Extraction system for extracting boric acid from magnesium-containing brine and extraction method thereof

Abstract

The invention discloses an extraction system for extracting boric acid from magnesium-containing brine and an extraction method thereof. The system comprises an extractant and a diluent which are mixed with one another, wherein the structure of the extractant is as shown in the formula 1, in the formula 1, R1 is the alkyl group selected from C4-C8, and R2 is the alkyl group selected from C6-C10. According to the system, solubility of the extraction system in water is very low, the boric acid can be effectively extracted from the magnesium-containing brine, and extraction saturated capacity ofthe extraction system is high, emulsification does not easily occur, and the extraction system is more suitable for industrial production. Compared with a conventional alcohol extractant in the priorart, not only is the conflict between extraction performance of a monohydric alcohol extractant and the problem of solution loss caused by solubility solved, but also the problem of polyhydric alcoholextractant loss in an aqueous phase is solved. The invention further provides an extraction method for extracting the boric acid from the magnesium-containing brine based on the extraction system.

Description

Technical field [0001] The present invention is the field of boric acid preparation technology. Specifically, it involves an extraction method of extracting boric acid from magnesium salt lake brine and extracting boric acid based on the extract system from the magnesium salt lake brine. Background technique [0002] Boric acid is an important basic chemical raw material. It is an important component of glass fiber, insulation material, permanent magnet material, ceramic, detergent, pesticide, flame retardant and other chemical products. , National Defense, Agriculture, Medicine and many other industries have a important role in the development of many industries. At present, the shortage of domestic boron resources has threatened the development of related industries, especially my country's solid boron mine resources have been exhausted after decades of mining; while the salt lake brine in western my country contains rich liquid boron mines. [0003] At present, the salt lake b...

AI Technical Summary

Problems solved by technology

The two most widely used extractants are monohydric alcohol extractant and binary fatty alcohol extractant; among them, the extraction performance of monohydric alcohol increases with the decrease of molecular weight, but the solubility of low molecular weight monohydric alcohol in brine Larger, the generated ester is easily hydrolyzed, and the separation is mainly achieved by phase balance, so the extraction effect is not ideal; relatively speaking, the six-membered ring boronic acid ester formed with boric acid is more stable and has a better effect on boric acid. The extraction effect, but its loss in the aqueous phase is also the main reason why it is difficult to apply in industry

[0005] At present, there are many reports on boron extraction by solvent extraction, such as: a method for extracting boric acid from boron-containing magnesium chloride solution, the raw material is acidified, filtered, extracted multiple times, stripped multiple times, filtered, hot-melt decolorized, filtered Boric acid product is obtained after deslagging, cold crystallization filtration, evaporation, and cold crystallization filtration. The extraction agent is a mixture of 2-octanol and iso-octanol in a ratio of 1:5 to obtain a monohydric mixed fatty alcohol with a main chain containing C5-C10 and branched chains. The recovery rate of boron can reach 95%; a kind of brine after extracting lithium from salt lake is used as raw material, and the mixed alcohol of 2-ethyl-1,3-hexanediol combined with isooctyl alcohol and isoamyl alcohol is extracted from the brine The method of boron, the method is experimented from the aspects of extractant volume fraction, acidity, phase ratio, extraction time, extraction temperature, saturated extraction capacity, stripping agent concentration, stripping time, etc., and obtains the method of extracting boron from brine with mixed alcohol. However, the organic phase of this method suffers from serious dissolution loss, and the solubility of isooctyl alcohol reaches 1g / L at room temperature; When the volume fraction of the extractant is 30%, the pH of the aqueous phase is 3, compared with 1:1, and the extraction time is 10 minutes, the best process conditions can be obtained. B 2 o 3 The maximum saturated capacity is 61.4g / L. However, the 1,3-dibasic fatty alcohol 2-ethyl-1,3-hexanediol used in this technology still loses seriously in aqueous solution, and its solubility at room temperature reaches 4.18g / L L, not economically applicable, thus limiting its industrial application

[0006] In summary, the existing boric acid extraction generally has defects such as high solvent loss of the extractant, low saturation capacity, and easy emulsification, which lead to high cost, high energy consumption, and serious environmental pollution.

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