En raison de l'épuisement des combustibles fossiles et en raison de son coût croissant, les déchets ont été utilisés comme combustibles alternatifs dans les fours rotatifs à ciment pendant plusieurs années. Afin de répondre aux exigences de protection de l'environnement et de qualité du produit final, il est nécessaire de comprendre et de quantifier les différents processus intervenant dans le four. Dans le cadre de cette thèse, nous nous sommes intéressés à la substitution partielle des déchets (pneus usés et Refuse Derived Fuel « RDF ») et biomasse (résidus d’agriculture) dans les fours tournants de production de ciment à un taux de 50 % d’apport énergétique. Le présent projet de thèse a été financé par la République Démocratique Congo, porté par l’Université Kongo (UK), dans le cadre du renfoncement des capacités des universités congolaises. Les travaux de recherche ont été réalisés au sein du Laboratoire de Thermique, Energétique et Procédés (LaTEP) de l’Ecole Nationale Supérieure en Génie de Technologies Industrielles (ENSGTI)/Université de Pau et des Pays de l’Adour (France), dans le but d’étudier et de comprendre les phénomènes thermochimiques se déroulant dans les fours tournants de production de ciments, dans le cas de substitution partielle des combustibles fossiles par des combustibles alternatifs. Pour cela, un modèle mathématique à deux sous-modèles a été établi : - Le modèle monodimensionnel stationnaire du lit de solides et de l’enveloppe du four, caractérisé dans sa première partie par le mélange de la farine de ciment, de déchets et/ou biomasse, et de gaz, et alors que dans sa deuxième partie par les échanges thermiques. Le travail de modélisation est effectué à l'aide du langage de programmation Fortran 90 dans lequel sont implémentées les équations de conservations de la masse, des espèces et de l’énergie, l’équation de transport de la charge, ainsi que les équations algébriques. - Le modèle tridimensionnel instationnaire, repose sur l’utilisation de la mécanique des fluides numérique, et l’outil commercial Fluent a été retenu pour représenter les processus se déroulant au-dessus de la surface libre du lit.Le modèle complet est le couplage entre les deux sous modèles, étant donné les échanges qui s’y effectuent.Deux grands groupes de simulations ont été réalisés dans cette thèse : le cas monodimensionnel et le cas global (couplage Modèle 1D-Modèle 3D). Dans les deux situations, les simulations ont été effectuées dans le cas de fonctionnement au fuel lourd seul, puis dans celui du fonctionnement avec substitution partielle du combustible fossile par les combustibles alternatifs. Pour le modèle monodimensionnel, les simulations ont été effectuées en imposant les flux de chaleur dans la surface libre du lit et dans la paroi découverte. Alors que pour le modèle global, les simulations ont été effectuées en considérant les densités de flux de chaleur associées aux phénomènes physico-chimiques (combustion du fuel lourd, rayonnement, turbulence) se déroulant dans le volume de gaz situé au-dessus de la surface libre du lit.Les résultats ainsi obtenus nous ont permis de conclure sur l’importance de mener en amont une étude expérimentale dans un four tournant à l’échelle pilote afin de pouvoir disposer des ordres de grandeur des différents flux de chaleur au sein du four tournant. Les résultats obtenus nous ont également permis de nous rendre compte de la nécessité de disposer de la géométrie exacte (emplacement) du brûleur dans le four tournant. / Because of the depletion of fossil fuels and because of its increasing cost, waste has been used as alternative fuels in cement rotary kilns for several years. In order to fulfill the requirements of environmental protection and quality of the final product, it is necessary to understand and quantify the different processes occurring in the kiln.As part of this thesis, we focused on the partial substitution of waste (used tires and Refuse Derived Fuel "RDF") and biomass (agricultural residues) in rotary kilns producing cement at a rate of 50 % of energy supply. This thesis project was funded by the Democratic Republic of Congo, led by Kongo University (UK), as part of the capacity building of Congolese universities. The research work was carried out within the Laboratory of Thermal, Energy and Processes (LaTEP) of the National School of Engineering in Industrial Technologies (ENSGTI) /University of Pau, with the aim of to study and understand the thermochemical phenomena taking place in rotary kilns for the production of cement, in the case of partial substitution of fossil fuels by alternative fuels. For this, a mathematical model with two sub-models has been established:- The stationary one-dimensional model of the bed of solids and furnace casing, characterized in its first part by the mixing of cement flour, waste and / or biomass, and gas, and while in its second part by thermal exchanges. The modeling work is performed using the Fortran 90 programming language in which the conservation equations for mass, species and energy, the load transport equation, and the algebraic equations are implemented.- The unsteady three-dimensional model relies on the use of digital fluid mechanics, and the Fluent commercial tool has been retained to represent the processes taking place above the free surface of the bed.The complete model is the coupling between the two sub models, because of the exchanges that take place there.Two large groups of simulations have been realized in this thesis: the one-dimensional case and the global case (Model 1D-3D model coupling). In both situations, the simulations were carried out in the case of operation with heavy fuel oil alone, then in the case of operation with partial substitution of the fossil fuel by alternative fuels. For the one-dimensional model, the simulations were performed by imposing the heat flux in the free surface of the bed and in the exposed wall. Whereas for the global model, the simulations were performed considering the heat flux densities associated with physico-chemical phenomena (combustion of heavy fuel oil, radiation, turbulence) taking place in the volume of gas located above the free surface of the bed.The results thus obtained allowed us to conclude on the importance of carrying out an experimental study in a pilot scale furnace in order to be able to have orders of magnitude of the different heat flows within the rotating furnace. The results obtained also allowed us to realize the necessity to model the exact geometry (location) of the burner in the rotary kiln.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-12-22T12:03:13Z No. of bitstreams: 1 Josué Claudio Metz_.pdf: 3580473 bytes, checksum: 4bb7f81d4d0a95ef4e39a7d4dffb0599 (MD5) / Made available in DSpace on 2016-12-22T12:03:13Z (GMT). No. of bitstreams: 1 Josué Claudio Metz_.pdf: 3580473 bytes, checksum: 4bb7f81d4d0a95ef4e39a7d4dffb0599 (MD5) Previous issue date: 2016-09-19 / Nenhuma / A concepção de desenvolvimento sustentável tem resultado no aumento de pressões ambientais para a melhoria da eficiência na utilização de recursos, e para a redução das emissões e da geração de resíduos. No processo de fabricação de aço, nas siderúrgicas com fornos elétricos a arco (FEA), ocorre a geração do resíduo sólido denominado pó de aciaria elétrica (PAE). O PAE é constituído por diferentes óxidos metálicos. Contém os elementos químicos cromo (Cr), chumbo (Pb) e cádmio (Cd) e, por isso, é classificado como resíduo classe I – Perigoso pela NBR 10004. Gerado em grandes quantidades diariamente em todo o país, o PAE ainda tem como principal destinação final o aterro industrial. A indústria de papel e celulose, outra atividade de destaque na indústria nacional, gera uma grande quantidade de resíduos em diferentes etapas do processo, entre os quais está o resíduo do forno de cal (RFC), cuja geração está associada a interrupções no funcionamento do forno de cal. A indústria da construção civil, devido a quantidade de matérias-primas consumida e variedade de materiais empregados – cimento, concreto, agregados, cerâmica, entre outros – apresenta-se como alternativa para a reciclagem de resíduos gerados em outros setores da economia. A incorporação do PAE no cimento e concreto produz retardo no tempo de pega em razão da presença de zinco (Zn) no resíduo. Estudos sugerem que em quantidades próximas a 1%, a incorporação de PAE não afeta de forma significativa as propriedades do cimento. O objetivo deste trabalho foi avaliar a influência do uso combinado de PAE e RFC no processo de endurecimento e evolução da hidratação de pastas de cimento. Para tanto, foi realizada a caracterização dos resíduos através dos ensaios de distribuição granulométrica, perda ao fogo, massa específica, área superficial específica, análise química elementar, difração de raios X com refinamento por Rietveld e microscopia eletrônica de varredura. A influência dos resíduos nas pastas de cimento foi avaliada através do ensaio de tempo de pega de acordo com a NBR NM 65 (ABNT, 2003b) e evolução da temperatura semi-adiabática das pastas em estado fresco, além de DRX, com refinamento por Rietveld, e microscopia eletrônica de varredura nas pastas de cimento com diferentes teores de substituição de resíduos (REF, 1%, 2%, 3%, 5% e 10%) em diferentes idades (1, 4 e 7 dias). Os resultados de tempo de pega e evolução da temperatura semi-adiabática indicaram a influência do PAE na hidratação das pastas de cimento. Nas pastas de cimento com substituição de 1% de PAE combinado ou não com RFC, não foram verificados retardos significativos no tempo de pega, demonstrando o potencial do uso de PAE e do RFC na produção de artefatos de cimento. / The sustainable development conception has resulted in increased environmental pressures to improve the efficient use of resources and reduction of emissions and waste generation. In the steelmaking process through electric arc furnaces (EAF), dust generation occurs which is called electric arc furnace dust (EAFD). EAFD is composed by different metal oxides. Some common elements those constitute this dust is chromium, lead and cadmium, and therefore, waste is classified as class I – hazardous by NBR 10004. EAFD has been generated in large quantities every day across the country and it still has mainly landfilled. The pulp and paper industry, another important activity in the domestic industry, generates a lot of waste in different stages of the process, among which is the lime kiln waste (LKW), whose generation is associated with disruptions in the lime oven. Due to expressive amount of raw materials consumed in civil construction industry and also the variety of products available - cement, concrete, aggregates, ceramics, among others - this seems to be an alternative for waste recycling generated in other sectors. The incorporation of EAFD in the cement and concrete produces delayed setting time due to the presence of zinc (Zn) in the waste. Studies suggest that in amounts up to 1%, EAFD incorporation does not affect significantly cement properties. The aim of this work was to evaluate the influence of the combined use of EAFD and LKW in the process of hardening and evolution of the cement pastes hydration. Therefore, were evaluated the characterization of the waste performed through the grain size distribution, loss on ignition, specific gravity, specific surface area, elemental chemical analysis, pH, X ray powder diffraction with refinement by Rietveld and scanning electron microscopy.. The influence of the waste on the cement pastes was evaluated through the setting time tests in accordance with the NBR NM 65 (ABNT, 2003b) and evolution of semi-adiabatic temperature in fresh conditions, XRD with refinement by Rietveld, and SEM in cement pastes with different levels of waste substitution (REF, 1%, 2%, 3%, 5% e 10%) at different ages (1, 4 and 7 days). The setting time results and evolution of semi-adiabatic temperature indicated an increase in the setting time with the increase of the EAFD in cement pastes. In cement pastes with replacement of 1% EAFD combined or not with LKW, significant delays were not verified in the setting time, demonstrating the potential use of EAFD in the production of cement artifacts.

Glass has been made and used for centuries but South African artists, isolated for the last three decades, are only now becoming aware of the potential of hot or warm glass as an art medium. In antiquity glass objects were created using various processes but the 'factory' tradition began with the discovery of the blowing iron in the first century AD. The invention of the tank furnace in the late 1950s revolutionised modem production, enabling individual artists to make glass in private studios without blowing teams. The research describes ancient.. glassmaking processes and indicates how they have been explored, adapted and used by contemporary artists world wide, challenging craft orientated paradigms, and proving that glass is a viable and important sculpture medium. The practical research demonstrates the application of many processes and relates technical issues to sculptural concepts which are realized through the physical and material properties of glass. / Art History, Visual Arts and Musicology / M.A. (Fine Art)

A finalidade deste trabalho é estudar a redução carbotérmica de minério hematítico com misturas e pelotas autorredutoras em um forno rotativo experimental. Trabalhou-se com duas temperaturas, a 1673 e 1773 K (1400 a 1500 °C), em fluxo de argônio de 1Nl/min, em um forno rotativo experimental aquecido por resistências, com uma rotação fixa de 5 rpm. Foram realizadas diversas experiências, alterando variáveis como a temperatura, composição e quantidade da escória, tipo de redutor, e tipo de conformação. Foi estudado o tempo de residência das pelotas e misturas autorredutoras dentro do forno e sua interrelação com a inclinação do mesmo. Mediu-se a resistência a compressão de diferentes composições de pelotas. Foi analisada a fração de redução atingida nas experiências com ajuda de um método indireto proposto neste trabalho, atingindo-se frações de redução acima de 98%. Especial atenção foi dada para os casos limites estudados, o primeiro com uma mistura autorredutora de 81% de minério hematítico de baixo teor, 19% de coque de petróleo,+10% cimento ARI, processada a 1773 K (1500 °C) com 33% de escória final, a qual, apesar da grande quantidade de escória, atingiu uma fração de redução de 98,7%; e o segundo, para uma mistura autorredutora de 43,5% de minério hematítico de baixo teor, 56,5% de pó de serragem, processada a 1773 K (1500 °C), a qual atingiu uma fração de redução de 99,2%, provando, com as ressalvas cabíveis, a factibilidade de reduzir diretamente com pó de serragem. Com base nas observações experimentais sugeriram-se modelos do processo de redução-fusão tanto das misturas como das pelotas autorredutoras no forno rotativo. Analisaram-se a composição da escória e a composição da fase metálica obtida. Para comparar o grau de coalescimento entre as amostras, foram levantadas as análises granulométricas de cada uma delas, comparando-se as porcentagens em massa dos nódulos de ferro-carbono com diâmetro superior a 7,93 mm. Atenção especial foi dada ao método de desagregação do produto; pela ausência de normas técnicas especificas para processos autorredutores, foi empregada uma adaptação do método de desagregação por tambor (ASTM E279-95), e validada por moagem manual. Estudou-se o efeito das variáveis: temperatura de processamento, temperatura liquidus da escória, da quantidade de escória de alta temperatura liquidus, da quantidade de voláteis do redutor, da quantidade do redutor, e da ausência de conformação. Entre os resultados destas experiências tem-se que a maior temperatura de processamento leva a maior grau de coalescimento. Na medida em que a escória do sistema não se liquefaz, o processo de coalescimento é prejudicado. Na medida em que a quantidade de escória com alta temperatura liquidus aumenta, o grau de coalescimento decresce. Ao se aumentar a quantidade do redutor acima do necessário para a correta redução, carburação e colaescimento, prejudica-se o processo de formação dos nódulos de ferro-carbono. Ao se comparar o grau de coalescimento obtido entre as misturas e as pelotas autorredutoras, temse que o desempenho das misturas autorredutoras é superior. Para aclarar o efeito da temperatura liquidus da escória no processo de carburação e coalescimento, foram realizadas experiências paralelas para estudar como a temperatura liquidus da escória e a ausência do FeO afetava o coalescimento. Ao estudar o transporte de carbono pelas escórias sem e com a presença de um óxido redutível, tem-se que o transporte do óxido de ferro na escória sem agitação é um fenômeno difusivo. / The purpose of this work is to study the carbothermal reduction of hematite ore as self-reducing mixtures or pellets in an experimental rotary kiln. Two different temperatures were employed, 1673 and 1773 K (1400-1500 ° C) in an experimental rotary kiln heated by resistors, with a fixed rotation of 5 rpm and under an argon flow of 1Nl/min. Several experiments were performed by changing variables such as temperature, composition and quantity of slag, type of carbonaceous material, and type of conformation. The residence time inside the furnace and its interrelation with the slope of the kiln containing self-reducing pellets or mixtures was studied. It was measured the compressive strength of pellets of different compositions. It has been analyzed the fractional reduction achieved in the experiments with the help of an indirect method proposed in this work, reaching fractional reduction above 98%. Special attention was given to some cases, the first one with a self-reducing mixture of 81% low grade ore, 19% petroleum coke, ARI +10%, processed to 1773 K (1500 ° C) with 33% final slag, which despite the large amount of slag reached a fractional reduction of 98.7%, and the second for a self-reducing mixture of 43.5% low-grade ore, 56.5% of sawdust processed to 1773 K (1500 ° C) which reached a fractional reduction of 99.2%, proving, with reasonable exceptions, the feasibility of reducing directly with sawdust. Based on experimental observations, process models of both the reduction-melting of self-reducing mixtures and pellets in the rotary kiln were proposed. The composition of slag and composition of the metallic phase obtained were analyzed. To compare the degree of coalescence between the samples, particle size analysis of each one was performed, comparing the percentages by weight of iron-carbon nuggets with a diameter greater than 7.93 mm. Regarding the method of disintegration of the product, due to the lack of technical standards for specific self-reducing processes, the drum method (ASTM E279-95) was adapted and validated by manual grinding. It was studied the effect of the following parameters: processing temperature, slag liquidus temperature, the amount of high liquidus temperature slag, amount of volatile matter of the reducing agent, the amount of reducing agent, and the absence of conformation. These experiments have shown that the higher the processing temperature, the greater the degree of coalescence, and also that as long as the slag does not melt, the coalescence process is impaired. As the amount of slag with high liquidus temperature increases, the degree of coalescence decreases. Increasing the amount of carbonaceous material above to that necessary to reduction and carburization undermines the process of formation of iron-carbon nuggets. When comparing the degree of coalescence obtained between the self-reducing mixtures and pellets, it has been shown that the performance of self-reducing mixtures is superior. To clarify the effect of the slag liquidus temperature in the carburization and coarsening process, experiments were conducted to study how the liquidus temperature of the slag and the absence of FeO affected the coarsening. By studying the transport of carbon in slags with and without the presence of a reducible oxide, it has been shown that the transport of iron oxide in the slag without agitation is a diffusive phenomenon.

Découvert dans les années 1970 sur le site palafitte aujourd’hui immergé du Crêt de Châtillon (lac d’Annecy, Haute-Savoie, France), le four de Sévrier, daté de l’âge du Bronze, est considéré comme un des plus anciens fours de potier d’Europe occidentale. Il incarne l’arrivée d’une nouvelle technologie qui marquera la disparition progressive des modes de cuisson en fosse ou en meule en usage depuis l’invention de la poterie. En cette fin de l’âge du Bronze l’acmé de l’art céramique, représenté par les productions de poteries fines, pouvait donc être lié à l’utilisation d’un tel dispositif. Le caractère unique de cette construction en argile, de dimensions modestes et à parois étonnamment minces, réside dans sa conception modulaire et portable. La découverte publiée en 1975 (Bocquet et Couren 1975) recueille aussitôt un échoeuropéen et près de quarante ans après, elle reste pratiquement sans équivalent. L’utilisation de fours de potier à l’âge du Bronze, dans un contexte occidental, demeure pourtant une question ouverte et depuis les années 80, l’interprétation avancée pour le four de Sévrier alimente régulièrement ce débat. L’objectif de cette thèse de doctorat est de porter un nouveau regard sur cet objet de référence quelque peu voilé par sa célébrité et réexaminer les hypothèses fonctionnelles non encore étudiées. Après une présentation du contexte et de l’historique de la découverte, un premier volet aborde différents aspects de l’objet archéologique: sa morphologie, sa conception, sa restauration, son comportement lors d’expérimentations de cuissons de céramiques, ses traits singuliers qui le rapprochent ou le distinguent des fours de potiers plus tardifs ou des structures d’argile à parois fines diversement interprétées. Notre analyse du four de Sévrier comporte trois volets : a) l’inventaire du matériel découvert sur le Crêt de Châtillon et l’intégration éventuelle d’éléments non pris en compte dans la reconstruction, b) une analyse archéométrique (minéralogie des argiles) portant sur les tessons du four et sur des argiles des gisements situés à proximité du Crêt de Châtillon. Une analyse des changements de phases des argiles cuites en fonction de l’intensité de la température, c) l’évaluation de la température minimale et maximale subie par le four afin de confirmer ou exclure certaines utilisations. L’analyse fonctionnelle du four aborde, en premier lieu, l’hypothèse privilégiée, celle consacrée à la cuisson des poteries. Une méthode expérimentale comparative permet de préciser les avantages et inconvénients de différents procédés de cuisson de poteries noires et cherche à évaluer l’apport technologique supposé avoir été introduit par le four de Sévrier. D’autres alternatives sont abordées, en particulier la fonction culinaire. Cette interprétation est confortée par la découverte d’inédits indices d’usages observés lors de cette étude sur des matériels similaires de même époque et provenance. L’inventaire des structures comparables constitue un autre volet de cette recherche. Elle témoigne de l’usage courant des structures de cuisson en argile de faible épaisseur aux âges du Bronze et du Fer. Leur diffusion géographique s’étend des Balkans à l’Espagne et de la Grande Bretagne à la Grèce. Le recensement d’une famille large et multiforme de dispositifs portables en argile à vocation domestique nous permet de poser les bases d’une typologie et de proposer un scénario d’évolution et d’influences entre des régions parfois très éloignées. / This study focuses on a unique archaeological finding from the Crêt de Châtillon, a late Bronze Age lacustrine village situated on a now submerged island in Lake Annecy (Haute-Savoie, France). The Sévrier kiln is considered to be one of the oldest pottery kiln in Western Europe. Over the years it has become internationally known and still forms the basis of research projects and experiments relating to Bronze Age ceramic technology. It embodies the arrival of a new technology that would mark the gradual disappearance of the open fire or pit firing modes that had been used since the invention of pottery. As such, the acme of ceramic art which marks the end of the Bronze Age, may therefore be related to the use of such a device. The uniqueness of this clay building of modest proportions and surprisingly thin walls, lies in it modular and portable design. The discovery, published in 1975 (Bocquet and Couren 1975) soon received a valuable feedback in Europe and nearly forty years later remains virtually unparalleled. However, the use of pottery kilns in the Bronze Age in a Western context remains an open question. Since the 1980s, several arguments will gradually undermine this interpretation. The purpose of this study is to take a fresh look at this inescapable object, somewhat veiled by its celebrity and review functional hypotheses hitherto not studied. After describing the background and the history of the discovery, we discuss various aspects of the archaeological kiln: morphology, design, restoration, use, experimentations and singular features that approximate or distinguish this furnace from later pottery kilns or thin-walled clay structures wich have been variously interpreted. This analysis of the kiln of Sévrier has been threefolds: (a) an inventory of the findings from the Crêt de Châtillon and a discussion about the integration of many components excluded from the reconstruction ; (b) archaeometric analysis (clay mineralogy) of the kiln and the clay deposits located near the site and (c) identification of the changing phases in clays, subjected to high temperatures and determination of the temperature experienced by the furnace. The functional analysis, reviews different hypotheses : (a) pottery firing : a comparative experimental method that aims to highlight the benefits and disadvantages of different processes to produce black pottery. The purpose is to underscore the technological contribution assumed to have been introduced by the Sévrier kiln. (b) Other functional alternatives will be discussed, especially the culinary function. This interpretation is supported by the discovery of unprecedented indices discovered during this study. The inventory of comparable structures is another aspect of this research. The relatively widespread use of such thin-walled clay structures during the Bronze and Iron ages is highlighted. Their geographical distribution extends from the Balkans to Spain and from Great Britain to Greece. The census of a multiform family of domestic portable clay ovens allows us to propose a new typology and a scenario of diffusion between regions sometimes very remote, completes this new outlook and draw new perspectives for the research.

No description available.

Under den andra stenbyggnadsperioden på Gotland började bönderna på landsbygden att bygga sina hus utav sten. De hade egna stenbrott där de kunde bryta både byggnadssten och sten till kalkbränning. Stenen brände de i milor eller husbehovsugnar. Även ekonomibyggnaderna uppfördes i sten på Gotland, detta är unikt i ett svenskt och nordiskt sammanhang. Murbruksprover från tio ekonomibyggnader har samlats in, alla gårdarna belägna i det stora kalkstensbältet på norra Gotland. Området är intressant att studera eftersom kalkbruksindustrin växte sig så stor här. En okulär besiktning av murbruksproverna i fält har genomförts, där provets kulör noterats och murbrukets innehåll av exempelvis sand och kalkklumpar med mera beskrivits. Det har tillverkats tunnslip av murbruksproverna för att på djupet kunna analysera dess innehåll och sammansättning. Genom analyserna kan vi spåra hur kalkbrukstraditionerna sett ut ute på landsbygden och vilka lokala traditioner som finns. Resultatet visar att stenen från Lärbroområdet har varierande kvalitet och egenskaper, där både ren och mer eller mindre oren sten bränts och nyttjats i kalkputs och kalkfärg. Stenen har gett ett kalkbruk med vissa orenheter i kalkpastan och inslag av ballastbildande hydrauliska korn, som inte gett bruket andra egenskaper än att det kan räknas som ett luftkalkbruk. Denna kalken är karakteristisk för gården i Vägume, där även en svagt hydraulisk kalk har dokumenterats. Denna har man dock behövt torrsläcka för att kunna göra bruk av den. En grynig luftkalk i vissa fall med inslag av hydrauliska ballastkorn ses också i bruksproverna från Hägvide i Lärbro, Stora Ire i Hellvi och vid Lunderhage i Fleringe där även ren kalkpasta använts. Gotland är känd för sin rena feta luftkalk, så som kan ses i proverna från Risungs i Rute, Gaustäde i Bunge och på Fårö. Det är därför intressant att se att svagt hydraulisk sten använts på Gotland och att de som haft tillgången till denna stenen lärt sig använda den. Hydraulisk kalk fanns även i ett av bruksproverna från Angelbos, denna var starkt hydraulisk och skulle kunna vara ett KC-bruk, eftersom de hydrauliska partiklarna näst intill är glasartade så som klinker. Blandningsförhållandet ligger generellt på 1:2 men även magrare och kalkrikare bruksblandningar förekommer i de undersökta proverna. Proverna är förhållandevis kompakta. I Rute och Bunge har man blandat fetare bruk, de flesta bruksproverna visar ett blandningsförhållande omkring 1:1, vissa något magrare. I Bunge påträffades troligen ett medeltida bruk, det var mycket kalkrikt, innehöll lite sand och många kalkklumpar som delvis bildade ballast. Fetare än 1:1. Det är en kalk som lagrats över länger tid och kan mycket väl ha jordsläckts. Denna traditionen ser vi inte i de andra bruksproverna där kalken släckts och använts direkt. Ballasten i näst intill samtliga bruksprover är mycket finkornig, omkring 0,5 mm och mindre. Inslag av större sandkorn förekommer med även dessa är små. Kalkklumparnas storlek varierar mycket från mm stora korn till 1 cm. De största mellan 2 – 3 cm. Ett modernare inslag och förhållningssätt till bruksblandning påträffades vid Risungs i Rute. Här har luftporbildare tillsatts vilket resulterat i ett bruk med ett kollapsat porsystem som ger dålig beständighet. Kontrasten är stor jämfört med de äldre feta och kompakta 1:1 bruken från Risungs.  Två av proverna innehöll större mängd lera. I provet från Vägume kommer lerinnehållet troligen från sanden som i delar av området är rik på lera, det är det enda provet som kan räknas som ett lerblandat kalkbruk i studien. Detta visar att även sanden kan skilja rätt mycket lokalt inom ett litet område som i sin tur ger bruk med olika egenskaper. I provet från Hägvide ses inslag av tegelröda partiklar som kommer av lerlager i den brända kalkstenen. Den tegelröda kulören kommer av att leran innehåller järnmineraler. I spritputsen har enbart kalk och naturgrus nyttjats, vilket är något ovanligt eftersom det gärna tillsätts lite sand även i spritputs. Det skulle kunna bero på att kalken i sig bidrar med ballast i form av kalkklumpar som gjort att sanden setts på som onödig. En regional variant som setts i flera av de analyserade bruksproverna. Studien visar att lokala material använts under den andra stenbyggnadsperioden på Gotland och att stenförekomsten har lokala variationer i och mellan socknarna, vilket gör att lokala traditioner kan utskiljas. Sanden är i större utsträckning av samma typ i de undersökta områdena, medans det i Vägume nyttjats både lerblandad sand och ren finkornig sand. Blandningsförhållandet generellt är omkring 1:2 vilket överensstämmer det nationala förhållningssättet som kom utöver 1700-talet. Så sätt skiljer sig Risungs och Gaustäde ut där traditionen för något fetare kalkbruk levt kvar. Vägumes lokala tradition där svagt hydraulisk kalk och grynig kalk med inslag av hydrauliska partiklar använts är därför intressant. / During the second stone building period on Gotland, the farmers in the countryside began to build their houses out of stone. They had their own quarries where they could mine both building stone and stone for lime burning. They burned the stone in lime kilns or household furnaces. The agricultural buildings were also built in stone on Gotland, this is unique in a Swedish and Nordic context. Mortar samples from ten agricultural buildings have been collected, they are all located in the large limestone belt in northern Gotland. This area is interesting to study because of the expansion in the lime industry here. An ocular inspection of the mortar samples was carried out during the field studies, where the colour of the sample was noted as well as the mortars content of, for example sand and lime lumps etc. Thin sections were made from the mortar samples in order to be able to analyse its content and composition. Through analysis we gained knowledge about the lime mortar traditions in the countryside and their local traditions.   The results shows that the stone from the Lärbro area has varying quality and properties, where both clean and more or less impure stone was burned and used in lime render and lime wash. The stone has given us a lime mortar with certain impurities in lime paste and elements of hydraulic grains forming aggregate. This type of lime is characteristic for the studied area in Vägume, where a sub hydraulic lime also where documented. The sub hydraulic one would have to be dry slaked in order to use it in mortar. A grainy lime in some cases with elements of hydraulic grains is also seen in the mortar samples from Hägvide in Lärbro, Stora Ire in Hellvi and at Lunderhage in Fleringe where pure lime paste also were used. Gotland is known for its pure and lime rich slime, as can be seen in the samples from Risungs in Rute, Gaustäde I Bunge and at Fårö. Its therefore interesting to see that sub hydraulic lime has been used on Gotland. Hydraulic lime was also found in one of the samples from Angelbos, where the amount of hydraulic binder was high, it could in fact be a KC-mortar, the hydraulic particles remind of clinker. The mixing ratio is generally 1:2, although leaner and more lime rich mortars occur in the examined samples. The mortars are relatively compact. In Runte and Bunge, the lime mortars appear to be fatter, most of the samples show a mixing ratio of around 1:1, some slightly leaner. In Bunge, a medieval mortar was probably found. It was extremely lime rich, containing little sand and many lumps of lime which partly formed aggregate. Fatter than 1:1. The lime that’s been used in this mortar has been stored for a long time and were probably earth slaked. We do not see this tradition in the other mortar samples where the lime was slaked and used directly. The aggregate in almost all of the mortars is very fine-grained sand, with a grain size around 0,5 mm and smaller. Elements of larger sand grains occur. The size of the lime limps varies greatly from mm-sized grains to 1 cm. The largest between 2-3 cm.  A more modern element and approach to traditional lime mortar was found in one of the samples from Risungs in Rute, where air entraining agent has been added. Resulting in a mortar with a collapsed pore system that gives the mortar poor durability. The contrast I great compared to the older lime rich and compact 1:1 mortars from Risungs.  Another interesting result showed that two of the samples contained larger amounts of clay. In the sample from Vägume the sand itself contained clay, which can be seen in parts of the area. This is the only clay-mixed lime mortar in the study. This shows that even the sand can differ quite a lot within a small area, which in turn produces mortars with different properties. In the sample from Hägvide, elements of brick-red particles can be seen in the thin section. This comes from layers of clay in the burnt lime stone. The brick-red colour comes from a clay containing iron minerals.  In the type of lime render that creates a granulated surface, only lime and see gravel have been used, which is somewhat unusual because a little amount of sand is often added. Maybe the sand was seen as unnecessary because the lime itself contributes with aggregate through the lime lumps. A regional variant seen in several of the analysed mortar samples.   The study shows that local materials were used during the second stone building period on Gotland, and that the stone that’s been used has local variations within and between the parishes, which means that local traditions can be distinguished. The sand is to a greater extent of the same type in the investigated areas, while in Vägume both clay-mixed sand and pure fine-grained sand were used. The mixing ratio is generally around 1:2, which corresponds to the national approach that came beyond the 18th century. This is how Risungs and Gaustäde stands out, where the tradition of somewhat fatter lime mortar has survived. Vägumes local tradition where sub hydraulic lime and gritty lime with elements of hydraulic particles were used is therefore interesting.

New technologies, such as an efficient vapor-compression evaporator, a stationary lime kiln (SLK), and the MixAlco process, compelled us to re-evaluate methods for producing sugar from cane. These technologies allow more water and lime to be used, and they add more value to bagasse. Extracting and preserving the sugars, and lime pretreating the bagasse to enhance biodigestibility, all at the same time in a pile, was demonstrated to be unfeasible; therefore, sugar extraction must occur before lime treating the bagasse. Sugar extraction should occur countercurrently by lixiviation, where liquid moves in stages opposite to the soaked bagasse (megasse), which is conveyed by screw-press conveyors that gently squeeze the fiber in each stage, improving extraction. The performance of a pilot-scale screw-press conveyor was tested for dewatering capabilities and power consumption. The unoptimized equipment decreased megasse moisture from 96 to 89%. Simulation of the process suggested that eight stages are necessary to achieve 98% recovery from typical sugarcane. The cumulative power for the screw-press conveyor system was 17.0±2.1 hp•h/ton dry fiber. Thin raw juice preserved with lime for several months showed no sucrose degradation and no quality deterioration, except for reducing sugar destruction. The lime loading needed for 1-year preservation is 0.20 g Ca(OH)2/g sucrose. Shorter times require less lime. After preservation, the juice was carbonated and filtered, and the resulting sludge pelletized. Due to their high organic content, the pellets were too weak for calcination temperatures used in the SLK. The organics must be decreased prior to pelletization and sodium must be supplemented as a binding agent. Long-term lime pretreatment of bagasse showed two delignification phases: bulk (rapid) and residual (slow). These were modeled by two simultaneous first-order reactions. Treatments with air purging and higher temperatures (50 – 57oC) delignified more effectively, especially during the residual phase, thus yielding higher cellulase-enzyme digestibilities after 2 – 8 weeks of treatment. At temperatures > 60oC, pure oxygen purging is preferred. Fresh bagasse was of better quality than old bagasse. Treatment with NaOH yielded a larger bulk delignification phase than Ca(OH)2. Long-term lime pulping of bagasse was unsuitable for copy-quality paper, but it was appropriate for strawboard and other filler applications.