Abstract: Based on the introduction to the basic theory of flash-wind magnetizing roaster，the influences of mineral particles' initial velocity，and gas flow velocity，particles' diameters and other factors on the motion law were investigated from the angle of the sport dynamics，where the single mineral particle in the vertical pipe of furnace was considered as the research target.Then，the movement law of mineral particle groups was derived，and the basic principles of the determination of terminal velocity of particle settling，the wind-cone design and the air flow control were proposed during the design process of the flash-wind roaster.

Key words: Flash-wind magnetizing roasting, Motion law, Terminal velocity of particle settling