提出了用聚苯乙烯包覆硝酸铵制备硝酸铵微胶囊的新方法 ,采用电子能谱仪研究了包覆效果 ,并对包覆前后的硝酸铵进行吸湿性测量 ,分析了改性后的硝酸铵吸湿结块性降低的原因和机理。 A new method of preparing ammonium nitrate microcapsules by using polystyrene coated ammonium nitrate was proposed. The effect of coating was studied by electron spectrometer. The hygroscopicity of ammonium nitrate before and after the coating was measured. The modified nitric acid Causes and Mechanism of Ammonia Absorption Caking Reduction.