Abstract: The digestion behavior of alumina from the hydrargillite by the mechanical activation digestion method was investigated.The effects of the mechanical activation stirring speed， digestion temperature and time on the digestion performance of the hydrargillite were examined， and the transformation rules of the process control procedures were also discussed. The results indicated that the mechanical activation effectively reduced the digestion temperature and time of the hydrargillite， and also relaxed the range of raw material sizes. The actual digestion rate of alumina from the hydrargillite reached over 85% under the conditions with digestion temperature of 150℃， the digestion time of 40min， the stirring speed of 100r/min， the ball addition ratio of 30% and the mass ratio of balls to the hydrargillite of 1.2∶1. The mechanical activation can greatly reduce the effect of diffusion control on digestion processes of the hydrargillite.

Key words: mechanical activation, hydrargillite, digestion performance, kinetics, control step