超细二氧化钛粉体的表面无机包膜及其机理

PROCESS AND MECHANISM OF INORGANIC COATING ON SURFACE OF SUPER-FINE TITANIA POWDER

在超细悬浮的TiO_2颗粒表面化学沉积Si(OH)_4和Al(OH)_3,经过洗涤、脱水、干燥、煅烧处理后形成致密的SiO_2,Al_2O_3包膜。研究了TiO_2表面形成SiO_2,Al_2O_3包膜的机理和工艺条件。利用扫描电镜、红外光谱和X射线荧光光谱对包覆产物进行了分析。结果表明:最佳包覆条件为:pH值在8～10,温度85～90℃,陈化时间1～3h。

The Si（OH）4 and Al（OH）3 were deposited on the surface of super-fine TiO2 particles by chemical precipitation, after washhag, dehydration, drying and calcinations, the dense coatings of SiO2, Al2O3 were formed on the TiO2 surface. The forming mechanism and process parameters of SiO2, Al2O3 coating were investigated. The coating products were characterized by scanning electron microscope, infrared spectrometer and X-ray fluorescence. The optimum coated conditions are： pH value of 8-10, process tempera- ture of 85-90 ℃, ageing time of 1-3 h.