Liquid-liquid Extraction of Iron (III) from Hydrochloric Acid Solutions by Tributyl Phosphate.

Abstract

The extraction of iron (III) from hydrochloric acid solutions has been investigated using tributyl phosphate (TBP) in benzene under different conditions. The organic extracts were examined by infrared and ultraviolet absorption spectroscopies. It was found that with increasing the concentration of aqueous hydrochloric acid solutions, the distribution coefficient increased steeply at above 2 -3 mol dm -3 HCl. Consequently, the following equi- In solvent extraction of metals from acid liquors, the separation of metals from iron (III) is an important problem. Therefore numerous reseachers have studied on solvent extraction of iron (III) from acid solutions. However, since there are few investigations to clarify the extraction mechanism of iron (III), the present author has engaged systematically in the fundamental study on solvent extraction of iron (III).The extraction of iron (III) from hydrochloric acid solutions by -hydroxyoxime, such as 5, 8-diethyl-7-hydroxy-6-dodecanone oxime (HR, the active component of LIX 63), has been reported previously 1) , because the information on the extraction of iron (III) by LIX 63 was little submitted, despite the fact that the discrimination of LIX 63 for copper over ferric iron was not so good as required. Furthermore, when dihexyl sulphoxide (DHSO) is used as an effective extractant for precious metal such as mercury, the problem to separate precious metal from iron (III) has been investigated in the extraction system from chloride media 2) . In the present paper, the work is extended to the extraction of iron (III) from acid solutions by neutral organophosphorus compound such as tributyl phosphate (TBP). TBP is using in various industrial fields, especially such operations have been remarcable in the nuclear field for conspicuous extractability of uranium and in the processing of radioactive products from nucler reactors. For the extraction of some base metals, however, there is a particular case in the extraction of iron from chloride solutions by TBP prior to the separation of cobalt from nickel by tertiary amine 3) . In the extraction of iron (III) from acid solutions by TBP, the extraction efficiency for iron (III) of TBP is in the order of the extraction systems HCl > HNO 3 >> H 2 SO 4 4) . As it seems that TBP is superior in the extraction of iron (III) from hydrochloric acid solutions, the extraction system for chloride media has been undertaken in this study. 2．Experimental 2・1 ReagentsThe TBP (Daihachi Chem. Ind. Co., Ltd.) was purified by usual method 5) and diluted with benzene. Aqueous solutions of iron were prepared by dissolving ferric chloride(FeCl 3 ・6H 2 O) in hydrochloric acid of the required concentration. In general the aqueous metal concentration was 1 g dm -3 ferric chloride except for the loading test. Other chemicals were of analytical reagent grade. 2・2 Extraction and analytical proceduresEqual volumes (15 cm 3 each) of the aqueous and organic phases were shaken for 10 min in 50 cm 3 stoppered conical flask at 293 K. Preliminary experiments showed t...

Immobilized Tris(hydroxymethyl)aminomethane as a Scaffold for Ion-Selective Ligands: The Auxiliary Group Effect on Metal Ion Binding at the Phosphate Ligand

“…The PE and amine resins begin at the same low affinity in 0.01 M HCl as they did in HNO 3 . However, their distribution coefficients increase as the HCl concentration increases, as would be expected from the behavior of TBP (extraction increases as the HCl concentration exceeds 2 M) 32 and soluble organophilic tertiary amines, 33 both of which complex Fe(III) from HCl as HFeCl 4 . With regards to the phosphonate diester and amine resins, it is the formation of anionic complexes that provides the most notable difference between the behavior of Fe(III) in HNO 3 versus that in HCl.…”

“…Eng. Jpn 1999, 32,[190][191][192][193][194][195][196] a For divalent and trivalent ions, the background solution without NaNO3 is 0.01 M HNO3. b The final pH of the solution in contact with the pTris resin.…”

Best Conditions for Extraction and Stripping of Iron from Chloridic Aqueous Medium

“…The temperature has two effects: the first, affected on physical properties of two phases (organic and aqueous) such as viscosity, surface tension and kinetics energy of solute (metal), this effect has a slight increase of the extraction coefficient. The second effect depends on the type of extractant and nature of linking of metal ions with it, if the combination of metal ions with extractant is an exothermic process, the effect of temperature will be inverse as in the extraction of copper (II) from chloride media by Cyanex 923 in kerosene [11] and extraction of iron (III) from hydrochloric acid solutions by tributyl phosphate [17], but if it is endothermic, then the action of temperature is proportional. If the combining of extractant with the metal is physical (neither exothermic nor endothermic), the influence of temperature is moderate, as in this study, extraction of iron by cyclohexanone.…”

Removal of mercury(II) by tri n-butyl phosphate based supported liquid membrane

“…)H Proton acquired TBP forms a complex when it reacts with the mercury chloride anion, which is present in the feed phase (Eq. 7) [25,26] HgCl . 2((RO) PO)H TBP complex reacts with NaOH available in the strip phase and forms mercuric(II) chloride with the separation of TBP as shown in Eq.…”

“…TBP as a cationic carrier has been successively employed for the extraction of various heavy metals as anionic halo compounds [23,24]. Extraction studies for mercury ions in acidic solution using TBP in benzene have been demonstrated [25]. They revealed that TBP acquires a positive charge in acidic conditions, and it forms a neutral complex with anionic mercury chloride.…”