C laim:
1 . Process for the recovery of lithium from lithium- and aluminum-bearing metallurgical
composition, comprising the steps of:
- Leaching the metallurgical composition by contacting with a sulfuric acid aqueous solution at a pH of 3 or less, thereby obtaining a residue comprising insoluble compounds, and a first leachate comprising lithium and aluminum;
- Optionally neutralizing the first leachate comprising lithium and aluminum to a pH of 2 to 4, thereby precipitating a residue comprising a first part of the aluminum, and obtaining a second leachate comprising lithium;
- Adding a source of phosphate ions to the first leachate comprising lithium and aluminum, or, with the proviso that the optional neutralizing of the first leachate is performed, to the second leachate comprising lithium and aluminum, thereby precipitating a residue comprising a second part of the aluminum, and obtaining a third leachate comprising lithium;
- Optionally neutralizing the third leachate comprising lithium and aluminum to a pH of 3 to 4, thereby precipitating a residue comprising a third part of the aluminum, and obtaining a fourth leachate comprising lithium; and,
-Separating the residue comprising the second part of the aluminum from the third leachate by filtration, or, with the proviso that the optional neutralizing of the third leachate is performed, separating the residue comprising the third part of the aluminum from the fourth leachate by filtration.
2 . Process according to 1 , wherein, after the step of leaching and before the step of adding a source
of phosphate, the first leachate comprising lithium and aluminum is separated by filtration.
3. Process according to claims 1 or 2, wherein, after the optional step of neutralizing the first
leachate and before the step of adding a source of phosphate, the second leachate comprising lithium and aluminum is separated by filtration.
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4. Process according to any one of claims 1 to 3, wherein lithium is precipitated from the fourth leachate, and separated by filtration.
5. Process according to any one of claims 1 to 4, wherein the metallurgical composition is a metallurgical slag.

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