Regarding the content of sodium carbonate in caustic soda
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This post was last edited by sunjl1981 on 2013-1-6 at 23:52. The finished caustic soda produced in caustic soda production facilities generally meets two standards: industrial sodium hydroxide and high-purity sodium hydroxide. For high-purity sodium hydroxide, the required level of sodium carbonate is less than 0.06, while for industrial sodium hydroxide it is less than 0.4. What is the level of sodium carbonate in the finished caustic soda produced by everyone? How are the metrics controlled then? ， ， -
We produce ion-exchange membrane caustic soda, in compliance with the GB11199-2006 standard for high-purity sodium hydroxide. For the 32% concentration grade of this caustic soda, the allowable level of sodium carbonate is ≤0.04% for top-quality products, and ≤0.06% for first-grade products. In all grades of high-purity sodium hydroxide, whether at 99.0%, 98.5%, 45.0%, 32.0%, or 30.0% concentration, the level of sodium carbonate is not 0.006% as mentioned by the poster; could the poster have made a mistake? Our factory doesn’t have any specific controls in place for this; as long as the performance of the membrane is good, it shouldn’t exceed the limits!
Reaching this 0.06 target seems a bit difficult! In particular, when the electrolyzer is used for electrolysis with alkaline salt solution without hydrochloric acid, the level of sodium carbonate exceeds the specified limit.