In chlor-alkali plants, how is bromine in raw salt or brine identified qualitatively? Does it have an impact on the ion membrane?
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Hello everyone, I would like to ask a question: In chlor-alkali plants, the raw salt contains more than 100 mg/L of bromine, and no equipment for bromine removal is used in the production process. Will this have an impact on ion exchange membranes and other components? For analysis, how to determine the nature?
Before there were bromine plants, ‘the original salt contained less bromine.’ Now, after bromine extraction and further salt drying, the bromine content is not lower
This post was last edited by qugd on 2019-2-1 11:23. The direct qualitative detection of bromide ions is generally quite complicated; it is better to use chromatographic methods for detection. Ion chromatography can be used to directly detect the presence of bromide ions. Secondly, potentiometric titration is carried out using silver ions as the titrant; however, the concentrated brine should first be subjected to preliminary desalination, that is, most of the sodium chloride is separated through crystallization, followed by the detection of bromide ions in the mother liquor. Because the detection of bromide ions is difficult in the presence of a large amount of chloride ions. If the bromide ion concentration is high, chlorine water can be added directly to release bromine as elemental bromine for further testing. Bromide ions have little effect on the ion exchange membrane; during electrolysis, bromine is electrolyzed along with chlorine and enters the dilute salt solution, proceeding to the salt purification stage. However, the bromine content of over 100 mg/L in the crude salt should make it valuable for bromine extraction.
The bromine content has no effect on the electrolyzer; however, if PVC is produced downstream, vinyl bromide impurities are generated during the conversion process, which may affect the quality of the resin. A level of 100 ppm in the saltwater has little impact
Could you explain how bromine gets into the PVC production process and is converted into bromoethylene?
The synthesis pathway for vinyl bromide and vinyl chloride is the same: hydrogen reacts with bromine to produce hydrogen bromide, which is then used together with acetylene to form vinyl bromide. We have tested primary brine, secondary brine, and hydrochloric acid, and found that the bromine content in these substances shows a gradual decrease. The vinyl bromide content in our crude monomer ranges from 20–60 ppm, and there is no corresponding change in the bromide content in the brines
We have online bromine concentration detectors and can provide solutions
Find information on brine chemistry or bromine extraction on your own; bromine extraction from brine is already a mature technology.