Ammonium nitrate (AN) has received attraction globally not only as a nitrogenous fertilizer but also as an oxidizer in gas generators and propellants. Nowadays, great attention is being focused on the development of composite solid propellants with green oxidizers in realizing eco–friendly combustion products. The ammonium perchlorate (AP), which is the work horse oxidizer in composite propellant, needs replacement due to its environmental and human health issues. In this context, AN is regarded as an alternative to AP because of its easy availability and environmentally friendly chlorine free combustion products. However, AN has its own inherent drawbacks such as hygroscopicity, room temperature phase transition, and low burning rate. Recently, several studies have been focused on its phase stabilization and burning rate modification so as to develop solid propellants with improved properties. The knowledge of thermal characteristics of AN is a crucial factor for its applications in propellants a...

Ammonium Nitrate as an Eco-Friendly Oxidizer for Composite Solid Propellants: Promises and Challenges

Effects of inhibitor and promoter mixtures on ammonium nitrate fertilizer explosion hazards

Ammonium nitrate (AN) is being explored as a high energetic oxidizer in propellants. The utilization of pure AN in propellants suffers from a low burning rate. To improve the burning rate, it is important to improve the thermal decomposition characteristics of AN to fasten its thermal decomposition. The effect of CoCuFe2O4 additive was explored to improve the thermos-kinetic parameters of AN's thermal decomposition. Coprecipitation was used to synthesize nanocrystalline CoCuFe2O4. The thermodynamic and kinetic parameters of decomposition of AN: CoCuFe2O4 were investigated using TG-DSC-DTA analysis at 5, 10, and 15 °C min−1. The thermodynamic and kinetic studies suggest that the thermal decomposition of AN+CoCuFe2O4 was more favorable than AN. The decomposition of AN+CoCuFe2O4 occurs at a lower 10 °C lower temperature with ∼44 % decrement in the activation energy and decreased pre-exponential factor. The faster decomposition at a lower temperature was obtained for AN+CoCuFe2O4 composition. Nano-sized particles with efficient optical and polarizable properties made this ferrite material easily separable and eco-friendly for the preparation of a chemical propulsion system based on AN. The AN+CoCuFe2O4 propulsion mixture can be utilized in place of pure AN for better thermal performance in a propellant system. CoCuFe2O4 was able to influence the thermal decomposition parameters of ammonium nitrate (AN) AN+CoCuFe2O4 decomposes at lower activation energy with a faster decomposition than pure AN Thermodynamics suggest favorable decomposition of AN+CoCuFe2O4 than pure AN 

Catalytic performance of nano-sized cobalt copper ferrite on thermal decomposition of ammonium nitrate

Review of thermal decomposition, kinetics parameters and evolved gases during pyrolysis of energetic materials using different techniques

Abstract The influence of cobalt, copper, iron(III), manganese and zinc nitrate salts on phase transitions and thermal stability of ammonium nitrate (AN) has been studied and discussed. Differential thermal analysis/differential scanning calorimetry coupled with thermogravimetry and mass spectrometry were used to evaluate the stability of analyzed systems. Each nitrate salt was appropriately mixed with ammonium nitrate to create samples with AN:salt mass ratios of 4:1, 9:1 and 49:1. It was concluded that the addition of every studied nitrate influenced phase transitions of AN. Most analyzed salts decreased the stability of AN by accelerating its exothermic decomposition process. Iron and cobalt nitrates were defined as the most hazardous additives, resulting in a creation of a highly destabilized mixture. Copper and manganese nitrates were also defined as catalysts of the AN decomposition process, lowering the initial decomposition temperature and increasing the rate of the observed process. Zinc nitrate hexahydrate was the only salt considered to be relatively neutral in such systems, especially in small amounts. The study allowed to define the influence of selected metal nitrate salts on the thermal stability of AN under conditions that are considered as potentially unsafe for such systems. 

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Thermal stability of ammonium nitrate systems containing d-metal nitrate salts under limited mass transfer conditions

Results of a thermal analysis of a system constituted by ammonium nitrate and a three-component additive with Mg(NO3)2 as a promising ecologically clean oxidizing agent for high-energy condensed systems are presented.

G. F. Klyakin

Papers

Thermal decomposition of ammonium nitrate with three-component additives