Method of removing Cr(VI) ions from an aqueous electrolyte solution

• Main Authors: Niegl, Max, Rast, Norbert, Koenitzer, Martin, Hill, Rudolf, Feiling, Nicole, Mauer, Dieter
• Format: Patent
• Language: English
• Published: 19.07.2022
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL; THEIR RELEVANT APPARATUS; TRANSPORTING; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE; WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OFELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKESTHE PLACE OF A TOOL

The invention relates to a method for removing Cr(VI) ions from an aqueous electrolyte solution, particularly an electrolyte solution for electrochemical metal machining, which comprises the reduction of Cr(VI) to Cr(III) with Fe(II) ions. The Fe(II) ions are added to the electrolyte solution in the form of an aqueous salt solution which has been brought into contact with an ion exchange resin loaded with Fe(II) ions. The invention further relates to a device (1) for electrochemical machining of a workpiece (2) by means of an aqueous electrolyte solution (6), which has an ion exchanger (11) which has been loaded with an ion exchange resin charged with Fe(II) ions.