The Synthesis And Characterization Of The Nano-Spinel Powders By Spray-Pyrolysis

MgAl2O4 nano-powders were prepared by the spray-pyrolysis method. An ethane-oxygen-assisted spray- pyrolysis equipment was designed and constructed, by which the spherical powders of crystalline with 10-60nm in diameter and agglomeration particle with 180nm in diameter were prepared. MgAl2O4 nano -powders were characterized by X-ray diffraction, SEM, laser granularity analysis equipment.The following conclusions have been approached from this study:1 Water, alcohol, magnesium nitrate and aluminum nitrate are more feasible start materials for preparing the spinel. Otherwise we found from the experiments that the chloride system erodes seriously the equipment, and that the powders from the sulfate system are too large in size. Therefore, only the powders from the system containing alcohol, compared with the powders from the system without alcohol, are fleecier and can be collected more easily.2 Several factors affect the crystalline size and the particle size of the powders. As the ratio of alcohol to water descends, both of them rise. As the solution concentration of nitrates descends, the crystalline size firstly descends and then rises. The nozzle pressure brings forth little affluence on the crystalline size of the powder, but the elevated pressure can enlarge the quantity and the size of the agglomeration.3 The nozzle pressure and the solution flux set up a magnificent influence on the powder yield, and the yield evidently rise as the pressure dose.4 The most part of powder is spherical with a broad particle size distribution. This is the typical characteristic of the powders by the SP method.