Effect of the temperature on the sintering behavior of CeO2 -La2 O3 doped with silicate

Abstract

This paper evaluates the sintering behavior of CeO 2-La 2 O 3-silicate at different temperatures. The sintered compact of this system may be a candidate to be used as a refractory lining for biomass (sugarcane bagasse) gasifier. The raw material (CeO 2-La 2 O 3-silicate powder) was characterized by granulometric distribution, differential thermal analysis (DTA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and dilatometry. Cylindrical compacts of this powder were heat treated at 1200 ºC, 1300 ºC and 1400 ºC for 1 h and characterized by X-ray diffraction (XRD), micro Raman spectroscopy, SEM/EDS, shrinkage and apparent porosity. The results show that the sintering degree of the samples increases with temperature, reaching shrinkage of about 16 % and apparent porosity of 3.5 % at 1400 ºC. The XRD and Raman spectroscopy results revealed that a cerium/ lanthanum silicate was formed which is stable against melting at temperature as high as 1400 ºC. The study of the reactivity of the bagasse ash and the CeO 2-La 2 O 3-silicate refractory will be presented in a future publication. Resumo Este trabalho teve como objetivo avaliar o comportamento de sinterização de CeO 2-La 2 O 3-silicato em diferentes temperaturas. O compacto sinterizado desse sistema pode ser um candidato para ser utilizado como um revestimento refratário para gaseificador de biomassa (bagaço-de-cana). A matéria-prima (pó de CeO 2-La 2 O 3-silicato) foi analisada por distribuição granulométrica, análise térmica diferencial (DTA), microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva (EDS) e dilatometria. Compactos cilíndricos deste pó foram tratados termicamente a 1200 ºC, 1300 ºC and 1400 ºC por 1