Made available in DSpace on 2014-12-17T14:58:13Z (GMT). No. of bitstreams: 1 RaquelGC_DISSERT.pdf: 1617455 bytes, checksum: fe137c67d61e0483bac922261c815e1e (MD5) Previous issue date: 2011-11-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In this study we used the plasma as a source of energy in the process of carbothermic reduction of rutile ore (TiO2). The rutile and graphite powders were milled for 15 h and placed in a hollow cathode discharge produced by in order to obtain titanium carbonitride directly from the reaction, was verified the influence of processing parameters of plasma temperature and time in the synthesis of TiCN. The reaction was carried out at 600, 700 and 800˚C for 3 to 4 hours in an atmosphere of nitrogen and argon. During all reactions was monitored by plasma technique of optical emission spectroscopy (EEO) to check the active species present in the process of carbothermal reduction of TiO2. The powder obtained after the reactions were characterized by the techniques of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The technique of EEO were detected in all reactions the spectra CO and NO, and these gas-phase resulting from the reduction of TiO2. The results of X-ray diffraction confirmed the reduction, where for all conditions studied there was evidence of early reduction of TiO2 through the emergence of intermediate oxides. In the samples reduced at 600 and 700˚C, there was only the phase Ti6O11, those reduced to 800˚C appeared Ti5O9 phases, and Ti6O11 Ti7O13, confirming that the carbothermal reduction in plasma, a reduction of the ore rutile (TiO2) in a series of intermediate titanium oxide (TinO2n-1) where n varies between 5 and 10 / Neste trabalho foi utilizado o plasma como fonte energ?tica no processo de redu??o carbot?rmica do min?rio rutilo (TiO2). Os p?s de rutilo e grafite foram mo?dos durante 15 h e introduzidos numa descarga produzida por c?todo oco a fim de obter carbonitreto de tit?nio diretamente da rea??o, sendo verificado a influ?ncia dos par?metros de processamento de plasma, temperatura e tempo na s?ntese de TiCN. As rea??o foram efetuadas a 600, 700 e 800˚C por 3 e 4 horas numa atmosfera de nitrog?nio e arg?nio. Durante todas as rea??es o plasma foi monitorado pela t?cnica de espectroscopia de emiss?o ?ptica (EEO) para verificar as esp?cies ativas presente no processo de redu??o carbot?rmica de TiO2. Os p?s obtidos ap?s as rea??es foram caracterizados pelas t?cnicas de difra??o de raios X (DRX) e microscopia eletr?nica de varredura (MEV). Pela t?cnica de EEO foram detectados em todas as rea??es os espectros CO e NO, sendo essas fases gasosas resultante da redu??o do TiO2. Os resultados de difra??o de raios X confirmou essa redu??o, onde para todas as condi??es estudadas houve evid?ncia de in?cio da redu??o do TiO2 atrav?s do aparecimento de ?xidos intermedi?rios. Nas amostras reduzidas a 600 e 700˚C observou-se apenas a fase Ti6O11, naquelas reduzidas a 800 ˚C apareceram as fases Ti5O9, Ti6O11 e Ti7O13, comprovando que com a redu??o carbot?rmica em plasma, houve redu??o do min?rio rutilo (TiO2) em uma s?rie de ?xido intermedi?rios de tit?nio (TinO2n-1) onde n varia entre 5 e 10