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This paper presents the results of a study on carbothermal reduction of iron ore made under the microwave field in equipment specially developed for this purpose. The equipment allows the control of radiated and reflected microwave power, and therefore measures the microwave energy actually applied to the load in the reduction process. It also allows performing energy balances and determining the reaction rate with high levels of confidence by simultaneously measuring temperature and mass of the material upon reduction with high reproducibility. We used a microwave generator of 2.45 GHz with variable power up to 3000 W. Self‐reducing pellets under argon atmosphere, containing iron ore and petroleum coke, with 3.5 g of mass and 15 mm of diameter were declined. We obtained the kinetic curves of reduction of iron ore and of energy consumption to the process in the maximum electric field, in the maximum magnetic field and at different values of power/mass. The data allow analyzing how the microwave energy was actually consumed in the reduction of ore.

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DEDICATÓRIAAos meus pais (in memorian) pelo empenho e incentivo em meus estudos. AGRADECIMENTOS Agradeço ao Instituto Mauá de Tecnologia e a Escola Politécnica daUniversidade de São Paulo, por propiciar condições para a realização deste trabalho.Agradeço a FAPESP, pelo apoio e ajuda financeira.Agradeço ao professor Dr. Marcelo Breda Mourão, pela sua relevante contribuição na orientação da elaboração desta dissertação. RESUMOO presente trabalho apresenta um equipamento para o processamento de reduções carbotérmicas sob campo de micro-ondas, permitindo pleno controle da potência fornecida e da medida da energia de micro-ondas efetivamente aplicada à carga em processo de redução podendo assim realizar balanços de energia e determinação de taxa de reação com altos níveis de confiança. O equipamento permite, sobretudo, a medida simultânea de temperatura e de massa do material sob redução, e a fácil reprodutibilidade das condições de ensaio.O protótipo opera com um gerador de micro-ondas de 2.45 GHz e potência variável até 3000 W. A amostra é mantida sob atmosfera de argônio. ABSTRACTThis work presents of a device for microwave enhanced carbothermic reductions which permits the full control of microwave power irradiated, the measurement of effectively applied microwave power to the charge in process thus performing a high confidence determination of rate of reaction and energy balance. In particular, the simultaneous records of its temperature and mass loss, and good reproducibility of operation parameters, are obtainable.This prototype works with a 2.45 GHz microwave generator with variable power up to 3000 W. Samples are processes under argon gas atmosphere.Operational tests for Carajás iron ore reduction with petroleum coke were performed using spherical pellets with weight of 3,5 g and diameter of 15 mm.Kinetic curves of iron ore reduction and effective consumption of microwave power curves were determined. These results made possible to perform an analysis of actual energy consumption for enhanced microwave iron ore carbothermic reduction.

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