Abstract:Enrichment mechanism of lithium in Bayer Process of alumina production was studied. The results show that 80% of lithium in bauxite first flows into sodium aluminate solution in form of lithium aluminate during pressure digestion, and then goes into crystallized aluminium hydroxide during seed precipitation. 25% of lithium aluminate loss occurs in sublimation, and the rest lithium is enriched in alumina in form of oxide. Lithium in alumina rises with increase of lithium concentration in bauxite, and drops with decrease of A/S of bauxite.