Seeking advice on chloride ions in ion-exchange membrane caustic soda
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This post was last edited by sunjl1981 on 2013-1-6 at 23:26. Sampling from the bottom of the 32% ion-exchange membrane caustic soda storage tank revealed a chloride ion concentration of 0.1%, while sampling from the upper layer showed normal levels. Dear teachers, what’s going on here? # hcbbs
This is because salts contained in the alkali precipitate at the bottom of the tank
As I understand it, what was said above makes some sense, but I haven’t seen any relevant materials specifically.
Whether accidental or long-term, the possibility of pollution is high.
Mainly, the alkali contains salts; when the hot alkali reaches the storage tank, a decrease in temperature causes some of the salts to precipitate, and the greater the temperature difference, the more salt precipitates. This is a very normal phenomenon. This is also why the transport tank needs to be washed after returning.
This issue still takes pollution into account; in the process of producing caustic soda using ion exchange membranes, the salt content even during operation is around 100PPM. Under normal conditions, it’s impossible for salts to precipitate. Has the purpose of the storage tank changed? It was originally used to store membrane caustic soda. If it is an ion-exchange membrane caustic, I personally think it’s better to look for the cause from outside.