Quantication of Valuable Chemical Elements present in Recyclable Printed Circuit Boards using Spectrum Radiography


Quantication of Valuable Chemical Elements present in Recyclable Printed Circuit Boards using Spectrum Radiography

Bhayani, G. S.

As of 2016, gold from electronic scrap was estimated to value almost e 19,000 million of the global e-waste [1]. This thesis aims at quantication of gold in scrap Printed Circuit Boards using Spectrum Radiography. The thesis is divided into two main sections- rst is where calibration of the detector takes place in order to estimate amount of x-rays that are transmitted through dierent thicknesses of gold and the second section is based on the results from scrap PCBs. The nal focus is to use the calibration, to quantify gold in Printed Circuit Board sample. Spectrum Radiography can help obtain the transmission of x-rays by a sample and based on the k-edge absorption theory, one can identify the element present in the sample.
The amount of transmission was estimated to relate to the thickness of the sample and the calibration data showed that with increasing sample thickness, gradual reduction in transmission was observed with the Spectrum Radiography. Hence, the thesis was based on quantifying elements based on k-edge transmission spectra. The resolution limit of the detector comes along, contributing to errors in quantication.
The thesis enlists and elaborates the statistical approaches for the quantication of gold using the radiographs obtained from the new prototype Spectral Detector and concludes the correlation of results obtained for geometrically analogous sample to x-ray beam orientations and also concludes the inapplicability of this method for samples with inhomogeneous thickness across the x-ray beam path.

Keywords: spectral CT; energy bins; 3D image; k-edge quantification

  • Master thesis
    Technical University Chemnitz, 2020
    Mentor: Jose R. A. Godinho

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Publ.-Id: 31815