摘要
以六水氯化镁和尿素为原料,采用均匀沉淀法制备出碱式碳酸镁纳米花。在不同干燥介质温度和不同物料床层厚度下,得到碱式碳酸镁纳米花的干燥曲线和干燥速率曲线。采用热分析动力学技术对干燥动力学实验数据进行处理后,得到碱式碳酸镁纳米花的干燥微分机理函数为f(1-MR)=6MR2/3(1-MR1/3)1/2,干燥积分机理函数为g(1-MR)=(1-MR1/3)1/2,干燥方程为MR=〔1-(kt)2〕3,干燥速率方程为-dMR/dt=6k2tMR2/3,干燥速率常数为k=Aexp〔-Ev(1+CLL)RT〕;指前因子A=4.0725min-1,界面蒸发活化能Ev=16.9334kJ/mol,经验常数CL=30.3135m-1。
Basic magnesium carbonate nanoflowers were synthesized by a homogenous precipitation reaction, using MgC12-6H20 and CO （NH2）2 as raw materials. Drying kinetics experiments of basic magnesium carbonate nanoflowers were made, and the drying curves as well as drying rate curves were obtained at different drying medium temperatures and different wet material bed-layer thicknesses , respectively. The experimental data of drying kinetics were simulated by means of thermal analysis kinetics method, and the drying differential mechanism function, the drying integral mechanism function, the drying equation, the drying rate equationas well as the drying rate constant were obtained. The pre-exponential factor is 4.0725rain-1, the activation energy of inter-face evaporation is 16.9334kJ/mol, and the experimental constantis 30.3135m-1.
关键词
热分析
干燥动力学
碱式碳酸镁
纳米花
thermal analysis
drying kinetics
basic magnesium carbonate
nanoflowers
