叔胺从硫酸盐溶液中萃Fe(Ⅲ)机理的研究

SOLVENT EXTRACTION OF Fe (Ⅲ) FROM SULFATE SOLUTIONS WITH TERTIARY AMINES

本文报道叔胺(TOA)从硫酸盐介质中萃取Fe(Ⅲ)的机理。研究了萃合物的紫外及红外光谱。根据实验结果提出了萃合物的可能结构形式。认为叔胺只能萃取部分水解的Fe(Ⅲ),而伯、仲胺既能萃取水解形式的Fe(Ⅲ)也能萃取非水解形式的Fe(Ⅲ),不同的条件下两种机理可以同时进行或相互转变。讨论了三类胺萃取Fe(Ⅲ)及硫酸反萃取Fe(Ⅲ)的性能的差别。

The tertiary amine can be used to extract Fe(Ⅲ) very effectively inthe pH range resulting into partial hydrolysis of Fe^(3+) ions. The iron extractedinto the organic phase can be stripped rather easily with dilute H_2SO_4 or evenwith H_2O. Fe (Ⅲ) is extracted inio the tertiary amine sulfate solution in the formof [(R_3NH)_2Fe(OH)(SO_4)_2]_2 complex by adduct formation. Equation was derived torepresent the chemical reactions involved during extraction. From the infraredspectrum studies on the extraction species in waxy solid form separated from thesolution, sulfate group is a bideniate ligand to the iron atom. The extraction spe-cies has been considered to contain (FeOH)_2 unit based on the ultra violet spectra.The possible structure of the extraction species has been proposed.