Ilmenite from the Chavara deposit, India: a critical evaluation

Abstract

The mineralogical status of ilmenite from a prominent modern placer deposit of India is illustrated using different techniques. Compositional, powder XRD, TGA and SEM analyses prove that consistent low temperature alteration took place in Chavara ilmenite leading to the formation of a pseudorutile-hydrated-ilmenite stage. Except for the indication of a geochemical zonation at the southern tip of the deposit, the Chavara ilmenite points to a common origin throughout its 22 km stretch along the coast. We advocate a major segregation activity by marine factors to the accumulated sediments in the shelf zone in order to originate such a huge deposit of homogeneous composition.

Weathering of ilmenite from Chavara deposit and its comparison with Manavalakurichi placer ilmenite, southwestern India

“…The Ti/ (Ti + Fe) ratio indicates that the Chavara fractions generally fall in the fields of 'Hydrated Ilmenite' and 'Pseudorutile' stages, and extend to that between 'Pseudorutile' and the most altered 'Leucoxene' stages (Table 1). This qualitative difference confirms the higher alteration undergone by the Chavara ilmenite (Nair et al, 1995;Ramakrishnan et al, 1997;Nair et al, 2002). Fig.…”

“…In spite of the commercial implications of the deposit due to its high quality ilmenite and its exploitation from the beginning of the 20th century, not many studies have focused on the alteration patterns of beach ilmenite (Viswanathan, 1957;Gillson, 1959;Ramakrishnan et al, 1997). Studies on the different magnetic fractions of beach ilmenite concentrate are useful to delineate the alteration trends and chemical variations of the mineral (Frost et al, 1986;Suresh Babu et al, 1994) that, in turn, have a bearing on the economic value of its deposit.…”

Weathering trends and parent material characteristics of polygenetic oxisols from Minas Gerais, Brazil: I. Mineralogy

“…Ilmenites present in saprolites and soils of group SJR-sap, as well as in group SJR-sed are weathered, whereas this is not clearly observed in group SL-sap. Weathering of ilmenite under oxidizing conditions has been frequently reported (Anand and Gilkes, 1984;Ramakrishnan et al, 1997). In group SJR-sap, ilmenite grains show altered surfaces, characterized in thin section by a pellicular, dotted and/or complex alteration pattern, similar to the pattern described by Anand and Gilkes (1984) for a lateritic layer in Australia.…”

Application of CCSEM to heavy mineral deposits: Source of high-Ti ilmenite sand deposits of South Kerala beaches, SW India

“…Johnson et al, 1977). After reworking and redeposition in beaches, relatively little further leaching appears to affect the ilmenite, since Ramakrishnan et al (1997) found only modest changes in Ti/Fe ratios in sample traverses perpendicular to the coastline.…”