Solvent extraction of substance containing chromium from aqueous waste liquor, e.g. from tanning or electroplating, uses phosphate ester or amine as carrier for trivalent or hexavalent chromium respectively

摘要

In solvent extraction of substances (I) containing chromium (Cr) from an aqueous waste liquor (II) with a water-insoluble solvent phase (III) of different density, in which (III) contains a dissolved carrier suitable for solvent extraction of Cr-III and/or Cr-VI compounds, the carrier is phosphate ester for extraction of Cr-III ions or an amine for extraction of Cr-VI ions. Solvent extraction of substances (I) containing chromium (Cr) from an aqueous feed solution (waste liquor) (II) involves passing (II) and a solvent phase (III) to extraction apparatus and discharging the extracted phase as raffinate and the extract phase with extracted (I). (III) consists of a water-insoluble solvent, with a density different from that of (II) and contains a dissolved carrier suitable for solvent extraction of Cr-III and/or Cr-VI compounds and optionally a solvent aid. The carrier is phosphate ester for extraction of Cr-III ions or an amine for extraction of Cr-VI ions.