磷酸三丁酯萃取硝酸的动力学

在改进的恒界面池内研究了磷酸三丁酯（ＴＢＰ）－正庚烷（ｎＣ７Ｈ１６）萃取硝酸的宏观动力学。采用热力学方法处理实验数据，计算了两相内组份的传质系数及传质阻力。研究结果表明，萃取过程的传质阻力主要在有机相内。根据动力学研究实验结果，进而分析了磷酸三丁酯萃取硝酸过程的机理，并以被萃组份的活度差为传质推动力作为计算基准建立了萃取速率的数学模型：模型计算结果与实验结果的平均相对偏差为２．５％。实验结果和理论分析表明，此萃取过程为有机相内的扩散控制机制，扩散阻力主要来自有机相内ＴＢＰ和萃合物ＨＮＯ３·ＴＢＰ分子的扩散。

Extraction Kinetics of Nitric Acid by TBP

The extraction kinetics of nitric acid by tributyl phosphate(TBP)-n-heptane was studied in an improved Lewis cell.The activity of component was calculated by Pitzeris equation for aqueous phase and UNIFAC model for organic phase.From the calculated mass transfer coeffieent and mass transfer resistance.it was concluded that the main mass transfer resistance in the extraction process came from the diffusion resistance in the boundary layer of organic phase.According to the experimental tesults,the mechanism of extraction process was discussed.In the mass transfer equation,the activity was adopted instead of concentration in driving force calculation.The initial extraction rate of nitric acid was expressed as following:The mean relative deviation between experimental data and modelcalculation results was 2.5%.