Extraction of lanthanum and cerium from Indian red mud

Abstract

Laboratory-scale experiments were conducted to recover lanthanum and cerium from Indian red mud in sulphuric 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. Whilst 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.