Title:
METHOD FOR RECOVERING MONOVALENT METAL IONS
Document Type and Number:
WIPO Patent Application WO/2023/058548
Kind Code:
A1
Abstract:
To obtain a high-purity monovalent metal ion recovery solution at a high recovery rate using a nanofiltration membrane and a reverse osmosis membrane from a solution in which monovalent metal ions and polyvalent metal ions are contained, the present invention provides a method for recovering monovalent metal ions from a solution containing monovalent metal ions and polyvalent metal ions using a nanofiltration membrane unit and reverse osmosis membrane unit, the method comprising: (a) concentration multi-stage NF step for supplying a concentrate of an nth nanofiltration membrane unit to an (n+1)th nanofiltration membrane unit using first to Nth nanofiltration membrane units, where N is an integer constant equal to or greater than 2 and n is an integer equal to or greater than 1 and no greater than (N-1), thereby performing multi-stage nanofiltration in a concentration direction DNF; (b) an RO step for using the reverse osmosis membrane unit to obtain, from a permeate of the first nanofiltration membrane unit, an RO permeate and an RO concentrate containing a higher concentration of monovalent metal ions than the RO permeate; (c) an NF supply solution dilution step for mixing a permeate of the (n+1)th nanofiltration membrane unit with a supply solution of any nanofiltration membrane unit located upstream of the (n+1)th nanofiltration membrane unit; and (d) a step for mixing a permeate of the reverse osmosis membrane unit with a supply solution of the Nth nanofiltration membrane unit.
Inventors:
YOSHIDOMI SHINICHIRO (JP)
HANADA SHIGEHISA (JP)
KOIWA MASAKAZU (JP)
SOYA TAKANORI (JP)
OKAMOTO YOSHIKI (JP)
YOSHIZAKI TOMOYA (JP)
MIYAMOTO RYOMA (JP)
HANADA SHIGEHISA (JP)
KOIWA MASAKAZU (JP)
SOYA TAKANORI (JP)
OKAMOTO YOSHIKI (JP)
YOSHIZAKI TOMOYA (JP)
MIYAMOTO RYOMA (JP)
Application Number:
PCT/JP2022/036419
Publication Date:
April 13, 2023
Filing Date:
September 29, 2022
Export Citation:
Assignee:
TORAY INDUSTRIES (JP)
International Classes:
B01D61/02; B01D61/58; B01D63/10; B01D63/12; B01D69/02; C02F1/44; C22B3/22; C22B23/00; C22B26/12; C22B47/00
Domestic Patent References:
| WO2012077610A1 | 2012-06-14 |
Foreign References:
| JP2018176033A | 2018-11-15 | |||
| JP2016186118A | 2016-10-27 |
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