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US 6,485,629 B1Granted
Process for separation of heavy metals from residues by use of ethylene-diamine-disuccinic acid (edds) complexant
AssigneeThe Procter & Gamble Company
InventorsDiederik Rudolf Schowanek, Tom Cornelis Jan Feijtel
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Abstract
A process for separating a first source of a heavy metal ion or mixtures of heavy metal ions, (Me1), from a solution comprising a complex of said Me1 and EDDS, (Me1-EDDS), by displacement of said Me1 with a second source of a heavy metal ion Me2 by addition to the solution of a salt of said Me2.
Claims18
A process for separating a first source of a heavy metal ion or a mixture of heavy metal ions (Me1) from a solution comprising a complex of said Me1 and EDDS (Me1-EDDS), the steps of said process comprising:
- a) obtaining a solution having a pH 1 to 6, comprising said Me1-EDDS;
- b) addition to said solution of step a) of a second source of a heavy metal ion (Me2), which is soluble in said solution having a pH 1 to 6, to produce a solution comprising a complex of Me2 and EDDS (Me2-EDDS);
- c) addition of an alkaline material to said solution of step b) to increase the pH to at least 8.5 thereby obtaining a precipitate of Me1;
- and
- d) optionally removing said precipitate of step c) from said solution.
2 more elements
Dependencies are inferred from the claim text.