Measuring gamma radiation with a portable gamma ray spectrometer at a measuring location consisting of multiple rock types

Measuring gamma radiation with a portable gamma ray spectrometer at a measuring location consisting of multiple rock types

Meijer, Tim (TU Delft Civil Engineering and Geosciences)

Guatame-Garcia, Adriana (mentor)
Ngan-Tillard, Dominique (mentor)

Delft University of Technology

2020-05-15

A pilot research was set up to determine the possibilities for using gamma-ray spectrometry to and possible value in mine waste piles. These waste piles consist of different waste rocks without any value and ore that was processed incorrectly. This method, if proven eective, will be used on mine waste from different commodities all over the world. However, there will be started with the waste pile Halde Haniel in the Ruhr area in Germany. The Ruhr area has been selected because of the manageable travelling time from Delft, the long history of coal mining activities in the area and the open-access of the waste pile. The thriving days of coal mining have left us with large amounts of waste piles (170 waste piles in the Ruhr area). Therefore, it will be essential to know if these waste piles have an impact on the environment by emitting gamma radiation. In Europe, this problem has not been addressed. However, in other countries, these waste piles are the cause of increased health risks. The Halde Haniel waste pile is a human-made object and consist mainly of shale, sandstone and bits of coal. Gamma-ray spectrometry is often used to determine lithology of a rock formation. To determine the lithology measurements are done on outcrops present in nature. In most literature gamma-ray spectrometry is used to determine the lithology of rock formations. However, in this research, the measuring location is a human-made object, which has destroyed the natural sequencing of the rocks. Therefore, the measurements taken on the Halde Haniel makes the research more challenging. Therefore, the accuracy of the measurements done on a site consisting of multiple rocks, such as the Halde Haniel, are essential to know in order to apply this method in future research. Field measurements were taken for two dierent reasons. First, a control study was executed in the Green Village in Delft. The main goal of these measurements was to select a correct measuring time for the measurements at the Halde Haniel waste pile. The rest of the measurements were done at the Halde Haniel waste pile. At the Halde Haniel waste pile, four dierent measuring locations were selected. From the results can be concluded that the amount of gamma radiation emitted from the Halde Haniel waste pile is higher than at a location without mining activities. However, this increase is still not high enough to result in health risks. The measuring error could not be determined to a satisfactory standard, because of the lack of soil moisture samples and the signicant impact of soil moisture on the error of measurements. Gamma-ray spectrometry should be supported with information about the lithology and the chemical composition of the rocks, because otherwise nding value in waste piles will be hard.

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Student theses

bachelor thesis

© 2020 Tim Meijer