Chemical characterization of ilmenite at different depths in extension areas of Brahmagiri mineral sand deposit, Puri district, Odisha Sudhakar Ch.*, Kumar K. Ramesh, Joshi G. B. Atomic Minerals Directorate for Exploration & Research, Department of Atomic Energy Begumpet, Hyderabad or Exploration Research, Hyderabad *E-mail: sudhakar-geo.amd@gov.in
Online published on 13 February, 2019. Abstract Ilmenite is the dominant heavy mineral in the shoreline placer deposits of Odisha, Andhra Pradesh, Tamil Nadu and Kerala coasts. Brahmagiri mineral sand deposit is one of the largest heavy mineral deposits in India. Heavy mineral suite in this area comprises of dominant ilmenite followed by sillimanite, garnet and other heavy minerals in lesser abundance. Chemical characterization of pure ilmenite separated from one representative borehole sample of Brahmagiri-Giral area was carried out to understand their nature, source from which they were derived and their suitability for industrial use. The economic viability of a mineral sand deposit depends on the heavy mineral grade, assemblage and chemical composition of the constituent economic heavy minerals. The study area is in north-eastern continuity of the Brahmagiri deposit. For this study, twelve samples from different depth intervals from one representative borehole were considered and processed for obtaining pure fractions of ilmenite. The purity of the representative ilmenite grains was confirmed under the microscope and the samples were analysed by wet chemical methods. It is noticed that ilmenites from the top 4.50 m zone have analysed higher TiO2 content compared to other samples. This may be due to oxidation of ilmenite which is reflected in higher Fe2O3/FeO ratio. The Fe2O3/FeO ratio gradually decreases with depth. The chemical characteristics of ilmenite derived from different source rocks give clue to provenance rocks. The Mn/Mg ratio of ilmenite is used as an indicator of source rocks for some deposits and the same analogy is applied to study these ilmenites. These ilmenites are suitable for value addition in synthetic rutile route. Study of critical elements indicates higher vanadium and this requires a careful study for using these ilmenites in pigment industry. Top Keywords Ilmenite, heavy minerals, characterization. Top |