Vibrational Spectroscopic Study for Qualitative Assessment of Mn-oxide Ore

Abstract

Manganese oxide ore from the Bonai-Keonjhar belt of Odisha, India, has been qualitatively assessed through Raman and FTIR spectroscopy, and X-ray diffraction. Three categories of ore, namely, high-grade (MnO2: >72%), medium-grade (MnO2: 55-72%) and low-grade (MnO2:40-55%) from four mine profiles, Purnapani, Joda West, Khandbandh and Bamebariwere, were collected and subjected to vibrational spectroscopic studies. The use of Raman analysis in the microscopic configuration allowed the spectra to be taken at different points on the polished ore. Besides the Raman features of the ss-MnO2(Pyrolusite) phases, other signals were assigned to isolated FeO ions accommodated in vacancies and to some aluminium silicates. The three grades of ore show different Raman spectra. The FTIR spectra also exhibit contrasting pattern in different grade sample and support these findings. This study demonstrates the use of vibrational spectroscopy to assess the quality of Mn-oxide ore that could provide a substitute to cumbersome wet chemical analysis