Mineralogical and Radiological Micro-Analysis of Raw Sands and Their Processed By-Products for Land Reclamation Applications

Abstract

In this study, forty samples of different types of raw sands, magnetite, green silicate and processed mixture of ilmenite, magnetite and green silicates have been mineralogical and radiometrically investigated after preparation. Determination of the mineral contents, radioactivity levels and their corresponding environmental impacts was also carried out. The radioactivity: 238U, 232Th, 226Ra and 40K, of these samples are of naturally occurring origin. The EDX analysis was applied for identification of trace elements in the samples. The microscopic investigations of the samples indicate that the black sand samples are economically rich in heavy minerals such as ilmenite, magnetite, zircon, rutile and monazite; in addition to leucoxene. While the processed and unprocessed green silicate contain ilmenite, zircon, sphene, monazite and calamine with quartz and other silicate minerals. The highest values of activity concentrations of 238U, 232Th, 226Ra and 40K were observed in black sand, processed and unprocessed green silicates samples. These high radioactivities are attributed to the presence of zircon, monazite and sphene. The radiological hazard parameters; the absorbed dose rate (D), annual effective dose equivalent AEDE, radium equivalent activity Raeq, external hazard index Hex, internal hazard index Hin and gamma activity concentration index Iγ of the studied samples were estimated. The results obtained were tabulated, evaluated, interpreted and discussed.