Imaging Process Control for Mining and Cominution of Construction Materials
Extraterrestrial mining activities will at first be concerned with the production of construction materials. Rock and earth materials can provide the strongest and most cost effective solutions. Scarce resources (energy, human intervention) in extraterrestrial mining operations, will limit many types of activities. At the same time, construction materials need to be processed, including blasting, crushing, screening, and milling, to exact specifications. Automation is the key to minimizing resource utilization, and optical sizing is crucial for these tasks, enabling automated process control without requiring excessive human quality control strategies.
WipFrag image based granulometry system
Quick and accurate measurements of size distribution are essential to managing fragmented rock and other materials. WipFrag is an automated image based granulometry system that uses digital image analysis of rock photographs and video tape images to determine grain size distributions. WipFrag images can be digitized from fixed video cameras in the field, or using roving camcorders. Photographic images can be digitized from slides, prints or negatives, using a desktop copy stand. Digital images in a variety of formats, delivered on disk or over electronic networks, can be used. WipFrag uses powerful image analysis techniques to isolate the individual fragment boundaries. Edge detection is optimized by setting Edge Detection Variables (EDV). Manual editing can be used to improve the fidelity of edge detection. WipFrag has the facilities for zoom-merge analysis, where the combined analysis of images taken at different scales of observation can be used to overcome the size limitations inherent with a single image. Alternatively, an empirical calibration mode is available.
Optical digital fragmentation measuring systems – inherent sources of error
Abstract Automated optical imaging systems of measuring fragmentation are increasingly being used in the mining, comminution, and materials handling industries. These methods have been well received in many of the industries involved. Considering that in many of these applications there are no alternative ways of sizing material, having even a rudimentary measurement of size distributions allows evaluations of explosive, blast design, detonator performance, crusher and milling performance, and material degradation due to transport. Optical methods have inherent limitations, which reflect on accuracy, precision, and reproducibility of measurement results. This stems from the fact that there are myriads of variables, which affect the outcome of the measurements. Errors start with the imaging process, which may distort the reality because of the scale of observation, may induce sampling bias, and may simply not return a good representation of the reality. More errors are introduced in the digital processing ...