A novel coating technology of KNO₃ to reduce the hygroscopicity of pyrotechnics

Strong hygroscopicity will pose a huge challenge to the safety of pyrotechnic agents. In this paper, surface modification of potassium nitrate was carried out by dry modification process to prepare a new type of pyrotechnic powder with low hygroscopicity and high safety. The effect of coated potassium nitrate on pyrotechnic powder was studied: a constant temperature and humidity box was used to test the hygroscopicity, the differential thermal analysis (DTA) curve was used to estimate the ignition temperature of the sample, and drop mass and friction sensitivity tester were used to test the mechanical sensitivity of the sample. The test results suggest that the hygroscopicity of pyrotechnics is significantly reduced up to 47%, the safety is greatly improved, the pyrotechnic effect can meet the requirements for use, and other safety is improved to a certain extent. The new coating technology greatly reduces the hygroscopicity of the medicament, thereby improving the safety of pyrotechnic powder.