Semi-continuous extraction or reextraction method for heat-sensitive and easily emulsifying organic phase

Abstract

The invention provides a method for semi-continuous extraction or back extraction of a heat sensitive and easily emulsified organic phase. The method comprises extraction or back extraction carried out in at least three extraction or back extraction reactors, wherein the first reactor firstly receives high-temperature oil-water mixture, after a certain period the second reactor receives high-temperature oil-water mixture, and the extraction or back extraction is performed in the first reactor; after a certain period, the third reactor receives high-temperature oil-water mixture, the oil-watermixture completely treated by the first reactor is discharged, an the extraction or back extraction is performed in the second reactor; and, after a certain period all reactors circularly carry out operations according to the working mode. When the method is applied to the extraction or back extraction of the heat sensitive and easily emulsified organic phase, the method is better connected with the previous and following continuous processes, and thoroughly resolves the defects of the conventional gap process that the treatment capability is weak, and the continuous process is unable to be stably operated.

Description

technical field [0001] The invention relates to a semi-continuous extraction or stripping method, in particular to a semi-continuous extraction or stripping method for heat-sensitive and easily emulsified organic phases. Background technique [0002] Extraction-stripping is an important separation technology, which has been widely used to separate and purify various metal ions (such as copper, gold, nickel, molybdenum, vanadium, cobalt, etc.) or organic substances (such as phenol, dimethyl formamide, carboxylic acid, etc.). Extraction-stripping usually consists of the following steps: first, the organic phase containing the extractant is mixed with the aqueous solution containing the target substance at a certain temperature and pH value according to a certain ratio, so that the target substance to be extracted in the water is transferred to the organic phase ( That is, load the organic phase), and then use the water phase containing the stripping agent to mix with the load...

AI Technical Summary

Problems solved by technology

Usually, people use continuous process equipment such as mixing-clarification, extraction tower or centrifugal extraction to process the target substance, but once the equilibrium pH value of the system deviates from the normal range, it is likely to cause emulsification of the organic phase, which will lead to the failure of the separation process. And once emulsification occurs, even if the pH value of the system is adjusted, it is difficult to return to the normal state in a short time; because some target substances have oxidation or reduction properties, they may undergo oxidation / reduction reactions after they are combined with the extractant, and The temperature rises and the reaction speed increases (this organic phase is called a heat-sensitive organic phase), which leads to an accelerated denaturation of the extractant, which eventually not only leads to excessive consumption of reagents, but also may cause too much intermediate layer in the extraction / stripping process. affect normal operation

For the extraction or stripping process of easily emulsified and heat-sensitive organic phase, people currently mainly use batch method to process materials, which is difficult to effectively connect with the continuous process before extraction or after stripping

[0004] In summary, there is currently no technology that can be used specifically for extraction or stripping of heat-sensitive, easily emulsified organic phases

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