Method for preparing extra high pure deuterium gas by using heavy water as raw material

Abstract

This invention relates to a method for preparing ultrahigh-purity deuterium from heavy water. The method comprises: mixing heavy water and KOH at a ratio of 1:(0.01-0.03) to obtain an electrolyte, performing volume reduction electrolysis at (-20)-(-10) deg.C in a diaphragm-free electrolytic tank, stopping electrolysis when the concentration of heavy water is 99.99%, performing volume reduction electrolysis at (-10)-(-5) deg.C in an electrolytic tank with diaphragm, and preparing ultrahigh-purity deuterium (99.99%). Both the diaphragm-free electrolytic tank and the electrolytic tank with diaphragm can utilize KOH electrolyte. The method has such advantages as no need for alkali-removal process by distillation, simple process, low investment and low cost.

Description

technical field [0001] The invention relates to a production method for producing ultra-high-purity deuterium gas by using heavy water. Background technique [0002] Deuterium gas is produced by using heavy water as a raw material. The traditional method is to obtain it by concentrating heavy water, distilling alkali, and deuterium gas production. Although there are some improvement measures, such as using low-temperature concentrated heavy water, using high-vacuum suction equipment to treat the residual water film on the pipeline, and filling heavy water and electrolyte potassium carbonate in a dry glove box, it is still not resolved that the purity of deuterium gas depends on heavy water. The problem of purity, the purity of deuterium gas is always lower than the purity of heavy water by an order of magnitude, that is to say, in order to stably produce deuterium gas with a purity of 99.99%, the purity of heavy water must always reach more than 99.999%, so it is difficult t...

AI Technical Summary

Problems solved by technology

Although there are some improvement measures, such as using low-temperature concentrated heavy water, using high-vacuum suction equipment to treat the residual water film on the pipeline, and filling heavy water and electrolyte potassium carbonate in a dry glove box, it is still not resolved that the purity of deuterium gas depends on heavy water. The problem of purity, the purity of deuterium gas is always lower than the purity of heavy water by an order of magnitude, that is to say, in order to stably produce deuterium gas with a purity of 99.99%, the purity of heavy water must always reach more than 99.999%, so it is difficult to obtain heavy water using existing methods Meet the requirements for the production of ultra-high purity deuterium gas

At the same time, there are still factors affecting the purity of deuterium gas in the existing production process: if the electrolyte of an electrolytic cell without a diaphragm is potassium carbonate, the bath solution is released after electrolysis, and the electrolyte is removed by distillation. The stage of alkali removal by distillation is essential Yes, the concentrated heavy water must be condensed into heavy water after many processes such as heating, boiling, distillation and condensation. Negative pressure operation in equipment and pipelines often affects the quality of heavy water; in electrolysis under low temperature conditions, in order to prevent the electrolyte from freezing, the concentration of potassium carbonate must be greatly increased. After the concentration of potassium carbonate is increased, its viscosity doubles and electrolysis The fluidity of the liquid becomes very poor, and the separation coefficient of the separated hydrogen isotope decreases, which seriously affects the enrichment quality and speed; the deuterium gas generator cannot control the quality of the deuterium gas, and the fluctuation of the deuterium gas quality directly affects the pass rate of the product, resulting in waste. greatly increase the cost

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