Method for extracting boric acid from boron-containing magnesium chloride solution by using an acidification-extraction method

Abstract

The invention belongs to the field of inorganic chemical technology, and particularly relates to a method for extracting boric acid from boron-containing magnesium chloride solution by using an acidification-extraction method. The method is characterized in that: (a) the process flows comprise acidification, filtering, and multiple extraction, and also have four processes, namely thermosol colorization, slag removal by filtration, cold crystallization filtration, and evaporation, and then a boric acid product is obtained after the crystallization filtration; and (b) the process conditions comprises that hydrochloric acid or sulfuric acid is added into boron-containing magnesium chloride brine in acidification, thereby leading the pH-value of brine to be 0-3; the acidification temperature is room temperature; the acidification time is 10-60 minutes; the mass percent of crude boric acid: industrial hydrogen peroxide: active carbon or fly ash in thermosol colorization is 100:0.01-5:0.5-5; and the heating temperature in thermosol colorization is 80-95 DEG C. The method is fully applicable to the industrial production need of the existing salt lake brine boron extract, greatly lowers the production cost and equipment investment, and lays down solid technology basis for the large-scale industrial salt lake brine extract.

Description

1. Technical field [0001] The invention belongs to the technical field of inorganic salt chemical industry, and in particular relates to a method for extracting boric acid from a boron-containing magnesium chloride solution by an acidification-extraction method. 2. Technical background [0002] Boric acid is an important chemical raw material, widely used in national defense, chemical industry, electronics, medicine, metallurgy, machinery and many other fields. my country's boron ore resources mainly include solid boron ore and brine boron ore in salt lakes. The mining of solid boron ore has formed a considerable scale. Due to the limited resources of solid boron ore, its mining and application have been greatly restricted. The reserves of brine boron ore resources are relatively large, but due to the low content in brine and immature extraction technology, the industrial exploitation of boron in salt lake brine is still in its infancy. There are currently three methods for ...

AI Technical Summary

Problems solved by technology

One is the acidification method to extract boric acid, which is only applicable to B 2 o 3 >20g / L brine, its recovery rate of crude boric acid is 70-75%, its recovery rate is low, it is not suitable for B 2 o 3 Salt lakes below 10g / L are not applicable

The second is the high-efficiency boron resin method, which can be applied to B 2 o 3 For brine below 10g / L, the recovery rate of boron can reach 99%, but this method has an obvious shortcoming, that is, B in the raw brine is required 2 o 3 2 o 3 6-10g / L high salinity brine, its disadvantage is that the branched chain alcohol has a certain water solubility, and the dissolution loss in the extraction process is large, and the dissolution loss in a single extraction can reach more than 1%.

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