Radiological assessment of different monazite grades after mechanical separation from black sand

Abstract

In Egyptian black sands, monazite is a precious mineral characterized by its composition, which includes crucial constituents such as thorium, trace amounts of uranium, and rare earth elements. It is essential to evaluate and quantify the extent of gamma-ray exposure resulting from the presence of primordial radionuclides. This necessity arises from human activities that extract and retrieve raw materials in uranium and thorium mining operations. The current study focuses on the radiological assessment of Monazite raw material in various grades and calculates the associated hazard indices. A hyper pure Germanium detector (HPGe) determined the particular activity. For grade, 90% Monazite samples, the average activities for 232Th, 238U, and 40K were 348,008 ± 1406, 69,299 ± 2086, and 27,510 ± 245 Bq/kg, respectively. For grade 75% Monazite samples, the average activities were 219,000 ± 901, 55,000 ± 500, and 18,300 ± 86 Bq/kg, while for grade 50% Monazite samples, it was 43,294 ± 1549, 9593 ± 629, and 4000 ± 211 Bq/kg for the same element, respectively. Also, 138La’s inherent radioactivity was taken into account. The computed effective and absorbed dosages exceed the worker’s exempt limit of 20 mSv/y. The calculated hazard parameters are higher than the maximum recommended limits. Therefore, it is imperative to employ radiation safety measures to mitigate the potential hazards of ionizing radiation.

Mapping the Spatial Distribution of Natural Gamma Dose Rates as a Baseline Study in the Province of Asti, Italy

“…These studies often included the measurement of radiation levels in soil, water, and air, as well as the examination of specific geological formations. Regions rich in monazite minerals that contain thorium have been inspected, and elevated levels of natural radioactivity sands were reported in Brazil [30], Egypt [31], India [32,33], Iran [34], Malaysia [35], Bangladesh [36], China [37], and others [38,39]. Radiological aspects related to the pri-mordial radioactive families 238 U, 232 Th, 226 Ra, and 40 K, combined with the distribution characteristics of presumably contaminating elements, were seldom simultaneously investigated in rare-earth element (REE)-processing activities [37].…”