微米级硝酸钾粉体的制备及防结块研究?

为了获得高分散性的微米级硝酸钾(KNO3)粉体,首先对KNO3原料用GQF-1型气流粉碎机进行超细粉碎,然后用十八烷胺对微米级KNO3粉体进行包覆处理;运用激光粒度仪和X射线粉末衍射(XRD)对微米级KNO3粉体的粒径分布及晶型进行了表征;采用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)对微米级KNO3粉体及十八烷胺包覆的微米级KNO3粉体的形貌及官能团进行了分析;通过吸湿率和接触角测试研究了其吸湿性;使用差示扫描量热法(DSC)分析其热分解特性。研究表明:微米级KNO3平均粒径d50为2.767μm,并保持与原料一样的晶型;用十八烷胺包覆的微米级KNO3粉体具有良好的分散性,吸湿率也有所降低,但KNO3热分解受到影响,所以应将十八烷胺占KNO3质量的比例控制在1%以内。

Preparation and Anti-caking Study on Micron Potassium Nitrate Powder

[ ABSTRACT] To obtain highly dispersed micron potassium nitrate( KNO3 ) powder, KNO3 was firstly ground through jet mill and then was coated by octadecylamine. The laser particle size analyzer and XRD were used to characterize the particle size, size distribution and phase transition of micron KNO3 powder. Morphology and functional groups of micron KNO3 powder and coated micron KNO3 powder were characterized by SEM and FT-IR, respectively. Moisture absorption was studied by the moisture absorption rate and water contact angle ( WCA) . Thermal decomposition of samples was analyzed by DSC. Results show that average size ( d50 ) of micron KNO3 powders is about 2. 767 μm,and the crystal form consists with the raw materials. With octadecylamine coated KNO3 micron powder presents good dispersibility and the moisture absorption rate is also decreased. However, the mass fraction of octadecylamine should be controlled less than 1% to avoid affecting the thermal decomposition of KNO3 .