METHOD FOR PURIFYING PHOSPHORUS PENTAFLUORIDE

摘要

The present invention provides a method for producing high-purity phosphorus pentafluoride (PF5), which is an industrially useful material in the fields of semiconductors and batteries, from PF5 containing a gas mixture of HCl, HF and the like. Specifically provided is a method for purifying phosphorus pentafluoride (PF5), which comprises: (1) an immobilization step of bringing phosphorus pentafluoride (PF5) containing a mixture into contact with a metal fluoride (MFn) having a specific surface area of 1.0 m2/g or more at 40 to 150ºC to immobilize phosphorus pentafluoride in the form of a hexafluorophosphate salt (M(PF6)n, M represents a n-valent metal); (2) a mixture separation step of discharging the mixture remaining in a gas phase part to the outside of the system to separate the mixture from the hexafluorophosphate salt; and (3) a heating/decomposition step of heating the hexafluorophosphate salt from which the mixture has been separated at 150 to 400ºC to produce phosphorus pentafluoride under a pressure of -0.1 to +0.1 MPa·G inclusive.