【摘要】 对HDEHP(H2A2),HEH/EHP(H2B2),Cyanex272(H2L2)萃取剂在硫酸介质中单独以及HDEHP-HEH/EHP和HDEHP-Cyanex272混合萃取剂萃取稀土元素Y(Ⅲ)的机制进行了研究。研究发现,单独采用HDEHP和HEH/EHP萃取Y(Ⅲ)时,SO42-参与了反应,造成反应过程中放出的H+个数随萃取剂浓度的变化而变化,对于单独采用Cyanex272萃取Y(Ⅲ)的过程中则是OH-参与了反应。计算了混合萃取剂萃取Y(Ⅲ)的协萃系数(R),当水相平衡pH=1.2时,HDEHP和HEH/EHP混合萃取体系与HDEHP和Cyanex272混合萃取体系萃取Y(Ⅲ)的R分别为27.68和48.99,并且协萃系数随水相平衡pH的升高而增加。确定了在HDEHP和HEH/EHP混合萃取体系中的协萃反应并计算了反应的平衡常数及萃合物形成反应的稳定常数,反应机制为阳离子交换反应。更多还原

【Abstract】 The extraction of Y(Ⅲ) in sulfuric acid medium using HDEHP(H2A2),HEH/EHP(H2B2),Cyanex272(H2L2) and their mixture have been investigated.The synergistic enhancement coefficients(R) were calculated,and R was increased with the increase of aqueous equilibrium pH.The configuration of the extracted complexes was determined to be Y(SO4)xH2x(HA2)3 with HDEHP,Y(SO4)xH2x(HB2)3 with HEH/EHP,Y(OH)(HL2)2 with Cyanex272 and Y(HA2)2(HB2) with HDEHP and HEH/EHP as the extractants.The equilibrium constants and stability constants were calculated.A cation exchange mechanism was proposed.更多还原