US 11,697,861 B2 · Processes for preparing lithium carbonate

Abstract

There are provided processes comprising submitting an aqueous composition comprising lithium sulphate and/or bisulfate to an electrolysis or an electrodialysis for converting at least a portion of said sulphate into lithium hydroxide. During electrolysis or electrodialysis, the aqueous composition is at least substantially maintained at a pH having a value of about 1 to about 4; and converting said lithium hydroxide into lithium carbonate. Alternatively, lithium sulfate and/or lithium bisulfate can be submitted to a first electromembrane process that comprises a two-compartment membrane process for conversion of lithium sulfate and/or lithium bisulfate to lithium hydroxide, and obtaining a first lithium-reduced aqueous stream and a first lithium hydroxide-enriched aqueous stream; and submitting said first lithium-reduced aqueous stream to a second electromembrane process comprising a three-compartment membrane process to prepare at least a further portion of lithium hydroxide and obtaining a second lithium-reduced aqueous stream and a second lithium-hydroxide enriched aqueous stream.

Claims10

Dependent claims

A process for preparing lithium carbonate, 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;
and
converting said lithium hydroxide into lithium carbonate by reacting said lithium hydroxide with carbon dioxide;
wherein said electrolysis is a monopolar membrane electrolysis process,
wherein said process is carried out in a three-compartment electrolysis cell comprising a central compartment, a cathodic compartment, and an anodic compartment, the cathodic compartment being separated from the central compartment by a cation exchange membrane, and the anodic compartment being separated from the central compartment by an anion exchange membrane, and
wherein said process is carried out_by introducing said aqueous composition comprising said lithium sulphate into the central compartment, an aqueous composition comprising lithium hydroxide into the cathodic compartment, and an aqueous composition comprising NH3 into the anodic compartment.

3 more elements

Dependencies are inferred from the claim text.

Processes for preparing lithium carbonate

Life of this patent

Processes for preparing lithium carbonate

Life of this patent

Abstract

Claims10