Tesi: "Cement clinkers"

1

Peterson, Vanessa Kate. "Diffraction investigations of cement clinker and tricalcium silicate using Rietveld analysis /". Electronic version, 2003. http://adt.lib.uts.edu.au/public/adt-NTSM20040830.173127/index.html.

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Thesis (Ph. D.)--University of Technology, Sydney, 2003.
"Submited for the degree of Doctor of Philosophy, University of Technology, Sydney, Dept. of Chemistry, Materials and Forensic Sciences, August 2003" Bibliographic references: leaves 224-232.

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2

Skalamprinos, Solon. "Hydration of calcium sulfoaluminate cements". Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=234036.

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The necessity to reduce CO2 emissions has increased the driving force for the cement research community to develop alternatives to traditional Portland cement (PC). One of the alternative cements being investigated is calcium sulfoaluminate cement (CS ̅A), first developed commercially in China in the 1970's. CS ̅A cements are produced by clinkering together limestone, bauxite, clay and calcium sulfate to produce mainly ye'elimite (C4A3S ̅) and belite (C2S). Due to the presence of ye'elimite, SO3 content is typically between 6 – 10 wt%. The abundance of elemental sulfur arising from the desulfurisation of oil and gas and its use to produce CS ̅A clinkers were the starting points of the Green Concrete Project (GCP), which aimed to develop a novel approach to produce CS ̅A cement via the combustion of elemental sulfur, recycling this by-product and reducing the dependence on hydrocarbon fuels. Integrating the current knowledge on the production of CS ̅A, a new generation of CS ̅A belite calcium sulfoaluminate (BCS ̅A) and belite-ye'elimite-ternesite (BYT) clinkers incorporating the combustion of elemental sulfur has been successfully developed and produced in a pilot plant production process. A high-temperature thermodynamic model was developed to predict stable assemblages and to complement and validate experimental results. Within the frame of the GCP, the title thesis focused on collecting conditional thermodynamic data for ye'elimite and ternesite (enthalpy of formation) that were determined experimentally using isothermal conduction calorimetry. The enthalpies of formation of ye'elimite and ternesite at 25 °C were determined to be -8523 kJ/mol and -5993 kJ/mol, respectively. The thesis was also focus on characterising two clinkers of interest (designated BCS ̅A and BYT) obtained from a pilot plant trial (with the novelty of sulfur combustion). The obtained clinkers, BCS ̅A and BYT, have a distinctive mineralogy where alpha prime belite (α΄-C2S) and ternesite (C5S2S ̅) are present, respectively. Both phases are candidates to replace a significant amount of ye'elimite and therefore reduce the need of expensive bauxite to establish a more sustainable cement. The alpha prime polymorph of belite proved to be more reactive than the beta. However, actions had to be taken to control the fast setting of this BCS ̅A cement. To provide a solution to the fast setting problem a variety of retarders were investigated: 0.5 wt% citric acid with an additional 5 wt% gypsum showed the best results. A fundamental solution was also Abstract 5 investigated in order to avoid the use of any retarders. The results showed that the clinkering temperature should be around 1300 °C. The hydration of ternesite in the BYT cement was found to be moderate. Therefore, a thorough investigation was conducted to understand and find ways to enhance its reactivity. It was found that the addition/presence of 0.4 wt% MgO, 0.2 wt% K2O and 0.1wt% Na2O in the raw meal required for the synthesis of ternesite, can increase its reactivity. Furthermore, it was found that particle size distribution above 600 m2/kg can also accelerate its reactivity. Single-phase chemically activated ternesite hydrated rapidly at 25 °C, achieving compressive strengths of ≈ 30 and ≈ 65 MPa at 28 and 90 days respectively, with C-S-H and gypsum as hydration products.

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3

Swart, Dustin W. "The utilization of alternative fuels in the production of Portland cement". Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/SWART_DUSTIN_26.pdf.

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4

Akkapeddi, Srikanth Schindler Anton K. "Alternative solid fuels for the production of Portland cement". Auburn, Ala., 2008. http://hdl.handle.net/10415/1432.

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5

Wilson, William S. M. Massachusetts Institute of Technology. "Grinding of cement clinkers : linking multi-scale fracture properties to system chemistry, mineralogy and microstructure". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82861.

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Thesis (S.M.)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 162-172).
Growing environmental concerns encourage the cement industry to improve its environmental performance, which in turn renews the interest in clinker grinding efficiency. Current knowledge on clinker grinding was built over the past decades, but contributions from fracture mechanics remained limited. This research aimed to contribute to this field by investigating industrial clinkers with innovative techniques such as multiscale microscratching and statistical electron-probe microanalysis (EPMA). Microstructure investigations were first performed with scanning electron microscopy (SEM), and three characteristic length scales were defined for clinkers: the nodules at the macroscale, the clinker matrix and porosity at the intermediate scale, and the clinker phases at the microscale. A statistical EPMA method was developed to allow simultaneous determination of the clinker bulk chemistry, the chemistry of the clinker phases, and their abundance. The microscratch test method was downscaled to measure the fracture properties at each characteristic scale of clinkers. Measurements on single silicate grains provided access to the intrinsic fracture toughness, which was three to four time lower than the macroscale fracture toughness. A combination of microstructure effects and toughening mechanisms (crack deflection, crack tip shielding by microcracks, crack trapping, and crack pinning) explained this behavior. Comparison of industrial clinkers showed that higher macroscale toughness (i.e., poor coarse grindability) was associated with oversized alite crystals, which was explained by the increase of microcracks toughening with larger grain size. In contrast, lower macroscale fracture toughness (i.e., better coarse grindability) was associated with either poorly burned clinkers showing excessive porosity or well burned clinkers having a good repartition of small silicates. However, difficulties in fine grinding were expected for the poorly burned clinkers because of the increased amounts of clustered belite. Overall, this thesis presents new experimental methods to investigate clinkers, as well as links between clinkers properties and grindability, both of which hold interest to the scientific community and the cement industry.
by William Wilson.
S.M.

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6

Puthur, Jayapalan Amal Raj. "Properties of cement-based materials in the presence of nano and microparticle additives". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49104.

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Cement clinker production is a highly resource and energy intensive process and contributes substantially to annual global anthropogenic greenhouse gas emissions. One potential pathway to reduce the environmental footprint of cement-based materials is through the reduction of clinker content in concrete by partial replacement of cement with fillers. In this investigation, the partial replacement of cement with chemically inert nano and microsized fillers of titanium dioxide (TiO₂) and limestone was examined. The effects of nano and micro fillers on early-age properties, long-term properties, photocatalytic properties (for TiO₂-cement mixtures) and life cycle costs were measured and compared. Investigation of early-age properties shows that nanoparticles increase rate and degree of early cement hydration and chemical shrinkage due to heterogeneous nucleation effect. In contrast, coarser microparticles (>3µm in this research) maintain or marginally decrease the rate and degree of early cement hydration and decrease chemical shrinkage due to a dilution effect. In addition, temperature sensitivity of hydration reactions increases in the presence of nanoparticles. Investigation of long-term properties shows that pore size refinement is possible with the partial replacement of cement with nanoparticle fillers. But the long-term tests of filler-cement mixes also demonstrate that, compared to ordinary portland cement mix, the strength decreases and permeability increases. Analysis of photocatalytic properties of TiO₂-cement mixtures showed a lack of an appropriate testing procedure for nitrogen oxide (NOₓ) gas conversion by cement-based materials. Thus, a new standardized procedure and photocatalytic efficiency factor for characterizing photocatalytic NOₓ binding by cementitious materials is proposed. Life cycle analysis demonstrates that although inclusion of TiO₂ increases initial environmental impact of cementitious materials, the innovative photocatalytic properties of TiO₂ could improve sustainability. Life cycle analysis also shows that partial replacement of cement with limestone decreases environmental impact of cementitious mixtures due to lower processing “costs” of limestone compared to cement. Thus, the results from the current research demonstrate that variation of dosage and particle size of inert fillers can be used to tailor properties and structure of cement-based materials and that environmental sustainability can be improved by partial replacement of cement with inert fillers that introduce additional functionalities or fillers with lower embodied-energy and emissions.

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7

Van, Rompaey Gilles. "Etude de la réactivité des ciments riches en laitier, à basse température et à temps court, sans ajout chloruré". Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210780.

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Le ciment Portland est de loin le liant hydraulique le plus connu et utilisé depuis de très nombreuses années tant dans le secteur de la construction civile qu’au niveau du stockage des déchets (barrières ouvragées ou matériau de confinement). Le processus industriel qui donne naissance au clinker, constituant de base du ciment Portland, n’a pas subi de modifications depuis des décennies.

Par ailleurs, au cours de ces dernières années, certaines considérations telles que le réchauffement climatique et le développement durable ont mis à mal les industries qui émettent des gaz à effets de serre et qui sont grosses consommatrices d’énergie.

Or, la production de ciment Portland n’est pas uniquement consommatrice de calcaires, d’argiles, de marnes et de combustibles fossiles, elle produit et libère ces gaz à effets de serre tels que le dioxyde de carbone (CO2) et l’hémioxyde nitreux (N2O). Le dioxyde de soufre (SO2), l’acide chlorhydrique (HCl) ainsi que d’autres oxydes d’azote (NOx) sont également émis lors du processus de fabrication du clinker. Le secteur des matériaux de construction contribue de façon importante aux émissions de CO2, le principal responsable du réchauffement climatique.

La problématique majeure de l’industrie cimentière provient d’un simple processus chimique de transformation :la décarbonatation du calcaire ou de la craie, débutant vers 550°C, qui forme de la chaux (CaO) et qui libère du dioxyde de carbone selon la réaction suivante :

CaCO3 =\
Doctorat en sciences, Spécialisation géologie
info:eu-repo/semantics/nonPublished

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8

Boulot, Karine. "Les éléments mineurs dans le procédé cimentier". Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL149N.

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Du potassium, sodium, soufre et chlore passent en phase gazeuse dans les fours de cimenterie. Ils circulent alors a contre courant de la matière, se condensent dans les zones plus froides du four, sont repris par le circuit matière et retournent en zone chaude. Ils constituent une charge circulante perturbant la cuisson. Or, il devient économiquement intéressant d'utiliser des matières et combustibles à fortes teneurs en éléments volatils. Il s'avère alors nécessaire d'en maitriser la recirculation. - introduction : mise en évidence des problèmes industriels lies a la recirculation. - éléments bibliographiques : étude bibliographique de base et industrielle dont la synthèse a permis le choix des voies de recherche. - étude de la volatilisation primaire : le sodium commence à se volatiliser à 1450C°. Le potassium commence à se volatiliser aux environs de 1200C° A 1450C°, il reste de 5 a 40 % du potassium initial (qui dépend de la phase minérale porteuse). - étude de la volatilisation secondaire : il se forme, dans les fours, du chlorure de potassium, du sulfate de potassium, de sodium et de calcium qui se comportent différemment les uns des autres. Le chlorure de potassium : volatilisation pour des températures bien inferieures a 1450C°. Le sulfate de potassium : en atmosphère oxydante, sa volatilisation est limitée par la pression de vapeur saturante du sulfate de potassium gazeux. En atmosphère réductrice, elle s'effectue par décomposition. Le sulfate de sodium : volatilisation très faible en atmosphère oxydante ; mais importante, par décomposition, en atmosphère neutre ou réductrice. Le sulfate de calcium : volatilisation par décomposition influencée par l'atmosphère de cuisson. - étude du piégeage du chlore gazeux. Entre 700 et 800c. - étude de la recirculation dans un four vertical a gradient thermique. - l'influence du sodium et de sulfates sur la clinkerisation : à hautes doses, ils sont des poisons de la clinkerisation

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9

Champenois, Jean-Baptiste. "Etude de l’hydratation des ciments sulfo-alumineux par des solutions de borate de sodium : de la spéciation du bore au retard à l'hydratation". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20252/document.

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Dans le circuit primaire des réacteurs nucléaires à eau pressurisée, le bore participe au contrôle des réactions de fission. Le traitement de cette solution génère des déchets aqueux contenant une forte concentration en bore (de 1 à 3 mol/L). Le conditionnement de ces déchets à l'aide d'un ciment silico-calcique est compliqué par le fort pouvoir retardateur des ions borate sur l'hydratation du liant. Un traitement des déchets à la chaux est nécessaire pour précipiter les ions borate sous forme d'hexahydroborite. Cette stratégie, si elle limite le retard d'hydratation, ne le supprime pas. Par ailleurs, l'hexahydroborite est instable en milieu cimentaire et se convertit dans le temps en boroaluminate de calcium. Une autre approche pourrait consister à utiliser un ciment sulfoalumineux bélitique à forte teneur en ye'elimite. Ce liant présente en effet l'avantage de former en quantité importante des phases de type AFm et/ou AFt lors de son hydratation, phases qui peuvent incorporer des ions borate dans leur structure.Au cours de ce travail, l'hydratation de ciments sulfoalumineux par des solutions de borate de sodium a été étudiée au jeune âge et à plus long terme (sur une durée de 2 ans) dans l'objectif de préciser l'influence d'un ensemble de paramètres (pH du déchet, concentration en bore, taux de gypse du ciment) sur la vitesse d'hydratation du liant, la nature des hydrates formés, et les propriétés du matériau obtenu (résistance mécanique, stabilité dimensionnelle). Pour ce faire, une démarche analytique, procédant par complexification progressive des systèmes étudiés, a été mise en œuvre. Ainsi ont été successivement abordées la spéciation du bore en solution alcaline, l'étude des phases précipitant au sein des systèmes {CaO, B2O3, Na2O, H2O}, {CaO, B2O3, Al2O3, H2O} et {CaO, Al2O3, B2O3, SO3, H2O}, puis celle des pâtes de ciment gâchées avec une solution boratée simulant le déchet. L'approche expérimentale a été complétée par des modélisations thermodynamiques s'appuyant sur une base de données spécialement développée pour les besoins de l'étude.Il apparaît que le gypse joue un rôle primordial dans le contrôle de la réactivité du ciment. L'ajout de gypse fixe, par un mécanisme indirect, le pH de la solution interstitielle à une valeur proche de 11, ce qui favorise la précipitation transitoire d'un composé boraté faiblement cristallisé, l'ulexite. La dissolution des phases anhydres du ciment est alors fortement ralentie jusqu'à l'épuisement du gypse, conduisant ainsi à des retards de prise considérables. En l'absence de gypse, le retard à l'hydratation est de plus faible amplitude. Dans ces conditions, le pH de la solution interstitielle atteint des valeurs plus élevées, ce qui permet de déstabiliser rapidement l'ulexite. A plus long terme, les ions borate sont incorporés au sein d'une phase de type AFt, en solution solide avec les ions sulfate. Les résultats obtenus permettent de conclure que ce sont les ciments sulfo-alumineux contenant une faible teneur en gypse qui sont les plus adaptés au conditionnement de solutions à forte concentration en bore
In the primary circuit of pressurized water reactors, boron helps controlling the fission reactions. The treatment of this solution produces aqueous low-level or intermediate-level and short lived radioactive with a high boron concentration (up to 1 to 3 mol/L). Stabilization/solidification of such wastes with calcium silicate cement is complicated by the strong retarding effect of borate ions on cement hydration. A calcium hydroxide addition is required to precipitate borate ions into hexahydroborite. With this approach, the hydration delay is limited, but not suppressed. Besides, hexahydroborite is unstable in the cement paste and is progressively converted into a hydrated calcium boroaluminate phase. Another strategy may consist in using belite calcium sulfoaluminate cement with high ye'elimite content. During hydration, this binder forms indeed large amounts of AFm and/or AFt phases which can incorporate borate ions into their structure.In this work, hydration of calcium sulfoaluminate cement by borated solutions was investigated at early age, and over a 2-year period, in order to determine the influence of a set of parameters (boron concentration and pH of the waste, gypsum content of the cement) on the hydration rate of the binder, on the phase assemblage formed, and on the properties of the resulting material (mechanical strength, volume change). An analytical approach was adopted, based on a progressive increase in the complexity of the investigated systems. The focus was successively placed on the speciation of boron in alkaline solution, on the study of the phases formed within the {CaO, B2O3, Na2O, H2O}, {CaO, B2O3, Al2O3, H2O} and {CaO, Al2O3, B2O3, SO3, H2O} systems, and on the characterization of cement pastes prepared with a borate solution which mimicked the waste. The experimental approach was completed by thermodynamic modelling using a database specially developed for the needs of the study. Gypsum appears to play a key role in controlling the reactivity of cement. The gypsum addition sets, by an indirect mechanism, the interstitial solution pH at a value close to 11, which promotes the precipitation of a poorly crystallized borated compound, ulexite. Dissolution of the anhydrous phases is strongly slowed down until the exhaustion of gypsum, and major delays are observed. Without any gypsum, the hydration delay is shorter. Under these conditions, the pore solution pH reaches higher values after mixing. Ulexite is consequently quickly destabilized. Borate anions are then incorporated into a mixed borate/sulphate AFt type phase. It appears that calcium sulfoaluminate cements with low gypsum contents should be recommended to solidify borated solutions

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Krour, Hichem. "Recyclage du ciment dans le ciment : incorporation des déchets de construction et de démolition dans le cru cimentier". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0008.

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Le projet Européen « SeRaMCo » vise à la fabrication d’éléments préfabriqués en béton contenant des granulats recyclés et du ciment « recyclé ». Ce ciment est fabriqué en incorporant des déchets de construction et de démolition dans le cru cimentier, notamment la fraction fine qui est la plus riche en pâte de ciment durci. Cette thèse de doctorat a permis de mieux comprendre l’impact de la variabilité chimique et minéralogique des granulats recyclés sur le taux d’incorporation et sur la proportion des autres constituants du cru. Les synthèses en laboratoire et caractérisations associées ont permis de suivre l’évolution de la minéralogie au cours de l’élévation de la température et pour plusieurs types et taux de granulats recyclés. Les essais ont aussi montré, notamment par microscopie électronique en transmission, que pour un taux élevé d’incorporation, la présence de quartz, de feldspath et de céramique peut altérer l’aptitude à la cuisson du cru et les mécanismes réactionnels. En partenariat avec le cimentier VICAT, les travaux ont prouvé qu’il est possible de produire un ciment « recyclé » industriel aux propriétés usuelles en ajustant au besoin le procédé de fabrication ou en réduisant le taux d’incorporation. Un taux d’incorporation même limité permet de valoriser sans difficultés les déchets disponibles à l’échelle régionale d’une cimenterie en préservant ses ressources naturelles. Ces travaux offrent également de nouvelles perspectives quant à la valorisation d’autres matériaux en cimenterie et l’étude de leur réactivité
The European "SeRaMCo" project aims to manufacture precast concrete elements containing recycled aggregates and "recycled" cement. This cement is obtained by incorporating construction and demolition waste into its raw material, in particular the fine fraction which is the richest in hardened cement paste. This PhD thesis provided a better understanding of the impact of the chemical and mineralogical variability of recycled aggregates on the incorporation rate and on the proportion of other raw materials. Laboratory syntheses and associated characterizations allowed to follow the evolution of the mineralogy during the rise in temperature and for several types and rates of recycled aggregates. Tests, including transmission electron microscopy, have also shown that for a high rate of incorporation, the presence of quartz, feldspar and ceramic can affect the burnability of the cement raw meal and the reaction mechanisms. In partnership with the cement manufacturer VICAT, the work has shown that it is possible to produce an industrial "recycled" cement with usual properties by adjusting the manufacturing process as needed or by reducing the rate of incorporation. Even a limited incorporation rate allows to recover easily the waste available on a regional scale from a cement plant while preserving its natural resources. This work also offers new perspectives for the recovery of other materials in cement works and the study of their reactivity

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Guo, Zongqi. "Coatability of cement clinker on basic refractories". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60938.pdf.

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12

Eriksson, Matias. "Sustainability measures in quicklime and cement clinker production". Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-112842.

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This thesis investigates sustainability measures for quicklime and cement clinker production. It is the aim of this thesis to contribute to the effort of creating a more sustainable modus of industrial production. The methods used comprises process simulations through multicomponent chemical equilibrium calculations, fuel characterization and raw materials characterization through dynamic rate thermogravimetry. The investigated measures relate to alternative fuels, co-combustion, oxygen enrichment, oxyfuel combustion, mineral carbonation and optimizing raw material mixes based on thermal decomposition characteristics. The predictive multicomponent chemical equilibrium simulation tool developed has been used to investigate new process designs and combustion concepts. The results show that fuel selection and oxygen enrichment influence energy efficiency, and that oxyfuel combustion and mineral carbonation could allow for considerable emission reductions at low energy penalty, as compared to conventional post-combustion carbon dioxide capture technologies. Dynamic rate thermogravimetry, applied to kiln feed limestone, allows for improved feed analysis with a deeper understanding of how mixing of different feed materials will affect the production processes. The predictive simulation tool has proven to be of practical value when planning and executing production and full scale campaigns, reducing costs related to trial and error. The main conclusion of this work is that several measures are available to increase the sustainability of the industry.

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Vikström, Amanda. "Separate Calcination in Cement Clinker Production : A laboratory scale study on how an electrified separate calcination step affects the phase composition of cement clinker". Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184038.

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Cement production is responsible for around 7% of the global anthropogenic carbon dioxide emissions. More than half of these emissions are due to the unavoidable release of carbon dioxide upon thermal decomposition of the main raw material limestone. Many different options for carbon capture are currently being investigated to lower emissions, and one potential route to facilitate carbon capture could be the implementation of an electrified separate calcination step. However, potential effects on the phase composition of cement clinker need to be investigated, which is the aim of the present study. Phases of special interest are alite, belite, aluminate, ferrite, calcite, and lime. The phase composition during clinker formation was examined through HT-XRD lab-scale experiments, allowing the phase transformations to be observed in situ. Two different methods of separate calcination were investigated, one method in which the raw meal was calcined separately, and one method where the limestone was calcined separately. The former yielded an alite amount similar to that of the reference experiments, whereas the latter method yielded a lower amount. It could, unfortunately, not be excluded that the difference was due to poor experimental conditions, and additional experiments are needed to investigate the matter further. The study does, however, indicate that a calcined raw meal might be used to produce a clinker of similar phase composition concerning major phases belite, aluminate, ferrite, alite, and free lime. A raw meal containing calcined limestone might, however, need longer residence time at clinkering temperature too obtain similar phase composition. In addition, a raw meal containing calcined limestone was observed to be carbonated to a greater extent upon reheating than a calcined raw meal. Further experiments are needed to fully understand the effects on clinker composition of an electrified separate calcination step, and several improvements to the experimental method are given in the study.

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Hökfors, Bodil. "Phase chemistry in process models for cement clinker and lime production". Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-86004.

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The goal of the thesis is to evaluate if developed phase chemical process models for cement clinker and lime production processes are reliable to use as predictive tools in understanding the changes when introducing sustainability measures. The thesis describes the development of process simulation models in the application of sustainability measures as well as the evaluation of these models. The motivation for developing these types of models arises from the need to predict the chemical and the process changes in the production process, the impact on the product quality and the emissions from the flue gas. The main chemical reactions involving the major elements (calcium, silicon, aluminium and iron) are relatively well known. As for the minor elements, such as sodium and potassium metals, sulphur, chlorine, phosphorus and other trace elements, their influence on the main reactions and the formation of clinker minerals is not entirely known. When the concentrations of minor and trace elements increase due to the use of alternative materials and fuels, a model that can accurately predict their chemistry is invaluable. For example, the shift towards using less carbon intensive fuels and more biomass fuels often leads to an increased phosphorus concentration in the products. One way to commit to sustainable development methods in cement clinker and lime production is to use new combustion technologies, which increase the ability to capture carbon dioxide. Introducing oxy-fuel combustion achieves this, but at the same time, the overall process changes in many other ways. Some of these changes are evaluated by the models in this work. In this thesis, a combination of the software programs Aspen Plus™ and ChemApp™ constitutes the simulation model. Thermodynamic data from FACT are evaluated and adjusted to suit the chemistry of cement clinker and lime. The resulting model has been verified for one lime and two cement industrial processes. Simulated scenarios of co-combustion involving different fuels and different oxy-fuel combustion cases in both cement clinker and lime rotary kiln production are described as well as the influence of greater amounts of phosphorus on the cement clinker quality.

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Galleguillos, Fuenzalida Francisco Antonio. "Estudio de variables operacionales en un horno rotatorio piloto para la empresa IDIEM". Tesis, Universidad de Chile, 2019. http://repositorio.uchile.cl/handle/2250/171021.

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Memoria para optar al título de Ingeniero Civil Químico
En el presente trabajo, se busca la puesta en marcha de un horno rotatorio, perteneciente a la empresa IDIEM, estudiando las distintas variables operacionales y como estas afectaron finalmente al clínker. Este proyecto se realizó con el fin de generar futuros servicios a empresas cementeras del país. Para esto se realizó un estudio bibliográfico, la descripción de metodología, posterior entrega y análisis de resultados, para finalizar entregando las conclusiones y mejoras al equipo. El cemento es un material cerámico fino que, al tener contacto con agua, genera distintas propiedades hidráulicas, las cuales son entregadas principalmente por el clínker. Este, posee cuatro fases principales, alita, belita, C_3 A y C_4 AF, siendo las dos primeras las encargadas de entregar las principales resistencias mecánicas. Por otra parte, las fases C_3 A ayuda a la velocidad de reacción y la fase C_4 AF ayuda a las resistencias químicas del material. La formación del clínker depende fuertemente de como este reacciona en el horno rotatorio, necesitando una temperatura de clinkerización cercana a los 1450-1500°C. Para esto, se estudiaron las distintas variables del horno, como los flujos de gas y aire, llegando a la conclusión de que un exceso de gas, además de generar un aumento en la temperatura en la zona de clinkerización, aumenta la temperatura en las partes posteriores del horno. Por otro lado, si se aumenta la concentración de aire, la mayoría de la combustión ocurrirá en la zona de clinkerización, disminuyendo la temperatura en otras zonas del horno. Adicionalmente, se calculó el tiempo de residencia para distintas velocidades de giro (2,2,5,3 y 3,5 RPM), y una formula general para el flujo de alimentación, para asegurar así, una mezcla óptica del crudo. Luego, se replicó el proceso industrial de Polpaico para la obtención de clinker, para luego realizar distintos análisis de laboratorio, tanto al clinker como al cemento. Aquí se obtuvo que, en comparación con el obtenido industrialmente, el de forma piloto presentó menos tiempo, y temperatura, de clinkerizacion, y que a su vez el enfriamiento secundario fue lento. Por lo cual, se generaron propuestas sobre el sistema de alimentación, flujo de gas, flujo de aire y enfriamiento del horno rotatorio piloto.

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GALIMBERTI, MATTEO. "ADVANCES IN ORDINARY PORTLAND CEMENT CLINKER: REDUCING THE ENVIRONMENTAL IMPACT OF THE PRODUCTION PROCESS". Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/478904.

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Abstract (sommario):

Ordinary Portland cement (OPC) clinker production process has a remarkable environmental impact in terms of energy consumption, raw materials exploitation and greenhouse gases emissions. The present thesis deals with advances in the characterization and formulation of OPC clinker raw meals, the limestone and clay minerals mixture that is thermally treated in the rotary kiln to obtain cement clinker. The purpose is to better understand some key points of the clinkerization, in order to reduce the environmental impact of the production process. First, the influence of limestone petrography and calcite crystals microstructure on the OPC clinker raw meals burnability was investigated. Starting from eight natural limestone samples, similar from a mineralogical and chemical point of view but very different concerning texture and diagenetic history, a reliable parameter linking the limestone features to the OPC clinker raw meals burnability was found. Then, for the first time the influence of different minor elements combinations on the clinkerization process was investigated, starting from an industrial raw meal instead from chemical reagents as in previous studies. This will allow to transpose results from the laboratory to the actual production process. Finally, an heterogeneous and unconventional raw meal configuration was tested: clay minerals were replaced by basalt and both coarse- and fine-grained limestone fractions were used, leading to very promising results in this still relatively unexplored field. These three topics were selected because held to be among the most relevant within the global framework to reduce the OPC clinker production process environmental impact. Moreover, they were studied separately but they actually interact with each other at the industrial scale.

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Hermansson, Anton. "Standardization and optimization of index for 28 day strength for cement made from standard clinker". Thesis, KTH, Kemiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-272830.

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Abstract (sommario):

This project regards the prediction of 28 day compressive strengths of cement. Using traditional multivariate analysis in combination with Artificial Neural Networks indexes have been developed which makes these predictions possible. Compressive strength is highly dependent on the cement hydration and clinker reactivity and literature on these topics have been studied followed by statistical analyses in Unscrambler X (Camo AS) and the Neural Networks model developed at Heidelberg Technology Center (HTC). After studying the theory behind compressive strength, some key parameters are identified including the Alite content, particle sizes as well as a variety of other parameters. Following this, a data set has been collected and formatted for the use in the project. Data on cement properties including compressive strength has been compiled by the quality engineer in Slite making the data collection simple. Having the data, the procedure includes a start with traditional multivariate analysis in Unscrambler to identify significant parameters in an effort of reducing the number of variables in the final model. In Unscrambler, Partial Least Squares regression has been used with uncertainty analysis as a selected option for parameter selection. Following the analysis in Unscrambler, the data set for each cement type is inserted into the neural networks models and the significant parameters are selected to act as input data, predicting either 1d or 28d strength. Before insertion into the Neural Networks model, the parameters are manually vetted with support of the literature and the accepted theories on cement hydration as correlations not necessarily mean that there is a causal link. Results are presented using the verification set of these indexes, indicating the prediction capacity of the indexes. Scenarios have also been used to study the underlying correlations between various properties and the compressive strengths. The results have shown good performance of the indexes created, and the procedure has proven to be fast and effective in creating these indexes. This opens up possibilities of using similar approaches to other areas of the plant in the future efforts to improve environmental and financial sustainability. Included in the final section of the report are also a few recommendations that would simplify the future work on this topic.

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Wang, Jia. "Hydration mechanism of cements based on low-CO2 clinkers containing belite, ye’elimite and calcium alumino-ferrite". Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10169/document.

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Abstract (sommario):

L’objectif de ce travail a été d’apporter une meilleure compréhension des mécanismes réactionnels de l’hydratation de ciments appartenant à la famille de ciment BCSAF afin de développer des schémas réactionnels simplifiés permettant d’optimiser les ciments à base d’un clinker BCSAF et d’autres constituants pour des applications spécifiques. Les ciments étudiés ont été réalisés à partir d’un clinker contenant 52% de belite, 33% de ye’elimite and 14% de ferrite et diverses quantités d’anhydrite et de calcaire. A partir de l’étude détaillée de l’hydratation d’un ciment contenant 95% de clinker et 5% d’anhydrite, il a été démontré que le mécanisme de l’hydratation est constitué de deux périodes successives : le début de l’hydratation est contrôlé par l’hydratation de la ye’elimite réagissant avec l’anhydrite, tandis que la suite de l’hydratation est contrôlée par les hydratations de la belite et de la ferrite qui réagissent avec certains des hydrates formés lors de la première période. La vitesse de nucléation de la strätlingite contrôle le début de l’hydratation de la belite. Le principal paramètre qui contrôle cette dernière est la concentration en sulfate de la phase aqueuse qui doit être très faible. Ainsi C-S-H n’est pas formé au début de l’hydratation de la belite certainement à cause de l’inhibition de sa nucléation par de trop fortes quantités d’aluminate en solution. Par conséquence, c’est indirectement la concentration en sulfate de la solution qui contrôle le début de l’hydratation de la belite and ainsi les réactions conduisant à sa réduction à travers la précipitation de phase notamment lors de l’hydratation de la ye’elimite pour former de l’ettringite. Ainsi d’une façon générale, la strätlingite commence à nucléer quand la ye’elimite a complètement réagi. D’autre part, une synergie entre les hydratations de la belite et de la ferrite permet de former des hydrogrenats et des C-S-H à des temps longs au détriment de la strätlingite formée auparavant. Un mécanisme d’hydratation similaire a été trouvé pour les ciments contenant des quantités plus importantes d’anhydrite à l’exception de ceux qui contiennent une quantité d’anhydrite supérieure que la quantité théorique permettant de faire réagir toute la ye’elimite en ettringite. Toutefois pour le premier type de ciments, une augmentation de la quantité d’anhydrite allonge à la fois le temps d’apparition de la seconde période et la durée des différentes étapes de cette dernière. Donc l’hydratation est globalement plus lente. Pour le second type de ciment, contenant de fortes quantités d’anhydrite, le mécanisme d’hydratation est assez différent car l’hydratation de la belite commence dès le début de l’hydratation et conduit à la formation, soit d’ettringite contenant Si, soit de C-S-H. L’effet de 15% de calcaire a également été étudié pour le ciment contenant 95% de clinker et 5% d’anhydrite. Les résultats ont montré que le calcaire ne change pas la première période de l’hydratation mettant en jeu principalement la ye’elimite et l’anhydrite. Par contre la seconde période, durant laquelle la belite et la ferrite s’hydratent, est fortement retardée à son début. Ceci peut être dû à un retard de la nucléation de la strätlingite à cause de concentrations en sulfate de la solution restant plus longtemps élevées par le fait que l’ettringite est stabilisée en présence de carbonate par la formation de phases AFm carbonatées qui inhibent la formation de monosulfoaluminate de calcium hydraté. Pour finir, des perspectives sont données notamment afin de réduire la durée de la première période de l’hydratation et ainsi permettre un démarrage plus rapide de l’hydratation de la belite et de la ferrite
The objective of this work was to better understand the hydration mechanisms of cements belonging to the family of BCSAF cement in order to develop simple mechanistic models which can help us to optimise mixtures of BCSAF clinker and other compounds for specific applications. The studied cements were made from a clinker containing 52% of belite, 33% of ye’elimite and 14% of a ferrite phase and various amounts of anhydrite and limestone. From the Detailed investigation of the hydration of cement containing 95% of clinker and 5% of anhydrite, it has been demonstrated that the mechanism of hydration has two main successive periods of hydration: the beginning of hydration is controlled by ye’elimite and anhydrite, while the remaining of hydration is governed by belite and the ferrite phase that react with some of the hydrates formed during the first period. It is C2ASH8 nucleation rate that governs the beginning of the hydration of belite. The main parameter that governs the nucleation rate of strätlingite is [SO4]2- that has to be low. C-S-H does not form as the initial hydrate for belite hydration due to the inhibition effect of high aluminate concentration on C-S-H nucleation. As a consequence, this is indirectly the sulphate concentration that controls the beginning of belite hydration and thus the reactions leading to its reduction, mainly the hydration of ye’elimite to form ettringite. Globally it is once ye’elimite has been completely reacted that strätlingite may nucleate. A synergy between the reactions of belite and ferrite is found to accelerate the formation of later hydrate, hydrogarnet and C-S-H at the expense of strätlingite.A similar mechanism of hydration has been found for cements having higher anhydrite contents at the exception of cements that have more anhydrite than the theoretical anhydrite content to consume all ye’elimite to form ettringite. For the former cements, more anhydrite can strongly delay the second period of the hydration where both belite and ferrite react. In the later cases, the mechanism of hydration is quite different as belite does start to react till the beginning of hydration certainly forming either a Si containing ettringite or C-S-H. The influence of 15% of limestone was investigated on the cement containing 95% of clinker and 5% of anhydrite. The results showed that limestone did not change the first period involving anhydrite and ye’elimite, but strongly delayed the beginning of the second period where both belite and ferrite hydrate. This may be due to a delayed nucleation of strätlingite induced by a longer period having higher [SO4]2- as ettringite is stabilised by the precipitation of carbonated AFm at the expense of calcium monosulfoaluminate hydrate, thanks to the carbonate ions brought by limestone. Finally some perspectives are given in order to reduce the duration of the first period and then to enable the hydration of both belite and ferrite more rapidly

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Herterich, Julia. "Microstructure and phase assemblage of low-clinker cements during early stages of carbonation". Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/17717/.

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Abstract (sommario):

Though it is well established that a reduced rate of hydration is observed in composite cement materials, both the PC and the SCM will hydrate simultaneously, there is still a significant lack of knowledge regarding the early age kinetics of the reactions taking place. This becomes of great importance when considering the early removal of formwork in practice, where the reliance is on models established for PC systems. A comprehensive understanding of the complex relationship between slower composite hydration, drying of the sample surface and phase carbonation kinetics is imperative. Current models derived from idealistic, i.e. fully hydrated and non-carbonated, materials, are ineffective for durability predictions. In addition to this, the existing models do not consider the effects that insufficient curing and phase carbonation have on the phase assemblage composition, development of the microstructure and the subsequent consequences for the transport properties. This study investigates the effects of carbonation following short curing periods (72 hours) on CEMI and composite cement systems (30% PFA, 30% & 60% GGBS) at a low (0.40) and high (0.57) w/b ratio. Modifications in carbonation behaviour were observed compared to idealised/28 day cured samples and natural carbonation studies in the literature. Although the carbonation of the hydrate phases was observed to occur simultaneously, it was only once CH had been completely consumed, or was no longer accessible, that carbonation of the other hydrate phases (C-S-H, AFt and AFm) was permitted to occur more extensively. Decalcification and dealumination of the C-S-H phase occurred following exposure to ambient [CO2], and CaCO3 microcrystals were observed in the outer product (Op) regions only. A reduction in the Ca/Si ratio of the Ip C-S-H appeared to be a result of migration of the Ca ions, driven by a concentration gradient. Furthermore, the rate and extent of carbonation and the nature of the carbonate species formed was dependent on the level of replacement, the replacement material and the degree of hydration. The formation of vaterite appeared to be related to the carbonation of C-S-H, particularly low Ca C-S-H, and silica gel was observed to form in the CEMI and blended materials following carbonation at ambient CO2 concentrations for 60 days. AFt was determined to be more resilient to carbonation compared to the AFm phases, remaining in heavily carbonated CEMI pastes in which portlandite was absent. The carbonation of the AFm phases was observed to occur in two stages; first, phase transformation from SO4 (monosulfoaluminate) to CO3 (hemi- and monocarboaluminate) bearing species was observed to occur, ultimately decomposing by decalcification. The availability of CH, however, prevented complete decomposition. Low w/b ratios were unable to mitigate the effects of short curing periods for systems with high levels of substitution but improved the carbonation resistance of cement systems with moderate levels of substitution (30%). The availability of CH was determined to be the rate determining factor for carbonation, but its consumption is primarily controlled by the ability of CO2 to diffuse through the microstructure.

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Terblanche, Ulrich. "Effective Use of Excess Heat in a Cement Plant". Thesis, KTH, Tillämpad termodynamik och kylteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104080.

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Abstract (sommario):

The report investigates the feasibility of accessing waste heat at kiln 7 in the Cementa AB cement plant in Slite, Gotland. The background is provided, with a description of the cement manufacturing process. Most of the report concerns itself with the heat transfer capabilities of the plant, therefore a short description of the heat flow within the most essential equipment is provided. The investigation follows a set of steps to derive the conclusion. The first step investigates previous studies to obtain the three most feasible heat sources. The second step investigates the available heat of the selected sources. In the third step, accessing the source is discussed and investigated for both convection and radiation heat transfer methods. It also includes the sizing of the required heat exchangers. Using the new sources, the connection possibilities to existing infrastructure and its benefits are investigated in step four. The connections were made to the existing infrastructure used at kiln 8 for electrical generation and district heating supply. The selections of the most feasible solutions are provided based on heat recovery, payback period and practicality. The final step in the study provides for the final design, which consists of three possible connections or all of them combined. In the conclusion, the final design would provide for a reduction in oil burned, fuel consumption and CO2 emissions and an increase in electricity generated by the existing system. It is recommended that only one of the three connections be installed.

The thesis was conducted at Cementa AB in Slite, Gotland. The supervisor at the plant was Fred Grönwall.

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21

Walter, Martin. "Vlastnosti portlandských cementů s ohledem na ekonomickou a ekologickou efektivitu výroby". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225915.

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Diploma thesis discusses about design composition and firing process modification of belite clinker. It also deals with the summary of knowledge about chemistry and production technology of portland cements with respect to its ecology and economy.

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22

Brzobohatý, Lukáš. "Odloučení dopravního vzduchu surovinové moučky". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230833.

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The dissertation is focused on the applied technical and economic analysis of the influence separation of transport air from raw meal on the economy clinker/cement production, in specific cement production. The analysis is performed on the basis of a detailed understanding and analysis of the function of each component of the technology of cement production, which are affected by separation of transport air from raw meal, mainly the dosing and preheat system of the raw meal. The results of the analysis show a significant effect (impact) separation of transport air on the production costs.

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23

Halešová, Adéla. "Studium tvorby a kinetiky hydratace belitického slínku". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265435.

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Abstract (sommario):

DIPLOMA THESIS IS DEVOTED TO THE STUDY OF PREPARATION OF PURE BELITE CLINKER FOR THE POTENTIAL INCREASE OF KINETICS OF THE HYDRATION PROCESS BY CHEMICAL ACTIVATION. THE THESIS OF THIS WORK IS BASED ON RESEARCH FINDINGS CONCERNING BELITE CLINKER AND RESEARCH AT THE INSTITUTE OF THD. THE THESIS AIMS TO DESIGN COMPOSITION OF THE RAW MEAL BURNING BELITE, FOLLOWING MODIFICATION BY SULPHATE AND POTASSIUM CARBONATE IN ORDER TO POTENTIALLY INCREASE THE REACTIVITY OF THE BURNT BELITE CLINKER AND THE LABORATORY FIRING OF PREPARED SAMPLES. THE LAST STEP WAS TO ASSESS THE MINERALOGICAL COMPOSITION OF BURNED SAMPLES XRD ANALYSIS AND FOLLOWING COMPARISON CELL PARAMETER OF BELITE WITH AND WITHOUT ADDED MODIFYING ADDITIVES.

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Magrla, Radek. "Modifikace vlastností portlandských cementů orientovaná na snížení emisí CO2". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225907.

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Abstract (sommario):

This thesis aims to burn raw material with a lower content of carbonate component for the production of Portland cement. Substitution of carbonate component is done by fluidized fly ash. The model cements are tested of basic technological properties and the hydration process is observed.

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Camalan, Mahmut. "Size-by-size Analysis Of Breakage Parameters Of Cement Clinker Feed And Product Samples Of An Industrial Roller Press". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614594/index.pdf.

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Abstract (sommario):

The main objective in this study is to compare breakage parameters of narrow size fractions of cement clinker taken from the product end and feed end of industrial-scale high pressure grinding rolls (HPGR) in order to assess whether the breakage parameters of clinker broken in HPGR are improved or not. For this purpose, drop weight tests were applied to six narrow size fractions above 3.35 mm, and batch grinding tests were applied to three narrow size fractions below 3.35 mm. It was found that the breakage probabilities of coarse sizes and breakage rates in fine sizes were higher in the HPGR product. This indicated that clinker broken by HPGR contained weaker particles due to cracks and damage imparted. However, no significant weakening was observed for the -19.0+12.7 mm HPGR product. Although HPGR product was found to be weaker than HPGR feed, fragment size distribution of HPGR product did not seem to be finer than that of the HPGR feed at a given loading condition in either the drop weight test or batch grinding test. Also, drop weight tests on HPGR product and HPGR feed showed that the breakage distribution functions of coarse sizes depended on particle size and impact energy (J). Batch grinding tests showed that the specific breakage rates of HPGR product and HPGR feed were non-linear which could be represented with a fast initial breakage rate and a subsequent slow breakage rate. The fast breakage rates of each size fraction of HPGR product were higher than HPGR feed due to cracks induced in clinker by HPGR. However, subsequent slow breakage rates of HPGR product were close to those of HPGR feed due to elimination of cracks and disappearance of weaker particles. Besides, the variation in breakage rates of HPGR product and HPGR feed with ball size and particle size also showed an abnormal breakage zone where ball sizes were insufficient to effectively fracture the coarse particles. Breakage distribution functions of fine sizes of HPGR product and HPGR feed were non-normalizable and depended on particle size to be ground. However, batch grinding of -2.36+1.7 mm and -1.7+1.18 mm HPGR feed yielded the same breakage pattern.

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Feizi, Sedige, e Fateha Yasmin Khan. "Study of crack width within a suspended concrete slab with different amount of cement clinker considering lower climate impact". Thesis, KTH, Betongbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-222024.

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Abstract (sommario):

This master thesis investigates the possibility of using a concrete recipe with only 70 % cement clinker for a building project named Gretas Glänta, regarding the demands of cracking for a suspended slab. The requirement to fulfill was a maximum crack width of 0.2 mm due to drying shrinkage and long- term loading. The purpose of using a lower amount of cement clinker in the concrete mix is to reduce the climate impact from the concrete. The thesis considers material testing and modelling of different concrete recipes with variation of the amount of cement clinker. Fly ash was used as the alternative binder. A total of five concrete mixes was tested. One mix with 100% cement clinker was through laboratory testing compared to mixes with 85 % and 70 % cement clinker content. A concrete mix with only 50 % cement clinker was also tested, but this mix is today not allowed according to the concrete standards, but was included in the study to test different material properties of the fresh and hardened concrete. All concrete mixes were tested with the effectivity factor 1, except for the recipe with 70 % cement clinker, which was tested for effectivity factors of 1 and 0.4. The performed study showed that the concrete mix 4 with 70 % cement clinker and with the effectivity factor 0.4 reached the strength class C35/45 after 28 days and also fulfilled the specified requirement of a maximum crack width of 0.2 mm due to drying shrinkage and long-term loading. Water permeability test showed that the concrete mix with 70 % cement clinker and an effectivity factor of 0.4 was waterproof. The concrete mix 3 with 70 % cement clinker and the effectivity factor 1 reached a strength class C30/37. The concrete mix 1 with 100 % cement clinker obtained the highest strength class C50/60 and the mix 2 with 85 % cement clinker reached strength class C45/55. The concrete mix 5 with 50 % cement clinker reached the strength class C20/25 which is the lowest strength class among the tested recipes. All the concrete recipes seemed to be waterproof according to the water permeability test. A background description of carbon dioxide emission from concrete and cement production is presented in the report. Research about ongoing methods to minimize the emission from concrete and cement industry is also summarized. FE-modelling with the software FEM-design and analytical calculations were performed to investigate the crack width due to drying shrinkage and long-term loading for the slab, for concrete mix 2 with 85 % cement clinker with effectivity factor 1 and mixes 3 and 4 with 70 % cement clinker and effectivity factors of 1 and 0.4. The properties obtained from the laboratory tests were used in the modelling and analytical calculations. Results from FEM-design and analytical calculations showed that concrete mixes 3 and 4 with 70 % cement clinker and effectivity factors of 1 and 0.4, and the concrete mix 2 with 85 % cement clinker with effectivity factor 1, fulfilled the demand on crack width. The calculation was not performed for concrete mixes 1 and 5 with 100 % and 50 % cement clinker, respectively, because they were not to be used in the building project. The results from the performed study showed that concrete mix 4 with 70 % cement clinker and an effectivity factor of 0.4 can be used in the building project Gretas Glänta in order to lower the climate impact from the concrete.
Examensarbetet undersöker möjligheten att använda ett betongrecept med endast 70 % cementklinker för ett husbyggnadsprojekt kallat Gretas Glänta med hänsyn till krav på sprickbildning i en fribärande platta. Kravet som ska uppfyllas är en sprickvidd på max 0.2 mm med hänsyn till krympning och långtidsbelastning. Syftet med att använda en lägre andel cementklinker i betongblandningen är att minska klimatpåverkan från betongen. Examensarbetet består av materialförsök och konstruktionsteknisk modellering för olika betongrecept, där andelen cementklinker varieras. Flygaska användes som alternativt bindemedel. Totalt undersöktes fem betongmixer. En mix med 100 % cementklinker jämfördes genom laboratorietestning med motsvarigheter med 85 % och 70 % cementklinkerinnehåll. Ett betongrecept med 50 % cementklinker undersöktes också i detta examensarbete, trots att detta idag inte tillåts enligt betongstandarderna, men inkluderades i studien för att testa olika materialegenskaper i färskt och hårdnat tillstånd. Alla betongmixerna testades med effektivitetsfaktorn 1 förutom receptet med 70 % cementklinkerandel som testades för både 1 och 0.4 i effektivitetsfaktor. Den genomförda studien visade att betongmix 4 med 70 % cementklinker och med effektiviseringsfaktor 0.4 uppnådde hållfasthetsklass C35/45 efter 28 dagar och uppfyllde också angivet krav på maximal sprickbredd 0,2 mm med hänsyn till krympning och långtidslast. Vattenpermeabilitetstest visade att betongmixen med 70 % cementklinker och effektiviseringsfaktor 0.4 var vattentätt. Betongmix 3 med 70 % cementklinker och effektivitetsfaktor 1 uppnådde hållfasthetsklass C30/37. Betongmix 1 med 100 % cementklinker erhöll den högsta hållfasthetsklassen C50/60 och betongmix 2 med 85 % cementklinker gav hållfasthetsklass C45/55. Betongmix 5 med 50 % cementklinker uppnådde hållfasthetsklass C20/25 vilket var den lägsta av de testade betongrecepten. Alla betongrecepten verkade ge vattentät betong enligt vattenpermeabilitetstest. En bakgrundsbeskrivning av koldioxidutsläpp från betong- och cementproduktion genomförs i rapporten. Forskning om pågående metoder för att minimera utsläppen från betong- och cementindustrin sammanfattas också. FE-modellering med programmet FEM-design och analytiska beräkningar utfördes för att undersöka sprickbredden med hänsyn till krympning och långtidslast för betongplattan för betongmix 2 med 85 % cementklinker och effektiviseringsfaktor 1 och betongmixerna 3 och 4 med 70 % cementklinker och effektiviseringsfaktorerna 1 och 0.4. Egenskaperna som erhölls i laboratorietesterna användes i modellerings och de analytiska beräkningarna. Resultat från FEM-design och analytiska beräkningarna visade att betongmixerna 3 och 4 med 70 % cementklinker med effektiviseringsfaktorerna 1 och 0.4 och betongmix 2 med 85 % cementklinker och effektiviseringsfaktor 1 uppfyllde kravet på sprickbredd. Beräkningen utfördes inte för betongmixerna 1 och 5 med 100 % cementklinker och 50 % cementklinker då de inte var aktuella för att användas i bostadsprojektet. Resultaten från den genomförda studien visade att betongmix 4 med 70% cementklinker och med en effektivitetsfaktor 0.4 kan användas i husbyggnadsprojektet Gretas Glänta för att sänka klimatpåverkan från betongen.

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27

Spurný, Marek. "Účinnost přídavků mletí používaných při výrobě Portlandských cementů". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401836.

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This work deals kinetics of grinding Portland cement clinker which is influenced by addition of grinding inlays surfactants. In an experiment, attritor-type stirred mill was used and surface active grinding additives such as polyethylenglykol (PEG), triethylamin (TEA) and acetate of ammonium were utilized. Granulometric distribution graph obtained from laser diffraction analysis provides data for plotting development diagrams for milling process.

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28

Esnault, Vivien. "Compréhension et modélisation du comportement du clinker de ciment lors du broyage par compression". Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1027/document.

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On appelle clinker le matériau obtenu par cuisson de calcaire et d'argile et qui constitue le principal ingrédient du ciment Portland, composant essentiel de la majorité des bétons produits dans le monde. Ce clinker doit être finement broyé avant de pouvoir présenter une réactivité suffisante. La maîtrise des procédés de broyage représente un enjeu considérable pour l'industrie cimentière : il s'agit du premier poste en termes de consommation électrique d'une usine, en partie du fait de l'inefficacité des procédés employés. Les techniques de broyage par compression, apparues au cours des années 80, ont constitué un progrès majeur du point de vue de l'efficacité énergétique, mais la généralisation de leur utilisation a été freinée par des problèmes de maîtrise du procédé, en particulier pour des finesses importantes. L'enjeu de cette thèse est une meilleure compréhension des phénomènes en jeu lors du broyage par compression du clinker, en vue d'un meilleur contrôle des installations industrielles lors de la fabrication de produits fins. Nous nous sommes intéressés en particulier au comportement, du point de vue fondamental, d'un matériau granulaire subissant une fragmentation de ses grains, en nous appuyant sur la simulation numérique d'un Volume Elémentaire Représentatif de matière par les éléments discrets (DEM). Nous avons aussi recherché une loi de comportement permettant de relier contraintes, déformation, et évolution de la taille des particules pour le matériau broyé, en nous appuyant à la fois sur la micromécanique et les techniques d'homogénéisation, et un modèle semi-empirique de bilans de masses. Enfin, un premier pas vers la modélisation du procédé industriel et notamment sa simulation par éléments finis a été esquissé, afin de résorber les difficultés rencontrées en pratique par les industriels
Noindent Clinker is the material obtained by calcination of a mix of clay and limestone, and it is the main component of Portland cement, a crucial ingredient for the majority of concrete used around the world. This clinker must be finely ground to have a sufficient reactivity. Mastering the grinding process is a key issue in the cement industry: it is the first source of expense in terms of electric consumption in a factory, partially because of the overall inefficiency of the process. Compressive grinding techniques, first appeared during the 80's, allow major improvements in terms of energy efficiency, but the general implementation is yet to come, hindered by process control issues, especially for high fineness. The goal of this study is a better understanding of phenomenons occurring during compressive grinding of clinker, in order to provide better process control for industrial installations when dealing with fine products. We particularly choose to study the behaviour, on a fundamental point of view, of a granular material subjected to grain fragmentation, using the numerical simulation of an Elementary Representative Volume of material through Discrete Element Method (DEM). We also looked for a behaviour law able to provide a link between stress, strain, and grain size evolution for the ground material, using at the same time micromechanics and homogenization technique, and a semi-empirical mass balance model. Finally, we made first efforts in the direction of modelling the whole process through numerical simulation by Finite Element Method (FEM), in order to tackle the issue met by the industrials in operations

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29

Naranjo, Cabello Óscar Ignacio. "Modelamiento geológico y estimación de recursos, Yacimiento La Niña, Tongoy, Cementos Melón S.A". Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/148670.

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Geólogo
En este estudio se presentan los resultados del modelamiento geológico y estimación de recursos de 〖CaCO〗_3 en el yacimiento La Niña, ubicado en Tongoy Región de Coquimbo, perteneciente a la empresa Cementos Melón SA. Por otro lado, este trabajo incluye la estimación de las concentraciones de Cl dentro del yacimiento, debido a que, altas concentraciones de Cl (>0.025%) son perjudiciales para los procesos de fabricación de cemento. Para la elaboración de un modelo geológico y estimación de recursos más preciso, durante los meses de enero y febrero del 2017, se realiza la campaña de sondajes Tongoy 2017, con la finalidad de aumentar la densidad de información, reduciendo la distancia entre sondajes a un promedio de 150 m, llegando a ser de 260 m en algunos casos. En esta campaña se adicionan 13 sondajes ubicados principalmente en la zona centro-sur del yacimiento. Utilizando la información de las campañas de sondajes anteriores (2001 y 2005), más la base de datos generada por la campaña de sondajes 2017 y levantamiento geológico en terreno, se utiliza el software Vulcan 10, para la elaboración del modelo geológico para Conchuela Alta y Baja. Con los modelos geológicos elaborados, se define el modelo de bloques con el que se discretizará el yacimiento, el cual, en base a los bancos del rajo actual, se construyen bloques de 20x20x5 m con sub-bloques de 5x5x1.25 m de espesor. La estimación de 〖CaCO〗_3 para cada bloque del modelo, se realizará utilizando inverso a la distancia al cuadrado, donde debido a la gran separación entre sondajes, y poca densidad de información, se imposibilita la aplicabilidad de un kriking ordinario. Los radios de búsqueda de la estimación son definidos según la distancia entre sondajes. La variable Cl, al presentar un comportamiento aleatorio sin continuidad apreciable, y ante la necesidad de caracterizar su distribución dentro del yacimiento, se estimó con los mismos criterios que la variable 〖CaCO〗_3. El cálculo final de recursos, o sumatoria de cada bloque para cada unidad Litológica estudiada, arroja que, para conchuela de alta ley, existirían 15 millones de toneladas con una ley promedio del 90.6%, y para conchuela baja se tendría 14 millones de toneladas con una ley promedio del 76%. En cuanto a la problemática de Cl, debido a las bajas concentraciones encontradas, se desestima su importancia como problemática en la producción eficiente de clinker.

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30

Yilmaz, Mustafa. "A Study On The Utilization Of Waste Cement-bonded Wood Particle Board As A Raw Material And A Secondary Fuel In Cement Manufacturing". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614695/index.pdf.

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A considerable amount of waste is obtained as a result of edge-cutting operations during cement-bonded wood particle board (CBWPB) manufacturing. This waste material which basically contains wood chips and hydrated cement has to be disposed of and does not have any economical value. However, it can be burned in cement rotary kilns and may result in energy savings to a certain extent due to the presence of wood particles as a secondary fuel and since the hydrated cement may be decomposed and then reform clinker compounds during the calcination process. In this experimental study, the possibility of using waste CBWPB in cement manufacturing and its effects on energy consumption and cement characteristics will be investigated. The reference mix, corrective limestone, CBWPB waste and coal, were used as raw materials to prepare six different raw meals whose chemical compositions was similar to reference mix. All six raw mixes (including the reference) were calcined under the same conditions to produce clinkers. The compositions and micro structure of the clinkers obtained were comparatively analyzed by wet analysis, XRF and XRD techniques. Cements were obtained by intergrinding the clinkers with 5% (by mass) gypsum rock and standard tests were carried out on each of the cements. In addition to these, since CBWPB waste contains wood about 30% by weight, its contribution to fuel consumption during clinker production was also analyzed. The test results revealed that CBWPB waste can be used as a cement raw material since CBWPB waste has the similar chemical composition with the reference raw mix. CBWPB, which contains about 30% (by mass) wood, contributes to the heating process during calcination and results in lower amount of primary fuel requirement.

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31

Martykán, Jiří. "Sledování vývoje AFt fází ve směsných portlandských cementech s fluidním popílkem". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240190.

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32

Mejeoumov, Gleb Gennadievich. "Improved cement quality and grinding efficiency by means of closed mill circuit modeling". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2478.

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33

Staněk, Theodor. "Vztah parametrů přípravy belitického cementu a jeho hydraulických vlastností". Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-233286.

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The dissertation thesis is devoted to the study of belite clinkers and to the possibilities of the increase in their hydraulic activity. The mechanism and the kinetics of belite clinker formation were studied together with the relation of the velocity of these processes and the hydraulic activity of clinker. The influence of various parameters (degree of lime saturation, duration and temperature of burning) of the belite clinker preparation on the belite clinker development in time, on belite polymorphism, on the chemical composition of belite crystals and on the belite cement hydraulic activity was studied, too. The research methods used for the investigation involved electron microscopy, optical microscopy, X-ray diffraction analysis, high-temperature microphotometry and calorimetry. The resulting clinkers were hydraulically activated by addition of calcium sulfate. The experiments have proven that the higher rate of belite formation does not lead to the increase of its hydraulic activity, as opposed to that of alite. On the other hand, the chemical activation by sulfate anions enables to prepare clinker with relatively higher degree of lime saturation with minor admixture of alite and anhydrite, which is hydraulically activated. The work was concluded by experimental burning of belite clinker doped with sulfate anions in a model rotary kiln and by the preparation of cements blended with common industrial alite clinker. The results indicate the possibility of separate industrial production of special belite clinker alongside with common alite clinker and the production of economically and environmentally beneficial blended Portland cements with suitable technological parameters, or targeted production of special cements with properties corresponding to their required utilization.

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34

Escadeillas, Gilles. "Les ciments aux fillers calcaires : contribution a leur optimisation par l'etude des proprietes mecaniques et physiques des betons fillerises". Toulouse 3, 1988. http://www.theses.fr/1988TOU30053.

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Il ressort de l'etude que: les proprietes rheologiques avant prise du liant sont ameliorees par l'ajout de filler, autorisant une diminution de la teneur en eau de gachage; la reactivite de la calcite est confirmee (formation de carboaluminates, diminution de l'aureole de transition); les resistances mecaniques aux jeunes ages sont ameliorees; la fragilite (fissuration. . . ) est attenuee. On envisage l'amelioration de ces procedes par addition d'un superplastifiant

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35

Mončeková, Miroslava. "Možnosti redukce šestimocného chromu při hydrataci portlandského cementu". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-216811.

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The issue of Hexavalent chromium toxicity to Portland cement hydration is a very actual these days. It takes much effort to obtain a cement containing Cr(VI) less than 2 ppm. The primary objective of this diploma theses is to find appropriate reducing substances and specify their efficiency, as well as to make an attempt to optimize their dosage. As reducing substances there were plumbed sulphites and tin(II) salts. The influence of reducing substances applied to the hydration and cement properties were validated by strenght tests, the calorimetric measurement and the volume-variation measurement. And also the changes in hydration products microstructure of Portland clinker after the gypsum replacement by sulphite ions were plumbed. The study of microstructure is based on SEM and XRD methods.

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36

AQUINO, AFONSO R. de. "Caracterizacao e estudo termoanalitico de clinquer produzido em industrias brasileiras". reponame:Repositório Institucional do IPEN, 1996. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10800.

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Made available in DSpace on 2014-10-09T12:44:08Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:07:00Z (GMT). No. of bitstreams: 1 02948.pdf: 2171704 bytes, checksum: 896d566852d96a5900bc907e2d478a43 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Química - Universidade de São Paulo - IQ/USP

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37

Schönberger, Harald [Verfasser], e Harald [Akademischer Betreuer] Garrecht. "State of the art of the co-incineration of waste-derived fuels and raw materials in clinker/cement plants / Harald Schönberger ; Betreuer: Harald Garrecht". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2021. http://d-nb.info/1236574028/34.

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38

Bordy, Arthur. "Influence des conditions thermo-hydriques de conservation sur l'hydratation de matériaux cimentaires à base d’une fine recyclée". Thesis, Cergy-Pontoise, 2016. http://www.theses.fr/2016CERG0876/document.

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La valorisation, comme granulats, des matériaux issus du recyclage du béton de démolition contribueà diminuer les surfaces dédiées au stockage des déchets et à limiter le recours systématique auxressources naturelles. L’emploi de fines recyclées à partir de béton de déconstruction s’inscrit danscette démarche et permet par ailleurs, quand la fine est utilisée en substitution partielle du cimentlors de la fabrication de nouveaux matériaux cimentaires, de réduire l’impact sur l’environnement deces matériaux.Cet usage conduit à mettre en présence dans la pâte à l’état frais du ciment anhydre et du cimenthydraté, ce qui pose la question de l’impact de cette situation sur le matériau. Pour y répondre enpartie, les travaux de recherche présentés dans cette thèse ont pour objectifs principaux d’étudier leprocessus d’hydratation d’une phase anhydre en présence d’autres phases hydratées, et d’analyserl’influence des conditions thermo-hydriques de conservation (HR et T°) sur les cinétiquesd’hydratation des matériaux cimentaires.Pour ce faire, une campagne expérimentale a été menée sur des mortiers et leurs pâtes de cimentéquivalentes fabriqués en remplaçant une partie de leur ciment Portland par une fine issue durecyclage d’une pâte de ciment durcie et bien hydratée. Un suivi au cours du temps des teneurs enPortlandite, de la porosité totale, de la résistance à la compression ainsi que de la résistance à lacarbonatation accélérée des matériaux a été réalisé. Les résultats obtenus montrent qu’il est possiblede fabriquer des mortiers en substituant le ciment par une fine obtenue uniquement par concassageet broyage d’une pâte de ciment durcie. Cependant, l’augmentation du taux de substitution massiquedu ciment par la fine recyclée s’accompagne d’une altération des propriétés et performances desmortiers. Les résultats du suivi d’hydratation couplés aux résultats d’analyse de la microstructure ontmontré que l’effet des conditions thermo-hydriques de conservation sur les cinétiques d’hydratationdes différentes pâtes de ciment dépend de leurs propriétés intrinsèques (microstructure). Celapourrait expliquer l’absence de consensus dans la littérature sur la valeur de l’humidité relativeambiante conduisant à l’arrêt de l’hydratation.En parallèle à l’étude expérimentale, une étude numérique de l’influence des conditions thermohydriquesde conservation sur l’hydratation des pâtes de ciment a été menée. Pour les besoins del’étude, une réadaptation du code de calcul utilisé, CEMHYD3D, a été nécessaire. Les résultatsobtenus montrent que, lors de l’hydratation, la Portlandite initialement présente dans le matériau(apportée par la fine recyclée) se dissout au contact de l’eau alors que la phase encore anhydre enproduit. Cette étude a également permis de conforter les résultats expérimentaux quant à l’influencede l’humidité relative ambiante sur l’hydratation
The use, as aggregates, of recycled materials from demolished concrete contributes to limit landfill and the systematic use of natural resources. Using recycled fines from the deconstruction concrete is an extension of this approach. When used as a partial substitution for cement in cementitious materials, it may also be a solution to reduce the environmental impact of these materials.This specific use induces the presence of anhydrous cement particles and hydrated cement phases in the fresh material. This raises the question whether and how it can impact the hydration process. With the aim to answer, at least partially, to this question, the thesis presents a study of the hydration process of an anhydrous phase in the presence of other hydrated phases, and analyzes the influence of the conservation conditions (RH and T°) on the hydration kinetics of cementitious materials.An experimental campaign was conducted on mortars and their equivalent cement pastes designed by replacing a part of their Portland cement by a recycled cement paste fine. The monitoring of the Portlandite content, the total porosity, the compressive strength and the accelerated carbonation of the materials was achieved. The obtained results show that it is possible to design mortars by substituting their cement by a fine obtained only from crushing and grinding of a hardened cement paste. However, increasing the substitution ratio of the cement by the recycled fine was find to be accompanied by a deterioration of the mortars properties and performances. The results of the hydration monitoring coupled to investigations of the microstructure showed that the effect of conservation conditions on the hydration kinetics of the different cement pastes depends on their intrinsic properties (microstructure). This could explain the lack of consensus in the literature on the drying conditions under which hydration kinetics are strongly affected.In parallel to the experimental study, a numerical study of the influence of the conservation conditions on the hydration of cement pastes was conducted. Readjustments of the parameters of the used code (CEMHYD3D) were necessary. The obtained results show that, during hydration, the Portlandite originally present in the material (provided by the recycled fine) dissolves in contact with water, while the anhydrous phase produces new Portlandite. This study consolidated moreover the experimental results on the influence of the ambient relative humidity on hydration

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39

Kozlová, Romana. "Možnosti využití popílků po SNCR pro výrobu portlandského cementu". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240583.

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The Master thesis deals with utilization possibilities of fly ash after selective non-catalytic reduction (SNCR) process for Portland cement preparation as a correction component to the raw material with regard to contaminated fly ash by ammonium sulphate or ammonium hydrogensulfate that is one of the products from SNCR process. Presented thesis was focused on behaviour of raw meal with ammonia hydrogensulfate contaminated fly ash after SNCR during burning of Portland clinker in simulated kiln conditions. The thesis deals with Portland clinker preparation from this kind of raw mix and it studies mainly clinker quality, clinker phases and structure. Quantitative phase composition of prepared samples of clinker was performed by optical microscopy measurements using point counting method and XRD analysis (Rietveld method). Hydration heat flow of prepared clinker was measured by Isothermal Calorimetry. TG-DTA analysis of prepared raw meal was studied due to better comparison of prepared samples and better understanding of processes during burning process.

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40

Havlík, Leoš. "Příprava a vlastnosti belitického slínku". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392334.

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DIPLOMA THESIS IS FOCUSED ON THE PREPARATION AND PROPERTIE OF BELITE CLINKER. IT IS BASED ON THE STUDY OF SCIENTIFIC ARTICLES DEALING WITH THE ABOVE MENTIONED TOPIC AS WELL AS THE ANALYSIS OF THE BRNO THD INSTITUTE´S RESEARCH RESULTS. AS PART OF MY EXPERIMENTAL WORK, A PROPOSAL OF THE COMPOSITION OF RAW MEAL TO EXTRACT BELITE CLINKER IN THE PRESENCE OF POTASSIUMS CARBONATE AND SULPHATE WAS MADE TO MODIFY RAW MEAL. THE PURPOSE OF MODIFYING RAW MEAL IS A POTENTIAL INCREASE IN BELITE CLINKER REACTIVITY. FURTHER THE EXTRACTION OF BYPASS DUST FROM A LOCAL CEMENT PLANT WAS CONDUCTED. THE EVALUATION OF THIS RESEARCH WAS MADE BY THE X-RAY DIFFRACTION (XRD) ANALYSIS METHOD.

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41

Rheinheimer, Vanessa. "A nanoscale study of dissolution and growth processes in cement hydrates". Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/285965.

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This thesis aims at providing new knowledge on the, otherwise poorly known, molecular-scale mechanisms that operate during hydration of cement phases and dissolution of their hydrates. In order to pursue this objective, a novel approach has been followed, including the development of a new procedure to synthesize thin films of calcium silicates, real time characterization of grain growth and dissolution with liquid-cell atomic force microscopy, and monitoring of their chemical evolution by X-ray photoelectron spectroscopy of thin films hydrated in-situ, avoiding atmospheric contamination. Nanometer-sized films of clinker phases have been prepared using electron-beam evaporation methods. After deposition on silicon substrates, film thicknesses and mineralogical composition were characterized by atomic force microscopy (AFM) or mechanical profilometry and grazing-angle X-ray diffraction (GAXRD), respectively. Chemical composition was determined by X-ray photoelectron spectroscopy (XPS). Results from the GAXRD and XPS analysis show that aluminates phases are not suitable to be evaporated by electron beam technique. However quantitative analysis of calcium silicates samples shows that the Ca:Si ratio of the deposited film is the same as in the bulk starting material, confirming the suitability of the technique for the synthesis of these materials. Calcium silicate thin films with different thicknesses were submitted to hydration in different ways. XPS results describe clear chemical changes when samples are exposed to water vapor by shifts on the silicon peak, broadening on the calcium peak and decreasing on the Ca:Si ratio, related to the silicon polymerization due to the C-S-H formation. In situ hydration in fluid cell followed by AFM in water and calcium hydroxide saturated solution allows observing the formation of C-S-H particles, that happens very fast in C3S, which is dissolved later, and slower in C2S. Finally, Scanning transmission X-ray microscopy (STXM) of samples hydrated in situ with water allows observing the formation of particles with different concentration of calcium and silicon, and different chemical state at some point. The development of this technique of synthesis and the results obtained on the hydration allow improving the knowledge of early stage clinker phase hydration at the molecular level and to better understand the behavior of these materials, shedding some additional light on the complex problem of the hydration mechanisms of cementitious materials.
Aquesta tesi té per objectiu proporcionar nous coneixements sobre els mecanismes, abans poc coneguts, que operen durant la hidratació de les fases de ciment i la dissolució dels seus hidrats a escala molecular. Per tal d'aconseguir aquest objectiu, un nou enfocament ha estat seguit amb l'elaboració d'un nou procediment per sintetitzar pel·lícules primes de silicats de calci, la seva caracterització en temps real del creixement del gra i de la dissolució amb les cel·les de líquid al microscopi de forces atòmiques i el seguiment de l'evolució de la seva composició química per espectroscòpia de fotoelectrons de raigs X de pel·lícules primes hidratades in-situ, evitant la seva contaminació atmosfèrica. S'han preparat pel·lícules nanomètriques de les fases del clínquer utilitzant l'evaporació per feix d'electrons. Després de la deposició en substrats de silici, es van caracteritzar el gruix mitjançant la microscòpia de forces atòmiques (AFM) i la perfilometria mecànica i la composició mineralògica amb la difracció de raigs X d'angle rasant (GAXRD). La composició química es va determinar per espectroscòpia fotoelectrònica de raigs X (XPS). Els resultats del GAXRD i d'XPS mostren que els aluminats no són adequats per a ser evaporats utilitzant l'evaporació assistida amb feix d'electrons. No obstant això, anàlisis quantitatives de les mostres de silicats de calci mostren que la relació Ca:Si de la pel·lícula dipositada és la mateixa que en el material de partida, el que confirma la idoneïtat de la tècnica per a la síntesi d'aquests materials. Les pel·lícules primes de silicat càlcic de gruixos diferents van ser sotmeses a hidratació de diferents maneres. Els resultats d`XPS descriuen canvis químics clars quan les mostres estan exposades al vapor d'aigua com s'infereix dels canvis en el pic del silici, l'eixamplament del pic del calci i la disminució en la relació Ca:Si, que es relaciona amb la polimerització del silici degut ala formació de C-S-H. La hidratació in situ en aigua o solució saturada d'hidròxid de calci a la cel·la de fluid de l'AFM permet observar la formació de partícules de C-S-H. La hidratació ocorre molt ràpidament en el C3S, que després es dissol, i és més lenta en el C2S. Finalment, la microscòpia de transmissió i escaneig de raigs X (STXM) de les mostres hidratades in situ amb aigua permet observar la formació de partícules amb diferents concentracions de calci i silici i, en alguns casos, la variació de l'estat químic . El desenvolupament d'aquesta tècnica de síntesi i els resultats obtinguts en la hidratació permeten millorar el coneixement de la hidratació de les fases del clínquer en estadis inicials a nivell molecular i entendre millor el comportament d'aquests materials, ajudant a aclarir el complex problema dels mecanismes d'hidratació dels materials del ciment

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Недашковська, Богдана Анатоліївна. "Обертова піч 4х60 з модернізацією футеровки". Master's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/30753.

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Метою магістерської дисертації є удосконалення конструкції корпусу обертової печі шляхом збільшення теплового опору футерівки. Об’єктом дослідження є піч обертова 4x60 при виробництві цементу «сухим» способом. Предмет дослідження встановлення додаткової теплоізоляції в футерівку печі для зменшення втрат тепла в навколишнє середовище. У магістерській дисертації зроблений вибір та обґрунтування модернізації обертової печі, що зменшує втрати тепла за рахунок чого можливо зменшити витрати палива та збільшити продуктивність печі. Теоретичні ідеї модернізації підтверджуються результатами розрахунку, які виконуються за допомогою сучасних систем САПР системи ANSIS. Отримані дані підтверджують працездатність модернізованої печі, так як отримані максимальні напруження не перевищують допустимих і дають можливість суттєво зменшити втрати тепла через корпус, що позитивно вплине на технологічний процес. В пояснювальній записці в достатньому обсязі представлені розрахунки обертової печі, проведено автоматизацію виробничого процесу, розглянуті основні вимоги до техніки безпеки та навколишнього середовища при роботі з машиною.
The aim of the master's thesis is to improve the design of the rotary kiln body by increasing the thermal resistance of the lining. The object of the study is a 4x60 rotary kiln in dry cement production. The subject of the study is the installation of additional thermal insulation in the furnace lining to reduce heat losses to the environment. In the master's thesis the choice and justification of the modernization of the rotary kiln is made, which reduces the heat loss due to which it is possible to reduce fuel consumption and increase the kiln productivity. The theoretical ideas of modernization are confirmed by the results of the calculation, which are performed using modern ANSIS CAD systems. The obtained data confirm the efficiency of the modernized furnace, since the maximum stresses obtained do not exceed the allowable and allow to significantly reduce heat losses through the housing, which will positively affect the technological process. The explanatory note sufficiently presents calculations of the rotary kiln, automation of the production process, the main requirements for safety and the environment when operating the machine.

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43

Hrdina, Matěj. "Ověření možnosti syntetické přípravy ettringitu a thaumasitu". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227221.

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The work is focused on the possibilities of using FBC fly ash for composite cements, monitoring their hydration processes, especially the creation of AFt phase. The possibility of preparing synthetic ettringite and thaumasite and their detection.

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44

Mungyeko, Bisulandu Baby-Jean Robert. "Modélisation de l'apport d'énergie par combustibles alternatifs dans les fours tournants de production de ciment". Thesis, Pau, 2018. http://www.theses.fr/2018PAUU3001/document.

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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

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45

Mantegazza, Ezio. "Aspectos ambientais do co-processamento de resíduos em fornos de produção de clínquer no Estado de São Paulo". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-18022016-100234/.

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A geração de resíduos sólidos é inerente ao desenvolvimento humano. O concreto armado é um dos materiais mais utilizados pelo homem e tem o cimento Portland como seu principal constituinte, o qual é produzido pela moagem de clínquer e gesso. O clínquer pode ser definido como um mineral artificial, obtido a partir das reações físico-químicas de calcário, argila e corretivos a altas temperaturas, em forno rotativo industrial, mediante a queima de combustíveis fósseis. No início da década de 70 foram realizadas as primeiras experiências de substituição de combustíveis fósseis por resíduos industriais nos Estados Unidos e países europeus, através da técnica denominada co-processamento, resultando na manufatura de um produto ao mesmo tempo em que os resíduos eram eliminados. O co-processamento se baseia na recuperação da energia disponível nos resíduos, substituindo parte daquela fornecida pelos combustíveis tradicionais ou na substituição de matérias-primas por resíduos com características químicas semelhantes àquelas normalmente empregadas na produção do clínquer. No estado de São Paulo as primeiras iniciativas para a utilização de resíduos industriais em fornos de clínquer ocorreram no início da década de 90. A partir de 1997 os órgãos ambientais de alguns estados brasileiros normatizaram procedimentos de licenciamento da atividade que foi, posteriormente, uniformizada por norma em âmbito federal. No ano de 1995 a Companhia de Cimento Ribeirão Grande/SP, Brasil, iniciou os procedimentos visando a substituição parcial dos combustíveis utilizados nos fornos rotativos por uma mistura de resíduos industriais. No período de 1995 a 2002 foram realizadas campanhas de amostragens em chaminés para avaliação das emissões atmosféricas dos dois fornos de produção de clínquer. A análise dos resultados obtidos associada às demais informações disponíveis de monitoramento das características das matérias-primas e combustíveis utilizados, bem como dos produtos finais, clínquer e cimento, não evidenciou alterações significativas nos níveis de emissões atmosféricas, sobretudo de material particulado e óxidos de enxofre, que pudessem ser associadas à utilização dos resíduos. Foram confirmadas as baixas emissões de inorgânicos e evidenciado o papel representado pelos resíduos no aporte dessas substâncias no sistema-forno, concluindo-se que esse aporte pode ser tão ou mais importante pela via da alimentação da farinha, cujos teores estão associados às características das jazidas minerais utilizadas. Foi também confirmada a alta eficiência do sistema-forno na destruição e remoção dos compostos orgânicos perigosos alimentados durante os testes de queima.
The production of industrial residues in inherent to the human development. The cement concrete is one of the most used material, manly the type portland cement, which is constituted by grinding clinker and gypsum together. Clinker can be defined as an artificial mineral obtained by applying physico-chemical reactions, at very high temperatures, to an appropriated mixture of limestone, clay, and some other materials in a rotating industrial kiln wich burns fossil fuels. In the early 1970 decade occurred the first experiences substituting fossil fuels by organic residues in USA and Europe through a technique named co-processing that results the production of certain manufacture while eliminates residues. Co-processing is based in the recovery of thermal energy and/or the mass of some constituents from some residues, with the same chemical characteristics of normal sources of energy, then economizing fuels and mass constituents and making better use of residues, otherwise useless and environmentally polluters. In the state of São Paulo this practice began in early 1990 decade and by 1997 it was started the standardization of the rules for its use in some units of the federation. Later this activity was regulated by nationally approved standard rules. In 1995 the industry Companhia de Cimento Ribeirão Grande (CCRG), a cement plant located in the city of Ribeirão Grande, São Paulo state, Brazil, started procedures searching the partial substitution of the normal fuels by a mixture of industrial residues in its two rotating kilns. The gaseous emissions from the chimneys of these two clinker kilns were studied from 1995 to 2002 about the use of residues as part of the fuel. Analyses of the final results associated with other informations concerning to the quality of raw minerals, fuels and products did not show significant alterations in atmospheric emissions, mainly for particulate material and sulfur oxides, related with the use of residues. The emissions of inorganic continued to be low and not significantly altered by the presence of residues. It was possible to conclude that the alterations in inorganic emissions depend more from the quality of the raw minerals feed in the kilns, which is more difficult to control, than from the presence of residues being burn with the fuel. It was shown a high efficiency in the destruction of dangerous organic compounds feed in the cement kilns, under test conditions.

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46

Kašpárková, Kateřina. "Vliv oxidů těžkých kovů na tvorbu a vlastnosti portlandského slínku". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240407.

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The Master’s thesis is focused on a study of the effect of increased content of heavy metals present in a raw meal on the formation and properties of prepared clinker and acquired cement. Main attention is devoted to changes on the physical, mechanical, microstructural and hydration properties. The theoretical part contains an overview of clinker minerals occurring in Portland cement including the possibility of incorporation of heavy metals into their structure and affecting the properities of the cement. In the experimental part, there is compared the effect of heavy metal oxides on the composition and hydration properties of portland clinker and physical-mechanical and microstructural properities of cement pastes prepared from this clinker.

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47

Joca, Jhonny Frank Sousa. "Determinação de manganês em amostras de cimento e clínquer por voltametria de redissolução catódica empregando eletrodos de ouro". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-31082011-160037/.

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Este trabalho apresenta o desenvolvimento e a aplicação de um método alternativo para determinação de manganês em amostras de cimento e clínquer por voltametria de redissolução catódica por onda quadrada empregando eletrodos de ouro. Após estudos exploratórios acerca do comportamento eletroquímico do manganês no eletrólito suporte H3BO3 0,20 mol L-1 / KCl 0,10 mol L-1 com pH 6,5 e a otimização dos parâmetros operacionais para a voltametria de onda quadrada, foram obtidos excelentes resultados na determinação de manganês nas amostras analisadas. Destacam-se a ótima linearidade, verificada em duas faixas distintas de concentração, e os baixos limites de detecção e quantificação obtidos (3,1 x 10-8 mol L-1 e 9,8 x 10-8 mol L-1, respectivamente), além da concordância entre os resultados obtidos pela técnica eletroanalítica quando comparados aos resultados fornecidos pela espectrometria de absorção atômica de chama (FAAS). Para o tratamento das amostras foi avaliada a eficiência da extração ácida assistida por ultrassom. Foram avaliados ácidos minerais individualmente (HCl, H2SO4 e HClO4 em diferentes concentrações), em mistura ou ainda associados a H2O2. Os melhores resultados foram obtidos utilizando uma solução de HCl 3 mol L-1, que extraiu quantitativamente o manganês nas amostras analisadas. Os resultados obtidos foram concordantes com a metodologia padrão utilizada para a abertura da amostra e posterior análise por espectrometria de absorção atômica de chama, que emprega o aquecimento em chapa e a mesma solução extratora.
This work describes the development and application of a new alternative method for determination of manganese in cement and clinker samples by square wave cathodic stripping voltammetry using gold electrodes. After exploratory studies on the electrochemical behavior of manganese in H3BO3 0.20 mol L-1 / KCl 0.10 mol L-1 supporting electrolyte at pH 6.5 and the optimization of operating parameters for the square wave voltammetry, excellent results were obtained for determination of manganese in the samples analyzed. Most notable are the excellent linearity, verified in two distinct concentration bands and the low limits of detection and quantification obtained (3,1 x 10-8 mol L-1 e 9,8 x 10-8 mol L-1, respectively), in addiction to the concordance between the obtained results by the electroanalytical technique when compared to the provided by the flame atomic absorption spectrometry. For samples treatment were tested the efficiency of the ultrasound-assisted extraction. Were evaluated individually mineral acids (HCl, H2SO4 and HClO4 at different concentrations) in a mixture or associated with H2O2. the best results were obtained using a 3 mol L-1 HCl solution, which extracted manganese quantitatively from the analysed samples, in comparison to the standard method for extraction, targeting a later atomic absorption flame spectrometry analysis, which uses the plate heating and the same extracting solution. The obtained results for the analysed samples agrees with the cement and clinker samples of the used literature

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48

Martins, Helena Margarida. "Reabilitação energética da indústria cimenteira portuguesa". Master's thesis, ISEG, 2002. http://hdl.handle.net/10400.5/22152.

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Mestrado em Economia e Política da Energia e do Ambiente.
A indústria cimenteira é um dos sectores mais intensivos em energia da economia Portuguesa. E também um sector intensivo em capital, dados os custos elevados com a energia e o facto de exigir grandes investimentos na construção das instalações e na aquisição e manutenção do equipamento básico. Actualmente, os principais impactes ambientais associados à produção de cimento são a exploração das pedreiras e as emissões de poluentes atmosféricos e de gases com efeito de estufa. O presente trabalho analisa a indústria cimenteira nacional, inserindo-a num contexto global, no que respeita à produção, consumo de energia e impactes ambientais. São caracterizadas as melhores tecnologias disponíveis actualmente para a produção de cimento e identificadas as áreas de actual investigação e desenvolvimento (I&D). Seleccionou-se a cimenteira da Secil no Outão como caso-estudo, para a qual se caracteriza a situação actual e se estuda a implementação de novas tecnologias e medidas para melhorar a eficiência energética. Para cada tecnologia e medida energeticamente eficientes são calculados os custos de investimento e de operação, as poupanças energéticas e o efeito nas emissões de dióxido de carbono (CO2). Como medidas e tecnologias principais a implementar com vista ao aumento da eficiência energética foram seleccionadas a introdução de pré-calcinador e arrefecedor de grades no sistema de queima, e a utilização de prensas de rolos para a moagem de clínquer. Para diminuir os impactes ambientais resultantes das emissões de CO2 e de óxidos de azoto (NOx) sugere-se o aumento da produção de cimentos compostos e a implementação da redução não-catalítica selectiva, respectivamente.
The cement industry is one of the most energy-intensive sectors in the Portuguese economy. It is also a capital-intensive sector, given the energy high costs and the fact of demanding big investments in the plant construction and basic equipment acquisition and maintenance. Currently, the main environmental impacts associated with cement production are the quarry exploration and the emissions of atmospheric pollutants and greenhouse gases. The present study analyses the national cement industry, inserting it in a global context, in what concerns production, energy consumption and environmental impacts. The best available technologies for cement production are characterized and the main areas of research and development (R&D) are identified. The SeciPs cement plant at Outão was selected as case study. The plant current situation is characterized and the implementation of new technologies and measures to increase energy efficiency are studied. The investment and operation costs, the energy savings and the effects on carbon dioxide (CO2) emissions are calculated for each energy-efficient technology and measure. As main measures and technologies to implement for obtaining increased energy efficiency, the introduction of a pre-calcinator and grate cooler were selected for the buming system, and the roller presses were selected for cement grinding. To decrease the environmental impacts of releasing CO2 and nitrogen oxides (NOx), it is suggested the increase of blended cements production and the implementation of selective non-catalytic reduction, respectively.
info:eu-repo/semantics/publishedVersion

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Schöler, Axel [Verfasser], Horst-Michael [Akademischer Betreuer] [Gutachter] Ludwig, Barbara [Gutachter] Lothenbach e Yuanzheng [Gutachter] Yue. "Hydration of multi-component cements containing clinker, slag, type-V fly ash and limestone / Axel Schöler ; Gutachter: Horst-Michael Ludwig, Barbara Lothenbach, Yuanzheng Yue ; Betreuer: Horst-Michael Ludwig". Weimar : F. A. Finger-Institut für Baustoffkunde, 2016. http://d-nb.info/1117091201/34.

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50

Cáceres, Alberto Eulogio Arias. "Caracterização da matéria-prima (Grupo Itapucumí) e sua queimabilidade para a produção de cimento Portland na industria nacional del cemento (Paraguai)". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/44/44137/tde-25042018-161847/.

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O presente trabalho consiste na detalhada caracterização geológica da Mina de Vallemí no Paraguai, utilizada para fabricação de cimento Portland pela Industria Nacional de Cemento (INC), seguida da caracterização das matérias-primas, por petrografia e análises químicas e mineralógicas, e posteriores testes de queimabilidade de seis farinhas experimentais, elaboradas com misturas das matérias-primas disponíveis. As farinhas foram sinterizadas e avaliadas qualitativamente, por microscopia do clínquer, e quantificadas por difração de raios-X (DRX) e método de Rietveld. A geologia da mina consiste em metapelitos, por vezes em alternâncias rítmicas, com metacalcários (metaritmito) da Formação Vallemí, basal, sobrepostos por metacalcários puros, com intercalações de metadolomito, da Formação Camba Jhopo, ambas do Grupo Itapucumí (Ediacarano), dispostas em dobra isoclinal com flanco invertido (Faixa de Dobramentos Vallemí). Dada à diversidade litológica e complexidade tectônica, o estudo requereu mapeamento geológico detalhado (escala 1:2000), com coleta de amostras e análise química concomitante, no laboratório de qualidade da indústria, e atualização da topografia e modelagem 3D. Foram individualizados nove litotipos: 1) Litotipo Misto (Itá jopara); 2) Litotipo Ritmito Verde (Itá hovy?); 3) Litotipo Ritmito Vermelho (Itá pytã); 4) Litotipo Calcário Cinza (Itá hungy); 5) Litotipo Calcrete (Itá manduvi sa\'yju); 6) Litotipo Dolomito (Itá pytãngy); 7) Litotipo Arenito Vermelho (Itá atã pytã); 8) Litotipo Lamprofiro (Itá h?); 9) Litotipo Vulcânica Básica (Itá kui sa\'yju), sendo os cincos primeiros apropriados para fabricação de cimento. O Litotipo Dolomito é apropriado se usado em misturas e os demais são materiais estéreis. Foram realizadas seis diferentes misturas de litotipos, além da normalmente empregada na indústria, utilizada como referência, com avaliação do índice de queimabilidade (IQ) nos laboratórios da Associação Brasileira de Cimento Portland (ABCP). As farinhas D1, D3 e D4 foram classificados como fácil de queimar, e as demais, D2, D5b e D6b, com queimabilidade normal. Pode-se dizer que todas apresentam índices de queimabilidade compatíveis com os padrões exigidos para a produção de cimento Portland, destacando que a melhor mistura foi obtida com a farinha D4 (composta por Litotipo Ritmito Vermelho 83,07%, Litotipo Ritmito Verde 14,45% e mineral de ferro 1,48%), e a de menor desempenho a D5b (composta por Litotipo Calcrete 50,17%, Litotipo Misto 48,32% e mineral de ferro 1,52%), o que foi possível também corroborar na quantificação das fases do clínquer.
The present work deals with a detailed geological characterization of the Vallemí Mine in Paraguay, explored to manufacture of Portland cement by the National Cement Industry (INC), followed by the characterization of the raw materials, by petrography, chemical and mineralogical analyzes, and subsequent burnability tests of six experimental raw mixtures, prepared with mixtures of available raw materials. The flours were sintered and evaluated qualitatively by clinker microscopy and quantified by X-ray diffraction (XRD) and Rietveld method. The geology of the mine includes metapelites, sometimes in rhythmic alternations, with metalimestone of the Vallemí Formation, basal, overlapped by pure metalimestone, with intercalation of metadolomite, of the Camba Jhopo Formation, both of the Itapucumí Group (Ediacaran), arranged in fold isoclinal with inverted flank (Vallemí Folding Belt). Due to the lithological diversity and tectonic complexity, the study required detailed geological mapping (scale 1: 2000), with sample collection and concomitant chemical analysis, in the industrial quality laboratory, and updating the topography and 3D modeling. Nine lithotypes were individualized: 1) Litotipo Misto (Itá jopara); 2) Litotipo Ritmito Verde (Itá hovy?); 3) Litotipo Ritmito Vermelho (Itá pytã); 4) Litotipo Calcário Cinza (Itá hungy); 5) Litotipo Calcrete (Itá manduvi sa\'yju); 6) Litotipo Dolomito (Itá pytãngy); 7) Litotipo Arenito Vermelho (Itá atã pytã); 8) Litotipo Lamprofiro (Itá h?); 9) Litotipo Vulcânica Básica (Itá kui sa\'yju), the first five suitable for manufacturing cement. Litotipo Dolomito is applicable if used in mixtures. The others lithotype are sterile materials. Six different mixtures of lithotypes were carried out, besides the one normally used in industry, used as reference, with evaluation of the burnability index (IQ) in the laboratories of the Assocciação Brasileira de Cimento Portland (ABCP). Flours D1, D3 and D4 were classified as easy to burn, and the others, D2, D5b and D6b, with normal burning. It is possible to say that all of them have a comparable burnability index compatible with the standards required for Portland cement production, the best mixture was obtained with the raw mixture D4 (composed by Litotipo Ritmito Vermelho 83,07%, Litotipo Ritmito Verde 14,45% and iron ore 1,48%) and the D5b (composed by Litotipo Calcrete 50,17%, Litotipo Misto 48,32% and iron ore 1,52%) appear as the worst, which were corroborated in the quantification of clinker phases.

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Tesi sul tema "Cement clinkers"

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