Separation of rare earth metals using a cation exchanger
AssigneeAsahi Kasei Kogyo Kabushiki Kaisha
InventorsTetsuya Miyake, Kunihiko Takeda, Hatsuki Onitsuka, Kazuo Okuyama, Yasuki Shimamura
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Abstract
A process for the separation of one rare earth metal from another in a mixture of rare earth metals by chromatographic displacement using a complexing agent and a cation exchanger, which process comprises using a cation exchanger having a micro-void volume void ratio of 0.5 to 0.95, preferably 0.5 to 0.88.
Claims10
In a process for the separation of one rare earth metal from another in a mixture of rare earth metals by passing a retaining agent solution through a bed of a cation exchanger to convert the cation exchanger into that of a retaining agent type, passing a solution of the mixture through the cation exchanger to form a rare earth metal adsorption zone on the bed of the cation exchanger, passing a complexing agent solution through the cation exchanger to effect migration of the rare earth metal adsorption zone through the bed of the cation exchanger and separating a fraction of one of the rare earth metals, the improvement which comprises using as the cation exchanger a cation exchanger having a micro-void volume ratio of 0.58 to 0.95 and a degree of crosslinking of 8 to 17 or having a micro-void volume ratio of 0.50 to 0.95 and a degree of crosslinking of 17 to 80 and passing the materials through the cation exchanger at a rate such that the migration velocity of the rare earth metal adsorption zone through the cation exchanger is from about 5 m per day to about 500 m per day.
In a process for the separation of one rare earth metal from another in a mixture of rare earth metals by passing a retaining agent solution through a bed of a cation exchanger to convert the cation exchanger into that of a retaining agent type, passing a solution of the mixture through the cation exchanger to form a rare earth metal adsorption zone on the bed of the cation exchanger, passing a complexing agent solution through the cation exchanger to effect migration of the rare earth metal adsorption zone through the bed of the cation exchanger and separating a fraction of one of the rare earth metals, the improvement which comprises using as the cation exchanger a cation exchanger having a micro-void volume ratio of 0.50 to 0.95 and a degree of crosslinking of 17 to 80 and passing the materials through the cation exchanger at a rate such that the migration velocity of the rare earth metal adsorption zone through the cation exchanger is from about 5 m per day to about 500 m per day.
Dependencies are inferred from the claim text.