Abstract: A method for obtaining high-purity phosphorus pentafluoride (PF5), which is industrially useful in the fields of semiconductors and batteries, from PF5 containing a gas mixture of HCl, HF, and so on. Specifically, provided is a process for purifying phosphorus pentafluoride including (1) an immobilization step in which phosphorus pentafluoride containing a mixture is brought into contact with a metal fluoride (MFn; M is an n-valent metal) having a specific surface area of 1.0 m2/g or more at 40° to 150° C. to immobilize phosphorus pentafluoride in the form of a hexafluorophosphate (M(PF6)n), (2) a separation step in which the mixture remaining in the gas phase is expelled out of the reaction system to separate the mixture from the hexafluorophosphate, and (3) a heat-decomposition step in which the hexafluorophosphate freed of the mixture is heated at 150° to 400° C. under a pressure of ?0.1 to 0.1 MPa·G to give phosphorus pentafluoride.

Abstract: A method for obtaining high-purity phosphorus pentafluoride (PF5), which is industrially useful in the fields of semiconductors and batteries, from PF5 containing a gas mixture of HCl, HF, and so on. Specifically, provided is a process for purifying phosphorus pentafluoride including (1) an immobilization step in which phosphorus pentafluoride containing a mixture is brought into contact with a metal fluoride (MFn; M is an n-valent metal) having a specific surface area of 1.0 m2/g or more at 40° to 150° C. to immobilize phosphorus pentafluoride in the form of a hexafluorophosphate (M(PF6)n), (2) a separation step in which the mixture remaining in the gas phase is expelled out of the reaction system to separate the mixture from the hexafluorophosphate, and (3) a heat-decomposition step in which the hexafluorophosphate freed of the mixture is heated at 150° to 400° C. under a pressure of ?0.1 to 0.1 MPa·G to give phosphorus pentafluoride.

Abstract: A treatment process of PF5 including an absorption step for inducing absorption of PF5 by an acidic solution containing an acid to obtain a solution containing PF5A?, an adjustment step to adjust concentration of HCl in the solution, and a thermolysis step for heating the solution containing PF5A? ions obtained in the absorption step or the adjustment step to decompose the solution to an acidic mixture containing H3PO4 and HF.