A total of 2.3 kg of PuF4 was fluorinated to PuF6 with elemental fluorine in a fluidized bed of alumina in three campaigns, each consisting of three separate fluorination runs followed by a fluorination-cleanup step in which any plutonium deposited in the lines and equipment was recovered. Each run involved 260 g of −325 mesh PuF4 powder; a single ∼6.5-kg bed of nominal 48–100 mesh alumina was used in each campaign. A 93% F2-7% N2 gas mixture, which was recycled, served as the fluidizing gas and reactant. The temperature of the fluidized alumina bed was increased incrementally to 550°C, and the total fluorination time for each run was 3 to 5 h. The PuF6 was collected in traps at ∼−65°C and subsequently was sorbed on NaF. Plutonium material balances were 97, 101, and 99%. Average production rates of PuF6 were 2.4 to 4.1 lb PuF6/(h ft2) but rates >6 lb PuF6/(h ft2) were attained in initial 30-min fluorination periods. Fluorine utilization efficiency (the ratio of fluorine reacted to that which could theoretically react based on equilibrium considerations) averaged 22, 17, and 28% although efficiencies near 100% were calculated for the earlier portions of a run, when large quantities of plutonium were present. Over 96% of the plutonium charged was recovered as PuF6 while ½% was discarded as waste in the alumina bed of the fluorinator. Less than 2% of the PuF6 was decomposed to PuF4 by radiation, and this was refluorinated and recovered without difficulty.