Abstract: Using 20 L cylindrical explosion vessel, the effect of different ignition delay time and mass concentration on explosion characteristics of magnesium powder was studied. The results showed that: when the mass concentration of magnesium dust cloud is lower than 200 g/m3, pmax and (dp/dt)max gradually decrease with the increase of ignition delay time; when the mass concentration is greater than 200 g/m3, pmax and (dp/dt)max increase first and then decrease; when the concentration of magnesium dust is high, the effect of ignition delay time on pmax is much less than that of low mass concentration. When the mass concentration of magnesium powder is low, the best ignition delay time increases with the increase of mass concentration; when the mass concentration of magnesium powder is more than 450 g/m3, the best ignition delay time is 60 ms. Under the condition of the same mass concentration of magnesium powder, with the increase of ignition delay time, the curve of explosion impulse presents a zigzag trend; under the same ignition delay time, the higher the mass concentration of magnesium powder is, the greater the explosion impulse will be.

Key words: magnesium powder, mass concentration, ignition delay time, explosive characteristics