Coating of magnesium powder by rapid expansion of supercritical solution method
(School of Chemical and Environmental Engineering, North University of China, Taiyuan 030051, China)
Abstract: In order to solve the reserve stability problem of pyrotechnic explosives containing magnesium powder, a coating method named rapid expansion of supercritical fluid is studied. Continuous coating film of paraffin can be formed on the surface of magnesium powder when paraffin content is about 1.5%. Humidity resistance property of the coated magnesium is promoted obviously. The flame sensitivity of the coated magnesium is 4.8% lower than that of the original magnesium powder after mixed with oxidant. The burning velocity of the coated magnesium is 4.7% lower than that of the contrastive sample. This method may be used to enhance the reserve stability problem of pyrotechnic explosives and the safety of magnesium powder modifying process.
Key words: magnesium powder; coating; supercritical fluid; pyrotechnic explosive