Liquid-liquid extraction process for the recovery of tungsten from low level sources
AssigneeGTE Laboratories Incorporated
InventorsSamuel Natansohn, Sophia R. Su
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Abstract
A recyclable process for the recovery of tungsten from low level aqueous sources comprises adjustment of the pH of the source solution to a value below about pH 6, extraction of the tungsten values into an organic phase comprising a chelating agent, an organic transfer agent, and an inert organic solvent. Preferred chelating agents include vicinally disubstituted aromatic compounds in which the substituents are selected from amino, carboxyl, hydroxyl, and sulfhydryl.
Claims17
A recyclable process for recovering tungsten from aqueous solutions containing low levels of tungsten comprises the steps of:
- (a) Adjusting the pH of the aqueous tungsten-containing solution to a value below about pH 6;
- (b) Contacting the pH-adjusted aqueous tungsten-containing solution with an extractant organic phase comprising:
- (1) A chelate compound comprising a vicinally disubstituted aromatic ring having substituents selected from the group consisting of amino, carboxyl, hydroxyl, and sulfhydryl,
- (2) A transfer agent, and
- (3) An inert organic solvent, to extract tungsten from said pH-adjusted aqueous solution into said organic phase;
- (c) Separating the tungsten-loaded organic phase from the tungsten-spent aqueous solution;
- (d) Contacting said tungsten-loaded organic phase with a basic aqueous stripping solution to transfer tungsten from said tungsten-loaded organic phase to said aqueous stripping solution;
- (e) Separating the tungsten-loaded aqueous stripping solution from the tungsten-spent organic phase and thereafter isolating the tungsten values from said tungsten-loaded aqueous stripping solution;
- (f) Contacting the tungsten-spent organic phase with an aqueous regenerating solution to regenerate said extractant organic phase;
- and
- (g) Recycling the regenerated extractant organic phase in step (b).
A recyclable process for recovering tungsten from aqueous solutions containing low levels of tungsten comprising the steps of:
- (a) adjusting the pH of the aqueous tungsten-containing solution to a value below about pH 6;
- (b) contacting the pH-adjusted aqueous tungsten-containing solution with an extractant organic phase comprising:
- (1) o-mercaptobenzoic acid,
- (2) a quaternary alkylammonium salt transfer agent, and
- (3) an inert organic solvent, to extract tungsten from said pH-adjusted aqueous solution into said organic phase;
- (c) separating the tungsten-loaded organic phase from the tungsten-spent aqueous solution;
- (d) contacting said tungsten-loaded organic phase with a basic aqueous stripping solution to transfer tungsten from said tungsten-loaded organic phase to said aqueous stripping solution;
- (e) separating the tungsten-loaded aqueous stripping solution from the tungsten-spent organic phase and thereafter isolating the tungsten values from said tungsten-loaded aqueous stripping solution;
- (f) contacting the tungsten-spent organic phase with an aqueous regenerating solution including hydrogen ion and chloride ion to regenerate said extractant organic phase;
- and
- (g) recycling the regenerated extractant organic phase to step (b).
Dependencies are inferred from the claim text.