Use of citric acid partial esters for the extraction of iron
AssigneeHenkel Kommanditgesellschaft auf Aktien
InventorsWilli Buchmeier, Ralf Kehl, Werner Schwab
Life of this patent
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Abstract
Citric acid partial esters corresponding to the following general formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 represent hydrogen or a straight-chain or branched C.sub.4 -C.sub.20 alkyl radical or a metal atom, with the proviso that at least one but at most two of the substituents R.sup.1, R.sup.2 and R.sup.3 represent such an alkyl radical, or mixtures of the citric acid partial esters corresponding to general formula (I), are used for the extraction of iron from aqueous solutions.
Claims16
A process for the extraction of iron from an aqueous solution in which iron ions are a component thereof comprising the steps of:
- A. contacting an aqueous solution containing iron ions with an organic extractant containing an iron extracting quantity of at least one citric acid partial ester of the formula ##STR3## in which R.sup.1, R.sup.2 and R.sup.3 represent hydrogen or a straight-chain or branched C.sub.4 C.sub.20 alkyl radical or an acid-soluble non-ferrous metal atom, with the proviso that at least one but at most two of the substituents R.sup.1, R.sup.2 and R.sup.3 represent such an alkyl radical, to extract iron from the aqueous solution;
- and
- B. separating the organic extractant from the aqueous solution.
A process for the extraction of iron from an aqueous solution in which iron ions are a component thereof comprising the steps of:
- A. contacting an aqueous solution containing iron ions with an organic extractant containing an iron extracting quantity of at least one citric acid partial ester of the fomula ##STR4## in which R.sup.1, R.sup.2 and R.sup.3 represent hydrogen or a straight-chain or branched C.sub.4 -C.sub.20 alkyl radical or an acid-soluble non-ferrous metal atom, with the proviso that at least one but at most two of the substituents R.sup.1, R.sup.2 and R.sup.3 represent 2-ethylhexyl and one of R.sup.1, R.sup.2 and R.sup.3 is Zn, to extract iron from the aqueous solution;
- and
- B. separating the organic extractant from the aqueous solution.
Dependencies are inferred from the claim text.