Structural and Morphological Quantitative 3D Characterisation of Ammonium Nitrate Prills by X-Ray Computed Tomography

Abstract

The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency.

Morphological characterisation of explosive powders by X-ray computed tomography: when grain number counts.

“…However, when looking at the specific surface values, the F2 value is much smaller that what was found for E1 and E2. A linear correlation was found between the specific surface area values extracted from the XCT data and the oil retention values, similarly to other results [9], demonstrating that XCT can be use to predict the performance of AN prills.…”

“…Figure 3. Overview of the data processing workflow for single prills.Regarding the data processing of the prills in the polyimide tube, the entire data processing workflow is fully detailed in[9]. A watershed segmentation is used to select the AN, air and polyimide tube materials.…”

Micro Non-Destructive Testing and Evaluation

“…This Special Issue shows that X-ray computed tomography is becoming a major tool for μ-NDT&E, being used for small and large components [ 3 , 5 , 6 ], and for sensitive materials [ 7 ]. Indeed, new methods are also being developed [ 6 , 7 , 8 ].…”

“…This Special Issue shows that X-ray computed tomography is becoming a major tool for μ-NDT&E, being used for small and large components [ 3 , 5 , 6 ], and for sensitive materials [ 7 ]. Indeed, new methods are also being developed [ 6 , 7 , 8 ]. At the same time, optical methods are being perfected to tackle challenging problems at the micro and macro scales [ 9 , 10 ].…”

Tunable X-ray dark-field imaging for sub-resolution feature size quantification in porous media

“…In the last 20 years, high-resolution computed X-ray tomography (µCT) has become an important method to non-destructively investigate the internal structure of materials in three (and even four) dimensions [5][6][7][8][9][10][11][12][13] . µCT is based on the X-ray attenuation properties of the materials, which depend on both their chemical composition and local density 9,14 , and can be performed with both synchrotronand laboratory-based sources.…”