Mineralogy and mineral chemistry of placer deposit around Jhatipodar, Odisha

Abstract

The heavy mineral placer sands of Jhatipodar deposit, Odisha, India extends in NE-SW parallel to the coast over a width of 750-980m. A total of 195 samples were collected vertically in a grid pattern from 46 bore holes in 5 transects from beach and dunes covering an area of 75 hectares. The total heavy minerals (THM) content of the samples vary from 3.01% to 44.38%. The heavy minerals as observed from field and laboratory investigations are ilmenite, leucoxene, garnet, sillimanite, zircon, rutile, monazite, magnetite and corundum together with hornblende, diopside, tourmaline, sphene, apatite and epidote. The heavy minerals show similar pattern of grain size distribution from beach to dunes and are dominantly in the size of 90-350 µm with a peak distribution in -180, +125 µm. A bulk sample of dunal sands analysed 20.48% THM, contain 7.85% ilmenite, 7.65% garnet, 4.09% sillimanite, 0.20% zircon, 0.18% rutile and 0.13% monazite. The mineral grains are well liberated, rounded to sub-rounded and mostly free from surface coatings. The ilmenites contain 47.87-56.59% TiO2 with an average of 51.76% TiO2. The high TiO2 content (9.86-16.30%) in exsolved hematite is due to Fe2O3–FeTiO3 solid solution. Compared to ilmenite, leucoxene has higher amounts of Ti, Al, Si, Cr and lower amounts of Fe and Mn. The Ti/(Ti+Fe) in ilmenite varies between 0.46% and 0.55% while that in leucoxene has a range from 0.64% to 0.96%. The provenance rocks for this deposit are the khondalites, quartzites, calcsilicate granulites, granitic gneisses, charnockite, basic granulite, anorthosite and pegmatites of the Eastern Ghats Mobile Belt in the catchment areas of Rushikulya river. This paper deals with the distribution of heavy minerals in beaches and dunes, mineralogical association and chemistry of different minerals to evaluate the economic potentiality of Jhatipodar placer deposit and to decipher the amenability of different heavy minerals for mineral processing.