Process for removing trace chlorine gas in gallium trichloride

Abstract

The invention relates to a process for purifying gallium trichloride; in the process, an end point of a reaction is determined by excess chlorine gas, and then the excess chlorine gas is consumed by adding metal gallium back to remove chlorine impurities; the process comprises the process steps: adding 500 g-3000 g of the metal gallium into a reaction kettle, at the reaction temperature of 180 DEG C, introducing chlorine gas, and carrying out a reaction; and when gallium trichloride is reacted to the end point, namely, a reaction solution is pale yellow green, stopping introduction of the chlorine gas, opening nitrogen gas purging, adding 1.0 g-2.0 g of metal gallium to the reaction kettle, and continuing to maintain 180 DEG C until the reaction solution turns from yellow green to colorless. In the process, the end point of the reaction is determined by excess chlorine gas, and then the excess chlorine gas is consumed by adding the metal gallium back to remove the chlorine impurities, so that the content of the chlorine gas impurities in the gallium trichloride is decreased to 1 ppm or less, and the product yield is high.

Description

technical field [0001] The invention relates to a process for purifying gallium trichloride, in particular to a process for removing trace amounts of chlorine in gallium trichloride, which belongs to the technical field of chemical industry. Background technique [0002] Since chlorine gas is used in the production process of gallium trichloride for reaction, gallium trichloride is formed after the transition of gallium dichloride in the reaction process. The judgment at the end of the reaction is judged by the color change. When the color changes from colorless to light yellow When it is green, the reaction has reached the end point, and the chlorine gas has been excessive at this time. Therefore, gallium trichloride products often contain a small amount of chlorine gas, and a small amount of chlorine gas will cause the color of the product to turn yellow. In the practical application of electronic-grade high-purity gallium trichloride, chlorine gas is a harmful impurity, ...

AI Technical Summary

Problems solved by technology

[0003] In order to meet the index requirements, most of them currently choose to use rectification towers for rectification and purification. However, due to the certain solubility of chlorine in gallium trichloride, simple distillation and purification are difficult to meet the purification requirements.