Cyro Takano | University of Sao Paulo (original) (raw)
Papers by Cyro Takano
Anais dos Seminários de Redução, Minério de Ferro e Aglomeração, Sep 1, 2017
Resumo O presente trabalho apresenta um forno para a produção de ferro gusa por redução carbotérm... more Resumo O presente trabalho apresenta um forno para a produção de ferro gusa por redução carbotérmica estimulada por micro-ondas de minério de ferro, na forma de pelotas autoredutoras. O forno de redução com potência regulável de até 15 kW de micro-ondas de 2.45 GHz foi especialmente projetado e construído para este processo. A estrutura do forno é em aço inoxidável e utiliza três geradores de micro-ondas focados para o centro de um aplicador cilíndrico. Com esta configuração conseguiu-se produzir um campo eletromagnético de alta densidade energética. As cargas de pelotas auto-redutoras, com massas em torno de 90 g e 30 g foram reduzidas em um cadinho de carbeto de silício. A potência de micro-ondas irradiada foi de 6 kW. A montagem do forno dispõe de uma balança elétrica adaptada para suportar o cadinho de redução. O presente forno dispõe de controle e medida da potência fornecida e refletida, permitindo medir a energia de micro-ondas efetivamente aplicada à carga. Esta característica permite realizar balanços de massa e de energia além de determinar a evolução da taxa de reação através da medida contínua da massa das pelotas sob redução, ao longo do tempo de processamento. Obtiveram-se curvas cinéticas de redução carbotérmica de minério de ferro incentivada por micro-ondas e de seu consumo de energia durante o processo. Palavras-chave: Forno redução carbotérmica; Micro-ondas; Ferro gusa. EQUIPMENT FOR CARBOTHERMAL REDUCTION OF IRON ORE APPLYING MICROWAVE Abstract This paper presents of furnace for production of pig iron by carbothermic reduction of iron ore in the form of self-reducing pellets enhanced by microwaves. The reduction furnace with adjustable up to 15 kW microwave power of 2.45 GHz has been specially designed and built for this purpose. The furnace structure is made of stainless steel and has three microwave generators focused to the center of a cylindrical applicator. With this setup we were able to produce a high energy density electromagnetic field. The burden of self-reducing pellets with mass around 90 g and 30 g were reduced in a crucible silicon carbide. The power microwave radiated is 6 kW. The oven features an electric balance appropriately adapted to support the crucible reduction. This oven allows the measurement and control of power supplied and reflected establishing the effective energy applied to load. This feature allowed for mass and energy balances and to observe the evolution of reduction rate by continuously measuring of reacting mass during its processing. Curves for carbothermic reduction of iron ore were determined and, also, the energy consumption during the process. This feature allows to perform mass and energy balances and to determine the progress of the reaction rate by continuously measuring the mass of pellets under reducing along the processing time. Curves for carbothermal reduction of iron ore were determined and, also, the energy consumption during the process.
Springer eBooks, 2013
The growing search for forms of clean renewable energy has placed wood charcoal as a possible alt... more The growing search for forms of clean renewable energy has placed wood charcoal as a possible alternative to coal in the Brazilian steel industry. The carbonization of Eucalyptus Saligna is an important step in the production of charcoal. The aim of this study is to analyze the behavior of the endothermic and exothermic reactions involved in the carbonization process. The carbonization of logs of Eucalyptus Saligna has been performed in a stainless steel reactor at different temperatures (300 ° C, 400 ° C and 500 ° C) and the results were compared with the ones obtained through thermal analysis (TG / DSC) of small samples (36 mg and 54 mg) of the same wood. The TG/DSC results indicated that the process presents both endothermic and exothermic features, at different ranges of temperature and time, in connection with the degradation of the three major macromolecules contained in the wood: cellulose, hemicellulose and lignin.
Isij International, 2001
The main advantage of the self-reducing pellets is related to the reaction rate: due to the close... more The main advantage of the self-reducing pellets is related to the reaction rate: due to the closeness of the reactants, their small size and nitrogen free environment, almost complete reduction can be achieved with reaction times ranging from 5 to less than 10 minutes for temperatures between 10000c and 1200'C. These reaction times depend on the nature of the iron bearing material. This paper presents the comparison of experimental results whencompacthematite iron ore and dust from sintering plant were used. Self-reducing pellets with 18 mm diameter were made with these materials composing with coal plus binder (40/0 Portland cement plus 4•/o Blast Furnace slag). The pellets were submitted to 8 different thermal paths for evaluating the high temperature behavior, that is: decrepitating, swelling, strength and reducing. The results showed that none of the pellets presented decrepitating and that the pellet with dust from sintering plant does not present any tendency for swelling. Theabnormal swelling of the pellets containing hematite iron ore can be minimized or avoided by designing a self-reducing process with controlled heating rate and completing the reduction at temperature higher than 11000c. The strength of 200-400 N/pellet, at room temperature, decreased to a minimumof 20-40 N/pellet after submitted to 900-950'C. The dust from sintering plant, to achieve high degree of reduction, is less dependentof the heat intensity supply and temperature than iron ore
STUDY OF THE PROCESS OF REDUCTION AND SMELTING OF SELF-REDUCING PELLETS BETWEEN 1573 AND 1673 K. ... more STUDY OF THE PROCESS OF REDUCTION AND SMELTING OF SELF-REDUCING PELLETS BETWEEN 1573 AND 1673 K. Alberto Eloy Anduze Nogueira, Marcelo Breda Mourao, Cyro Takano 2 nd International Meeting ...
John Wiley & Sons, Inc. eBooks, Feb 20, 2013
The organic household waste has a growing disposal problem, requiring costly disposal systems. It... more The organic household waste has a growing disposal problem, requiring costly disposal systems. It is necessary to find new applications for these materials; one could be the steelmaking raw material production. In this paper is studied the development of self-reducing pellets from the organic waste pyrolysis, where is generated carbon and condensable and non-condensable volatiles. Non-condensable volatiles were burned and condensable volatiles were recovered. The resulting tar was mixed with iron ore, coal powder and flux (CaO), to then be pelletized together. Compression, falls and tumbler tests were conducted to characterize the pellets before and after heat treatment and reduction processes. The reduction curve and their physical and morphological characterization were measured. The results were as was expected, the fluidized coal create sufficient adhesion that pellets earned resistance with an equivalent resistance of common pellets, showing a good feasibility of this process.
... 65% Carepas 83% reciclado p/ óleo < 2% 74% Em aciaria ou DRI ... A resistência de 300N/pel... more ... 65% Carepas 83% reciclado p/ óleo < 2% 74% Em aciaria ou DRI ... A resistência de 300N/pelota da pelota P1 foi devido a utilização de 10% de cimento, por outro lado abaixo de 6,5% de cimento ( P3, P4 e P5) há uma queda na resistência à compressão da pelota. ...
Anais dos Seminários de Redução, Minério de Ferro e Aglomeração, 2017
Resumo A degradação durante o processo de redução de minérios de ferro é bastante conhecida pelos... more Resumo A degradação durante o processo de redução de minérios de ferro é bastante conhecida pelos fenômenos de crepitação e inchamento. Em aglomerados a frio, auto-redutores utilizando cimento como aglomerante, há também degradação pela decomposição de hidratos que conferem resistência a frio, além de aumentar os vazios deixados pelo consumo do redutor. Outro fenômeno que afeta na velocidade da reação de redução é a formação de escória. Esses aspectos são analisados neste trabalho e principalmente em processos de auto-redução.
Anais dos Seminários de Redução, Minério de Ferro e Aglomeração, Sep 1, 2017
Resumo O presente trabalho apresenta um forno para a produção de ferro gusa por redução carbotérm... more Resumo O presente trabalho apresenta um forno para a produção de ferro gusa por redução carbotérmica estimulada por micro-ondas de minério de ferro, na forma de pelotas autoredutoras. O forno de redução com potência regulável de até 15 kW de micro-ondas de 2.45 GHz foi especialmente projetado e construído para este processo. A estrutura do forno é em aço inoxidável e utiliza três geradores de micro-ondas focados para o centro de um aplicador cilíndrico. Com esta configuração conseguiu-se produzir um campo eletromagnético de alta densidade energética. As cargas de pelotas auto-redutoras, com massas em torno de 90 g e 30 g foram reduzidas em um cadinho de carbeto de silício. A potência de micro-ondas irradiada foi de 6 kW. A montagem do forno dispõe de uma balança elétrica adaptada para suportar o cadinho de redução. O presente forno dispõe de controle e medida da potência fornecida e refletida, permitindo medir a energia de micro-ondas efetivamente aplicada à carga. Esta característica permite realizar balanços de massa e de energia além de determinar a evolução da taxa de reação através da medida contínua da massa das pelotas sob redução, ao longo do tempo de processamento. Obtiveram-se curvas cinéticas de redução carbotérmica de minério de ferro incentivada por micro-ondas e de seu consumo de energia durante o processo. Palavras-chave: Forno redução carbotérmica; Micro-ondas; Ferro gusa. EQUIPMENT FOR CARBOTHERMAL REDUCTION OF IRON ORE APPLYING MICROWAVE Abstract This paper presents of furnace for production of pig iron by carbothermic reduction of iron ore in the form of self-reducing pellets enhanced by microwaves. The reduction furnace with adjustable up to 15 kW microwave power of 2.45 GHz has been specially designed and built for this purpose. The furnace structure is made of stainless steel and has three microwave generators focused to the center of a cylindrical applicator. With this setup we were able to produce a high energy density electromagnetic field. The burden of self-reducing pellets with mass around 90 g and 30 g were reduced in a crucible silicon carbide. The power microwave radiated is 6 kW. The oven features an electric balance appropriately adapted to support the crucible reduction. This oven allows the measurement and control of power supplied and reflected establishing the effective energy applied to load. This feature allowed for mass and energy balances and to observe the evolution of reduction rate by continuously measuring of reacting mass during its processing. Curves for carbothermic reduction of iron ore were determined and, also, the energy consumption during the process. This feature allows to perform mass and energy balances and to determine the progress of the reaction rate by continuously measuring the mass of pellets under reducing along the processing time. Curves for carbothermal reduction of iron ore were determined and, also, the energy consumption during the process.
Springer eBooks, 2013
The growing search for forms of clean renewable energy has placed wood charcoal as a possible alt... more The growing search for forms of clean renewable energy has placed wood charcoal as a possible alternative to coal in the Brazilian steel industry. The carbonization of Eucalyptus Saligna is an important step in the production of charcoal. The aim of this study is to analyze the behavior of the endothermic and exothermic reactions involved in the carbonization process. The carbonization of logs of Eucalyptus Saligna has been performed in a stainless steel reactor at different temperatures (300 ° C, 400 ° C and 500 ° C) and the results were compared with the ones obtained through thermal analysis (TG / DSC) of small samples (36 mg and 54 mg) of the same wood. The TG/DSC results indicated that the process presents both endothermic and exothermic features, at different ranges of temperature and time, in connection with the degradation of the three major macromolecules contained in the wood: cellulose, hemicellulose and lignin.
Isij International, 2001
The main advantage of the self-reducing pellets is related to the reaction rate: due to the close... more The main advantage of the self-reducing pellets is related to the reaction rate: due to the closeness of the reactants, their small size and nitrogen free environment, almost complete reduction can be achieved with reaction times ranging from 5 to less than 10 minutes for temperatures between 10000c and 1200'C. These reaction times depend on the nature of the iron bearing material. This paper presents the comparison of experimental results whencompacthematite iron ore and dust from sintering plant were used. Self-reducing pellets with 18 mm diameter were made with these materials composing with coal plus binder (40/0 Portland cement plus 4•/o Blast Furnace slag). The pellets were submitted to 8 different thermal paths for evaluating the high temperature behavior, that is: decrepitating, swelling, strength and reducing. The results showed that none of the pellets presented decrepitating and that the pellet with dust from sintering plant does not present any tendency for swelling. Theabnormal swelling of the pellets containing hematite iron ore can be minimized or avoided by designing a self-reducing process with controlled heating rate and completing the reduction at temperature higher than 11000c. The strength of 200-400 N/pellet, at room temperature, decreased to a minimumof 20-40 N/pellet after submitted to 900-950'C. The dust from sintering plant, to achieve high degree of reduction, is less dependentof the heat intensity supply and temperature than iron ore
STUDY OF THE PROCESS OF REDUCTION AND SMELTING OF SELF-REDUCING PELLETS BETWEEN 1573 AND 1673 K. ... more STUDY OF THE PROCESS OF REDUCTION AND SMELTING OF SELF-REDUCING PELLETS BETWEEN 1573 AND 1673 K. Alberto Eloy Anduze Nogueira, Marcelo Breda Mourao, Cyro Takano 2 nd International Meeting ...
John Wiley & Sons, Inc. eBooks, Feb 20, 2013
The organic household waste has a growing disposal problem, requiring costly disposal systems. It... more The organic household waste has a growing disposal problem, requiring costly disposal systems. It is necessary to find new applications for these materials; one could be the steelmaking raw material production. In this paper is studied the development of self-reducing pellets from the organic waste pyrolysis, where is generated carbon and condensable and non-condensable volatiles. Non-condensable volatiles were burned and condensable volatiles were recovered. The resulting tar was mixed with iron ore, coal powder and flux (CaO), to then be pelletized together. Compression, falls and tumbler tests were conducted to characterize the pellets before and after heat treatment and reduction processes. The reduction curve and their physical and morphological characterization were measured. The results were as was expected, the fluidized coal create sufficient adhesion that pellets earned resistance with an equivalent resistance of common pellets, showing a good feasibility of this process.
... 65% Carepas 83% reciclado p/ óleo < 2% 74% Em aciaria ou DRI ... A resistência de 300N/pel... more ... 65% Carepas 83% reciclado p/ óleo < 2% 74% Em aciaria ou DRI ... A resistência de 300N/pelota da pelota P1 foi devido a utilização de 10% de cimento, por outro lado abaixo de 6,5% de cimento ( P3, P4 e P5) há uma queda na resistência à compressão da pelota. ...
Anais dos Seminários de Redução, Minério de Ferro e Aglomeração, 2017
Resumo A degradação durante o processo de redução de minérios de ferro é bastante conhecida pelos... more Resumo A degradação durante o processo de redução de minérios de ferro é bastante conhecida pelos fenômenos de crepitação e inchamento. Em aglomerados a frio, auto-redutores utilizando cimento como aglomerante, há também degradação pela decomposição de hidratos que conferem resistência a frio, além de aumentar os vazios deixados pelo consumo do redutor. Outro fenômeno que afeta na velocidade da reação de redução é a formação de escória. Esses aspectos são analisados neste trabalho e principalmente em processos de auto-redução.