| 摘要 |
PURPOSE:To perform electrolysis of sodium chloride without causing the rise of electrolytic voltage to take place by removing cyano-ferrates contained in sodium chloride after converting into iron ion by oxidation and then by supplying the sodium chloride solution into the anodic room of an electrolytic bath provided with cation ion exchange membranes. CONSTITUTION:A sodium chloride solution deprived of Cl2 gas from the pipe 8 in the anodic solution tank 7 is further sent to the dechlorination tower 9 to control the amount of dissolved chlorine gas to 30 to 200ppm. And, the supplemental water 10 and the NaOH 11 are added to the sodium chloride solution to regulate pH value to approx. 9 or less. Then, a sodium chloride containing a solidification inhibitor, e.g., potassium ferro-cyanate, etc., is added to the sodium chloride solution tank 12, the saturated sodium chloride solrtion is sent from the tank 12 to the oxidative decomposition tank, ahere the solution is heated at more than 60 deg.C, through the heat exchanger 14, and the solution after a necessary residence time is sent back to the heat exchanger 14 for cooling. At the reaction tank 17, Na2CO3, NaOH, and BaCO3 and a precipitation accelarator, as needed, are added, iron hydroxide with Mg(OH)2, CaCO3, etc., are discahrged at the thickner 20, and the sodium chloride solution purified through the filter 22 and the chelate resin tower 23 is supplied to the anodic solution tank 7 supplementally. |
