Method and a reagent mixture for removing metal ions from an aqueous solution by means of liquid-liquid extraction
AssigneeBerol Kemi AB
InventorsHans Reinhardt, Harald D. Ottertun
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Abstract
A liquid-liquid extraction process is disclosed, in which an aqueous solution, containing metal ions, is contacted with an organic liquid substantially insoluble in water. The organic liquid contains two water-insoluble reagents, viz. a diester of dithiophosphoric acid and an organic phosphate, in a preferred volume ratio of between 1:10 and 2:1. The organic liquid may also contain a diluent for the reagents.
Claims11
A method of extracting metal ions from an aqueous solution by means of liquid-liquid extraction which comprises bringing an aqueous solution containing metal ions into contact with an organic liquid which is insoluble in water and which contains a reagent mixture including a water-insoluble diester of dithiophosphoric acid having the general formula ##STR3## wherein R.sub.1 and R.sub.2, independently of each other, represent a hydrophobic group, R.sub.1 and R.sub.2 being selected so that the dithiophosphoric acid is insoluble in water, as well as a water-insoluble phosphate having the general formula ##STR4## wherein R.sub.3 represents a hydrophobic group and R.sub.4 and R.sub.5, independently of each other, represent hydrogen or a hydrophobic group, R.sub.3, R.sub.4 and R.sub.5 being selected so that the phosphate is insoluble in water, in a ratio by volume between the dithiophosphoric acid and the phosphate of from 1:99 to 9:1, whereupon the metal ions pass to the organic liquid from where said metal ions can be readily re-extracted and stripped therefrom.
Dependencies are inferred from the claim text.