Monoammonium phosphate (MAP) was mixed with ammonium nitrate (AN) by the mechanical mixing method (1) and the solution mixing method (2). The UN gap test and Koenen test of UN-Recommendations on the transport of dangerous goods

were used to determine the propagation of detonation and the effect of heating under confinement

and DSC was used to study the thermal decomposition characteristic. The results of UN gap test showed that samples with different mixing methods had the same result. When the MAP content reached 25%

the result was negative

i.e.

the modified AN did not propagate detonation. In the Koenen test

when the MAP content in the modified AN-1 and modified AN-2 reached 30% and 25% respectively

the samples were not sensitive to intense heat under test confinement. The results of DSC showed that the Tonset of modified AN-1 was lower than AN

but the Tonset of modified AN-2 was higher than AN. The mechanical mixing method could improve the passivation effect of MAP on AN.