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以三辛胺 (TOA)为反应萃取剂 ,正辛醇、甲基异丁基酮 (MiBK)、正己烷、四氯化碳和氯仿为稀释剂 ,甲酸、乙酸、丙酸、丁酸、戊酸、一氯乙酸、二氯乙酸、三氯乙酸、乙醇酸、乙醛酸、乳酸为被萃溶质 ,开展了萃取平衡特性的实验研究 .结果表明 ,羧酸的亲油性和酸性是影响TOA萃取羧酸的关键参数 .萃取平衡条件下 ,羧酸的酸性差别较小时 ,TOA的负载率主要取决于羧酸的亲油性lgP ,且lgP越大 ,TOA负载率越高 ;羧酸的酸性差别较大时 ,TOA的负载率主要与羧酸的酸性pKa 有关 ,且pKa 越小 ,TOA负载率越高 .稀释剂种类、TOA浓度对TOA的表观碱度和TOA的负载率有影响 ,TOA负载率Z <1时 ,稀释剂对羧酸萃取平衡的促进作用为正辛醇≥氯仿 >MiBK >四氯化碳≥正己烷 ,且TOA的负载率随TOA浓度的增大而减小 .TOA的表观碱度是定量表现萃取剂在萃取分离环境中性质的重要参数 .
To take octoxic amine (TOA) as reaction extractant, n-octanol, methyl isobutyl ketone (MiBK), hexane, carbon tetrachloride and chloroform as diluent, formic acid, acetic acid, propionic acid, Acetic acid, acetic acid, glyoxylic acid and lactic acid as extracted solutes.The experimental results show that the lipophilicity and acidity of carboxylic acid are the factors influencing TOA extraction The key parameters of carboxylic acid extraction equilibrium conditions, carboxylic acid difference is small, the TOA load factor mainly depends on the lipophilic carboxylic acid lgP, and lgP the higher, the higher the TOA load rate; The TOA loading rate is mainly related to the carboxylic acid pKa, and the smaller the pKa, the higher the TOA loading rate. The type of diluent, TOA concentration has an impact on the TOA apparent alkalinity and the TOA loading rate, The accelerating effect of the diluent on the carboxylic acid extraction equilibrium at the rate Z <1 was n-octanol ≥ chloroform> MiBK> carbon tetrachloride ≥ n-hexane, and the loading of TOA decreased with the increase of TOA concentration. Apparent alkalinity is an important parameter that quantitatively characterizes the nature of the extractant in the extraction and separation environment.