# Detonability of Ammonium Nitrate Mixtures with the Addition of Organic Materials
## 1 Introduction  
Ammonium nitrate (AN, H\({}_{4}\)N\({}_{2}\)O\({}_{3}\)) plays an important role in agriculture as a high-nitrogen fertiliser, but also in the production of commercial explosives. It is present in the form of colourless or white-to-grey crystals or odourless globules, with a molecular weight of 80.06 and a specific weight of 1.725 g/cm\({}^{3}\). It has a melting point of 169.51 \({}^{\circ}\)C and boils at 210 \({}^{\circ}\)C, forming nitrous oxide [1]. As an oxygen carrier and strong oxidising agent, ammonium nitrate readily forms explosive mixtures with other explosives or with fuels (such is fuel oil, various organic materials, aluminium powder, etc.). The typical examples of commercial AN-based explosives are ANFO (mixture of 94% AN and 6% fuel oil) and emulsion explosives (an aqueous solution of AN separated by thin films of fuel/emulsifier) [1]. By changing the type and content of organic material in AN-based explosives, the detonation properties can be adjusted so to obtain the best blasting effect. If recycled organic materials (e.g., recycled rubber, hay, etc.) are used as ingredients, the additional benefit of the disposal or exploitation of such materials may be obtained. The first research on the development of AN-based explosives with the addition of organic materials started in the 1960s, with the addition of various low-density materials to commercial ANFO explosives. The main goal of this research was to develop simple-to-use and cost-effective explosives with appropriate detonation properties [2, 3]. Similar research was conducted in Norway, where a blend of ANFO and sawdust in a 50:50 volume ratio was used [4]. The first commercialized explosive with organic material was Isanol, an ANFO explosive with the addition of expanded polystyrene (EPS) [5, 6, 4]. The modification of ANFO detonation properties by decreasing its density by addingpolystyrene [7], expanded polystyrene [2; 8; 9; 10], sawdust [11; 12], sawdust and used mineral oil [12], organic waste from sugar manufacturing [3; 12], perlite [13; 14; 15], rubber [16], corn, coal, and fly ash [17], wheat husk [18], and rice husks [6] has been also investigated. The effects of different parameters on the detonation performance of ANFO have been well researched and published. The main parameters include [19] the properties of AN prills [20; 21; 22] and the density of the mixture and charge diameter [22]. The effects of other parameters, such as the initiation energy [23], charge temperature [24], presence of additives [25], and presence of confinement [26; 27], have also been reported. During the planning, monitoring, and execution of blasting operations, there is a need to develop an explosive suitable for blasting in the vicinity of inhabited areas or surrounding buildings. Such an explosive should be made of products with sufficient heat and volume properties to carry out the mechanical work of the fragmentation of rock. In addition, it should have a favourable ratio between the density of the explosive and the detonation velocity and pressure. The detonation pressure level and the duration of the resulting stress impulse, i.e., the duration of the expansion of detonation products due to the ambient pressure, ensure sufficient mechanical work is performed on the rock, which leads to the formation of new cracks, the expansion of existing cracks, the formation of fragments, and the displacement of blasted rocks. A part of the blasting energy that is not used for crushing spreads as elastic waves in the surrounding area and leads to undesirable seismic effects. By reducing the density of the explosive mixture by adding some organic waste material, the detonation velocity and detonation pressure change, which can reduce the unwanted seismic effect of the explosion. In this study, we investigated explosive mixtures based on AN and recycled rubber or hay as organic additives.