In this paper, techniques of digital image processing are developed to determine the size distribution of fragmented rock before and after blasting. Several different image processing techniques are demonstrated. Also, a set of experiments have been conducted to validate the assumptions made in the image processing analysis. Our results indicate a close agreement in the size distribution between the image processing analysis and traditional sieving. Also, the methods that have been developed are able to determine three dimensional block distributions from images taken of the surface of the volume. Finally, it is shown how images of fragmented rock can be used estimate the surface area per unit volume, from which the energy per unit volume can be calculated using fracture mechanics principles.
Des techniques numeriqies de traitement d"images ont ete developees pour determiner la distribution de la taille des fragments rocheux avant et apreès l"abattage. Differentes techniques numeriques des traitement d"images on ete hypothèses emises dans l"analyse de traitement d"images. Nos resultats indiquent en ce qui concerne la distribution de la taille des fragments, une similarite entre l"analyse de traitement d"images et le tamisage traditionnel. Les methods qui ont ete developees sont aussi capable de determiner la distribution en 3-dimensions des blocs, à partir des images de la surface d"un volume. Enfin, il a ete montre comment les images des fragments rocheux peuvent être utilisees pour estimer la surface par unite de volume, à partir de laquelle l"energie par unite de volume peut être calculee en utilisant les principes de la mecanique des fractures.
ZUSAMMENFASSUNG Es wurde eine Abbildungstechnique entroickelt um die Korngrössenverteilung beurteilen zu Können, vor und nach der Schiessarbeit, Mehrere verschiederse Abbildungstechnicken sind beschrieben, Verschiedene Experiments wurden durchgefuehrt um die Gultigkeit Annchringen zu pruefen. Unsere Resultate zeigen eine enge Übereinstimmung zwischen Prezess Annalyse und traditionellern sieben. Die Methoden die entwickelt wirden Rönnen die drei-dimensionalen Blockvereilungen wiedergeben von Bildern der Oberflache des Gesteinhaufens zum Schluss wird gezeigt wie Bilder gebraucht werden können um die Flache vom zersplitterten Gestein jper Volum-Einheit zu beurteilen. Datum die Energie-per Volum Einheit kann mit Hilfe von Fracture Mechanics Prinzip berechnetwerden.
Predicting the level and extent of fragmentation from blasting is important to the mining industry. In heap leaching of copper oxides, for instance, blasting is the only size reduction that occurs prior to leaching, and a correlation exists between the size of the fragments in the leach pile and the percentage of copper that can be recovered. In most mining applications, processing requires finely ground ore, and optimizing the fragmentation from blasting can result in large reductions in crushing and grinding costs.
Dynamic rock fragmentation depends on many variables, including the intact rock properties, the properties of joints and fractures, and the blasting parameters. The importance of in-situ joints and fractures on the level of fragmentation following blasting has been demonstrated recently by Ghosh et al, (1990), Mojtabai et al. (1989), and others. The primary method of evaluating the effects of pre-existing joints and faults, and of different blasting variables, is to compare the distribution of block sizes before and after blasting (Clark, 1987). Prior to blasting, the block size distributions can be obtained from core logging or mapping of the rock face. Following blasting, the block size distributions can be obtained by sieving, photography.ABSTRACT In this paper, techniques of digital image processing are developed to determine the size distribution of fragmented rock before and after blasting. Several different image processing techniques are demonstrated. Also, a set of experiments have been conducted to validate the assumptions made in the image processing analysis. Our results indicate a close agreement in the size distribution between the image processing analysis and traditional sieving. Also, the methods that have been developed are able to determine three dimensional block distributions from images taken of the surface of the volume. Finally, it is shown how images of fragmented rock can be used estimate the surface area per unit volume, from which the energy per unit volume can be calculated using fracture mechanics principles.
Des techniques numeriqies de traitement d"images ont ete developees pour determiner la distribution de la taille des fragments rocheux avant et apreès l"abattage. Differentes techniques numeriques des traitement d"images on ete hypothèses emises dans l"analyse de traitement d"images. Nos resultats indiquent en ce qui concerne la distribution de la taille des fragments, une similarite entre l"analyse de traitement d"images et le tamisage traditionnel. Les methods qui ont ete developees sont aussi capable de determiner la distribution en 3-dimensions des blocs, à partir des images de la surface d"un volume. Enfin, il a ete montre comment les images des fragments rocheux peuvent être utilisees pour estimer la surface par unite de volume, à partir de laquelle l"energie par unite de volume peut être calculee en utilisant les principes de la mecanique des fractures.
Es wurde eine Abbildungstechnique entroickelt um die Korngrössenverteilung beurteilen zu Können, vor und nach der Schiessarbeit, Mehrere verschiederse Abbildungstechnicken sind beschrieben, Verschiedene Experiments wurden durchgefuehrt um die Gultigkeit Annchringen zu pruefen. Unsere Resultate zeigen eine enge Übereinstimmung zwischen Prezess Annalyse und traditionellern sieben. Die Methoden die entwickelt wirden Rönnen die drei-dimensionalen Blockvereilungen wiedergeben von Bildern der Oberflache des Gesteinhaufens zum Schluss wird gezeigt wie Bilder gebraucht werden können um die Flache vom zersplitterten Gestein jper Volum-Einheit zu beurteilen. Datum die Energie-per Volum Einheit kann mit Hilfe von Fracture Mechanics Prinzip berechnetwerden.
Predicting the level and extent of fragmentation from blasting is important to the mining industry. In heap leaching of copper oxides, for instance, blasting is the only size reduction that occurs prior to leaching, and a correlation exists between the size of the fragments in the leach pile and the percentage of copper that can be recovered. In most mining applications, processing requires finely ground ore, and optimizing the fragmentation from blasting can result in large reductions in crushing and grinding costs.
Dynamic rock fragmentation depends on many variables, including the intact rock properties, the properties of joints and fractures, and the blasting parameters. The importance of in-situ joints and fractures on the level of fragmentation following blasting has been demonstrated recently by Ghosh et al, (1990), Mojtabai et al. (1989), and others. The primary method of evaluating the effects of pre-existing joints and faults, and of different blasting variables, is to compare the distribution of block sizes before and after blasting (Clark, 1987). Prior to blasting, the block size distributions can be obtained from core logging or mapping of the rock face. Following blasting, the block size distributions can be obtained by sieving, photography.
