(19)
(11) EP 0 555 996 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
15.12.1993 Bulletin 1993/50

(43) Date of publication A2:
18.08.1993 Bulletin 1993/33

(21) Application number: 93300841.9

(22) Date of filing: 04.02.1993
(51) International Patent Classification (IPC)5: G21F 9/10, G21F 9/06
(84) Designated Contracting States:
FR GB

(30) Priority: 10.02.1992 JP 23733/92

(71) Applicant: HITACHI, LTD.
Chiyoda-ku, Tokyo 101 (JP)

(72) Inventors:
  • Fukasawa, Tetsuo
    Hitachi-shi, Ibaraki 316 (JP)
  • Chino, Koichi
    Hitachi-shi, Ibaraki 316 (JP)
  • Matsuda, Masami
    Hitachi-shi, Ibaraki 316 (JP)
  • Baba, Tsutomu
    Hitachi-shi, Ibaraki 316 (JP)
  • Sasahira, Akira
    Hitachi-shi, Ibaraki 316 (JP)
  • Nakamura, Tomotaka
    Hitachi-shi, Ibaraki 316 (JP)

(74) Representative: Stoner, Gerard Patrick et al
MEWBURN ELLIS York House 23 Kingsway
London WC2B 6HP
London WC2B 6HP (GB)


(56) References cited: : 
   
       


    (54) Methods and apparatus for treating aqueous indutrial effluent


    (57) Aqueous industrial effluent containing dissolved species which it is desired to separate from the effluent, such as valuable, poisonous or radioactive metal ions, is treated preliminarily to release gas which is, or is derived from, secondary dissolved species which tend to stabilise the desired species in solution in the effluent. The effectiveness of a subsequent separation treatment for the desired species, such as coprecipitation, ion exchange, adsorption or solvent extraction, is thereby increased.





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