Process for separation of heavy metals from residues by use of ethylene-diamine-disuccinic acid (EDDS) complexant

摘要

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 the Me1 and EDDS (Me1-EDDS), comprising the steps of; (a) obtaining a solution having a pH 1 to 6, comprising the Me1-EDDS, (b) addition to the solution of step (a) of a second source of a heavy metal ion (Me2), which is soluble in the 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 the solution of step (b) to increase the pH to at least 8.5, thereby obtaining a precipitate of Me1.