Etapas de cominuição representam uma grande parcela do capital e custo operacional em uma usina de processamento mineral. Em 1983, Cohen estimou que os processos de cominuição podem ser responsáveis por 30% a 50% do consumo energético da usina representando tipicamente 50% dos custos operacionais de uma mineração. Sendo assim, sua otimização está diretamente relacionada com a redução destes custos de operação. Entre os equipamentos de britagem, o moinho de martelos é aquele dedicado às operações que visam a alta taxa de redução com geração controlada de finos. Este britador é recomendado para minérios friáveis e pouco abrasivos, apresentando alta capacidade produtiva. O presente trabalho tem por objetivo propor e validar um modelo matemático para modelagem e simulação de moinho de martelos, visando a simulação do circuito da britagem industrial de beneficiamento de minério de ouro do Córrego do Sítio I, localizada em Santa Bárbara - MG. As simulações visaram identificar gargalos operacionais e estabelecer cenários que permitam otimizar o circuito estudado. A amostragem foi executada conforme o plano traçado. As amostras obtidas foram utilizadas tanto para a caracterização do minério quanto para a calibração do modelo do Caso Base da operação da usina. As simulações indicaram acréscimos significativos de vazão de alimentação na usina, a partir do aumento da velocidade de rotação do moinho de martelos, com uma tendência de geração maior de finos no processo. Para simulação do aumento de velocidade de rotação dos martelos foi criado um modelo com base na energia de quebra das partículas, associada aos incrementos correspondentes na energia cinética dos martelos. A fim de validar o modelo proposto, foram planejados ensaios específicos em moinho de martelos de laboratório, e executados com o mesmo minério alimentado na usina industrial selecionada. Os ensaios consistiram em variações de velocidade de rotação dos martelos, de forma a corresponder às simulações anteriormente realizadas do equipamento industrial. O modelo criado foi validado com base em campanha experimental específica. / Comminution represents a large portion of the capital and operating cost of a mineral processing plant. In 1983, Cohen estimated that comminution processes could account for 30% to 50% of the power consumption of the mill, and typically represents 50% of the operating costs of a mine. Therefore, its optimization is directly related to reduction of these operating costs. Among the crushing equipment, the hammer mill is one which is dedicated to operations that aim for high reduction ratio with controlled generation of fines. This crusher is recommended for friable and low abrasive ores presenting a high productive capacity. This study aims to develop a stepwise approach that allows the use of the classical crusher model (Whiten-Andersen) in modeling and simulation of circuits containing a hammer mill, simulating the resulting product according to variation of rotation speed within the equipment. The existing model for crushers developed by Whiten-Andersen considers the Perfect Mixing Model, which represents crushing through equations related to selection and breakage functions, that provide an equilibrium condition. The present work aims at the validation of a mathematical model of hammer mill, aiming at a simulation of the circuit of the industrial crushing of gold ore of Córrego do Sítio I, located in Santa Bárbara - MG. The simulations aimed at identifying operational bottlenecks and establishing scenarios that allow optimizing the studied circuit. Sampling was performed according to the drawn plan. The samples obtained were used both for the characterization of the ore and for the calibration of the Base Case model of the plant operation. The simulations indicated significant increases in feed flow at the plant, due to the increase in the speed of rotation of the hammer mill, with a trend of higher generation of fines in the process. To simulate the increase of rotational velocity of the hammers, a model was created based on the energy of breaking of the particles, associated to the corresponding increments in the kinetic energy of the hammers. In order to validate the proposed model, specific tests were planned in laboratory hammer mill, and executed with the same ore fed in the selected industrial plant. The tests consisted of variations in the speed of rotation of the hammers, in order to correspond to the previous simulations of the industrial equipment. The model created was validated based on specific experimental campaign.

The two main sources of biomass for energy generation are purpose-grown energy crops and waste materials. Energy crops, such as Miscanthus and short rotation woody crops (coppice), are cultivated mainly for energy purposes and are associated with the food vs. fuels debate, which is concerned with whether land should be used for fuel rather than food production. The use of residues from agriculture, such as barley, canola, oat and wheat straw, for energy generation circumvents the food vs. fuel dilemma and adds value to existing crops. In fact, these residues represent an abundant, inexpensive and readily available source of renewable lignocellulosic biomass. In order to reduce industrys operational cost as well as to meet the requirement of raw material for biofuel production, biomass must be processed and handled in an efficient manner. Due to its high moisture content, irregular shape and size, and low bulk density, biomass is very difficult to handle, transport, store, and utilize in its original form. Densification of biomass into durable compacts is an effective solution to these problems and it can reduce material waste. Upon densification, many agricultural biomass materials, especially those from straw and stover, result in a poorly formed pellets or compacts that are more often dusty, difficult to handle and costly to manufacture. This is caused by lack of complete understanding on the natural binding characteristics of the components that make up biomass. An integrated approach to postharvest processing (chopping, grinding and steam explosion), and feasibility study on lab-scale and pilot scale densification of non-treated and steam exploded barley, canola, oat and wheat straw was successfully established to develop baseline data and correlations, that assisted in performing overall specific energy analysis. A new procedure was developed to rapidly characterize the lignocellulosic composition of agricultural biomass using the Fourier Transform Infrared (FTIR) spectroscopy. In addition, baseline knowledge was created to determine the physical and frictional properties of non-treated and steam exploded agricultural biomass grinds. Particle size reduction of agricultural biomass was performed to increase the total surface area, pore size of the material and the number of contact points for inter-particle bonding in the compaction process. Predictive regression equations having higher R2 values were developed that could be used by biorefineries to perform economic feasibility of establishing a processing plant. Specific energy required by a hammer mill to grind non-treated and steam exploded barley, canola, oat and wheat straw showed a negative power correlation with hammer mill screen sizes. Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. A novel procedure to quantitatively predict lignocellulosic components of non-treated and steam exploded barley, canola, oat and wheat straw was developed using Fourier Transformed Infrared (FTIR) spectroscopy. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively. Application of steam explosion pre-treatment on agricultural straw significantly altered the physical and frictional properties, which has direct significance on designing new and modifying existing bins, hoppers and feeders for handling and storage of straw for biofuel industry. As a result, regression equations were developed to enhance process efficiency by eliminating the need for experimental procedure while designing and manufacturing of new handling equipment. Compaction of low bulk density agricultural biomass is a critical and desirable operation for sustainable and economic availability of feedstock for the biofuel industry. A comprehensive study of the compression characteristics (density of pellet and total specific energy required for compression) of ground non-treated and steam exploded barley, canola, oat and wheat straw obtained from three hammer mill screen sizes of 6.4, 3.2 and 1.6 mm at 10% moisture content (wb) was conducted. Four preset pressures of 31.6, 63.2, 94.7 and 138.9 MPa, were applied using an Instron testing machine to compress samples in a cylindrical die. It was determined that the applied pressure (60.4%) was the most significant factor affecting pellet density followed by the application of steam explosion pre-treatment (39.4%). Similarly, the type of biomass (47.1%) is the most significant factor affecting durability followed by the application of pre-treatment (38.2%) and grind size (14.6%). Also, the applied pressure (58.3%) was the most significant factor affecting specific energy required to manufacture pellets followed by the biomass (15.3%), pre-treatment (13.3%) and grind size (13.2%), which had lower but similar effect affect on specific energy. In addition, correlations for pellet density and specific energy with applied pressure and hammer mill screen sizes having highest R2 values were developed. Higher grind sizes and lower applied pressures resulted in higher relaxations (lower pellet densities) during storage of pellets. Three compression models, namely: Jones model, Cooper-Eaton model, and Kawakita-Ludde model were considered to determine the pressure-volume and pressure-density relationship of non-treated and steam exploded straws. Kawakita-Ludde model provided the best fit to the experimental data having R2 values of 0.99 for non-treated straw and 1.00 for steam exploded biomass samples. The steam exploded straw had higher porosity than non-treated straw. In addition, the steam exploded straw was easier to compress since it had lower yield strength or failure stress values compared to non-treated straw. Pilot scale pelleting experiments were performed on non-treated, steam exploded and customized (adding steam exploded straw grinds in increments of 25% to non-treated straw) barley, canola, oat and wheat straw grinds obtained from 6.4, 3.2, 1.6 and 0.8 mm hammer mill screen sizes at 10% moisture content (wb). The pilot scale pellet mill produced pellets from ground non-treated straw at hammer mill screen sizes of 0.8 and 1.6 mm and customized samples having 25% steam exploded straw at 0.8 mm. It was observed that the pellet bulk density and particle density are positively correlated. The density and durability of agricultural straw pellets significantly increased with a decrease in hammer mill screen size from 1.6 mm to 0.8 mm. Interestingly, customization of agricultural straw by adding 25% of steam exploded straw by weight resulted in higher durability (> 80%) pellets but did not improve durability compared to non-treated straw pellets. In addition, durability of pellets was negatively correlated to pellet mill throughput and was positively correlated to specific energy consumption. Total specific energy required to form pellets increased with a decrease in hammer mill screen size from 1.6 to 0.8 mm and also the total specific energy significantly increased with customization of straw at 0.8 mm screen size. It has been determined that the net specific energy available for production of biofuel is a significant portion of original agricultural biomass energy (89-94%) for all agricultural biomass.

The two main sources of biomass for energy generation are purpose-grown energy crops and waste materials. Energy crops, such as Miscanthus and short rotation woody crops (coppice), are cultivated mainly for energy purposes and are associated with the food vs. fuels debate, which is concerned with whether land should be used for fuel rather than food production. The use of residues from agriculture, such as barley, canola, oat and wheat straw, for energy generation circumvents the food vs. fuel dilemma and adds value to existing crops. In fact, these residues represent an abundant, inexpensive and readily available source of renewable lignocellulosic biomass. In order to reduce industrys operational cost as well as to meet the requirement of raw material for biofuel production, biomass must be processed and handled in an efficient manner. Due to its high moisture content, irregular shape and size, and low bulk density, biomass is very difficult to handle, transport, store, and utilize in its original form. Densification of biomass into durable compacts is an effective solution to these problems and it can reduce material waste. Upon densification, many agricultural biomass materials, especially those from straw and stover, result in a poorly formed pellets or compacts that are more often dusty, difficult to handle and costly to manufacture. This is caused by lack of complete understanding on the natural binding characteristics of the components that make up biomass. An integrated approach to postharvest processing (chopping, grinding and steam explosion), and feasibility study on lab-scale and pilot scale densification of non-treated and steam exploded barley, canola, oat and wheat straw was successfully established to develop baseline data and correlations, that assisted in performing overall specific energy analysis. A new procedure was developed to rapidly characterize the lignocellulosic composition of agricultural biomass using the Fourier Transform Infrared (FTIR) spectroscopy. In addition, baseline knowledge was created to determine the physical and frictional properties of non-treated and steam exploded agricultural biomass grinds. Particle size reduction of agricultural biomass was performed to increase the total surface area, pore size of the material and the number of contact points for inter-particle bonding in the compaction process. Predictive regression equations having higher R2 values were developed that could be used by biorefineries to perform economic feasibility of establishing a processing plant. Specific energy required by a hammer mill to grind non-treated and steam exploded barley, canola, oat and wheat straw showed a negative power correlation with hammer mill screen sizes. Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. A novel procedure to quantitatively predict lignocellulosic components of non-treated and steam exploded barley, canola, oat and wheat straw was developed using Fourier Transformed Infrared (FTIR) spectroscopy. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively. Application of steam explosion pre-treatment on agricultural straw significantly altered the physical and frictional properties, which has direct significance on designing new and modifying existing bins, hoppers and feeders for handling and storage of straw for biofuel industry. As a result, regression equations were developed to enhance process efficiency by eliminating the need for experimental procedure while designing and manufacturing of new handling equipment. Compaction of low bulk density agricultural biomass is a critical and desirable operation for sustainable and economic availability of feedstock for the biofuel industry. A comprehensive study of the compression characteristics (density of pellet and total specific energy required for compression) of ground non-treated and steam exploded barley, canola, oat and wheat straw obtained from three hammer mill screen sizes of 6.4, 3.2 and 1.6 mm at 10% moisture content (wb) was conducted. Four preset pressures of 31.6, 63.2, 94.7 and 138.9 MPa, were applied using an Instron testing machine to compress samples in a cylindrical die. It was determined that the applied pressure (60.4%) was the most significant factor affecting pellet density followed by the application of steam explosion pre-treatment (39.4%). Similarly, the type of biomass (47.1%) is the most significant factor affecting durability followed by the application of pre-treatment (38.2%) and grind size (14.6%). Also, the applied pressure (58.3%) was the most significant factor affecting specific energy required to manufacture pellets followed by the biomass (15.3%), pre-treatment (13.3%) and grind size (13.2%), which had lower but similar effect affect on specific energy. In addition, correlations for pellet density and specific energy with applied pressure and hammer mill screen sizes having highest R2 values were developed. Higher grind sizes and lower applied pressures resulted in higher relaxations (lower pellet densities) during storage of pellets. Three compression models, namely: Jones model, Cooper-Eaton model, and Kawakita-Ludde model were considered to determine the pressure-volume and pressure-density relationship of non-treated and steam exploded straws. Kawakita-Ludde model provided the best fit to the experimental data having R2 values of 0.99 for non-treated straw and 1.00 for steam exploded biomass samples. The steam exploded straw had higher porosity than non-treated straw. In addition, the steam exploded straw was easier to compress since it had lower yield strength or failure stress values compared to non-treated straw. Pilot scale pelleting experiments were performed on non-treated, steam exploded and customized (adding steam exploded straw grinds in increments of 25% to non-treated straw) barley, canola, oat and wheat straw grinds obtained from 6.4, 3.2, 1.6 and 0.8 mm hammer mill screen sizes at 10% moisture content (wb). The pilot scale pellet mill produced pellets from ground non-treated straw at hammer mill screen sizes of 0.8 and 1.6 mm and customized samples having 25% steam exploded straw at 0.8 mm. It was observed that the pellet bulk density and particle density are positively correlated. The density and durability of agricultural straw pellets significantly increased with a decrease in hammer mill screen size from 1.6 mm to 0.8 mm. Interestingly, customization of agricultural straw by adding 25% of steam exploded straw by weight resulted in higher durability (> 80%) pellets but did not improve durability compared to non-treated straw pellets. In addition, durability of pellets was negatively correlated to pellet mill throughput and was positively correlated to specific energy consumption. Total specific energy required to form pellets increased with a decrease in hammer mill screen size from 1.6 to 0.8 mm and also the total specific energy significantly increased with customization of straw at 0.8 mm screen size. It has been determined that the net specific energy available for production of biofuel is a significant portion of original agricultural biomass energy (89-94%) for all agricultural biomass.

Composites are the materials which can be used for a wide variety of applications andproducts such as sports equipment, aerospace and marine because of light and stiffnessproperties. Composites are often made from thermoset resin with glass fibers.In this study, two ways of recycling composites were evaluated, which are microwavepyrolysed composites (MGC) and mechanical composites (GC). These glass fibers weregoing to be compounded with Polypropylene (PP) or Maleic Anhydride ModifiedPolypropylene (MAPP) and then injection moulded the sample by Micro-compounder.In order to get better adhesion to the polymer, a coating was added. The Neoxil 5682-polypropylene water emulsion was evaluated.The samples were characterized by Tensile Testing, Thermogravimetric Analysis (TGA),Different Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA) to find aoptimum combination of recycled glass fiber reinforced polymer.Microwave pyrolysis is a new research area. The glass fiber, polymer oil and gas can beobtained by heating the composite with microwaves to in an inert atmosphere. The polymeroil can be distillated and then evaluated with GC-MS; in order to obtain the chemicalcompositions.Keywords: Composites, grinded and microwave pyrolyse composites (MGC), grindedcomposites (GC), Polypropylene (PP), Maleic Anhydride Modified Polypropylene (MAPP),Micro-compounder, Tensile Testing, Thermogravimetric Analysis (TGA), Different ScanningCalorimetry (DSC), and Dynamic Mechanical Analysis (DMA), Microwave pyrolysis,polymer oil, distillation, GCMS Analysis. / Program: MSc in Resource Recovery - Sustainable Engineering

In mehrfaktoriellen 2 x 2 x 4 Untersuchungen im Zeitraum vom 7. - 28. Lebenstag und in Bilanzversuchen vom 15. - 20. Lebenstag mit männlichen Broilerküken (Cobb 500) wurden die Effekte der Versuchsfaktoren Zerkleinerung (Hammermühle vs. Walzenstuhl), thermische Behandlung (Konditionierung bei 70°C vs. Konditionierung/Expandierung 100°C) und Zusätze von Zink-Bacitracin bzw. Roxazym G2 (ohne Zusatz, mit Zink-Bacitracin 50 mg, mit Roxayzm G2 150 ppm und deren Zusatzkombination A+E) sowie die Interaktionen untersucht. Als Kriterien dienten die Parameter Futterverzehr, Lebendmassezunahme, Futteraufwand, Nährstoffansatz und -verwertung, ileale Verdaulichkeit von ausgewählten Aminosäuren, Proteinverwertung/Proteinqualität und Umsetzbarkeit der Energie. Die Versuchstiere erhielten ab dem 7. Lebenstag die entsprechenden Versuchsmischungen. Der Gehalt an XP und MEn aller Versuchsmischungen war einheitlich (XP 21,7% und MEn 12,3 MJ/kg Futter). Die Lysinversorgung wurde auf 90 % unter der optimalen Bedarfsdeckung in allen Futtermischungen limitiert. Die Auswirkungen der Versuchsfaktoren lassen sich wie folgt zusammenfassen: - Zerkleinerung : Die Zerkleinerungstechnologie mit dem Walzenstuhl übte einen signifikanten Einfluss auf den Futterverzehr (-3,5 %) und Futteraufwand (-2,8 %) gegenüber der Zerkleinerung mit der Hammermühle aus. Die Nährstoffverwertung (XP und Energie) zeigten durch Walzenstuhl-Zerkleinerung tendenzielle Verbesserungen. Die ileale Lysinverdaulichkeit blieb unverändert, die ileale Verdaulichkeit von Threonin und Met+Cys wurde signifikant erhöht. Die Walzenstuhl-Zerkleinerung führte zu einer besseren Futterstruktur und zu einer höheren Nährstoffdichte in den Pellets. Das wird deutlich durch die höhere N-Aufnahme bzw. N-Bilanz sowie durch gesteigerte N-Verwertungsparameter und einen erhöhten Gehalt an N-korrigierter umsetzbarer Energie (MEn). - Thermische Behandlung : Durch erhöhte Hitzeapplikation mit dem Expander konnten in der vorliegenden Arbeit hinsichtlich der Leistungsparameter, Nährstoffansatz und -verwertung keine Unterschiede gegenüber der Konditionierung festgestellt werden. Die Expandierung führte zu einer signifikant erhöhten ilealen Lysinverdaulichkeit, die durch die gemessene Lysinwirksamkeit im Bilanzversuch jedoch nicht widergespiegelt wurde. Auch signifikant niedrigere N-Bilanz und physiologische Proteinnutzwerte (PNu) sowie die tendenzielle Verringerung der N-Verdaulichkeit und des Gehaltes an umsetzbarer Energie deuten auf eine negative Wirkung der intensiveren thermischen Behandlung durch Expandieren hin. Hierzu sind weitere klärende Untersuchungen notwendig. - Futterzusätze: Durch die alleinige Supplementierung mit dem Antibiotikum Zink-Bacitracin oder NSP-spaltenden Enzym Roxazym G2 bzw. deren Kombination reagierten Mastleistung und Futterverwertung signifikant positiv. Während der Effekt der Enzymzulagen bei Nährstoffverwertung und ilealer Verdaulichkeit ausgewählter Aminosäure signifikant höher gegenüber der unsupplementierten Gruppe war, blieb ein Effekt von Zink-Bacitracin hinsichtlich dieser Parameter aus. Der Effekt der Zusatzkombination war bei Mastleistung, Nährstoffansatz und -verwertung und bei der ilealen Verdaulichkeit der ausgewählten Aminosäuren gegenüber der Kontrolle oder dem alleinigen Zusatz signifikant höher. Das deutet auf einen synergistischen Effekt der gleichzeitigen Applikation der beiden Additive hin. Die N-Verwertung einschließlich des Gehalts an N-korrigierter scheinbar umsetzbarer Energie lag nach alleiniger Applikation von Zink-Bacitracin unerwartet signifikant niedriger gegenüber den anderen Zusätzen bzw. tendenziell gegenüber der Kontrolle. Die Gehalte an scheinbar umsetzbarer Energie (AMEn) waren deutlich durch den Enzymzusatz allein oder in Kombination mit Zink-Bacitracin erhöht. -Interaktionen: Die Abhängigkeit der Versuchsfaktoren voneinander im Mastversuch war nicht stark ausgeprägt. Die Zerkleinerung in Verbindung mit anschließender thermischer Behandlung führte zur Beeinflussung der Futterverzehrsdaten. Danach verbesserten die Verfahrenskombinationen Hammermühle x Konditionierung oder Walzenstuhl x Expandierung bedingt durch einen erhöhten Futterverzehr die Lebendmassezunahme und den Nährstoffansatz signifikant. Hinsichtlich der ilealen Aminosäurenverdaulichkeit zeigten die Futterzusätze eine Abhängigkeit von der Behandlung bzw. Zerkleinerung und Behandlung. Die Enzymzulage allein oder in Kombination mit Zink-Bacitracin zeigte stärkere Effektivität in Verbindung mit der thermischen Behandlung durch Expandieren.