Chlorate Decomposition Process in Ion Membrane Caustic Soda Production

Abstract

The invention discloses a chlorate decomposition process method in the production of caustic soda by ion membrane method. The light brine is pumped from the chlorate to the electrolytic anode circulation tank through the chlorate heat exchanger to the outlet of the chlorate decomposition tank, which can be directly The light brine pipeline sent to the protected refined brine main pipe is controlled by a flow meter, an acid concentration meter and a regulating valve to add saturated refined brine to the main pipe, and is sent from the electrolytic anode circulation tank to the dechlorination tower through the electrolytic anode circulation pump, and sent to the protected refined brine main pipe The light brine pipeline sent to the chlorate decomposition tank, the light brine sent to the dechlorination tower is subjected to vacuum physical dechlorination and chemical dechlorination by the water ring vacuum pump unit, and then sent to the primary brine salt, and the brine from the saturated refined brine main pipe Distributed to each electrolytic cell, and then distributed to each electrolytic cell for electrolysis, after the strong acidic brine from the chlorate outlet of this invention is directly added to the circulation tank, the acidic brine from the chlorate outlet can be fully mixed with the light brine from the electrolytic cell outlet , The dechlorination system control is more stable.

Description

technical field [0001] The invention relates to a chlorate production process in the field of industrial ion membrane caustic soda production, in particular to a chlorate decomposition process in the ion membrane caustic soda production. Background technique [0002] At present, the known ion membrane caustic soda production process technology is very mature. Ionic membrane caustic soda production runs for a long period of time without interruption. The brine in it will produce chlorate in the whole system, and the chlorate will continue to accumulate. If the concentration is high, the concentration of sodium chloride in the brine will decrease, which will affect the electrolysis. The current efficiency of the cell and the amount of electrolyte, chlorate is more harmful to the entire electrolysis system, seriously affecting production safety and high efficiency. Part of the light brine (NaCl concentration: 205-230g / L) at the outlet of the electrolytic anode circulation pump...

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Problems solved by technology

[0004] 1. Because the acidity of the acidic light brine at the outlet of the chlorate decomposition tank device is relatively high, it is added to the inlet of the dechlorination tower and mixed with the electrolytic undechlorinated light brine (2≤pH≤4), because the dechlorination tower has a pH index requirement (1.1≤pH ≤1.5), the flow rate of the chlorate decomposition device cannot be increased, otherwise the pH at the inlet of the dechlorination tower will exceed the standard, and the strong acid brine will cause hidden dangers to the dechlorination equipment

[0005] 2. When the ionic membrane runs to the later stage, the chlorate generated by the side reaction of the electrolytic cell increases, but the decomposition flow rate of the chlorate decomposition device is limited and cannot be increased any more. The chlorate content in the brine system increases, and the chlorate in the liquid caustic soda The salt content also increases, which affects the quality of liquid caustic soda products. Chlorate also causes corrosion damage to the equipment of the subsequent caustic soda evaporation plant, which increases the maintenance cost of equipment and affects the economic benefits of the chlor-alkali system.

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