Methods for treating lithium-containing materials

A method for preparing lithium hydroxide, said method comprising:

• mixing a lithium-containing material with an acidic aqueous composition comprising sulfuric acid and optionally comprising lithium sulfate and thereby obtaining a mixture;
• roasting said mixture to obtain a roasted, lithium-containing material;
• leaching said roasted material to obtain a first aqueous composition comprising lithium sulfate;
• submitting said first aqueous composition comprising lithium sulfate to an electromembrane process to at least partially convert said lithium sulfate into lithium hydroxide and to obtain a second aqueous composition comprising lithium sulfate and sulfuric acid;
• increasing concentration of sulfuric acid in said second aqueous composition by removing water from said second aqueous composition;
• recovering lithium sulfate from said second aqueous composition thereby obtaining an aqueous composition reduced in lithium sulfate;
• reusing said recovered lithium sulfate in said electromembrane process;
• and
• using said aqueous composition reduced in lithium sulfate as said acidic aqueous composition comprising sulfuric acid and optionally comprising lithium sulfate for mixing with said lithium-containing material and to obtain said mixture.