Flow improvement of fine oxidizer using nano-additives

Ammonium perchlorate (AP) is an oxidizer and major component for any solid composite propellant. The handling and processing of AP powder plays an important role in the performance of rocket fuel. AP being hygroscopic in nature; especially particle size < 50 mu m is highly cohesive in nature, which results in exten-sive agglomeration and poor flowability. This causes inherent handling problems in the propellant pro-cessing plant. In this work, the flowability of 8 mu m and 50 mu m AP particles was improved through the dry coating method using nano-additives such as TiO2 and Fe2O3. In addition, the influence of hydropho-bic nano-silica (R972 type) coating on AP particles under high humidity was investigated. The results showed that coating of AP with nano-additive reduced the inter-particle forces hence cohesivity and improves the packing and flowability of fine AP powder. Hydrophobic coating was found to have added advantage at higher humidity. Moreover, coating with these nano-additives also improved the exother-micity of AP. (C) 2022 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights reserved.

Automated summary

Ammonium perchlorate (AP) is a crucial component for solid composite propellants, and the handling and processing of AP powder significantly impact the performance of rocket fuel. This study utilized the dry coating method with nano-additives such as TiO2 and Fe2O3 to improve the flowability of 8 μm and 50 μm AP particles. Additionally, the impact of hydrophobic nano-silica coating on AP particles under high humidity was investigated. The results demonstrated that the nano-additive coating reduced inter-particle forces, enhancing the packing and flowability of fine AP powder. The hydrophobic coating showed added benefits at higher humidity levels. Furthermore, the coating with these nano-additives also improved the exothermicity of AP.