微热量热计法研究几种盐对硝酸铵晶变的影响

Effect of Four Inorganic Salts on Crystal Phase Transition of Ammonium Nitrate Detected by Micro Calorimeter

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-Ⅰ is 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-Ⅱ could 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.