Abstract: The present invention is directed to an improved reaction process that allows for the achievement of excellent NF3 production yields, while minimizing the amount of unreacted fluorine exiting with the process gases and minimizing the amount of liquid melt waste (HF/NH3) produced by the process. The basic NF3 process resides in reacting F2 with an ammonium ion source, e.g., ammonium acid fluoride, under conditions for forming NF3. The improvement in the process comprises: introducing F2 and said ammonium ion source cocurrently and downflow through a packed column or monolith column at a first temperature; reacting said F2 and ammonium ion source in said column; and, removing a mixture of NF3 and byproducts from said column at a second temperature higher than said first temperature.