A drowning-out crystallization process was designed to produce purified lithium oxide monohydrate. The study started with the development of the ternary phase diagram for the LiOH - water-ethanol system. This was followed by process conceptualization integrating crystallization, downstream processing and solvent recovery. LiOH - H2O Crystals with a mean size between 0.3mm and 0.4mm depending on the operating conditions and compositions were obtained. Keywords: