| 摘要 |
PURPOSE:To prevent corrosion of cathode chamber and prevent performance degradation of ion exchange membranes by lowering the brine concentration in the anode chamber of the electrolytic cell after turning off of power supply and supplying slight current between the cathode and anode at the time of electrolyzing of an aqoues alkali chloride solution by an ion exchange membrane method. CONSTITUTION:When the current supply to the electrolytic cell of the case when the aqueous solution of the chloride of alkaline metals such as NaCl is electrolyzed by an ion exchange membrane, the cathode chamber is corroded by the diffusion of Cl2 dissolved in the brine in the anode chamber. In order to prevent this, the anode chamber brine is extracted and the water flooding and extracting are repeated. At the time of the final water flooding, dilute brine is fed, if necessary, to make concentrations 5 g/lto 0.01g/l. At the same time, the slight current of current density of 5 to 100 mA/dm<2> is flowed. This method enables the prevention of the corrosion of the cathode chamber and performance degradation of the ion exchange membrane to be achieved. |
