Process for the in situ recovery of chemical values from UF 6 gaseous diffusion process equipment
First Claim
1. A process for the recovery of uranium and nickel values from one or more items of process equipment theretofore employed in a uranium hexafluoride isotope enrichment gaseous diffusion plant employing the steps ofconditioning an item of process equipment to ensure its freedom from undesirable chemical values,subjecting said conditioned item of process equipment to a quantity of a gaseous fluorinating agent that is capable of converting at least uranium oxide and/or uranyl fluoride to gaseous uranium hexafluoride at a temperature not greater than about 65°
- C., and at subatmospheric pressure, for a time sufficient to convert at least uranium compounds disposed on the surfaces of the item of process equipment to gaseous uranium hexafluoride,withdrawing and capturing said uranium hexafluoride,thereafter, subjecting said item of process equipment to a mixture of gaseous carbon monoxide and a gaseous promoter, at subatmospheric pressure and at a temperature less than the temperature at which nickel carbonyl decomposes when at a subatmospheric pressure, for a time sufficient to convert metallic nickel exposed on the surfaces of the item of process equipment to gaseous nickel carbonyl,withdrawing said gaseous nickel carbonyl, andconverting said gaseous nickel carbonyl to metallic nickel.
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Accused Products
Abstract
A process for the recovery of chemical values, particularly uranium, nickel and/or radionuclides from process equipment theretofore employed in a uranium hexafluoride isotope enrichment cascade. Preferably, the process is carried out, in situ, at subatmospheric pressure employing the existing process equipment from which the chemical values are to be recovered. In one aspect, the process includes recovery of uranium values employing a gaseous fluorinating agent at subatmospheric pressure, followed by recovery of nickel values employing a gaseous reactant comprising a mixture of carbon monoxide and a promoter, preferably hydrogen sulfide and at subatmospheric pressure.
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Citations
35 Claims
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1. A process for the recovery of uranium and nickel values from one or more items of process equipment theretofore employed in a uranium hexafluoride isotope enrichment gaseous diffusion plant employing the steps of
conditioning an item of process equipment to ensure its freedom from undesirable chemical values, subjecting said conditioned item of process equipment to a quantity of a gaseous fluorinating agent that is capable of converting at least uranium oxide and/or uranyl fluoride to gaseous uranium hexafluoride at a temperature not greater than about 65° - C., and at subatmospheric pressure, for a time sufficient to convert at least uranium compounds disposed on the surfaces of the item of process equipment to gaseous uranium hexafluoride,
withdrawing and capturing said uranium hexafluoride, thereafter, subjecting said item of process equipment to a mixture of gaseous carbon monoxide and a gaseous promoter, at subatmospheric pressure and at a temperature less than the temperature at which nickel carbonyl decomposes when at a subatmospheric pressure, for a time sufficient to convert metallic nickel exposed on the surfaces of the item of process equipment to gaseous nickel carbonyl, withdrawing said gaseous nickel carbonyl, and converting said gaseous nickel carbonyl to metallic nickel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 35)
- C., and at subatmospheric pressure, for a time sufficient to convert at least uranium compounds disposed on the surfaces of the item of process equipment to gaseous uranium hexafluoride,
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18. A process for the recovery of metallic nickel from an item having metallic nickel exposed on the surface thereof comprising
disposing the item having metallic nickel exposed on the surface thereof in a closed reaction vessel, circulating through the reaction vessel a mixture of gaseous carbon monoxide and a gaseous promoter, at subatmospheric pressure and at a temperature less than the temperature at which nickel carbonyl decomposes, to convert the nickel exposed on the surface of the item to gaseous nickel carbonyl to develop a flowing gas stream containing carbon monoxide, gaseous promoter and nickel carbonyl, continuously withdrawing at least a portion of the flowing gas stream from the reaction vessel, and continuously converting at least a portion of the nickel carbonyl in the flowing gas stream which is withdrawn from the vessel to metallic nickel.
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23. A process for the in situ recovery of uranium and nickel values from one or more items of process equipment theretofore employed in a uranium hexafluoride isotope enrichment gaseous diffusion plant employing the steps of
conditioning an item of process equipment in situ to ensure its freedom from undesirable chemical values, subjecting said conditioned item of process equipment to a quantity of a gaseous fluorinating agent that is capable of converting uranium oxide and/or uranyl fluoride to gaseous uranium hexafluoride at a temperature not greater than about 65° - C., and at subatmospheric pressure, for a time sufficient to convert uranium compounds disposed on the surfaces of the item of process equipment to gaseous uranium hexafluoride,
withdrawing and capturing said uranium hexafluoride, thereafter, subjecting said item of process equipment to a quantity of a mixture of gaseous carbon monoxide and a gaseous promoter, at subatmospheric pressure, and a temperature less than the temperature at which nickel carbonyl decomposes, for a time sufficient to convert metallic nickel exposed on the outer surfaces of the item of process equipment to gaseous nickel carbonyl, withdrawing said gaseous nickel carbonyl, and converting said gaseous nickel carbonyl to metallic nickel. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
- C., and at subatmospheric pressure, for a time sufficient to convert uranium compounds disposed on the surfaces of the item of process equipment to gaseous uranium hexafluoride,
Specification