Study on the extraction of AP components in HTPB solid propellant by water/ethanol recovery

In order to improve the recovery of ammonium perchlorate (AP) components in scrapped HTPB solid propellants, the AP in HTPB solid propellants were extracted by water/ethanol mixed solvent system. The effects of extraction time, extraction temperature, volume ratio of water/ethanol, ratio of liquid to material, thickness of sample and extraction rate on AP extraction rate were discussed. The extraction results were characterized by scanning electron microscopy (SEM). The results showed that the best process parameter for extracting AP components from HTPB solid propellants: the extraction temperature was 70°C, the extraction time was 6h, the volume ratio of water/ethanol was 1:1, the ratio of liquid to material was 6:1(water/ethanol volume and sample mass ratio, ml/g) and the extraction frequency was 2 times. Under this condition, the recovery of AP was 90.5% and the purity of AP was 91.1%.