Title:
METHOD FOR PURIFYING CRYSTALLINE SUBSTANCE
Document Type and Number:
WIPO Patent Application WO/1997/024303
Kind Code:
A1
Abstract:
A method for efficiently purifying a particular substance contained in a raw material mixture, comprising the steps of: (1) subjecting the raw material mixture in a liquid form or a slurry form wherein part of the particular substance has crystallized to crystallization under high pressure to precipitate crystals and settle them in a pressure vessel; (2) lowering the pressure in the pressure vessel to entirely or mostly dissolve the settled crystals, thereby forming a liquid phase or a slurry having a high concentration of the particular substance in the lower part of the pressure vessel; and then (3) enhancing the pressure in the pressure vessel to crystallize the particular substance in the lower part, followed by discharge of the mother liquor out of the pressure vessel.
Inventors:
NAGAOKA KOICHI (JP)
YAMAMOTO KOJI (JP)
MORIYA KEIKO (JP)
YAMAMOTO KOJI (JP)
MORIYA KEIKO (JP)
Application Number:
PCT/JP1996/003669
Publication Date:
July 10, 1997
Filing Date:
December 17, 1996
Export Citation:
Assignee:
KOBE STEEL LTD (JP)
NAGAOKA KOICHI (JP)
YAMAMOTO KOJI (JP)
MORIYA KEIKO (JP)
NAGAOKA KOICHI (JP)
YAMAMOTO KOJI (JP)
MORIYA KEIKO (JP)
International Classes:
B01D9/02; B01J3/00; C07B63/00; C07C7/14; C07C15/24; (IPC1-7): C07B63/00; B01D9/02; C07C7/14; C07C15/24
Foreign References:
| JPH02214503A | 1990-08-27 | |||
| JPS61157304A | 1986-07-17 | |||
| JPH01250329A | 1989-10-05 |
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