N,N′-二(十二烷基)乙二胺萃取铬(Ⅵ)的研究

STUDY OF THE EXTRACTION OF CHROMIUM(Ⅵ) WITH A NEW EXTRACTION REAGENT N,N′-DI(DODECYL)-ETHYLENEDIAMINE

摘要: 合成了N,N′-二(十二烷基)乙二胺(用R2en表示),并用元素分析,红外光谱ESI及1HNMR等方法对其组成及结构进行了分析.研究了在微酸性介质中对铬(Ⅵ)的萃取行为,考察了初始水相酸度、铬(Ⅵ)浓度、R2en浓度、相比及温度等因素对铬(Ⅵ)萃取率的影响.用等摩尔系列法确定了R2en与Cr2O2-7的摩尔比为2∶1.用1.0 mol·L-1氢氧化钠溶液对含铬(Ⅵ)有机相进行反萃取,一次反萃率达98.11%.经反萃后的有机相可再循环利用.

Abstract: A new extraction reagent,N′N-di(dodecyl)-ethylenediamine (expressed as R2en below) was synthesized,and its composition and structure were analyzed and proved by elementary analysis,IR spectrometry,ESI and 1HNMR.Chloroform solution of R2en was used in the study of its extraction behavior toward chromium(Ⅵ) ion.Various factors (including acidity of the aqueous solution containing Cr(Ⅵ),concentration of Cr(Ⅵ) in solution,concentration of R2en in CHCl3,ratio of volume of water phase and CHCl3 phase and temperature of the extraction system) affecting the rate of extraction were tested.Mole ratio of R2en to Cr(Ⅵ) was found to be 2 to 1.Chromium(Ⅵ) in the organic phase was stripped effectively by 1 mol·L-1 NaOH solution,and the CHCl3 was recovered and re-used in succeeding extraction.The rate of back-extraction was 98.11%.