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US 6,143,260 AGranted
Method for removing magnesium from brine to yield lithium carbonate
AssigneeChemetall Foote Corporation
InventorDaniel A. Boryta
Life of this patent
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Abstract
A method for producing lithium carbonate by precipitating magnesium as the hydroxide from a brine concentrated to a lithium concentration of about 6%. Lithium is then precipitated from the brine by addition of recycled limed mother liquor from a previous lithium precipitation step.
Claims4
A process for recovering lithium carbonate from a brine containing lithium and magnesium comprising:
- (a) preparing a feed brine by concentrating a brine comprising lithium and magnesium ions to saturate the brine with magnesium chloride and lithium chloride and to precipitate LiCl.MgCl.sub.2.7H.sub.2 O;
- (b) adding Ca(OH).sub.2 to the mother liquor recycled from step (e) to yield limed mother liquor;
- (c) mixing the limed mother liquor with said feed brine while maintaining a pH of from 8.40 to 8.80 to precipitate the magnesium ions as magnesium hydroxide and to precipitate calcium carbonate,
- (d) recovering the brine from step (c) and adding a sufficient amount of sodium carbonate to precipitate lithium carbonate;
- (e) separating the precipitated lithium carbonate from the mother liquor;
- and
- (f) recycling the mother liquor produced in step (e) to step (b).
4 more elements
Dependencies are inferred from the claim text.