Grading of Manganese Oxide Ore from Bonai-Keonjhar Belt, Odisha Using Vibrational Spectroscopic Technique

Abstract

Manganese oxide ore, in different grade, have been studied by Raman, FTIR spectroscopy and X-ray diffraction. Three categories of ore viz. high-grade (MnO2: >72%), medium-grade (MnO2: 55-72%) and low-grade (MnO2: 40-55%) from two mine profiles of Bonai-Keonjhar belt, Odisha were collected and subjected to vibrational spectroscopic studies. The Raman spectra are taken at different points of the polished surface of the ore to determine the in-homogeneity of the sample. Besides the results of Raman analysis of the beta-MnO2 phases, other signals were assigned to isolated FeO ions and to some aluminium silicates. The three grades of ores show different Raman shift. The FTIR spectra, also exhibit different bands in different grade sample and support these findings. Vibrational spectroscopy can thus be employed to grade the manganese oxide ore as a substitute to cumbersome chemical analysis.