Near infrared sensors for minerals identification and discrimination in the extractive industries

This paper considers the early identification and discrimination of copper bearing minerals from their associated gangue minerals. The proposed mineral identification and discrimination is based on individual mineral spectral signature(s) in the near infrared region. Ten copper ore samples, sampled from Akiri mine, Akiri, Awe Local Government Area of Nasarawa State Nigeria were analysed. Individual samples were subjected to mineralogical analysis using X-ray diffraction equipment and elemental analysis using hand-held X-ray florescence equipment. Prior to the mineralogical and elemental analysis, samples were scanned with a near infrared line scanner. Results of the X-ray diffraction, X-ray florescence and near infrared were compared. The comparison indicated that in addition to the minerals identified by the XRD, other NIR-active minerals with concentration below the XRD detection limit (5%) were also detected by the near infrared line scanner. Hence, the near infrared line scanner had a better detection limit. Furthermore, eight out of the ten samples analysed showed a good correlation where near infrared and elemental data were compared