阅读说明：本技术 一种高丰度、高纯度核级硼-10酸制造方法 (Preparation method of high-abundance and high-purity nuclear-grade boron-10 acid ) 是由 周鸿刚 王明辉 李超 李长虹 魏娇 韩启超 于 2020-03-30 设计创作，主要内容包括：本发明属于化学合成与分离领域,特别是涉及一种高丰度、高纯度核级硼-10酸的制造方法。本发明以自然丰度的三氟化硼甲醚络合物为起始原料,经精馏、水解、酯化三段式工艺流程,制造得到了<Sup>10</Sup>B丰度≧95.0％、化学纯度≧99.9％、杂质含量≦1ppm的硼-10酸,且已经实现工业化生产。本发明提高了生产效率、降低了制造成本、提升了产品品质、消除了环境负担。(The invention belongs to the field of chemical synthesis and separation, and particularly relates to a method for preparing high-abundance and high-purity nuclear-grade boron-10 acid. The invention takes boron trifluoride methyl ether complex with natural abundance as an initial raw material, and the boron trifluoride methyl ether complex is prepared by three-stage process flows of rectification, hydrolysis and esterification 10 The abundance ratio of B is not less than 95.0%, the chemical purity is not less than 99.9%, the impurity content is not less than 1ppm of boron-10 acid, and the industrial production is realized. The invention improves the production efficiency, reduces the manufacturing cost, improves the product quality and eliminates the environmental burden.)

1. A method for preparing nuclear grade boron-10 acid with high abundance and high purity is characterized by comprising the following steps:

(1) taking a boron trifluoride methyl ether complex with natural abundance as an initial raw material, continuously adding the initial raw material into a rectification system, adding a dehydrating agent into a tower kettle of a rectification tower, fully contacting the boron trifluoride methyl ether complex with the dehydrating agent in the rectification process, continuously absorbing moisture in the complex by the dehydrating agent, and continuously taking the moisture out of the rectification system by the dehydrating agent, wherein the moisture content of the complex is less than 50 ppm;

(2) controlling the distribution flow rate, gas-liquid ratio, vacuum degree and temperature of each rectifying tower, and rectifying to continuously enrich to obtain high abundance¹⁰Boron trifluoride methyl ether complex of B;

(3) will be rich in¹⁰B, carrying out alkaline hydrolysis, acidification and neutralization on boron trifluoride methyl ether complex at normal temperature to form boron-10 acid solution and salt, then removing solid salt precipitate through liquid-solid separation, and carrying out evaporative crystallization on boron-10 acid mother liquor to obtain crude boron-10 acid;

(4) boiling and washing crude boron-10 acid with a solution C at 80-100 ℃, transferring ionic impurities in the boron-10 acid into the solution C, cooling the solution C to room temperature, separating a solvent A from the solution C, removing the ionic impurities from the separated solvent A through ion exchange resin, repeatedly boiling and washing and separating until the content of the ionic impurities in the boron-10 acid is less than or equal to 1ppm, and obtaining wet boron-10 acid;

(5) drying the wet product of the boron-10 acid to obtain the final product of the boron-10 acid, and obtaining the boron-10 acid¹⁰The abundance ratio of B is not less than 95.0%, the chemical purity is not less than 99.9%, and the impurity content is not less than 1 ppm.

2. The method of claim 1 wherein said dehydrating agent is cyclopentane, cyclohexane or cycloheptane.

3. The method of claim 1, wherein the dehydrating agent is added in an amount of 10 to 15 times the amount of water in the complex.

4. The method for producing a high-abundance high-purity nuclear-grade boron-10 acid as claimed in claim 1, wherein the dehydrating solvent is left in the rectifying system of the rectifying system and then is naturally separated from water by standing in a separator, and the solvent is returned to the column for recycling.

5. The method for producing a high-abundance and high-purity nuclear-grade boron-10 acid according to claim 1, wherein the volume ratio of the gas phase to the liquid phase of each rectifying tower is 1: 2-5 at the bottom of the tower and 1: 0.2 to 0.5; the vacuum degree is set within the range of 60-120 mmHg; the temperature of the evaporator is set to 110-140 ℃.

6. The method of claim 1, wherein the solvent A is a saturated carbonated aqueous solution, the solution C is a saturated carbonated aqueous solution in volume ratio: pure isobutanol is 1: 2-8.

Technical Field

The invention belongs to the field of chemical synthesis and separation, and particularly relates to a method for preparing high-abundance and high-purity nuclear-grade boron-10 acid.

Background

The natural isotopes of boron in nature include boron-10 and boron-11, wherein the natural abundance of boron-10 is less than 20%. The abundant boron-10 series products must be prepared manually. Boron-10 acid is one of the boron-10 homologues, and boron-10 powder and other boron-10 homologues are generally produced from boron-10-acid as the starting material. The boron-10 acid can be directly used as a neutron absorber, and can also be used as a raw material for manufacturing other boron-10 series neutron absorbers.

The boron-10 separation technology has high barrier and great industrialization difficulty, and only developed countries such as America, Japanese, English, French and Russia can realize industrialized production at present. At present, similar manufacturers in China also have Dalian Boentatake technology Limited, Boentatan also adopts a boron trifluoride-methyl ether system to separate boron-10 isotopes, but the technical difficulty of separating high-abundance boron-10 isotopes cannot be broken through, and boron-10 acid with high abundance and high purity (the abundance is more than or equal to 95 percent and the purity is more than or equal to 99.5 percent) cannot be produced so far.

The orthomethyl ether complex method for preparing boron-10 acid comprises five chemical units: a dehydration unit, namely removing water in a raw material complex by phosphorus pentachloride; a rectification unit for obtaining the rich content by chemical exchange rectification¹⁰A complex of B; hydrolysis unit-the complex is dissociated and converted to boric acid via chemical processes; refining unit, namely obtaining the final product of boron-10 acid through esterification, purification and impurity removal; and (3) a wastewater unit, namely treating the acidic wastewater containing chlorine and phosphorus generated by the dehydration unit.

The problems of blockage of a rectifying system, difficulty in enrichment of abundance, low product purity, high impurity content and the like can not be effectively solved all the time, and the harm of chlorine and phosphorus derived from phosphorus pentachloride dehydration is not easy to eliminate. This situation restricts the product productivity and product quality, which leads to China's republic of China¹⁰The B isotope product depends on import for a long time, and the development of the related nuclear technology field in China is inhibited.

Disclosure of Invention

Aiming at the existing problems, the invention provides a method for preparing high-abundance and high-purity nuclear-grade boron-10 acid, which aims to remove water in a complex in real time in the rectification process through online dehydration, ensure the smooth operation of the rectification process through an anti-blockage technology, perform gas-liquid balance control in the rectification process and obviously improve the quality of the product¹⁰And the enrichment efficiency and the enrichment abundance of B obviously remove product impurities.

The method for preparing the high-abundance and high-purity nuclear grade boron-10 acid comprises the following steps:

(1) taking a boron trifluoride methyl ether complex with natural abundance as an initial raw material, continuously adding the initial raw material into a rectification system, adding a dehydrating agent into a tower kettle of a rectification tower, fully contacting the boron trifluoride methyl ether complex with the dehydrating agent in the rectification process, continuously absorbing moisture in the complex by the dehydrating agent, and continuously taking the moisture out of the rectification system by the dehydrating agent, wherein the moisture content of the complex is less than 50 ppm;

(2) controlling the distribution flow rate, gas-liquid ratio, vacuum degree and temperature of each rectifying tower, and rectifying to continuously enrich to obtain high abundance¹⁰Boron trifluoride methyl ether complex of B;

(3) will be rich in¹⁰B, carrying out alkaline hydrolysis, acidification and neutralization on boron trifluoride methyl ether complex at normal temperature to form boron-10 acid solution and salt, then removing solid salt precipitate through liquid-solid separation, and carrying out evaporative crystallization on boron-10 acid mother liquor to obtain crude boron-10 acid;

(4) boiling and washing crude boron-10 acid with a solution C at 80-100 ℃, transferring ionic impurities in the boron-10 acid into the solution C, cooling the solution C to room temperature, separating a solvent A from the solution C, removing the ionic impurities from the separated solvent A through ion exchange resin, repeatedly boiling and washing and separating until the content of the ionic impurities in the boron-10 acid is less than or equal to 1ppm, and obtaining wet boron-10 acid;

(5) drying the wet product of the boron-10 acid to obtain the final product of the boron-10 acid, and obtaining the boron-10 acid¹⁰The abundance ratio of B is not less than 95.0%, the chemical purity is not less than 99.9%, and the impurity content is not less than 1 ppm.

Wherein the dehydrating agent is cyclopentane, cyclohexane or cycloheptane.

The addition amount of the dehydrating agent is 10-15 times of the moisture content in the complex.

After leaving the rectification system, the dehydrating agent is kept stand in a separator to be naturally separated from water, and the solvent returns to the tower to be recycled.

The volume ratio of gas phase to liquid phase of each rectifying tower is 1: 2-5 at the tower bottom and 1 at the tower top: 0.2 to 0.5; the vacuum degree is set within the range of 60-120 mmHg; the temperature of the evaporator is set to 110-140 ℃.

The solvent A is a saturated carbonic acid aqueous solution, the solution C is a saturated carbonic acid aqueous solution according to the volume ratio: pure isobutanol is 1: 2-8.

Compared with the prior art, the invention has the characteristics and beneficial effects that:

the invention takes boron trifluoride methyl ether complex with natural abundance as an initial raw material, and the boron trifluoride methyl ether complex is prepared by three-stage process flows of rectification, hydrolysis and esterification¹⁰B abundance is not less than 95.0%, chemical purity is not less than 99.9%, impurity content is not less than 1ppm of boron-10 acid, and industrial production is realized; the invention improves the production efficiency, reduces the manufacturing cost, improves the product quality and eliminates the environmental burden.

Detailed Description

The following description is of preferred embodiments of the present invention, and it should be understood that the preferred embodiments described herein are for purposes of illustration only and are not intended to limit the invention.