Automated radiation profiling and shotcreting of uranium mine drifts

点击翻译按钮获取中文摘要

The goal of this project is to develop a system to automatically profile the radiation levels across a uranium mine drift (tunnel) and apply, in an automated manner, shotcrete (sprayable concrete) to the face, walls, and ceiling of the drift to reduce radiation exposure to mine personnel to acceptable levels. In a uranium mine, radiation levels are generally related to the grade (percent concentration) of uranium in the ore. The grades are not consistent, and have high variability along the extent of mineralization. One of the techniques used in uranium mines to control radiation exposure is to coat the uranium ore with a layer of shotcrete. The higher the uranium grade, the thicker the shotcrete "shielding" that must be applied. Current manual methods do not provide accurate enough data and potentially expose workers to radiation and rock-fall hazards. The ability to accurately map uranium deposits is key to improved mine efficiency, allowing for better planning of mining operations. Automating the shotcrete process based on the radiation readings will allow for improved operating efficiency and enhanced worker safety through the optimal application of shotcrete. It is proposed to develop a robotic system to systematically gather accurate radiation measurements across the drift and then apply shotcrete to the required thickness. The radiation sensor, a sodium-iodide (NaI) sensor, will be equipped with shielding to allow more accurate radiation measurements to be taken. A mobile robotic base will be used to move the system to the face and a manipulator will be used to move the sensor and shotcrete nozzle along the face. Depending on the size of the drift, the mobile base may need to reposition itself multiple times in order to scan and shotcrete the entire drift. Simultaneous Localization and Mapping techniques will be used to generate a 3D map of the drift while determining the position of the mobile base relative to the drift. In addition, colour images will be captured of the drift so that the geologists can match the radiation measurements not only to the generated 3D map, but to actual images of the drift as well. The end result will be a system that generates an accurate 3D model of the drift face showing precise radiation measurements.