Separation Science and Technology, Vol.44, No.12, 2928-2941, 2009
Solvent Extraction of Iron(III) from Chloride Media by N-Methyl-N-alkyloctanamide Derivatives
N-methyl-N-cyclohexyloctanamide (MCHOA) and N-methyl-N-phenyloctanamide (MPHOA) were synthesized, characterized, and tested to recover iron(III) from chloride media. Both compounds efficiently extract Fe(III) from HCl solutions above 4 M, although a decrease in extraction at 10 M HCl, involving MCHOA, is noticed. Stripping of Fe(III) by water may be easily and efficiently achieved. Results on the re-utilization of the organic phases are also presented. Preliminary selectivity experiments point out to a rather good performance of both compounds towards Fe(III) when in the presence of Cu(II), Ni(II), and Zn(II). Assuming that the extractants are under a monomeric form, average species such as [3 LH+ center dot FeCl4- center dot 2 Cl-] (L, MCHOA or MPHOA) are proposed as being involved on Fe(III) extraction from 6 M HCl solutions.