Extended ion exchange process for removal and recovery of technetium from soluble waste

A well-established method of separation of /sup 99/Tc from soluble waste is sorption of pertechnetate ion, TcO/sub 4//sup -/, onto a strong base anion exchange resin such as Dowex 1x8. Pertechnetate ion can then be removed from the resin by elution with 4M HNO/sub 3/. An improved ion exchange method which encompasses removal and recovery of /sup 99/Tc from defense waste supernate has been demonstrated. The introduction of a second ion exchange step using a weak base resin allows for the reclamation and recycling of large volumes of nitric acid generated in the initial collection of TcO/sub 4//sup -/ on the strong base resin. Also, the total amount of waste NaNO/sub 3/ which is added to the system in the process of removing /sup 99/Tc from the supernate is significantly reduced from 8% to 1%. /sup 99/Tc can be recovered from solution by precipitation as Tc/sub 2/S/sub 7/ with sulfide or as TcO/sub 2/ following reduction with aluminum or zinc amalgam, affording the ultimate recovery of the pure metal.