Monazite ore is mainly composed of rare earth elements (such as Ce, Nd, La, etc.). These rare earth elements are widely used in several high technology and industrial products. Thailand Institute of Nuclear Technology has performed research on the separation and purification of rare earth elements from Thai monazite ore for supporting industrial applications. In this work, the raw material, intermediate and by-product samples obtained from Thai monazite ore processing were characterized by various physicochemical techniques (WDXRF, XRD and SEM-EDS) for understanding their structural and morphological characteristics. The WDXRF analysis showed that the monazite ore sample contained primarily cerium (30.37 wt% of CeO2) which matched well with the XRD result. An increase in CeO2 concentration up to 39.19 wt% and 64.62 wt% in the intermediate mixed rare earth and cerium hydroxide cake samples were observed after alkali digestion and nitric acid leaching of monazite ore, respectively. No rare earth elements could be detected in the tri-sodium phosphate by-product. Thorium oxide at 6.34% in uranium cake sample was observed. A considerable amount of NaOH in thorium cake sample was noticed.
