热分解法测定水盐体系中硝酸铵和水含量研究

Determination of NH_4NO_3 and H_2O in Salt-water System with Thermal Decomposition Method

针对复杂硝酸铵水盐体系溶解度的测定,传统分析方法操作步骤繁琐,且试剂较贵,引入一种简单准确的分析方法,即热分解法,对LiNO3-KNO3-NH4NO3-H2O体系和NaNO3-KNO3-NH4NO3-H2O体系中硝酸铵和水的含量进行精确分析。结果表明,热分解温度控制在230～240℃,若控制样品质量为1.5 g,分解时间不低于36 h,能将LiNO3-KNO3-NH4NO3-H2O体系中的硝酸铵和水彻底分解,且随着样品中硝酸铵含量增加,热分解时间也将延长,分析相对误差能控制在0.2%以内。针对复杂NaNO3-KNO3-NH4NO3-H2O体系,热分解温度控制在230～255℃,若控制样品质量为1.5 g,分解时间不少于44 h,且随着样品中硝酸铵含量的增加,相应延长热分解时间,能将复杂NaNO3-KNO3-NH4NO3-H2O体系中的硝酸铵和水彻底分解,分析相对误差能控制在0.2%以内。

Based on the solubility determination of complex ammonium nitrate water system ,the traditional analysis methods are complicated and reagents are expensive. A new method, thermal decomposition law, was proposed in this paper in order to determine the NH4NO3-H20 content in the LiNO3-KNO3-NH4NO3- H20 system and NaNO3-KNO3-NH4NO3-H2 0 system. Controlling the thermal decomposition temperature 230 - 240 ℃, the time of decompostion experiment with less than 1.5 g sample is more than 36 h, with the content of sample of ammonium nitrate increased, the thermal decomposition time will be extended, NH4NO3-H20 can be decomposed completely in the LiNO3-KNO3-NH4NO3-H20 system;Controlling the thermal decomposition temperature 230 - 255 ℃, the time of decomposition experiment with less 1.5 g sample is more than 44 h, with the content of sample of ammonium nitrate increased, the thermal decom- position time will be extended, NH4NO3-H20 can be decomposed completely in the NaNO3-KNO3- NH4NO3-H2 0 system, the relative error can be controlled within 0. 2%.