Determination of coal seam thickness in blast holes utilizing geophysical well logging data and its use in short term mine planning

The use of geophysical well logging data can help to solve problems related to the loss and absence of core samples in a coal deposit, providing extremely valuable information and at the same time reducing exploration cost. In this context, blast holes drilled in a total area of 50x50m, were logged with a geophysical probe in a coal deposit. The geophysical parameters measured in the blast holes were natural gamma radiation and resistivity. Bibliographically, it is known that coal as a mineral exhibits low natural gamma radiation emissions and high resistivity values respectively. The coal seams were easily identified from the other lithotypes in the deposit since the measured parameters varied in recorded values when in the coal seam regions with respect to other lithological regions down the blast holes. As a result of the variations in the measured parameters in regards to coal, the thickness of the coal seams present in the deposit were able to be determined using the logs obtained down the blast holes. This study was able to compare the mass of the mined coal seams to the mass calculated using data obtained from geophysical logs and the relative error did not exceed ±12% with an insignificant global difference of less than 2.5%.