Process for reducing fouling in evaporators in lithium hydroxide recovery
AssigneeVeolia Water Technologies, Inc.
InventorsThomas Anthony Pecoraro, Katie A. Winn, David E. Gamache
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Abstract
A method of concentrating and/or producing lithium hydroxide in an evaporator entails feeding a stream comprising lithium, hydroxide and carbonate to the evaporator. In the evaporator, the feed is concentrated to form lithium hydroxide and lithium carbonate crystals. Further, the method entails reducing the tendency of lithium carbonate to scale the evaporator by increasing the concentration of lithium carbonate crystals in the evaporator by: (1) clarifying at least a portion of the concentrate in the evaporator to form a clarified solution; and (2) discharging the clarified solution as a clarified solution stream from the evaporator.
Claims11
A method of concentrating lithium hydroxide in an evaporator, and at the same time, reducing the tendency for lithium carbonate to scale the evaporator, comprising:
- (A) directing a feed comprising lithium, hydroxide, and carbonate to the evaporator;
- (B) concentrating the feed in the evaporator to produce a concentrate including lithium hydroxide, and lithium carbonate crystals;
- (C) reducing the tendency for lithium carbonate to scale the evaporator by increasing the concentration of lithium carbonate crystals in the evaporator by:
- (i) clarifying at least a portion of the concentrate in the evaporator to form a clarified solution;
- and
- (ii) discharging the clarified solution as a clarified solution stream from the evaporator.
A method of producing lithium hydroxide monohydrate crystals in a system comprising an evaporator and a crystallizer arranged in series, and reducing the tendency of lithium carbonate to scale the evaporator, the method comprising:
- (A) directing a feed comprising lithium, hydroxide, and carbonate to the evaporator;
- (B) concentrating the feed in the evaporator to produce a concentrate including lithium hydroxide, and lithium carbonate crystals;
- (C) reducing the tendency for lithium carbonate to scale the evaporator by increasing the concentration of lithium carbonate crystals in the evaporator by:
- (i) clarifying at least a portion of the concentrate in the evaporator to form a clarified solution;
- (ii) discharging the clarified solution as a clarified solution stream from the evaporator;
- (D) separately discharging a portion of said concentrate from the evaporator as a slurry stream;
- (E) directing the clarified solution stream and the slurry stream from the evaporator to the crystallizer where the clarified solution stream and the slurry stream form a lithium hydroxide solution in the crystallizer;
- (F) circulating the lithium hydroxide solution through the crystallizer and concentrating the lithium hydroxide solution;
- (G) employing the crystallizer to form the lithium hydroxide monohydrate crystals and lithium carbonate crystals in the crystallizer;
- and
- (H) separating the lithium hydroxide monohydrate crystals from the lithium carbonate crystals.
Dependencies are inferred from the claim text.