After potassium nitrate, barium nitrate, and potassium perchlorate, ammonium perchlorate should be the fourth largest oxidizer for fireworks, but because it is easier to absorb moisture than the three major oxidizers, it is only used in some specific effects. For a long time, there has been a little misunderstanding about the nature of ammonium perchlorate. In this paper, the analysis of its physical and chemical properties is intended to update the understanding of ammonium perchlorate.
Ammonium perchlorate does not absorb moisture because of the reaction
Some people believe that the reason why ammonium perchlorate absorbs moisture is because it reacts with potassium nitrate to produce ammonium nitrate, which is very easy to absorb moisture. Mr. Takeo Shimizu also mentioned in the "Fireworks Principle and Practice" that the reaction equation is as follows: KNO3+NH4ClO4→KClO4↓+NH4NO3 This reaction occurs because potassium perchlorate is slightly soluble in solution, which can be regarded as precipitation, and the compound decomposition reaction proceeds in the forward direction, resulting in the following reaction. That's right.
However, in fireworks and medicine, the water content between the powder and the powder is mostly less than one percent, so the ions present in the aqueous solution are almost negligible, so this reaction is almost not carried out.
At the same time, the reaction of ammonium perchlorate with nitrate also produces ammonium nitrate, which makes no sense at all: Ba(NO3)2+ NH4ClO4→Ba(ClO4)2+NH4NO3 Barium can also be replaced with sodium, barium perchlorate and sodium perchlorate are both soluble in water, do not react in solution, let alone in drug powder.
The only explanation for the moisture absorption of ammonium perchlorate is that all ammonium salts of inorganic acids absorb moisture. Of course, there is another situation, that is, the purchased potassium nitrate itself absorbs moisture, absorbs water in the air first, and then reacts, which cannot be blamed on ammonium perchlorate.