VERFAHREN ZUR ABTRENNUNG MULTIVALENTER METALLIONEN

摘要

A method and apparatus are described for removing iron cations and/or zinc cations from an autodeposition coating bath (T1) by passing a limited number of bed volumes through a column (IEX) containing a gel type SAC IEX resin when iron cations are to be removed and passing a substantially larger number of bed volumes through the column (IEX) when zinc cations are to be removed. To prevent clogging when zinc cations are being removed the direction of the flow through the column (IEX) is periodically reversed.