Abstract
Ferromanganese oxide ores collected from three captive mines, viz., Koira, Kusumdih, Dengura, located in the western part of the Koira Valley, Sundargarh district, Orissa (India) have been investigated for their infrared absorption. Mineralogical assignment of the ore samples was made by infrared spectroscopic studies vis-a-vis XRD — microscopic interpretations. The common feature in all the IR Spectra is the presence of three major absorption bands in wave number regions of 1120–800, 710–410 and 350–250 cm−1. The ores in general, exhibit three broad spectral patterns which when correlated with their respective composition are found to represent three categories of samples corresponding to high, medium and low grade types. The effect of temperature (calcination) on the characteristics of IR absorption spectra has also been discussed. The IR results have been of value in characterising the manganese ores of the Koira region in general.
