The unique physical and chemical properties of rare earth elements lay the foundation for their extensive application. N,N,N’,N’ Tetra-octyl-3-oxopentanediamide(TODGA) is excellent in its ability of extracting rare ...The unique physical and chemical properties of rare earth elements lay the foundation for their extensive application. N,N,N’,N’ Tetra-octyl-3-oxopentanediamide(TODGA) is excellent in its ability of extracting rare earth elements and it is favored for green initiative. In this paper, the extraction and back-extraction of14 rare earth elements by TODGA were studied. Experiments show that in conditions of 6 mol/L sulfuric acid, the extraction temperature of 25 ℃,the phase ratio of 1:1 and 0.04 mol/LTODGA(aviation kerosene as the diluent), the extraction rates of 14 rare earth elements including lanthanum, cerium, praseodymium,neodymium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium were 99.00%-99.73%. Mixed with hydrochloric acid and nitric acid(HCl 3.5 mol/L, HNO30.5 mol/L), the recoveries of the 14 rare earth elements are 91.52%-99.91% when the extraction temperature is 25 ℃ and the ratio is 1:1. The following application is based on the optimum conditions above with practical samples(from the roasting production line of China North Rare Earth High-tech Company Limited) for extraction and back-extraction experiments. Experiments show that TODGA has excellent enrichment effect on 14 rare earth elements, the extraction rates are 91.36%-99.80%, the back-extraction rates are 87.29%-99.64% and the total recoveries are 81.19%-99.44%.展开更多
Eu3+ is extracted at pH 6 with 5. 0×10-2 mol/L benzo-15-crown-5 in dichloromethane from 5. 0×10-2 mol/L aqueous solution of lithium picrate. The enriched extractability has been investigated. In a concentrat...Eu3+ is extracted at pH 6 with 5. 0×10-2 mol/L benzo-15-crown-5 in dichloromethane from 5. 0×10-2 mol/L aqueous solution of lithium picrate. The enriched extractability has been investigated. In a concentration range from 2. 4 ×10-4 to 1. 8 ×10-3 mol/L solution of europium nitrates, the enrichment coefficients are calculated with the phasc ratio (organic/aqueous) of 1: 5 or 4: 25. The ability of 0. 5 mol/L HNO3 as a back-extractant is discussed with the volume ratio [organic/(0. 5 mol/L HNO3)] of 1 : 3. Crown ether and picric acid exist in the back-extractivephase. Eu3+ is effectively separated from the organic phase by the electrochemical method. The separation efficiency is more than 84%. The optimum electrolysis time or cell voltage is obtained from the relation between the electrolysis current and the time or the voltage.展开更多
基金supported by Beijing Natural Science Foundation(8172033)Fundamental Research Funds for the Central Universities of China(FRF-BR-15-015A)
文摘The unique physical and chemical properties of rare earth elements lay the foundation for their extensive application. N,N,N’,N’ Tetra-octyl-3-oxopentanediamide(TODGA) is excellent in its ability of extracting rare earth elements and it is favored for green initiative. In this paper, the extraction and back-extraction of14 rare earth elements by TODGA were studied. Experiments show that in conditions of 6 mol/L sulfuric acid, the extraction temperature of 25 ℃,the phase ratio of 1:1 and 0.04 mol/LTODGA(aviation kerosene as the diluent), the extraction rates of 14 rare earth elements including lanthanum, cerium, praseodymium,neodymium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium were 99.00%-99.73%. Mixed with hydrochloric acid and nitric acid(HCl 3.5 mol/L, HNO30.5 mol/L), the recoveries of the 14 rare earth elements are 91.52%-99.91% when the extraction temperature is 25 ℃ and the ratio is 1:1. The following application is based on the optimum conditions above with practical samples(from the roasting production line of China North Rare Earth High-tech Company Limited) for extraction and back-extraction experiments. Experiments show that TODGA has excellent enrichment effect on 14 rare earth elements, the extraction rates are 91.36%-99.80%, the back-extraction rates are 87.29%-99.64% and the total recoveries are 81.19%-99.44%.
文摘Eu3+ is extracted at pH 6 with 5. 0×10-2 mol/L benzo-15-crown-5 in dichloromethane from 5. 0×10-2 mol/L aqueous solution of lithium picrate. The enriched extractability has been investigated. In a concentration range from 2. 4 ×10-4 to 1. 8 ×10-3 mol/L solution of europium nitrates, the enrichment coefficients are calculated with the phasc ratio (organic/aqueous) of 1: 5 or 4: 25. The ability of 0. 5 mol/L HNO3 as a back-extractant is discussed with the volume ratio [organic/(0. 5 mol/L HNO3)] of 1 : 3. Crown ether and picric acid exist in the back-extractivephase. Eu3+ is effectively separated from the organic phase by the electrochemical method. The separation efficiency is more than 84%. The optimum electrolysis time or cell voltage is obtained from the relation between the electrolysis current and the time or the voltage.
