Technical help! ! ! What to do if the high-purity acid does not meet the standards? Urgent! Urgent
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This post was last edited by sunjl1981 on 2013-1-6 21:43. The acid produced in our facility does not meet the quality standards. It contains a high level of free chlorine. It is well known that the acid used for regenerating resin towers must not contain free chlorine. Our unit has an acid intermediate tank for the secondary brine. The acid is all applied there. The acid used for the regeneration of the resin column. I’m now seeking help from fellow sailors: how can I remove free chlorine from the acid in the middle tank? Can sodium hyposulfite be used? Can free chlorine be removed under acidic conditions? ， ， -
I only know that in high school chemistry, it seems AgCl is formed and precipitates out.
The reason for adjusting the pH with a base before adding sodium sulfite to the dechlorinated brine is not that sodium sulfite loses its reducing properties in acidic conditions, but rather that it first reacts with acids to form sulfur dioxide under acidic conditions; this sulfur dioxide then reacts with sodium hypochlorite. As a result, the efficiency of sodium sulfite is very low – I have personally found that its efficiency in hydrochloric acid is only 30%. However, there is not much free chlorine in hydrochloric acid, and very little sodium sulfite is added, so this method can be employed
What was said upstairs is absolutely correct. However, the high level of free chlorine in highly pure acids requires an investigation into the production process; are you using a two-in-one or three-in-one furnace? Control the flow rates of chlorine and hydrogen. If the hydrogen in the north contains water, it can cause fluctuations in the hydrogen flow rate; therefore, proper water removal is necessary.
Reply to 1# hjg420: Add ascorbic acid solution; it’s fine once no free chlorine is detected.
It is relatively difficult to ensure the absence of free chlorine during the synthetic production process; generally, sodium sulfite is added to achieve this.
To prevent free chlorine levels from exceeding the allowed limits at their source, the three-in-one hydrochloric acid furnace we use works fairly well; the key is to ensure stability in the hydrogen and chlorine systems as well as to maintain proper vacuum levels； Under normal circumstances, the acids are all qualified.
Adding sodium hyposulfite will allow it to come out; that’s what we do now
It is indeed very difficult to make high-purity acids free of free chlorine. Especially, it is more difficult to control some older equipment. Everyone uses the method of adding sodium sulfite, and the amount added is not large; just keeping it under control is sufficient.
Yes, simply put, it’s sodium bisulfite – after all, it’s used to remove free chlorine from lightly salted water, so there’s no need to buy something separate.