# Detonability of Ammonium Nitrate Mixtures with the Addition of Organic Materials
## 3 Results and Discussion  
Input information for the studied substances needed for the thermochemical calculation is given in Table 1. The experimentally measured detonation velocities of the AN/Hay and AN/Rubber mixtures are given in Table 2.  
By comparing the experimental and the calculated detonation velocities (Table 2), it becomes clear that the experimental detonation velocities are about 50% lower than the calculated ones. For illustration, the maximum calculated value for the AN/Rubber \begin{table}
\begin{tabular}{l l c c c} \hline \hline
**Name** & **Formula** & **Relative** & **Density** & **Enthalpy of Formation** \\  & & **Molar Mass** & **(g/cm\({}^{3}\))** & **(k/mol)** \\ \hline Ammonium nitrate (\({}^{\text{a}}\)) & NH\({}_{4}\)NO\({}_{3}\) & 80.05 & 0.942 & \(-\)365.26 \\ A rubber (\({}^{\text{b}}\)) & C\({}_{51}\)H\({}_{87}\) & 700.21 & 0.466 & \(-\)674.99 \\ Hay (dried grass) (\({}^{\text{c}}\)) & C\({}_{10.55}\)H\({}_{16.39}\)O\({}_{7.72}\) & 266.71 & 0.391 & \(-\)1616.0 \\ \hline \end{tabular} Note: \({}^{\text{a}}\) and \({}^{\text{b}}\) data taken from [36]; \({}^{\text{c}}\) data derived when assuming hay is composed of cellulose, hemicellulose, and lignin.  
\end{table} 
Table 1: Input data for reactants (taken from EXPLOS database). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Composition** & \begin{tabular}{c} **Volume** \\ **Ratio** \\ **AN/Fuel** \\ \end{tabular}  & \begin{tabular}{c} **Oxygen** \\ **Balance,** \\ **OB (\%)** \\ \end{tabular}  & \begin{tabular}{c} **Density,** \\ **op,** \\ **(g/cm\({}^{3}\))** \\ \end{tabular}  & \begin{tabular}{c} **Experimental** \\ **Bust Velocity,** \\ **(g/cm\({}^{3}\))** \\ \end{tabular}  & \begin{tabular}{c} **Detonation** \\ **Velocity,** \\ **(m/s)** \\ \end{tabular}  & \begin{tabular}{c} **Detonation** \\ **Pressure,** \\ **(GPa)** \\ \end{tabular}  & \begin{tabular}{c} **Detonation** \\ **Temperature,** **T,** **(K)** \\ \end{tabular}  & \ \begin{tabular}{c} **Detonation** \\ **tion,** \\ **(Q,**k/kg)** \\ \end{tabular}  & \begin{tabular}{c} **Value** \\ **(dm/kg)** \\ \end{tabular}  \\ \hline AN & 100/0 & 19.99 & 0.942 & 1246 & 4490 & 4.638 & 1643 & 1582 & 979 \\ AN/Rubber & 98/2 & 14.64 & 0.928 & NA & 4609 & 4.938 & 1889 & 1989 & 977 \\ AN/Rubber & 97/3 & 14.66 & 0.921 & NA & 4661 & 5.047 & 2007 & 2197 & 974 \\ AN/Rubber & 96/4 & 12.86 & 0.914 & NA & 4708 & 5.176 & 2124 & 2404 & 974 \\ AN/Rubber & 95/5 & 11.03 & 0.914 & 2153 & 4779 & 5.376 & 2239 & 2615 & 973 \\ AN/Rubber & 94/6 & 9.20 & 0.900 & NA & 4792 & 5.375 & 2354 & 2862 & 971 \\ AN/Rubber & 93/7 & 7.33 & 0.893 & NA & 4829 & 5.453 & 2466 & 3042 & 970 \\ AN/Rubber & 92/8 & 5.47 & 0.886 & NA & 4863 & 5.509 & 2575 & 3258 & 968 \\ AN/Rubber & 91/9 & 3.56 & 0.879 & NA & 4896 & 5.581 & 2687 & 3479 & 993 \\ AN/Rubber & 90/10 & 1.63 & 0.851 & 2534 & 4943 & 5.699 & 2801 & 3703 & 965 \\ AN/Rubber & 89/2/108 & 0.07 & 0.840 & NA & 5002 & 5.845 & 2873 & 3867 & 965 \\ AN/Rubber & 85/15 & \(-\)8.31 & 0.821 & 2551 & 4818 & 5.133 & 2692 & 3532 & 1010 \\ AN/Rubber & 80/20 & \(-\)18.82 & 0.789 & 2408 & 4720 & 4.674 & 2445 & 3134 & 1055 \\ AN/Rubber & 75/25 & \(-\)29.92  
mixture is 5002 m/s, while the maximum experimental value equals 2551 m/s. Such a large difference between the calculated and experimental detonation velocities is due to the effect of the charge size (the ideal detonation velocity corresponds to an infinite charge radius, and the experimental values were obtained for confined charges with a radius of 10.8 mm), which confirms the non-ideal behaviour of the studied mixtures. To gain a better insight into the behaviour of the AN mixtures used in our small-scale experiments, we modelled the propagation of detonation in a standard ANFO explosive (which is a mixture of drilled AN and fuel oil) using the AUTODYN hydrocode. The reason why we used ANFO for modelling and not the studied mixtures are that there is no necessary input data (equation of state and reaction rate parameters) for these.