微热量热计法研究几种盐对硝酸铵晶变的影响

摘要

硝酸铵(AN)中添加质量分数5%的无机盐并碾磨混合,通过微热量热计研究4种常用无机盐对AN晶型Ⅳ~Ⅰ型转变的影响.结果表明:两种氯盐使AN晶型Ⅱ~Ⅰ型开始转变的温度明显提前;4种无机盐使AN晶型Ⅳ~Ⅲ型转化温度降低;硝酸钾使AN晶型Ⅲ~Ⅱ型转变温度提高约7℃,氯化钾提高约3℃;氯化钾可以使AN晶型的Ⅳ~Ⅲ型、Ⅲ~Ⅱ型相转变焓降低,使晶型转变难度增大;氯化钠使AN晶型转变焓明显增大,促进AN晶型转变.%5%(mass fraction) inorganic salt was added into ammonium nitrate (AN) and mixed under grinding. Effect of four common inorganic salts on the crystal transition (Ⅳ-Ⅰ) of AN was studied by micro calorimeter.The results show that transition temperature of Ⅱ-Ⅰis obviously advanced by adding two kinds of chloride salts;transition temperature of Ⅳ-Ⅲ is reduced by addition of four inorganic salts.Transition temperature has been raised by about 7℃by KNO3 , and by about 3℃by KCl.Phase transition enthalpy in conversion of crystal type Ⅳ-Ⅲ and Ⅲ-Ⅱcould be reduced by addition of KCl, and it can increase the difficulty of crystal transition.Enthalpy of AN crystal transition increases and transformation of AN crystal is facilitated by NaCl.