Due to the Naturally Occurring Radioactive Materials (NORM) existing in the earth’s crust, the entire natural ore always contains some amount of radioactivity. In particular, rare-earth ore tends to contain relatively high amount of radioactive materials due to the geochemical property of rare-earth element. The main components of radioactivity in rare-earth ore are Uranium, Thorium and their descendant nuclides in the radioactive decay series. Therefore, the refinement and other processing of these ores, especially Monazite, Bastnasite and Zircon, could bring concentrated portions of U, Th or other radioactive materials, which might conflict to the laws and regulations on the handling of radioactive materials, depending on the collected amount and the concentration.
In this article, the analysis method for the radioactivity in the ore based on γ-ray spectrometry and α spectrometry are introduced with the results for several rare-earth ores. Then, the concerning regulation laws and guideline on the nuclear source material, nuclear fuel material and radioisotopes are explained by focusing on the treatment of natural radioactive materials. Finally, the basics of chemical separation techniques of radioactive materials from rare-earth elements, i.e., conventional precipitation method, solvent extraction method and advanced chelate impregnated absorbent method are explained with the help of chemical equilibrium calculations and reported experimental data.
