Ammonium nitrate fuel oil (ANFO) is a mixture of solid ammonium nitrate and mineral oil. Easy handling allows it to be used safely in mining, stone quarrying, and tunnel construction. The basic reaction during detonation is the decomposition of the hydrocarbon and the ammonium nitrate into CO2, nitrogen and water. For this test a mixture of NH4NO3 and toluene was used. Three phase transitions (endothermal peaks) up to 150°C and the large exothermal decomposition peak starting at approx. 235°C can be detected. (measurement with MMC 274 Nexus®)
A clay sample (powder) was tested in air using a TMA-MS (Aëolos®) coupling in the temperature range from RT to 800°C. At the beginning of the measurement, the adsorptively bound water and the interlayer water are released (shrinkage of 0.01%). Above 300°C, the sample’s organic constituents burn up (maxima in the curves for m18, water, and m44, CO2). There is no visible influence on the expansion curve here, due to the very low proportion. Between 487°C and 536°C, dehydroxylation of the sample’s clay mineral content takes place. Associated with that is a sample shrinkage of 0.05%.