This work investigated the optimum parameters for the recovery of caesium alum (aluminium caesium sulphate dodecahydrate) from pollucite (caesium alumino silicate ore) obtained from Bikita in Zimbabwe by sulphuric acid leaching. The pollucite ore was characterized by AAS before leaching and after leaching. The mineralogical composition of the polucite ore before leaching was found to contain of the following phases: 17.17% aluminium oxide, 25.68% caesium oxide, 49.73% silica and less than 2% impurities of rubidium, potassium, sodium, lithium and iron. Batch optimisation studies were carried out to investigate the effects of process parameters namely leaching time and acid concentration at a constant temperature. -200 mesh size pollucite ore particles were digested in sulphuric acid at 100oC with a 30%-55% solution of sulphuric acid within a time frame of 1 – 6hs. Acid digestion was followed by hot water wash and vacuum filtration. Caesium alum was crystallized from the leach filtrate by stage cooling to room temperature. Optimum conditions to achieve 90% mass recovery of caesium alum with caesium content of 23% analysed by AAS after leaching were, leach time of 4h at 100oC and acid concentration of 40%. It is possible to economically recover caesium alum from Bikita pollucite ore by sulphuric acid leaching
Key words: pollucite, caesium alum, optimum,caesium, leaching.