电解法制备氢氧化镁粉体的非等温动力学解析

Non-isothermal kinetic analysis of magnesium hydroxide powder produced by electrolysis

氢氧化镁分解动力学对研究氧化镁的生产具有重要的理论意义.本文中以隔膜电解法制备的氢氧化镁粉体为样品(纯度可达到99.02%,片状结构),采用热分析技术获得了氢氧化镁在不同升温速率下的热分解动力学数据,并利用等转化率法对其进行动力学解析.研究结果表明:采用Kissinger法计算的氢氧化镁热分解反应活化能分别为121.68和110.43 kJ/mol,指前因子分别为2.050×10^(10)和1.426×10^(9)min^(-1);采用FWO法计算的活化能为130.18 kJ/mol,分解反应的机理函数为n=1.5的随机成核和生长机理模型.该研究结果可为制备性能优良的氧化镁奠定理论基础.

The research on the decomposition kinetics of magnesium hydroxide has important theoretical significance for the production of magnesium oxide.In current study,the magnesium hydroxide powder has been prepared by diaphragm electrolysis method(its purity can reach 99.02%,which is a flake structure).Thermal analysis technology is used to obtain the thermal decomposition kinetic data of magnesium hydroxide at different heating rates.The kinetics is analyzed by the isoconversion method.The results show that the activation energies of the thermal decomposition reaction of magnesium hydroxide calculated by the Kissinger method are 121.68 and 110.43 kJ/mol,and the preexponential factors are 2.050×10^(10)and 1.426×10^(9)min^(-1),respectively.The activation energy calculated by the FWO method is 130.18 kJ/mol,and the mechanism function of the decomposition reaction is a random nucleation and growth mechanism model of n=1.5.The research results lay a theoretical foundation for the preparation of magnesium oxide with excellent performance.