Study on the Thermal Behavior of Mixtures of Ammonium Nitrate and Micronutrient Chelates with Potential toward Enhancing the Efficiency of Precision Agriculture

Abstract

Co-decomposition of ammonium nitrate (AN) and its mixtures with microelement chelates of ethylenediaminetetraacetic acid (EDTA) and iminodisuccinic acid (IDHA) has been studied. The TG-DTA-DTG method has been used to evaluate the thermal stability characteristics of the composition containing up to 0.5 mass % of Cu, Mn, or Zn metal ions. The aim of the study was to evaluate the effect of micronutrient chelates on the thermal decomposition of AN in terms of the possibility of the production process of AN-based fertilizers enriched with micronutrient additives. AN mixtures with EDTA maintain consistent decomposition temperatures, while IDHA mixtures show reduced temperatures with an increasing chelate content. For evaluation, the thermal decomposition rate index (TDRI) based on the TG-DTA-DTG characteristic has been calculated. Zn-EDTA and Mn-EDTA mixtures are relatively stable, whereas IDHA mixtures exhibit reduced stability compared to pure AN. Results show that increasing metal ion content generally decreases thermal stability and quickening decomposition. In general, research highlights the negative impact of micronutrient chelates on AN decomposition, cautioning against their use in traditional fertilizer production processes with a high AN content.