胺類萃取劑對金屬螯合物萃取之平衡研究

Extraction equilibrium of metal chelates from aqueous solutions with amine-based extractants

陳彥政(Chen, Yann Cheng)

指導教授 ： 莊瑞鑫

元智大學/工程學院/化學工程與材料科學學系/碩士(1996年)

摘要

本文針對水溶液中的螯合銅以溶於煤油中的四級銨鹽(Aliquat 336)為
萃取劑作萃取平衡之研究。螯合銅水溶液選用EDTA(
ethylenediaminetetraacetic acid)作為螯合劑。實驗控制之變數為水相
的pH值、水相中銅離子的濃度、銅離子跟螯合劑的比值(α值)、有機相中
四級銨鹽的濃度及溫度等。由實驗可知不論水相中初始pH值為酸性或鹼性
，在萃取平衡達到時其pH值皆趨向於中性(pH=7)。而銅離子在有機(油)及
水相的分配比(D)開始時隨著pH值的增加而加大，然而在pH值超過7以後則
其分配比隨著pH值的增加而下降。本研究亦將溫度、pH值、螯合銅初始濃
度及α值(Cu2+/EDTA4-)對萃取平衡分配比的影響作一比較。亦將不同溫
度下之平衡常數作一簡單的估算，以約略估算此萃取平衡之反應熱。

關鍵字

四級銨鹽 ； 萃取劑 ； 螯合劑

並列摘要

The extraction equilibrium of Cu2+ from aqueous solutions in
the presence ofchelating agent with a quaternary amine, Aliquat
336, in kerosene were studied.The chelating agents EDTA
(ethylenediaminetetraacetic acid) was selected here.Experiment
variables were controled as pH of aqueous phase, the aqueous-
phaseconcentration of Cu2+ and its ratio to chelating agent
(α), the organic-phaseconcentration of amine and temperature.
It was shown that whether the aqueousphase was initially acidic
or basic, it tends to become pH = 7 after extraction finished.
Also, the distribution ratios of Cu2+ between orginic and
waterphase initially increased with the pH, and then decreased
when pH > 7. The effects of temperature, pH, initial
concentration of Cu2+ and α(Cu2+/EDTA4-) on extraction
equilibrium are also compared. Finally, the equilibrium
contanstantsin different temperature were calculated in roughly
for calculate the reaction ethalpy of the extraction equilibrium
reaction.

並列關鍵字

Quaternary amine salt ； Extraction agents ； Chelating agents