KINETIC-STUDY OF THE DEHYDRATION OF LITHIUM-SULFATE MONOHYDRATE

The dehydration of lithium sulphate monohydrate has been studied by is othermal thermogravimetry at 80 degrees C, under various partial press ures in water vapour. The kinetic curves are sigmoid, they are interpr eted with a model involving nucleation and growth steps: the nucleatio n is supposed to occur at the surface of the grains and is followed by a rapid two-dimensional growth, the new phase developing towards the centre of the grains. The studied powder being composed of ellipsoidal particles, this geometry is taken into account in the model.