Study on hygroscopicity of ammonium nitrate particle coated by polystyrene

The phase separation method was used in preparation of the ammonium nitrate particles with polystyrene.The effects of the volume ratio of toluene and n-hexane,the mass ratio of polystyrene and ammonium nitrate,the ratio of ammonium nitrate and mixed solvent and the precipitating agent addition rate on the covering situations of ammonium nitrate particles were investigated.The results showed that the ammonium nitrate process conditions of polystyrene-coated ammonium nitrate are 1:3 of volume ratio of toluene and n-hexane,3.5 ml/g of ratio of mixed solvent and ammonium nitrate,room temperature,and 6 sec/drop of addition rate of precipitating agent.When the 60 mesh ammonium nitrate was coated with polystyrene and the mass ratio of polystyrene and ammonium nitrate was 1.54%,the reduction of moisture rate was 75%.When the mesh number of ammonium nitrate was increased and the reduction of moisture rate was equal,the required polystyrene amount was significantly increased.