Geophysical Measurements to Detect Ahead of Bucket Wheel Excavators the Problematic Hard Formations in Coal Mines

Frequent problems that need to be addressed in mining coal deposits is the presence of cohesive materials of high mechanical strength in relation to the dominant environment of soft material series. These are generally called “hard formations” or “hard inclusions” and are in the form of either continuous layers or boulders. This problem is of particular importance in Europe where lignite deposits are exploited in large opencast mines utilizing Bucket Wheel Excavators (BWEs) as the main means of excavation. In the frame of BEWEXMIN project co-funded by the Research Fund of Coal and Steel of the European Union experiments of geophysical measurements with ERT, GPR and EM methods have been done in South Field Mine Kozani Greece of PPC showing promising results for further design for instruments mounted on the BWEs and detect the hard inclusions before excavation or for off-line mode for mid-term planning operation of excavators.