using two databases, one consisting of images of a human performing a series of dynamic arm gestures under different environmental conditions and a second database consisting of images of an android performing the same series of arm gestures. The linguistic recognition system (LRS) module uses a novel formal grammar approach to accept DGL-wise valid sequences of dynamic gestures and reject invalid ones. LRS consists of two subsystems: one using a Linear Formal Grammar (LFG) to derive the valid sequence of dynamic gestures and another using a Stochastic Linear Formal Grammar (SLFG) to occasionally recover gestures that were unrecognized by the IP module. Experimental results have shown that the DGLR system had a slightly better overall performance when recognizing gestures made by a human subject (98.92% recognition rate) than those made by the android (97.42% recognition rate).

Vanadium extraction methods were developed for iron-vanadium-phosphorus (Fe-V-P) melts derived from processing of V-bearing titanomagnetites and steel slags. Studies on phase relationships of V slags were carried out to provide important understanding of the extraction processes. Phase relationship in vanadiferous slag was investigated experimentally at 1573K, 1673K and 1773K, for the compositional range of 0-6mass% Al2O3, 1-5mass% CaO, 10-17mass% SiO2, with MnO and V2O3 fixed at 5.5mass% and 30mass%, balanced with FeO. The slags were found to be solid-liquid mixtures, of liquid, spinel and in some cases free silica. Alumina was identified as the preferred additive to prohibit precipitation of free silica. A method for V extraction to vanadiferous slag was developed based on Fe-V(2mass%)-P(0.1mass%) melts at 1677K using a semi-industrial scale BOF. Oxidation was carried out with an oxygen enriched air jet and iron ore pellets. The complete dissolution of pellets was achieved by deliberately creating good stirring conditions utilising high momentary decarburisation rates. The P distribution to the slag was low when good stirring conditions was obtained. Phase relationship in Al2O3-CaO(25-35mass%)-SiO2-VOx slag was investigated experimentally at an oxygen partial pressure of 9.37•10-11atm and 1873K. The maximum solubility of V-oxide in the slag was 9-10mass% V2O3. Two solid phases were found, a solid solution of Al2O3 in V2O3 (karelianite) and hibonite with fractionation of V into the crystal structure. V extraction experiments to Al2O3-CaO-SiO2 based slags were carried out in 150kg scale by blowing CO2 gas into the metal bath consisting mainly of 1-10mass% V and 1mass% P. At these conditions, oxidation of V was favoured over Fe. Up to 10-13mass% V2O3 could be dissolved in the slag before a viscous slag saturated in V-oxide was observed. The phosphate capacity in the slag was low and as a result this slag could at once be subjected to a final reduction step for production of ferrovanadium with 40-50mass% V. / Metoder för att utvinna vanadin till högvärdiga vanadinslagger från metallsmältor innehållande främst järn (Fe), vanadin (V) och fosfor (P) utvecklades. Metallsmältorna framställs genom att processa primära V råvaror, såsom titanomagnetit, och sekundära råvaror av i huvudsak vanadinrik stålslagg. Fasstudier av högvärdiga vanadinslagger genomfördes som grund för utvecklingsarbetet. Experimentella fasstudier av vanadinspinellslagg med 30vikt% V2O3 och 5.5vikt% MnO genomfördes vid en temperatur av 1573K, 1673K och 1773K. Övriga komponenter i slaggen varierades inom ett intervall av 0-6vikt% Al2O3, 1-5vikt% CaO och 10-17vikt% SiO2, viktad med järnoxid. Samtliga slagger var sammansatt av både flytande- och fastfas. Den fasta fasen utgjordes främst av en vanadin- och järnrik spinellfas och i vissa fall även av fri SiO2. Genom försök i en stålkonverter i semi-industriell skala utvecklades och validerades en metod för vanadinutvinning från råjärnsmältor innehållande 2vikt% V och 0.1vikt% P, vid en temperatur av 1677K. Oxidationen utfördes med syreanrikad luft via en vattenkyld topplans och genom tillsats av hematit pellets. Omsättningen av pellets säkerhetsställdes genom god omrörning som erhölls under korta perioder med höga gasvolymer som en effekt av hög avkolningstakt. Råjärnet efter behandlingen innehöll cirka 3vikt% C och 0.1vikt% V. Producerad vanadinspinellslagg bestod av upp till 30vikt% V2O3. Fosforfördelningen till slaggen var låg under processbetingelser med god omrörning. Experimentella fasstudier av Al2O3-CaO(25-35vikt%)-SiO2-VOx slagg genomfördes vid en temperatur av 1873K och ett syrepartialtryck av 9.37·10-10atm. Den maximala lösligheten av vanadinoxid i slaggen var 9-10vikt% V2O3. Två fasta faser identifierades, V2O3 (Karelianit) med fast löslighet av Al2O3 och Hibonit med vanadinoxid inlöst i kristallstrukturen. Experimentella försök för att utvinna vanadin från en stålsmälta bestående av 1-10vikt% V och 1vikt% P till en slagg med en initial sammansättning av 7-40vikt% Al2O3, 25-35vikt% CaO och 27-64vikt% SiO2 utfördes i en skala av 150kg. Oxidation av vanadin åstadkoms genom att blåsa in CO2 gas i stålsmältan via en spolsten. Under dessa processförhållanden var oxidationen av vanadin gynnsam framför järn och fosfor. Lösligheten av vanadinoxid i slaggen var upp till 10-13vikt% V2O3. Slagg mättad med vanadinoxid var viskös som en konsekvens av utfällning av V2O3 med inlöst Al2O3. Slaggens gynnsamma vanadin och järn- samt vanadin och fosfor förhållande möjliggör att genom slutreduktion producera ferrovanadin med en vanadinhalt av 40-50vikt% och låg fosforhalt. / <p>QC 20170912</p>

A novel technique for measuring gas temperature and spectral particle emissivity in high-temperature gas-particle streams is presented. The main application of this optical sensor is to improve the process control of batch unit operations, such as steelmaking furnaces. The spectral emission profile of CO and CO2 and the continuous particle emission in the 3.5 to 5 μm wavelength region was recorded and analyzed in real time with a low-resolution passive sensor. The sensor consisted of light collecting optics, a dispersion element (grating spectrometer) and a 64-pixel pyroelectric array. Wavelength and radiance calibrations were performed. The temperature of the gas-particle medium (Tg+p) followed from the least-squares minimization of the difference between the measured radiance in the 4.56-4.7 μm region –which saturates due to the large CO2 concentrations and path lengths in industrial furnaces– and the corresponding blackbody radiance. Particle emissivity (εp) was calculated at 3.95 μm from an asymptotic approximation of the Radiative Transfer Equation that yields the emerging radiance from a semi-infinite particle cloud. The major source of error in the magnitude of Tg+p and εp could come from particle scattering. Through the method of embedded invariance an expression was developed to estimate the lowering effect of particle size and volume fraction on the saturation of the 4.56-4.7 μm CO2 emission region. An iterative procedure for correcting the values of the gas-particle temperature and particle emissivity was applied to the datasets from the two industrial tests. Results from the measurement campaigns with the infrared sensor prototype at two full-scale furnaces are presented. A proof-of-concept test at a coal-fired boiler for electricity production was followed by more extensive measurements at a Basic Oxygen Furnace (BOF) for steelmaking. The second test provided temperature and particle emissivity profiles for eight heats, which highlighted the simplicity of the technique in obtaining in-situ measurements for modeling studies. Through the analysis of the particle emissivity profile in the BOF and the definition of a new variable –the minimum carbon time– a novel end-point strategy to stop the injection of high-purity oxygen during low-carbon heats in BOF converters was proposed.