The LEDIDICO LTD aspect and direction, page-30

This is the traditional method of breaking down spodumene using heat then sulphuric acid then caustic soda.
The use of Oleic acid in the process is as "During processing, and following the removal of lithium, the pH or the residual material (tailings) is adjusted with the addition of sodium carbonate (Na2HCO3) to increase the pH to~ 8 and buffer the material before being deposited as a slurry in the tailings storage facilities. " Appendix C– Assessment of Acid and Metalliferous Drainage – Greenbushes Lithium Mine Expansion – 2018 Mining Proposal (GHD 2018) and Talison Leaching Study – Stage 2 AMD Testing Results (GHD 2019)