Inclusion, occlusion and adsorption of rare earth elements from chloride media onto barite-gypsum composite

Abstract

Abstract In this study, a synthetic BaSO 4 ·CaSO 4 composite was prepared by co-precipitation technique, characterised and examined for REE sorption. The sorption parameters were; pH = 4, equilibrium time = 20 min, temperature = 303 K, and REE liquor volume to composite mass ratio of 0.2:1 L g −1 . The sorption reaction was controlled by pseudo 2nd order kinetic mechanism and Langmuir adsorption isotherm with an adsorption capacity of 168.63 mg g −1 . 90.14% of REE (III) was desorbed using 1 mol L −1 HNO 3. The process was endothermic and spontaneous. Accordingly, 1:1 barite-gypsum (natural ingredient for BaSO 4 ·CaSO 4 ), with 136 mg g −1 loading capacity, was used for REEs extraction.