Potentiality of some Synthesized Benzimidazolo-quinazolinone and Pyrimido-benzimidazole Ligands for Selective Extraction of the Rare Earth Elements

摘要

Three synthesized multidentate organic solvents; namely 1,2-dihydro-3H-benzimidazolo [1,2-a] quinazolin - 4 - one (4a), 1,2-dihydro - 2, 2 dimethyl benzimidazolo [1,2-a] quinazolin - 4 (3H) - one(4b) and 3 - (cyclohexane - 1 - on - 2yl)pyrimido[1,2-a] benzimidazole (4c) were examined for their extractive potentiality of the rare earth elements from Kadabora sulfate leach liquor. The influential parameters controlling the extraction process including the extractant type, the sulfuric acid concentration, the contact time, the organic/aqueous ratio and the solvents concentration were determined. It was also found that the extractability of the synthesized multidentate organic compounds (4a, 4b and 4c) for rare earths decreases in the order 4a > 4b > 4c. The effects of the stripping agent type, concentration, contact time and O/A ratio on the stripping efficiency of the rare earth elements from the loaded extractants were also tested. A rare earth cake was finally obtained from the strip solution by the addition of oxalic acid as a precipitating agent.