Process for the preparation of phosphorus pentafluoride

A method for the preparing phosphorus pentafluoride (PF5), the method comprising:

• (a) reacting phosphoric acid (H3PO4) with hydrogen fluoride (HF) to form a reaction mixture comprising phosphorus pentafluoride;
• (b) removing the phosphorus pentafluoride formed in process step (a) from the reaction mixture;
• and
• returning the hydrogen fluoride obtained in process step (b) to process step (a) until the hydrogen fluoride formed in process step (a) has a water content of at most 5% by weight based on the hydrogen fluoride containing water, and/or treating the hydrogen fluoride containing water obtained in process step (b).