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...