The pulp and paper industry has been struggling to meet the new and stringent TRS (Total Reduced Sulphur) emission compliance standards established in recent years. However, a new approach by some regulatory bodies gives intricate operational parameters a new and important role in achieving environmental compliance. TRS compounds that cause the distinctive pulp mill odour, originate from sodium sulphide in white liquor used in the kraft pulping process. Up to 20% of TRS emissions could originate from the lime kiln and lime mud solids content is one of the operational parameters that could help reduce the TRS emissions from the lime kiln. Residual sodium sulphide in the lime mud that results in TRS gases, is dissolved in the moisture content of the mud. Although efficient lime mud washing can remove most of the residual sodium sulphide, the remaining moisture content of the mud still contains some sodium sulphide. Therefore, improved lime mud dewatering can be effective in reducing the TRS emissions from the lime kiln. Data presented in this study confirms that as the lime mud solids content increases, TRS emissions from the lime kiln decrease. Data analysis demonstrates a negative linear correlation at 5% significance level between TRS emissions and lime mud solids.

The characteristics of cement kiln dusts (CKDs) and their effects as partial replacement of Portland Cement (PC) were studied in this research program. The materials used in this study were two different types of PC (normal and moderate sulfate resistant) and seven CKDs. The CKDs used in this study were selected to provide a representation of those available in North America from the three major types of cement manufacturing processes: wet, long-dry, and preheater/precalciner. Two fillers (limestone powder and quartz powder) were also used to compare their effects to that of CKDs at an equivalent replacement of PC. It was found that CKDs can contain significant amounts of amorphous material (>30%) and clinker compounds (>20%) and small amounts of slag and/or flyash (<5%) and calcium langbeinite (<5%). The study found that CKDs from preheater/precalciner kilns have different effects on workability and heat evolution than CKDs from wet and long-dry kilns due to the presence of very reactive and high free lime contents (>20%). The blends with the two CKDs from preheater/precalciner plants had higher paste water demand, lower mortar flows, and higher heat generation during initial hydrolysis in comparison to all other CKD-PC blends and control cements. The hardened properties of CKD as a partial substitute of PC appear to be governed by the sulfate content of the CKD-PC blend (the form of the CKD sulfate is not significant). According to analysis of the ASTM expansion in limewater test results, the CKD-PC blend sulfate content should be less than ~0.40% above the optimum sulfate content of the PC. It was also found that the sulfate contribution of CKD behaves similar to gypsum. Therefore, CKD-PC blends could be optimized for sulfate content by using CKD as a partial substitute of gypsum during the grinding process to control the early hydration of C3A. The wet and long-dry kiln CKDs contain significant amounts of calcium carbonate (>20%) which could also be used as partial replacement of limestone filler in PC.

Finite volume method was employed for analyzing the three-dimensional turbulent flow structures, species distributions, and mixing behaviors of combustion flows in a rotary kiln under various operation conditions. The modified £e-£`turbulence model together with wall functions was adopted. Devolatilization of solid wastes were simulated by gaseous methane (CH4) non-uniformly distributed along the kiln bed. Combustion process was considered as a two-step reaction when primary air entered and mixed with methane gas in the first combustion chamber. Mixing-controlled eddy-dissipation model was employed for predicting the reaction rates of CH4, O2, CO2, CO and H2O. Effects of inleakage air, kiln rotation speed and methane distribution along the kiln bed were also examined. Results show that 128% excess air will get the best combustion efficiency, above which the combustion efficiency will decrease. The temperature and species are not uniformly distributed and are vertically stratified on cross-sectional plane. The combustion efficiency will also be lowered if there is inleakage airflow. Results also show rotation speed and methane distributions have little effect on combustion efficiency.

Water contaminated due to mining activities is often acidic and can contain high concentrations of dissolved metals. Cement kiln dust (CKD) is a fine-grained, alkaline material that is generated as a by-product of cement production. Its high lime (CaO) content makes it attractive as a substitute for quicklime in the generation of slurries for the treatment of mine water. The first part of this study analyzed six CKD samples for several physical and chemical properties to determine their variability and to compare them to the characterization of a commercial quicklime sample. Neutralization and precipitation experiments using acidic mine water containing high concentrations of zinc and iron determined that all slaked CKD slurries performed comparably to the quicklime slurry in terms of precipitation of soluble metals. The results of this research show that CKD can be effectively used to neutralize mine water and precipitate and remove dissolved metals.

Thesis (MSc (Forest and Wood Science))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The Saasveld solar kiln, valued at US$ 10,000 (R 70,000), is a greenhouse-type solar kiln requiring no additional heating. A unique auto-regulated process of natural dehumidification at night controls the humidity, and uses no venting system, nor any human/controller intervention. The natural dehumidification is achieved by circulating the humid kiln air through an air jacket on the periphery of the solar kiln. Diurnal temperature fluctuations allow condensation in the air jacket when air is cooled to below its dew-point temperature. The process is simple as colder night temperatures are a certainty. Almost no research has been done on similar kilns. The purpose of this thesis was to study the operation and performance of a solar drying kiln to dry high density hardwoods utilising natural dehumidification. The kiln load consisted of 20.1m 3 of a high density hardwood, Eucalyptus diversicolor, with air-dry density of 893kg/m 3 . The ZA Dry Q drying quality assessment indicated outstanding moisture distribution with little drying stress, a few surface checks and no internal checks, collapse, short bow or surface discolouration. The results conformed to the ZA Dry Q softwood appearance grade specification, except for end checks – remarkable for the drying of any hardwood. The final moisture content (MC) distribution was extremely tight with MC average of 11.5 per cent (%), standard deviation of 0.97% and the moisture gradient averaged 1.49%, standard deviation of 0.5%. The MC and MG were equally distributed in all three geometric directions throughout the load. The timber dried in 130 days. The kiln operation was analysed by temperature and humidity parameters at five positions inside and outside the kiln while monitoring the MC. The extent of moisture evaporation from the timber and the dehumidification of air were derived from this data. The results showed that the average of the daily kiln temperature, independent from the external temperature, increased from 18.0°C initially to 25.7°C. A maximum temperature of 38.1°C was recorded at the end of drying. Cell collapse did not occur under these low temperatures. Evaporation occurred generally from 07h30 to 16h45. The rate reduced at lower moisture contents. There was no effect of stack width. Natural dehumidification by condensation happened generally from 17h00 to 07h30. The equilibrium moisture content (EMC) decreased automatically from an initial daily average of 18.1% (variation 5%) to 8% (variation 2%) finally. It was similar to a smoothed T3C2–schedule. The mild drying conditions, with EMCs above 7.3%, ensured minimal moisture gradients and drying stresses. This reduced surface and internal checks. Nocturnal equalising and conditioning, comparable to intermittent schedules, resulted from: no evaporation, improved diffusion of heated timber and adsorption of moisture on the wood surface. The kiln protected the timber in extreme climatic conditions. It was found that the main circulating fan could be switched off from 17h00 to 07h30. A 30-minute manual venting at noon was permitted once fibre saturation point had been reached. Beneficiaries to this study can include hardwood processors who need to dry high density hardwoods within a reasonable time to an excellent drying quality. Processors in developing countries or who have little drying expertise could also benefit. / AFRIKAANSE OPSOMMING: Die Saasveld sondroër, met ‘n beraamde waarde van US$ 10,000 (R70,000), is ‘n groentetonneltipe sondroër met geen addisionele verhitting nie. ‘n Unieke auto-reguleerder beheer die humiditeit snags deur natuurlike dehumidifikasie. Dit gebruik geen ventileerder of enige menslike/kontroleerder inmenging nie. Die natuurlike dehumidifikasie word verkry deur die vogtige lug te sirkuleer deur ‘n lugkussing op die omtrek van die tonnel. Dag-en-nag temperatuur skommelings laat kondensasie toe binne-in die lugkussing sodra die lug benede die doupunttemperatuur afkoel. Dit is ‘n eenvoudige proses aangesien kouer nagte ‘n gegewe is. Byna geen navorsing is nog op soortgelyke sondroërs gedoen nie. Die doel van die tesis was om die werking en werkverrigting van ‘n sondroër wat hoë digtheid loofhout met behulp van natuurlike dehumidifikasie droog, te bestudeer. Die houtvrag het bestaan uit 20.1m 3 van hoë digtheid loofhout, Eucalyptus diversicolor, met ‘n gemiddelde lug-droë digtheid van 893 kg/m 3 . Die ZA Dry Q drogingskwaliteit toets het uitstaande resultate getoon. Daar was min drogingspannings, ‘n paar oppervlak krake en geen interne krake, sel-ineenstorting, kort-boog of oppervlak-verkleuring nie. Die resultate bevredig die ZA Dry Q naaldhout voorkomsgraad spesifikasie, behalwe vir end-krake – merkwaardig vir die droging van enige hoë digtheid loofhout. Die finale vogverspreiding was nou-verspreid met ‘n gemiddelde voggehalte van 11.5%, standaard afwyking van 0.97% en ‘n gemiddelde vog-gradiënt van ‘n 1.49%, standaard afwyking van 0.5%. Die voggehalte en vog-gradiënt was eweredig verspreid in al drie geometriese rigtings van die houtvrag. Die hout het in 130 dae gedroog. Die werking van die sondroër is geanaliseer deur temperatuur- en humiditeits-parameters by vyf posisies binne- en buite die droogkamer tegelykertyd met die voggehalte te monitor. Die omvang van vogverdamping uit die hout en dehumidifikasie van die lug is afgelei van hierdie data. Die gemiddelde daaglikse sondroër-temperatuur, wat onafhanklik van die buite temperatuur was, het verhoog van 18.0°C aanvanklik tot 25.7°C. Die maksimum temperatuur van 38.1°C is gemeet aan die end van droging. Sel-ineenstorting het nie voorgekom by hierdie lae temperature nie. Verdamping het algemeen voorgekom vanaf 07h30 tot 16h45, teen ‘n vertragende verdampingstempo by laer voggehaltes. Die stapelwydte-effek was van geen belang nie. Natuurlike dehumidifikasie deur kondensasie het gereeld voorgekom vanaf 17h00 tot 07h30. Die ewewigsvoggehalte (EVG) het outomaties verminder vanaf ‘n aanvanklike daaglikse gemiddelde van 18.1% (variasie van 5%) na 8% (variasie van 2%). Dit was soortgelyk aan ‘n gelykmatige T3C2 –drogingskedule. Die matige drogingskondisies, met EVG bokant 7.3%, het minimale vog-gradiënte en drogingspannings verseker wat oppervlak-krake en interne-krake verhoed het. Nagtelike houtvog egalisasie en kondisionering, vergelykbaar met puls-humiditeit skedules, was die gevolg van: geen verdamping, verbeterde diffusie in verhitte hout en adsorpsie van vog op die hout oppervlak. Die droogkamer het die hout beskerm teen buitengewone klimaatstoestande. Daar is gevind dat die hoof-waaier afgeskakel kan word vanaf 17h00 tot 07h30 en dat ‘n 30-minute nie-outomatiese ventilering smiddae kan plaasvind sodra veselversadigingspunt bereik is. Hierdie studie sal van nut wees vir die loofhout verwerkers wat hoë-digtheid loofhout moet droog binne ‘n redelike tydperk met ‘n uitstekende drogings-kwaliteit, asook houtverwerkers in opkomende lande of met gebrekkige drogingsvaardighede.

O pó de aciaria elétrica é um importante subproduto da indústria siderúrgica devido ao seu alto teor de zinco. Assim, tecnologias vêm sendo desenvolvidas visando seu aproveitamento, sendo o forno Waelz a mais difundida delas atualmente. No entanto, sua operação, por contar com um forno rotativo de grandes dimensões que abriga uma infinidade de fenômenos físico-químicos, apresenta difícil previsibilidade ab initio. Por essa razão, este trabalho faz uso de uma ferramenta avançada da termodinâmica computacional, destinada à modelagem de processos, chamada SimuSage, a fim de modelar o seu comportamento. Para a criação do modelo utilizou-se também uma base de dados termodinâmicos advinda do software FactSage e a plataforma de desenvolvimento Lazarus. Com base em dados e resultados operacionais da literatura, foi possível realizar simulações nos modos adiabático e isotérmico, comparando os resultados com os da prática industrial. Constatou-se uma grande capacidade do modelo de reproduzir os resultados da literatura, mesmo quando não há muita informação para aferição dos parâmetros, gerando boa concordância com a composição química relatada dos produtos Óxido Waelz e Escória Waelz. / The electric arc furnace dust is an important by-product of the steel industry due to its high content of zinc. Thus, technologies have been developed aiming for its use, and the Waelz Kiln is the most widespread of them today. However, counting on a very large rotary kiln that houses an infinity of physico-chemical phenomena, its operation is difficult to predict ab initio. For this reason, in order to model its behaviour this work uses an advanced tool of computational thermodynamics designed to process modelling, called SimuSage. To create the model, a thermodynamic database, provided by the FactSage software, as well as a development platform, Lazarus IDE, were also used. Based on operational data and results from de literature, it was possible to perform simulations on both adiabatic and isothermal modes comparing its results with the industrial practice. A great capability of the model to reproduce results from the literature was found, even when there is not much information for the parameters calibration, generating good agreement regarding the reported chemical composition for the products, Waelz Oxide and Waelz Slag.

Ce travail s’inscrit dans le projet LORVER, soutenu par la Région Grand Est et le FEDER. Il est destiné à créer une filière de production de biomasse végétale non alimentaire par valorisation de sites dégradés et de sous-produits industriels, en Lorraine. Un des procédés de valorisation de la biomasse produite est un procédé thermochimique de pyro-gazéification qui générerait de la chaleur et de l’électricité. Ce procédé, développé par SEA Marconi, se compose de trois réacteurs différents : un tambour tournant, pour la pyrolyse de particules de bois, la chaleur étant amenée par des billes d’acier chauffées ; un réacteur à vis sans fin pour l’oxydation du char qui permet de réchauffer les billes d’acier ; un réacteur de craquage des goudrons. L’objectif de cette thèse est de réaliser des modèles qui puissent permettre d’avoir une prédiction adaptée du comportement du système. Des modèles 3D du type DEM et CFD-DEM ont été conçus pour la modélisation des phénomènes qui interviennent dans le système. Les paramètres du modèle DEM ont été calibrés dans un tambour tournant de laboratoire. Pour le réacteur de pyrolyse, la simulation DEM a permis de prédire de façon satisfaisante la ségrégation pour des mélanges de billes d’acier et de particules non sphériques de bois, et de concevoir un modèle thermique et chimique 1D, sur lequel une étude de sensibilité a été effectuée. Un modèle CFD-DEM a été codé et validé sur un rhéomètre granulaire, permettant la simulation du réacteur d’oxydation partielle du char, qui n’a pas pu être réalisé dans le cadre de cette thèse / This work is part of the LORVER project, funded by Grand Est Région and FEDER. It aims to create a non-food biomass production chain by using and upgrading brownfields and industrial by-products in Lorraine. One possible valorization process of the produced biomass is a thermochemical pyro-gasification process that would generate heat and electricity. This process, developed by SEA Marconi, involves three different reactors: a rotating drum, for the pyrolysis of wood particles, the heat required being brought by hot steel balls; an Auger for partial oxidation of the char that allows heating the steel balls; a reactor for tar cracking. The aim of this thesis is to develop models that can predict the behavior of the system. 3D models based on DEM or CFD - DEM were designed for the modeling of phenomena involved in the system. The DEM model parameters were first calibrated in a rotating drum. The DEM simulation was able to predict in a satisfactory manner segregation between steel balls and non-spherical wood particles; it also helped to design a 1D thermal and chemical model, on which a sensitivity study has been done. A CFD - DEM model has been coded and validated on a granular rheometer allowing the simulation of the char oxidation reactor, even if this simulation was not possible during the PhD

Made available in DSpace on 2014-06-11T19:22:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-09-21Bitstream added on 2014-06-13T19:26:11Z : No. of bitstreams: 1 silva_kj_me_ia.pdf: 10781522 bytes, checksum: 6ae93e94722fbb3f492608d29b15136c (MD5) / Cunha é uma pequena cidade situada a extremo leste do Estado de São Paulo, que tem sua origem, em meados do século XVIII, atrelada ao fluxo de tropas que percorriam a trilha do ouro das Minas Gerais ao porto de Paraty-RJ, atualmente como Estrada Real. Desde cedo sua história demonstrou afinidade com a produção de objetos cerâmicos: a princípio com peças utilitárias, feitas por mulheres conhecidas como Paneleiras, influenciadas entre outras coisas, na hoje extinta produção ceramista de tribos indígenas que habitavam aquela região, posteriormente pelas Olarias que a partir da forma retangular do tijolo, permitiram à cidade se reedificar. Mais recentemente, na década de 1975, a chegada de um grupo de pretensos ceramistas, a maioria deles estrangeiros, imprime ali, outros olhares sobre a produção do objeto cerâmico que ao longo dos últimos trinta e seis anos, projetaram a cidade como um importante pólo ceramista nacional. Interessa-nos buscar entender quais as principais características identificam este processo de transformação, para então termos condições de responder à questão que motivou grande parte desta pesquisa: será possível nos referirmos à cerâmica produzida em Cunha, como sendo de Cunha? O corpo principal deste texto está dividido em quatro capítulos, cuja ordem tem por objetivo compilar de forma didática informações que permitam o entendimento daquilo que chamaremos: Caminhos da Cerâmica em Cunha. No primeiro capítulo buscaremos situá-los, mostrando algumas de suas particularidades históricas e estéticas. Esclarecidos sobre a existência e importância deste corpo cultural maior, poderemos imergir no universo da Alta Temperatura, a começar pelo entendimento das características que conferem ao forno Noborigama importância primordial... / Cunha is a small town located in the east part of the state of São Paulo. It was originated in the 18th century, due to the troops that covered the so called “gold path” from Minas Gerais to the port of Paraty-RJ. Since its beginning, Cunha´s history is related to the production of ceramic objects: at first, with utilitarian objects made by women known as Paneleiras, who were influenced by the now extinct ceramics of Indian tribes of the region, and later by the brick factories that enabled the town to re-edify. More recently, in 1975, the arrival of a group of ceramists- most of them foreigners- implanted a different way of thinking this production, that during the past thirty six years propelled the town to become an important Brazilian ceramist center. Our goal is to understand the main characteristics that identify this transformation, in order to answer the question that motivated most of this study: is it possible to refer to the ceramic production made in Cunha as being, in fact, typically “Cunhan”? The main part of this text is divided in four chapters; which´s ordering has the goal to compile information in a didactic way that allows the understanding of what we decided to call the Ceramic Path from Cunha. In the first chapter we try to point these paths, revealing some of their historical and aesthetic characteristics. After the understanding of their existence and importance, we can explore the universe of High Temperature, starting with the recognition of the great importance that this study confers to Noborigama kiln. The third chapter is focused on the process of ceramic production and will analyze technical procedures practiced by nowadays ceramists from Cunha. It shows the preparation of clay, modeling and burning of the pieces. On the end, it analyses the specific dynamic of some studios, which reveals... (Complete abstract click electronic access below)

Orientador: Geralda Dalglish / Banca: José Leonardo do Nascimento / Banca: Zandra Cunha de Miranda Santos / Resumo: Cunha é uma pequena cidade situada a extremo leste do Estado de São Paulo, que tem sua origem, em meados do século XVIII, atrelada ao fluxo de tropas que percorriam a trilha do ouro das Minas Gerais ao porto de Paraty-RJ, atualmente como Estrada Real. Desde cedo sua história demonstrou afinidade com a produção de objetos cerâmicos: a princípio com peças utilitárias, feitas por mulheres conhecidas como Paneleiras, influenciadas entre outras coisas, na hoje extinta produção ceramista de tribos indígenas que habitavam aquela região, posteriormente pelas Olarias que a partir da forma retangular do tijolo, permitiram à cidade se reedificar. Mais recentemente, na década de 1975, a chegada de um grupo de pretensos ceramistas, a maioria deles estrangeiros, imprime ali, outros olhares sobre a produção do objeto cerâmico que ao longo dos últimos trinta e seis anos, projetaram a cidade como um importante pólo ceramista nacional. Interessa-nos buscar entender quais as principais características identificam este processo de transformação, para então termos condições de responder à questão que motivou grande parte desta pesquisa: será possível nos referirmos à cerâmica produzida em Cunha, como sendo de Cunha? O corpo principal deste texto está dividido em quatro capítulos, cuja ordem tem por objetivo compilar de forma didática informações que permitam o entendimento daquilo que chamaremos: Caminhos da Cerâmica em Cunha. No primeiro capítulo buscaremos situá-los, mostrando algumas de suas particularidades históricas e estéticas. Esclarecidos sobre a existência e importância deste corpo cultural maior, poderemos imergir no universo da Alta Temperatura, a começar pelo entendimento das características que conferem ao forno Noborigama importância primordial... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cunha is a small town located in the east part of the state of São Paulo. It was originated in the 18th century, due to the troops that covered the so called "gold path" from Minas Gerais to the port of Paraty-RJ. Since its beginning, Cunha's history is related to the production of ceramic objects: at first, with utilitarian objects made by women known as Paneleiras, who were influenced by the now extinct ceramics of Indian tribes of the region, and later by the brick factories that enabled the town to re-edify. More recently, in 1975, the arrival of a group of ceramists- most of them foreigners- implanted a different way of thinking this production, that during the past thirty six years propelled the town to become an important Brazilian ceramist center. Our goal is to understand the main characteristics that identify this transformation, in order to answer the question that motivated most of this study: is it possible to refer to the ceramic production made in Cunha as being, in fact, typically "Cunhan"? The main part of this text is divided in four chapters; which's ordering has the goal to compile information in a didactic way that allows the understanding of what we decided to call the Ceramic Path from Cunha. In the first chapter we try to point these paths, revealing some of their historical and aesthetic characteristics. After the understanding of their existence and importance, we can explore the universe of High Temperature, starting with the recognition of the great importance that this study confers to Noborigama kiln. The third chapter is focused on the process of ceramic production and will analyze technical procedures practiced by nowadays ceramists from Cunha. It shows the preparation of clay, modeling and burning of the pieces. On the end, it analyses the specific dynamic of some studios, which reveals... (Complete abstract click electronic access below) / Mestre

O pó de aciaria elétrica é um importante subproduto da indústria siderúrgica devido ao seu alto teor de zinco. Assim, tecnologias vêm sendo desenvolvidas visando seu aproveitamento, sendo o forno Waelz a mais difundida delas atualmente. No entanto, sua operação, por contar com um forno rotativo de grandes dimensões que abriga uma infinidade de fenômenos físico-químicos, apresenta difícil previsibilidade ab initio. Por essa razão, este trabalho faz uso de uma ferramenta avançada da termodinâmica computacional, destinada à modelagem de processos, chamada SimuSage, a fim de modelar o seu comportamento. Para a criação do modelo utilizou-se também uma base de dados termodinâmicos advinda do software FactSage e a plataforma de desenvolvimento Lazarus. Com base em dados e resultados operacionais da literatura, foi possível realizar simulações nos modos adiabático e isotérmico, comparando os resultados com os da prática industrial. Constatou-se uma grande capacidade do modelo de reproduzir os resultados da literatura, mesmo quando não há muita informação para aferição dos parâmetros, gerando boa concordância com a composição química relatada dos produtos Óxido Waelz e Escória Waelz. / The electric arc furnace dust is an important by-product of the steel industry due to its high content of zinc. Thus, technologies have been developed aiming for its use, and the Waelz Kiln is the most widespread of them today. However, counting on a very large rotary kiln that houses an infinity of physico-chemical phenomena, its operation is difficult to predict ab initio. For this reason, in order to model its behaviour this work uses an advanced tool of computational thermodynamics designed to process modelling, called SimuSage. To create the model, a thermodynamic database, provided by the FactSage software, as well as a development platform, Lazarus IDE, were also used. Based on operational data and results from de literature, it was possible to perform simulations on both adiabatic and isothermal modes comparing its results with the industrial practice. A great capability of the model to reproduce results from the literature was found, even when there is not much information for the parameters calibration, generating good agreement regarding the reported chemical composition for the products, Waelz Oxide and Waelz Slag.