| 摘要 |
PURPOSE:To stably separate high purity Eu in a high yield by bringing a cation exchange soln. contg. extracted zinc into contact with an aqueous inorg. acid soln. contg. bivalent Eu and other tervalent rare earth element to separate an Eu-rich aqueous phase and by oxidizing the aqueous phase so as to take out the Eu as tervalent Eu. CONSTITUTION:A SOLVESSO(R) soln. 11 contg. naphthenic acid and an aqueous ammonia soln. 12 are fed to a zinc extractor 1 and brought into countercurrent contact with water 13 contg. zinc to obtain a cation exchange soln. contg. zinc and this soln. is degassed with gaseous N2. An aqueous soln. contg. tervalent Eu and tervalent Sm is degassed with gaseous N2 and reduced with zinc powder. The resulting aqueous inorg. acid soln. contg. bivalent Eu, tervalent Sm and zinc is introduced into a separator 2 through a zinc recovering unit 3. In the separator 2, the cation exchange soln. contg. zinc is brought into contact with the aqueous inorg. acid soln. to take out an Eu-rich aqueous phase 18 and this aqueous phase 18 is air-oxidized in a reactor 5, introduced into a zinc separator 6 and brought into countercurrent contact with a cation exchange soln. to obtain a tervalent Eu-rich aqueous phase 27. This aqueous phase 27 is introduced into an Eu back-extractor 7. Thus, Eu can be separated efficiently and stably.
|
