Extraction of lanthanum and cerium from Indian red mud

• Red mud sample contained La (110 ppm) as Allanite and Ce (70 ppm) as Dissakisite.
• 99.9% La and Ce were leached out with 3M H2SO4 at 35 °C and 75 °C respectively.
• CYANEX 301 extracted La, Ce and Sc completely from the leach liquor of the red mud.

Laboratory-scale experiments were conducted to recover lanthanum and cerium from Indian red mud in sulfuric acid medium. The method includes acid leaching of red mud pulp and subsequent liquid–liquid extraction of the leached metals with different organic extractants, in order to establish the technical feasibility of extraction and separation simultaneously. Maximum recovery of lanthanum (99.9%) was recorded with 3 M H2SO4 at ambient (35 °C) temperature, S/L ratio of 10 g/L and agitation rate of 200 rpm in 1 h time. While 99.9% cerium recovery was achieved at 75 °C and solid/liquid ratio of 10 g/L in 3 M H2SO4. Significant specificity for complete extraction of lanthanum, cerium and scandium by Cyanex 301 was noted as compared to the solvents such as DEHPA and Cyanex 272.