Optimizing Extraction and Enrichment of Lanthanide from Indonesian Low Grade Bauxite Using Sequential Magnetic Separation, Acid Leaching, and Precipitation Processes

Abstract

In this work, investigation on the extraction of lanthanide from Indonesian low grade bauxite using three processes, namely magnetic separation, acid leaching and precipitation methods. The magnetic separation produced three fractions, namely magnetic (3.37%), low magnetic (12.97%) and non-magnetic (81.54%) with recovery value of 97.9%. The non-magnetic fraction containing lanthanides with size of 200 mesh was used for leaching process using sulfuric acid (3 M) with a solid and liquid (S/L) ratio of 1: 5. The final treatment using precipitation reaction consisted of two stages using sodium sulfate and sodium hydroxide. The first stage using sodium sulfate produced lanthanide metal of ~ 13.00035% consisting of 11.84% (La), 1.16% (Ce), and 0.00035% (Y). The second stage using sodium hydroxide resulted lanthanide of ~0.00392% with consisting composition of La (0.00108%), Ce (0.00262%), and Y (0.00022%). After the series treatments, the concentration of lanthanides increased from 0.00396 % (39.6 ppm) to 13.00427 % (130,042.7 ppm). The total of lighter lanthanides La (54.66%) and Ce (4.80%) and heavy lanthanide of Y (0.013%) were obtained. These resulted showed that the application of acid leaching using sulfuric acid and precipitation reaction were recommended for enrichment of lanthanide from Indonesian low grade bauxite.