Rare earth precipitation from chloride solution with oxalic acid in monazite processing.

The potential of Rare Earth Elements (REE) in Indonesia is very abundant, its locations are spread across Sumatra Island (Bangka Belitung Province), Kalimantan Island, Sulawesi Island and Papua Island with an estimated total potential of 1.5 billion tons. Global demand for rare earth elements is increasing in line with the increase of electronic equipment, permanent magnets for hybrid electric car applications, rechargeable batteries, lasers, hydrogen storage tanks, superalloy materials for the aerospace industry, television, computer screens, as well as for the development of alternative energy like a fuel cell. One of the minerals containing rare earth metals is monazite. The process of making REE concentrate from monazite can be done through the stages of decomposition, partial dissolution, and precipitation. In this study, it was focused on the precipitation stage using oxalic acid (H2C2O4) as reagent. The purpose of this study was to determine the best concentration of oxalic acid, temperature, and time of precipitation by looking at the results of oxalate and thorium recovery. In this study, feed chloride solution (REE-Cl3) containing REE 100.93 g/L and thorium 0.047 g/L was precipitated with oxalic acid as reagent, using variable mole ratio REE: oxalic acid, at 1: 1.5; 1.6; 1.7; 1.8; 1.9; 2, temperatures of 30, 40, 50, 60, 70, 80 °C, and precipitation times for 15, 20, 25, 30, 35, 40, and 50 minutes. The slurry was filtered to obtain the filtrate and residue. The filtrate was characterized using ICP-OES, and spectrophotometer UV-VIS. The result showed that the highest REE recovery was 99.06 % and the lowest thorium recovery was 89.71 %, with the condition mole ratio of REE : oxalic acid was 1: 1.7, temperature was 60 °C, and the precipitation time was 15 minutes. [ABSTRACT FROM AUTHOR]