Method for synthesizing nuclear grade boric acid through hydrolysis of boron trifluoride

Abstract

The invention discloses a method for synthesizing nuclear-grade boric acid by hydrolyzing boron trifluoride, which comprises the following steps: (1) reacting boron trifluoride with boron 10 abundance of more than 96% with water, setting nitrogen or other inert gases as shielding gas or not, setting the molar ratio of boron trifluoride to water to be 10: 1-1: 100, the initial reaction temperature to be-20 to 100 DEG C, and the reaction time to be 0-40 hours, collecting a boric acid aqueous solution at the bottom of the reaction kettle, and absorbing generated hydrogen fluoride with water or alkali liquor; and (2) recrystallizing and purifying the boric acid obtained in the step (1), setting the crystallization temperature to be 0-50 DEG C, and setting the solution concentration to be 0-50%. The method disclosed by the invention is a process capable of directly obtaining the boron 10-enriched nuclear grade boric acid, the raw materials are easy to obtain, the process waste is less, and remarkable economic and environmental benefits are brought; and high temperature and high pressure are not needed, and energy waste is not caused, so that the overall cost of the process is reduced, the purity and yield of the product are improved, the purity of the synthesized boron-10-rich boric acid can reach 99.9%, the abundance of boron-10 is greater than 96%, and the boron-10-rich boric acid can be used for nuclear power station neutron protection.

Description

technical field [0001] The invention relates to a method for synthesizing nuclear-grade boronic acid, in particular to a method for synthesizing nuclear-grade boronic acid by using boron trifluoride with a boron 10 abundance of more than 96% as a reactant. Background technique [0002] Boric acid and boronic acid derivatives have a wide range of applications, and the demand for their production is increasing year by year. In the high-tech field, especially in the nuclear field, the required boric acid has extremely high quality requirements. The removal purity needs to reach more than 99.5%, and the content of some metal impurities needs to be controlled at the ppm level. The existing boric acid synthesis methods are difficult to meet the requirements of the nuclear field. Require. The boric acid required in the high-tech field has extremely high requirements on the quality of boric acid. The boric acid needs to achieve a purity of more than 99.9% and a boron 10 abundance o...

AI Technical Summary

Problems solved by technology

The traditional one-step and two-step methods consume a lot of acid and are easy to corrode equipment; the raw materials of the ammonium bicarbonate method can be reused, but the process is complicated and not suitable for large-scale industrial applications; although the acid crystallization method can be used in industrial applications, the recovery rate is low; Electrolytic electrodialysis is expensive and not suitable for industrial production; carbon dioxide method is mainly used abroad to prepare boric acid, which is green and environmentally friendly. The main problem is that the dissolution rate of raw boron ore is not high; generally speaking, the most prominent problem in the preparation of nuclear grade boric acid is purity. Not enough, big environmental impact

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