Patent ID: 8461831
Filing Date: 2013-06-11
Classification: G01B

Abstract:
1. A method of monitoring a flow of ore from an ore body during block caving mining operations, said method including the steps of: implanting a beacon in the ore body; generating a polar alternating magnetic signal with the beacon, wherein the beacon generates the magnetic signal at predetermined intervals for predetermined periods; monitoring a magnetic field in the ore body area with a plurality of magnetometers to identify the magnetic signal from the beacon, wherein each of the plurality of magnetometers is respectively disposed in a vertical borehole and moveable along a vertical monitoring axis disposed in the vertical borehole, wherein each vertical borehole is substantially adjacent to and surrounding the ore body; wherein monitoring includes monitoring with the plurality of magnetometers a strength of the magnetic signal as each magnetometer is moved along its respective vertical axis to determine a location of a peak strength of the magnetic signal on the monitoring axes, and determining a depth of the beacon based on the location; wherein monitoring includes monitoring with the plurality of magnetometers a relative timing of a phase of the magnetic signal as each magnetometer is moved along its respective vertical axis to determine a relative angular displacement of each magnetometer with respect to the beacon, and determining a position of the beacon on a horizontal plane based on the relative angular displacements; and calculating an origin of the magnetic signal at discrete intervals based on the depth of the beacon and the position of the beacon on the horizontal plane to determine a path of the beacon and derive the flow of the ore as it is mined.