热处理法再生活性氧化铝的微结构研究

Microstructures of active alumina reproduction by heat-treatment method

采用直接煅烧法再生废弃活性氧化铝,可去除废弃氧化铝中易挥发的组分,并通过再结晶过程使载体重新获得一定的孔结构和比表面,达到再生的目的.探讨了热处理温度与时间对活性氧化铝微结构的影响.用XRD、SEM、BET等方法表征活化后氧化铝的微结构,从而确定最佳的热处理制度.结果表明:再生后的试样均形成2种晶相,分别是(A l2O3)1.333和A l2.85O3.45N0.55,属于立方晶系,Fm3m空间群;最佳的热处理制度为在550℃下保温2 h,其对应的比表面积达242.2 m2/g,平均孔径为7.1 nm,活化后样品的各项性能指标达到采用恩醌法生产双氧水所用的活性氧化铝球的使用要求.

Direct calcination method is employed to regenerate waste activated alumina. Calcination can remove the components which are easy to volatilize in waste aluminum oxide, and via the crystallization process, the carriers with certain pore structure and specific surface can be reacquired so as to realize the regeneration. In this paper, the influence of heat treatment temperature and time on the microstructure of active aluminum oxide is discussed. The methods such as XRD, SEM, BET and et al, are used to characterize the microstructure of aluminum oxide after it is activated so as to determine the optimal heat treatment plan. The results show that there are two crystalline phases, （Al2O3） 1.333 and Al2.85O3.45N0.55, in the samples after regeneration, which belong to cubic system and Fm3m space group; the optimal heat treatment plan is to preserve heat for 2 h at the temperature of 550℃, its corresponding specific area can reach 242.2 m^2/g, and the mean pore size is 7. 1 nm, so that the properties of samples after regeneration can match the requirements in the application of producing hydrogen peroxide through Anthroquinone.