Monitoring the area surrounding the underground block cave is possible but little was known about the movement of the rock inside the cave itself. Markers placed in drill holes within the cave were measured where and when they came out at the extraction level, but there was no ability to evaluate what happened in between. This lack of real-time information commonly led to part of the orebody being left behind or diluted.
Markers placed in drill holes within the cave were measured where and when they came out at the extraction level, but there was no ability to evaluate what happened in between. This lack of real-time information commonly led to part of the orebody being left behind or diluted.
Real-time monitoring and flow management
The Cave Tracker system uses a series of trackers and detectors placed in and around the orebody to track the rock three-dimensionally inside the cave as it moves in real time. The system can transmit signals through two hundred metres of rock and will continue working remotely for many years, even as it is impacted by the rock deep underground.
In addition to delivering significant productivity improvements, the technology also has the potential to make cave mining safer. In some cases, large voids can develop within the cave, and if a large enough air gap collapses, air can be pushed through the mine with incredible force. The Cave Tracker system, in conjunction with other cave monitoring systems, can be used to detect the formation of air gaps and manage them before they pose a safety threat.
How it Works
Cave Tracker is a highly sensitive but robust system that consists of the following components:
Beacon: A rugged cylindrical fiberglass enclosure containing a strong magnet, batteries and electronic circuitry. A microcontroller in the Beacon is programmed to control an electric motor which spins the magnet at desired intervals. Beacons are embedded in a mine’s ore-body so that their 3D position may be tracked at regular intervals by Cave Tracker System Detectors. Beacons are intended to be installed in deep mine holes. Calibration Beacons are identical to Beacons, with the exception that they can be powered and can communicate with the outside world via an umbilical cable.
Detector: A rugged cylindrical fiberglass enclosure containing a sensitive magnetometer and various electronic circuitry including a small computer. Detectors are strategically placed throughout the mine so that the system may detect the 3D positions of Beacons installed in the mine. Detectors are also intended to be installed in deep mine holes. Detectors send the measured Beacon ranging information via the Communication Adaptor Module’s (ITCAM) serial link to the Cave Tracker Management System server for data storage and analysis.
Communication Adapter Module (ITCAM): The Communication Adapter Module provides a DC power and serial data communication link for Detectors and Calibration Beacons. Messages between Cave Tracker Management System, Wireless User Interface and Calibration Beacons/Detectors are relayed through the ITCAM.
Cave Tracker Management System (CTMS): The CTMS is responsible for data storage of Detector range readings, converting received Detector ranges into 3D Beacon positions, and managing installed Cave Tracker System Devices.
Wireless User Interface: A small ruggedised laptop + USB Activation Wand is used for system commissioning and the wireless activation of Beacons prior to installation.