Patent DE-102006016688-B3 (DE)
Title: Electrical deionization method for processing of rinsing waters from chemical and/or electro-chemical surface treatment of metals, comprises cleaning of metal-containing liquids by ion-exchanger along with recovery of ion-exchange material
Inventor: BERGMANN HENRY
IPC: C02F1/42
Filed: 2006-04-08
Granted: 2007-09-20
Abstract: The electrical deionization method for processing of rinsing waters from chemical and/or electro-chemical surface treatment of metals, comprises cleaning of metal-containing liquids by ion-exchanger along with periodic recovery of ion-exchange material by electrodialysis. The processing takes place in a chamber consisting six partial chambers, which are separated by four separators (8) that are built as a diaphragm and/or ion-exchange membrane. The rinsing waters exhibit a portion of heavy metals in anionic and/or cationic form as well as with other components of process baths. The electrical deionization method for processing of rinsing waters from chemical and/or electro-chemical surface treatment of metals, comprises cleaning of metal-containing liquids by ion-exchanger along with periodic recovery of ion-exchange material by electrodialysis. The processing takes place in a chamber consisting six partial chambers, which are separated by four separators (8) that are built as a diaphragm and/or ion-exchange membrane. The rinsing waters exhibit a portion of heavy metals in anionic and/or cationic form as well as with other components of process baths. The partial chambers house an anode (9) or cathode (10) as a differently polarized electrode and one of the partial chambers housing an electrode contains an ion-exchange material that is directly contacted with the electrode. The individual chamber systems are combined into a complex unit for the operation of the method. The partial chambers filled with the ion-exchange material accommodate cationic and/or anionic ion-exchange material. The partial chambers are electrically connected in an electrically parallel or instrumentally sequential manner or by a bipolar electrode and/or a bipolar membrane. A separation device or an electrodialysis mechanism is connected to the electrical deionization module directly to a concentration chamber or to a concentration chamber for simultaneous or periodic metal separations and/or concentrations as well as pH value corrections. Ion-exchange and/or recovery for individual liquid currents, volume flow rate of a liquid current, flow intensity or chamber tension, temperature or unification of partial cycles are changed with respect to time. The electrodes are assigned to two of the partial chambers, which accommodate different ion-exchange material and lie next to each other and are separated by a bipolar membrane or a bipolar electrode. The ion-exchange materials are directly contacted with both the poles of the bipolar membrane or the bipolar electrode. Species of H +>or OH ->ions are electro-chemically produced for recovery of the ion-exchange material. Two partial chambers are present between the ion-exchanger chamber and the electrode chamber and are separated from them by two separators as well as undertake an electrodialytic concentration function and protection function against unwanted electrode reactions. In the current-free loading of the ion-exchange material, a rinsing water liquid current is led parallelly through both the chambers of the ion-exchange material, and simultaneously a recovery is carried out. Two independent liquid currents are led in separate cycles through the ion-exchanger chambers and undertake concentration functions by separators at the partial chambers adjacent to the ion-exchanger chambers. During the recovery of the ion-exchanger two separate liquid currents are flown through and a liquid current is parallelly flown through the anode chamber (1) and the cathode chamber (2).