Filter the flocs in the extracted organic phase
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After using the organic phase for a short period of time, flocs were observed in it, which caused the phase separation to deteriorate gradually. I was wondering if it’s possible to remove these flocs through filtration? If possible, what type of filtration should be used, and what is the precision level? Do we still have to use white clay? The aqueous phase is acidic, and there is also a certain amount of acid in the organic phase; will kaolin dissolve in this acid and cause contamination of the organic phase?
1. What is your liquid material system? How is the extractant selected? 2. There are many reasons for the formation of flocs in the organic phase; impurities carried in the feed solution can enter the extraction system and cause floc formation, and an inappropriate selection of the extractant can also lead to floc formation ； Certain substances can be removed through filtration. The filtration mesh size needs to be determined through experimentation. 3. Acidic solutions do not affect the treatment with clay; by controlling the amount of clay added, it will not contaminate the organic phase.
I guess the conditions for back-extraction and extraction are too different – one is acidic and the other alkaline – which makes emulsification likely. Clay treatment only provides temporary relief; what’s crucial is to add a washing step in between. Also, try to keep the organic phase from becoming saturated, as a saturated organic phase tends to emulsify easily, and the concentration of the unsaturated material obtained through back-extraction cannot be increased
Thank you all. The flocs are in the organic phase; at first, phase separation occurs quickly, and after some time the flocs appear. After phase separation, the flocs can be seen at the oil-water interface, but the interface remains clear as a whole. The properties of the flocs are very similar to those of the flocs that form when the liquid mixture contains impurities. The problem is that over time, I don’t know how to deal with it. Furthermore, after low-acidity back-extraction, the oil phase becomes turbid; after standing for a long time, an aqueous phase forms and the turbidity of the oil phase decreases. In order to clarify the oil phase, would it be effective to add a TBP phase modifier or to use centrifugation? I look forward to everyone's insightful opinions.
Is it that the back-extraction conditions are related to the high acidity of the organic phase?
The material being extracted is highly acidic (10% sulfuric acid); in this case, the organic phase is relatively clear. After back-extraction under low-acid conditions, the organic phase becomes cloudy upon phase separation. After standing for an extended period, an aqueous phase precipitates, improving the clarity of the mixture. The extractant used is isooctanol
It might be insoluble substances brought in by concentrated sulfuric acid; after all, not all chemicals have an insoluble substances parameter, so it’s just speculation