METHOD AND DEVICE FOR REGENERATING PEROXODISULFATE PICKLING SOLUTION

摘要

The aim of the invention is to regenerate peroxodisulfate pickling solutions for copper materials exhausted in a circulatory method in a divided recycling electrolysis cell, in that the dissolved copper is first separated at the cathode and then the caustic peroxodisulfate is reoxidized at the anode. According to the invention, a pickling solution circulating past the pickling bath and the recycling electrolysis cell is used, said solution having excess sulfate and free sulfuric acid having a total sulfate content of 1 to 3 mol/l, in addition to 0.2 to 1.0 mol/l of peroxodisulfate, wherein the dissolved copper is reclaimed from the exhausted pickling solution in the recycling electrolysis cell at planar cathodes having cathode current densities of 4 to 7 A/dm2, and the catholyte comprising residual peroxosulfate then runs through the anode spaces in which peroxodisulfate is reoxidized at the anodes made of a diamond-coated valve metal and divided into 5 to 10 mm wide vertical strips or bars, having current densities of 20 to 50 A/dm2. The invention enables efficient performance of the recycling pickling process without additives for increasing potential, and without requiring that the residual peroxosulfate still present in the exhausted pickling bath be completely destroyed prior to anodic reoxidation. By said means, and by the use of a relatively simply constructed recycling electrolysis cell, good efficiency is achieved using said method, at a continuously high quality level of the treated surface.