The synthesis and characterization of rare-earth hydroxide as a processed result of monazite sand

Abstract

The synthesis and characterization of rare-earth hydroxide as a processed result of monazite sand have been carried out. The synthesis and characterization of rare-earth hydroxide resulting from monazite sand processing are necessary to support the pilot plant activity of rare earth hydroxide produced in the Center of Nuclear Mines Technology BATAN. Rare-earth hydroxide is produced through several stages of the process, namely decomposition of monazite sand with NaOH at 140 °C, partial dissolution with HCl at 80 °C, uranium and thorium deposition, and rare-earth hydroxide deposition with NH4OH. The rare-earth precipitate was dried in an oven at 110 °C. The rare-earth hydroxide produced is characterized and certified. The rare-earth hydroxide powder is homogenized, then a homogeneous test, stabilization test, and characterization test are conducted. In the evaluation of data obtained the rare earth hydroxide that has been homogeneous, stable, contains the minerals of perovskite (La0.9Sr0.1CrO3), villiaumite (NaF), calcium aluminum silicate (CaAl2Si2O8), bredigite (Ca13.5B0.3Mg1.8Mn0.4Si9O32) and cesium sodium uranium chloride (CsNaUCL6). Certificate of parametric test results in rare-earth hydroxide from 10 laboratories accredited with statistical methods obtained 8 rare earth elements, ie Ce: (27.670 ± 3.004) %, La: (13.846 ± 1.503) %, Nd: (8.447 ± 0.816) %, Y: (1.667 ± 0.140) %, Pr: (6.254 ± 0.286) %, Sm: (1.496 ± 0.330) %, Gd: (0.994 ± 0.211) % and Dy: (0.172 ± 0.005) %. Compared with the rare earth hydroxide product of Myanmar, in the rare earth hydroxide the result from Indonesian monazite sand, Pr content higher, but for Ce, La, Nd contents is lower.