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US 11,078,583 B2Granted
Processes for preparing lithium hydroxide
AssigneeNemaska Lithium Inc.
InventorsJean-François Magnan, Guy Bourassa, Gary Pearse, Peter Symons, J. David Genders
Life of this patent
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Abstract
There are provided processes for preparing lithium hydroxide that comprise submitting an aqueous composition comprising a lithium compound to an electrolysis or an electrodialysis under conditions suitable for converting at least a portion of the lithium compound into lithium hydroxide. For example, the lithium compound can be lithium sulphate and the aqueous composition can be at least substantially maintained at a pH having a value of about 1 to about 4.
Claims18
A process for preparing lithium hydroxide, said process comprising:
- submitting an aqueous composition comprising lithium sulphate to an electrolysis under conditions suitable for converting at least a portion of said lithium sulphate into lithium hydroxide;
- wherein during said electrolysis, said aqueous composition comprising lithium sulphate is at least substantially maintained at a pH having a value of about 1 to about 4;
- wherein said aqueous composition comprising lithium sulphate is prepared by a process comprising:
- leaching an acid roasted lithium-containing material with water so as to obtain an aqueous composition comprising Li+ and at least one metal ion, wherein said lithium-containing material is a material that has been previously reacted with H2SO4;
- reacting said aqueous composition comprising Li+ and said at least one metal ion with a base so as to obtain a pH of about 4.5 to about 6.5 and thereby at least partially precipitating said at least one metal ion under the form of at least one hydroxide so as to obtain a precipitate comprising said at least one hydroxide and an aqueous composition comprising Li+ and having a reduced content of said at least one metal ion, and separating said aqueous composition from said precipitate comprising said at least one hydroxide;
- reacting said aqueous composition comprising Li+and having said reduced content of said at least one metal ion with another base so as to obtain a pH of about 9.5 to about 11.5, thereby at least partially precipitating at least one metal ion so as to obtain a precipitate and an aqueous composition comprising Li+and having a reduced content of said at least one metal ion;
- seperating said aqueous composition from said precipitate;
- and
- contacting said aqueous composition comprising Li+ and having said reduced content of said at least one metal ion with an ion-exchange resin so as to at least partially remove at least one metal ion from said composition, thereby obtaining said aqueous composition comprising lithium sulphate.
6 more elements
A process for preparing lithium hydroxide, said process comprising:
- submitting an aqueous composition comprising a lithium compound to an electrolysis under conditions suitable for converting at least a portion of said lithium compound into lithium hydroxide;
- wherein during said electrolysis, said aqueous composition comprising said lithium compound is at least substantially maintained at a pH having a value of about 1 to about 4;
- wherein said aqueous composition comprising said lithium compound is prepared by a process comprising:
- leaching an acid roasted lithium-containing material with water so as to obtain an aqueous composition comprising Li+ and at least one metal ion;
- reacting said aqueous composition comprising Li+ and said at least one metal ion with a base so as to obtain a pH of about 4.5 to about 6.5 and thereby at least partially precipitating said at least one metal ion under the form of at least one hydroxide so as to obtain a precipitate comprising said at least one hydroxide and an aqueous composition comprising Li+ and having a reduced content of said at least one metal ion, and separating said aqueous composition from said precipitate comprising said at least one hydroxide;
- reacting said aqueous composition comprising Li+and having said reduced content of said at least one metal ion with another base so as to obtain a pH of about 9.5 to about 11.5, thereby at least partially precipitating at least one metal ion so as to obtain a precipitate and an aqueous composition comprising Li+and having a reduced content of said at least one metal ion;
- separating said aqueous composition from said precipitate;
- and
- contacting said aqueous composition comprising Li+ and having said reduced content of said at least one metal ion with an ion exchange resin so as to at least partially remove at least one metal ion from said composition, thereby obtaining said aqueous composition comprising said lithium compound.
6 more elements
Dependencies are inferred from the claim text.