摘要
在pH>1、0<pH≤1两种不同pH条件下,采用原子吸收光谱测定P204-HCl-H3AOH体系萃取P(rⅢ)过程两相中的Pr浓度,分别考察酸度和萃取剂浓度对Pr的分配比的影响,通过对P204+煤油体系以及P204-HCl-H3AOH体系负载Pr有机相进行红外光谱测试分析探究P204-HCl-H3AOH体系萃取Pr的机理,并确定萃取平衡常数。研究结果表明,当pH>1时,萃取过程的实质是Pr离子与P-OH置换,遵循阳离子交换机制。其萃取平衡常数KPr为10-1.26;当0<pH≤1时,萃取过程较为复杂,柠檬酸的存在阻碍了P204二聚体的形成,萃取过程是由P=O基团与P-OH基团同时参与与Pr的配合作用,其配合机制为阳离子交换机制和溶剂化配合双重机制,该机制增强了对Pr的萃取能力使萃取容量提高。其萃取平衡常数KPr为100.40。
Under the conditions of pH 〉1 and 0〈pH≤ 1, Pr concentration is determined by the method of atomic absorption spectroscopy in the two phases of P204-HCl-H3AOH extraction system. The effects of acidity and extractant concentration on distribution ratio of Pr are investigated. And by infrared spectrum testing and analysis of P204+ kerosene system and the organic phase loading Pr in the P204-HCl-H3AOH extraction system, the effect on extraction mechanism of Pr in P204-HCl-H3AOH extraction system by acidy is also studied. Whereby, the extraction equilibrium constant can be calculated. The results show that displacement reaction between Pr and P-OH happens and the extraction process abides by cation exchange mechanism under the condition of pH〉l, and the extraction equilibrium constant KPr is 10^-1.26. Then both the group of P=O and P-OH can do complex reaction with Pr and the extraction mechanism is the dual mechanism theory of cation exchange mechanism and solvation complex mechanism, which can increase the extraction capacity of Pr under the condition of 0〈pH≤ 1, and the extraction equilibrium constant KPr is 10^0.40.
出处
《化学与粘合》
CAS
2010年第2期65-67,共3页
Chemistry and Adhesion