(重庆大学 机械工程学院, 重庆 400044)
摘 要: 以天青石还原分解产物的浸取液(SrS)为原料, 氢氧化钠为辅助化工原料制备纯度>99.70%的Sr(OH)2·8H2O。 利用差示扫描量热-热重法(DSC-TG)对Sr(OH)2·8H2O进行非等温热分解试验研究, 并用Kissinger法和Freeman-Carroll法分析计算了热分解脱水反应动力学参数。结果表明: Sr(OH)2·8H2O在50℃左右开始脱水分解, 至130℃以上基本完全分解成粉末状的Sr(OH)2; Sr(OH)2·8H2O的热分解过程以两个阶段进行, 且两阶段吸热峰之间的温度范围小;两阶段的热分解反应表观活化能分别为E1=75.26kJ/mol, E2=95.11kJ/mol, 其热分解反应级数依次为n1=1.17, n2=1.29。
关键字: 八水氢氧化锶; 制备; 非等温热分解; 动力学参数
(College of Mechanical Engineering, Chongqing University, Chongqing 400044, China)
Abstract: High purity Sr(OH)2·8H2O(>99.70%) was prepared from NaOH and leaching water containing SrS, which was produced by reductive process of celestite. Non-isothermal decomposition of Sr(OH)2·8H2O was investigated by differential scanning calorimetry and thermogravimetry method, and kinetic parameters of decomposition was calculated and analyzed using Kissinger method and Freeman-Carroll method, respectively. The results show that Sr(OH)2·8H2O begin to decompose about 50℃ and change into powder strontium hydrate(Sr(OH)2) completely above 130℃. The decomposition process of Sr(OH)2·8H2O is divided into two stages, whose activation energies and reactive indexes are following: E1=75.26kJ/mol, n1=1.17(first stage); E2=95.11kJ/mol, n2=1.29(second stage), respectively.
Key words: Sr(OH)2·8H2O; preparation; non-isothermal decomposition; kinetic parameter