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Ammonium nitrate (AN) is considered to be a very hazardous and difficult to handle component of mineral fertilizers. Differential thermal analysis coupled with thermogravimetry and mass spectrometry was used to determine the possible inhibiting effect of selected magnesium compounds on thermal decomposition of AN. Each additive was mixed with AN to create samples with AN:magnesium compound mass ratios of 4:1, 9:1 and 49:1. Most of analyzed compounds enhanced thermal stability of ammonium nitrate, increasing the temperature of the beginning of exothermic decomposition and decreasing the amount of generated heat. Magnesium chloride hexahydrate was determined to accelerate the decomposition of AN while magnesium sulphate, sulphate heptahydrate, nitrate hexahydrate together with magnesite and dolomite minerals were defined as inhibiting agents. [ABSTRACT FROM AUTHOR]

Samples of pure ammonium nitrate (AN) and its mixtures with calcium carbonate, potassium hydrogen carbonate and potassium carbonate were investigated with the use of differential thermal analysis with mass spectrometry, powder X-ray diffraction and scanning electron microscopy. The main objective of the study was to determine the influence of selected carbonate materials on phase transitions of ammonium nitrate and to consider a possibility to use such potassium salts as fillers in fertilizer production. It was proven that all carbonate salts caused the absence of a phase transition that normally would occur at around 84–86 °C. Potassium carbonates were too reactive in systems containing AN. Based on the performed study, it was concluded that even though potassium carbonates are not fit to replace mineral fillers in the production process of fertilizers containing ammonium nitrate, they could be used in lesser amounts to remove the presence of low-temperature phase transitions of AN. [ABSTRACT FROM AUTHOR]

• Potassium salts influence phase transitions of ammonium nitrate. • Potassium chloride accelerates and amplifies the exothermic decomposition. • Carbonates and metabisulfite are too reactive for industrial use. • Potassium phosphates, nitrate and sulphate inhibit the decomposition. • Small amounts of salts tend to worsen thermal stability of ammonium nitrate. Ammonium nitrate (AN) has proven to be an unstable and hazardous component of mineral fertilizers. In order to analyze the influence of various potassium salts on thermal properties of ammonium nitrate, differential thermal analysis coupled with thermogravimetry and mass spectrometry was used. Each potassium salt was mixed with AN to create samples with AN:salt mass ratios of 4:1, 9:1 and 49:1. It was concluded that an addition of potassium influences phase transitions of AN. Depending on the salt used, an exothermic decomposition of AN was either accelerated (potassium chloride) or inhibited to the varying degree. Carbonate salts and potassium metabisulfite were too reactive to be used in a fertilizer production, while nitrate, sulphate and both phosphates are considered to be appropriate additives and could be used in a multicomponent fertilizer production. [ABSTRACT FROM AUTHOR]