Interestingly this process can also use PLS as a feedstock.
'The benefits of the Outotec Lithium Hydroxide Process when compared to traditional methods (sulfuric acid roasting, caustic conversion process) include:
• Acid and sulphate-free process
• Inert and neutral mineral residue
• Produces battery-grade LiOH·H2O
• Simple process with fast throughput'
https://www.mogroup.com/insights/blog/mining-and-metals/the-outotec-lithium-hydroxide-process--a-novel-direct-leach-process-for-producing-battery-grade-lithium-hydroxide-from-spodumene/