Methods are provided for processing a lithium-containing material (e.g., a mineral like spodumene) whereby a lithium sulfate solution derived from the material is reacted with a primary reagent (e.g., Na.sub.2CO.sub.3 or NaOH) to produce a mixed solution of primary lithium product (e.g., Li.sub.2CO.sub.3 or LiOH) and Na.sub.2SO.sub.4. In addition to primary lithium product, a separated Na.sub.2SO.sub.4 solution is produced and converted to a byproduct (e.g., CaSO.sub.4, NaNO.sub.3, NaOH, H.sub.2SO.sub.4) by reaction with a salt chemical (e.g., Ca(NO.sub.3).sub.2) or alkali chemical (e.g., Ca(OH).sub.2), or by electrolysis or electrodialysis. Byproducts are re-used to reduce reagent inputs. Residual lithium in an output solution is reacted with a secondary reagent (e.g., CO.sub.2 from flue gas, or H.sub.3PO.sub.4) to produce secondary lithium products (e.g., Li.sub.2CO.sub.3 or Li.sub.3PO.sub.4), which may be re-used to reduce reagent inputs and increase lithium recovery.

The present disclosure relates to a method for extracting lithium from a lithium-containing material. For example, the method can comprise leaching a roasted lithium-containing material under conditions suitable to obtain an aqueous composition comprising a lithium compound such as lithium sulfate and/or lithium bisulfate. The aqueous composition comprising lithium sulfate and/or lithium bisulfate can optionally be used, for example, in a method for preparing lithium hydroxide comprising an electromembrane process. The roasted lithium-containing material can be prepared, for example by a method which uses an aqueous composition comprising optionally lithium sulfate and/or lithium bisulfate which can be obtained from a method for preparing lithium hydroxide comprising an electromembrane process such as a two-compartment monopolar or bipolar electrolysis process.

In some embodiments the application pertains to processes comprising reacting a component comprising an alkaline earth weak acid with a component comprising an acid to form a component comprising an alkaline earth acid anion and a component comprising a weak acid derivative. At least a portion of the component comprising the alkaline earth acid anion is reacted with a component comprising an alkali sulfate to form a component comprising alkaline earth sulfate and a component comprising an alkali acid anion. At least a portion of the component comprising alkaline earth sulfate is decomposed to form a component comprising alkaline earth oxide, or alkaline earth hydroxide, or alkaline earth carbonate, or alkaline earth sulfide, or a derivative thereof, or any combination thereof, and a component comprising sulfur dioxide, or oxygen, or sulfur trioxide, or a derivative thereof, or any combination thereof.

In some embodiments the application pertains to processes comprising reacting a component comprising an alkaline earth weak acid with a component comprising an acid to form a component comprising an alkaline earth acid anion and a component comprising a weak acid derivative. At least a portion of the component comprising the alkaline earth acid anion is reacted with a component comprising an alkali sulfate to form a component comprising alkaline earth sulfate and a component comprising an alkali acid anion. At least a portion of the component comprising alkaline earth sulfate is decomposed to form a component comprising alkaline earth oxide, or alkaline earth hydroxide, or alkaline earth carbonate, or alkaline earth sulfide, or a derivative thereof, or any combination thereof, and a component comprising sulfur dioxide, or oxygen, or sulfur trioxide, or a derivative thereof, or any combination thereof.

In some embodiments the application pertains to processes comprising reacting a component comprising an alkaline earth weak acid with a component comprising an acid to form a component comprising an alkaline earth acid anion and a component comprising a weak acid derivative. At least a portion of the component comprising the alkaline earth acid anion is reacted with a component comprising an alkali sulfate to form a component comprising alkaline earth sulfate and a component comprising an alkali acid anion. At least a portion of the component comprising alkaline earth sulfate is decomposed to form a component comprising alkaline earth oxide, or alkaline earth hydroxide, or alkaline earth carbonate, or alkaline earth sulfide, or a derivative thereof, or any combination thereof, and a component comprising sulfur dioxide, or oxygen, or sulfur trioxide, or a derivative thereof, or any combination thereof.

In some embodiments the application pertains to processes comprising reacting a component comprising an alkaline earth weak acid with a component comprising an acid to form a component comprising an alkaline earth acid anion and a component comprising a weak acid derivative. At least a portion of the component comprising the alkaline earth acid anion is reacted with a component comprising an alkali sulfate to form a component comprising alkaline earth sulfate and a component comprising an alkali acid anion. At least a portion of the component comprising alkaline earth sulfate is decomposed to form a component comprising alkaline earth oxide, or alkaline earth hydroxide, or alkaline earth carbonate, or alkaline earth sulfide, or a derivative thereof, or any combination thereof, and a component comprising sulfur dioxide, or oxygen, or sulfur trioxide, or a derivative thereof, or any combination thereof.

A process for battery chemical production, where a sodium sulfate stream is treated with an ion exchange process to provide potassium sulfate and sodium chloride. The sodium chloride may be treated with a chlor-alkali to produce sodium hydroxide for use upstream in the battery chemical production process.

A process for battery chemical production, where a sodium sulfate stream is treated with an ion exchange process to provide potassium sulfate and sodium chloride. The sodium chloride may be treated with a chlor-alkali to produce sodium hydroxide for use upstream in the battery chemical production process.