Study On The Preparation And Performances Of Spherical Ultrafine Ammonium Perchlorate By Mechanical Grinding

Spherical energtic materials could significantly enhance their packing density and also improve their safety performance.But the reports on preparation and performances study of spherical Ammonium perchlorate(AP) are seldom.In this paper,spherical AP were preparated by spray crystallization planetary ball mill and vertical stirring ball mill respectively.Finally using the third method could get spherical ultrafine AP,and its process parameters and performances were investigated and studied.The main contents were shown as follows:Firstly, Process for preparation of spherical AP were studied,finally spherical ultrafine AP were preparated by vertical stirring ball mill successfully, its partical size (d50) were 5.7μm,and have a regular shape and smoth surface. Then the optimal process parameters for preparing spherical ultrafine AP were obtained which are as follows:alternately varying forward-reverse rotation every one hour and grinding 6 hours, stirrer speed is 400r/min, the ratio of milling ball to materal is 60, and grinding liquid medium is mixed with ethanol and isobutanol solvent.Secondly,the basic physical and chemical properties of spherical ultrafine AP were studied The results showed:spherical ultrafine AP has small particle size and high purity,while compared with the non-spherical AP, its moisture-blocking performance and fluidity are improved, meantime its specific surface area decreases,loose bulk density increases.Thirdly, the sensitivity and thermal decomposition of spherical ultrafine AP with were characterized. The results show that the impact and friction sensitivities of the spherical ultrafine AP were reduced by 32% and 22%, respectively, compared with the non-spherical AP. The thermal decomposition peak temperature and apparent activation energy of the spherical ultrafine AP were higher than that of the non-spherical AP. That implies the great improvement in thermal stability of spherical ultralfine AP.At last, the thermal decomposition performance of the AP/Al and AP/CuCr2O4 were explored. The results indicate that Al powders could inhibit the thermal decomposition of AP at low temperature, and promote the thermal decomposition of AP at high temperature. With the use of nano-CuCr2O4, the DTG peak temperature of AP at both tow and high temperature were decreased considerably, and the decomposition rate of AP was increased at high temperature specially.