Method for producing phosphorus oxychloride with purity of 99.99999 percent

Abstract

The invention discloses a method for producing phosphorus oxychloride with the purity of 99.99999 percent. The method comprises the following steps of: adding 1-4 percent by mass of composite complexing agent A into industrial grade phosphorus oxychloride with the concentration of 99.5 percent and collected heavy components produced by primary distillation at the temperatures of lower than 100 DEG C and higher than 107 DEG C, controlling the temperature between 20 DEG C and 50 DEG C, fully stirring for reaction of 40-60 minutes, distilling and extracting a fraction with the temperature of between 100 DEG C and 107 DEG C to obtain a primary distillation product; adding 5.1-11 parts of collected low-boiling-point substance produced by secondary distillation at the temperature of lower than 100 DEG C, 5.1-11 parts of collected heavy component produced by secondary distillation at the temperature of lower than 100 DEG C and 78-89 parts of primary distillation product into an enamel reaction kettle, adding a composite complexing agent B of which the mass is 1-5 percent of that of phosphorus oxychloride, controlling the temperature between 25 DEG C and 50 DEG C, fully stirring for reaction of 40-100 minutes, depositing, delaminating, filtering supernate, distilling filtrate and extracting a fraction with the temperature of between 100 DEG C and 107 DEG C to obtain a secondary distillation product; and rectifying the secondary distillation product to obtain electronic grade phosphorus oxychloride with the purity of 99.99999 percent. The method has the advantages of simple process, high product yield, environmental-friendly production technology and high product purity.

Description

[0001] The invention relates to the technical field of chemical industry, in particular to a production method of phosphorus oxychloride. Background technique [0002] High-purity phosphorus oxychloride is a dopant for the production of integrated circuits and solar cells, and one of the raw materials for manufacturing optical fiber preforms. Its purity requirement is as high as 99.9999%, especially phosphorus oxychloride for large-scale integrated circuits, which requires a single item The metal impurity content does not exceed 10ppb. [0003] Chinese Patent Publication No. CN1613752 disclosed a "99.99999% phosphorus oxychloride production process" on May 11, 2005, which uses high-purity yellow phosphorus and high-purity chlorine to react to produce phosphorus trichloride, and the resulting phosphorus trichloride is The pure phosphorus trichloride is obtained by distillation. The pure phosphorus trichloride forms phosphorus oxychloride after dripping chlorine, and then reflux...

AI Technical Summary

Problems solved by technology

[0003] Chinese Patent Publication No. CN1613752 disclosed a "99.99999% phosphorus oxychloride production process" on May 11, 2005, which uses high-purity yellow phosphorus and high-purity chlorine to react to produce phosphorus trichloride. The pure phosphorus trichloride is obtained by distillation. The pure phosphorus trichloride forms phosphorus oxychloride after dripping chlorine, and then refluxes, distills, and rectifies to obtain high-purity phosphorus oxychloride. The process route is quite long. It needs to go through tertiary purification of yellow phosphorus, phosphorus trichloride, phosphorus oxychloride, etc., especially the loss of phosphorus in the refining of high-purity yellow phosphorus is large, and it is difficult to control the process of dripping chlorine in the process of synthesizing phosphorus oxychloride from phosphorus trichloride, and Its quality index is not high (single metal impurity does not exceed 9ppb)

The process is also complex in process, and due to the wide range of process control temperature, the product quality is unstable due to factors such as easy precipitation of impurities in the double-layer glass, the process of dripping chlorine water is difficult to control, and the product recovery temperature is quite narrow, resulting in product recovery. The rate is low, it is difficult to realize industrial production

[0005] The US5993609 patent discloses a purification process for purifying and recovering phosphorus oxychloride containing reactive organic matter, adding 0.1-5% mass fraction of organic matter (pyridines) to phosphorus oxychloride to eliminate metal ions through its complexation, Carry out atmospheric distillation then, obtain the carbon content (TOC)<200ppm of final product, the high-purity phosphorus oxychloride of the total content<5ppm of Fe, Cr, Ni, as seen its quality grade is relatively poor