Abstract: A novel method of feed preparation for silicothermic process was proposed in order to solve low efficiency of heat transfer in Pidgeon process. In this method， dolomite and ferrosilicon were mixed to produce pellets and then were calcined. The pre-prepared pellets were charged into the retorts for Mg extraction at once after calcinations. Heat transfer in a retort for the novel process was investigated by a numerical method. The results show that a better heat transfer can be obtained by increasing the amount of Si-Fe addition， pellet diameter or decreasing the packed bed density. The time for heating the center of the retort into 1473K decreases from 300min to 178min， after increasing the boundary temperature from 1473K to 1498K. In a retort of 300mm diameter， the heating time is 90min for the center of the retort charged by pre-prepared pellets of 25mm diameter reaching 1473K， compared with that of 288min in Pidgeon process.

Key words: heat transfer in a retort, pre-prepared pellets, Pidgeon process, magnesium production