An Example of Negative Explosives: Magnesium Sulfate/Magnesium Mixture

Dr Takeo Shimizu


At the Eleventh International Pyrotechnics Seminar, 1986, in Vail, Colorado, I reported on a study of pyrotechnic mixtures with a theme, “A Concept and the Use of Negative Explosives”. A further study has been continued on the same subject as before. In the former report it was known that magnesium sulfate/magnesium mixture detonates on heating. I studied if it is suitable for the noise mixture of fireworks in place of the ordinary one which contains aluminum and potassium perchlorate and which has long been a cause of serious accidents in the firework industry. The chemical reaction of the magnesium sulfate/magnesium mixture on detonation is thought to be:

MgSO4 + 4 Mg → MgS + 4 MgO + 353 kcal.

From several experiments following results were obtained:

(1) The intensity of the explosive noise from the magnesium sulfate/magnesium mixture is almost the same as that from the ordinary aluminum mixture when the weight of the charge of the former is two or two and a half times as large as that of the latter.

(2) The magnesium sulfate/magnesium mixture is far safer on handling than the ordinary aluminum mixture. It was proved by an iron ball dropping test and a fire propagation test.

(3) The tone quality of the noise from the magnesium sulfate/magnesium mixture is mild and superior to that from the ordinary aluminum mixture.

(4) In practical use it is necessary to protect the noise unit which contains the magnesium sulfate/magnesium mixture from moisture.


Download/Purchase Options :

You must be logged in to purchase or download articles.

Comments are closed.