Method for preparing high purity phosphorus pentafluoride gas

Abstract

The invention discloses a preparation method of high-pure phosphorus pentafluoride gas, which comprises: phosphorus pentoxide is put into a reaction container lined with PTFE and is introduced with anhydrous hydrogen fluoride, and the temperature is preserved to be minus 20 to 0 DEG C; according to the chemical reaction counting, the anhydrous hydrogen fluoride is overdosed by 50 to 60 percent; the reaction is carried out for 3 to 5 hours. After the reaction is completed, 60 percent of oleum is added in an intermittent way with stirring and the dosage of the oleum is 35 to 40 percent more than a theoretic value. The intermediate outcome of the reaction is heated for decomposing under the temperature of 120 to 150 DEG C so as to generate the phosphorus pentafluoride; the product is guided into a condenser for cooling the impurity and then the high-pure phosphorus pentafluoride is obtained. The content of PF<5> obtained by the method is greater than 99.9 percent, the content of impurity is low, the water content is less than 10ppm, HF content is less than 50ppm; moreover, the process equipment is comparatively simple, thus being beneficial to the industrial manufacturing.

Description

technical field [0001] The invention relates to the preparation of high-purity phosphorus pentafluoride gas. Background technique [0002] Phosphorus pentafluoride (PF 5 ) is a colorless and odorless gas under normal conditions, with a melting point of -93.78°C and a boiling point of -84.5°C. As a fluorinating agent, PF 5 It can perform ion transfer and is widely used in the fields of electronics industry, battery manufacturing, polymer materials and catalysts. [0003] At present, lithium hexafluorophosphate has become the mainstream as the electrolyte salt of lithium-ion batteries, while PF 5 Lithium hexafluorophosphate with excellent performance can be prepared as a raw material, making PF 5 The preparation of is more research and strategic. Domestic related PF 5 The research is almost blank, and a few companies produce commercial PF 5 All manufacturers adopt foreign technology. This has led to the fact that my country's lithium-ion batteries have been highly mono...

AI Technical Summary

Problems solved by technology

[0014] Solvents are used in the traditional preparation methods. Due to the inherent characteristics of the solvent method, the prepared products have high impurities and are difficult to separate and purify; while the indirect method prepares PF 5 The process is long, the process changes frequently, and many raw materials are used, which leads to the introduction of many impurities in the process; at the same time, the traditional preparation method requires high equipment requirements, which increases the production cost