• Resources Recycling
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• v.14 no.2
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• pp.33-42
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• 2005

Solvent extraction experiments have been performed to separate Nd and Sm from chloride solution with PC88A. The effect of the saponification of PC88A on the extraction and separation of the two metals were studied. In the experimental ranges conducted in this study, the distribution coefficients of Sm were higher than those of Nd and separation factor between them increased with the equilibrium pH of aqueous solution. Saponification of PC88A enhanced the distribution coefficients of Sm and Nd and the separation factor. A chemical model was developed to predict the distribution coefficients of metals and separation factor from the initial extraction conditions. The measured distribution coefficients of Nd and Sm with PC88A and saponified PC88A agreed well with those calculated in this study.

• Resources Recycling
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• v.17 no.1
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• pp.12-19
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• 2008

Solvent extraction experiments have been performed to separate Gd and Nd from chloride solution with PC88A and saponified PC88A. In the experimental ranges conducted in this study, the extraction percentage of Gd was higher than that of Nd. Use of 40% saponified PC88A increased the distribution coefficients of Gd and Nd. A chemical model was developed to predict the distribution coefficients of the two metals from the initial extraction conditions. The measured distribution coefficients of Gd and Nd with PC88A and saponified PC88A agreed well with those calculated in this study.

• Resources Recycling
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• v.13 no.4
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• pp.39-45
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• 2004

Solvent extraction experiments of Nd from chloride solution were studied with PC88A. Solvent extraction reaction of Nd with PC88A and the equilibrium constant were evaluated from the extraction experimental data and extraction conditions. Nd$aq^{3+}$ + 1.5 $H_2$$A_2$,org = $NdA_3$,org + 3H/sun $aq^{+}$ , K=0.25 The predicted distribution coefficients of Nd agreed well with the experimental results. The effect of saponification of PC88A on the extraction of Nd and on the change of equilibrium pH was investigated. Saponified PC88A present as a monomer in the organic reaction and enhanced the distribution coefficient of Nd. The initial extraction conditions had a great effect on the equilibrium pH.

• Resources Recycling
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• v.20 no.5
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• pp.46-51
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• 2011

An extraction study of neodymium (Nd) was investigated with different individual and mixer of extractants such as PC88A, D2EHPA, Cyanex 272, Versatic acid 10 and D2EHPA+Alamine-304-1, D2EHPA+Alamine-308, D2EHPA+TBP, D2EHPA+TOPO, PC88A+Alamine-336 and PC88A+TBP respectively. In all cases, it was observed that the extraction percentage of Nd increased with increasing equilibrium pH and extractant concentration but rather opposite observation was found that the extraction percentage of Nd decreased with increasing TBP concentration along with D2EHPA. Adding TBP to PC88A had no favorable effect on the extraction of Nd, whereas use of a mixture of PC88A with Alamine336, increased the extraction percentage of Nd under the same condition. Based on our experimental studies, this paper reports the results on the basic approach and extraction of neodymium.

• Resources Recycling
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• v.23 no.1
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• pp.17-24
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• 2014

Solvent extraction experiments have been performed to separate Nd and Pr from chloride leaching solution of monazite sand using PC88A and D2EHPA. For this purpose, the effect of the saponification of PC88A and D2EHPA on the extraction and separation of the two metals were studied by varying the pH of aqueous solution. In the experimental ranges conducted in this study, the distribution coefficients of Nd were higher than those of Pr and separation factor value increased with the increase of solution pH. Saponification of PC88A enhanced the distribution coefficients of Nd and Pr as well as the separation factor. Saponification of D2EHPA had some effect on the extraction of the two metals but little effect on the separation factor.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.28-32
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• 2005

본 연구는 Karr column을 이용한 희토류원소의 분리에 대한 기초 연구로서, 수상의 초기 pH와 유기상 중 PC-88A의 비누화도에 따른 Nd, Sm의 분리특성을 파악하였다. 실험결과 pH $0.8{\sim}2.3$ 범위에서 PH가 높아짐에 따라 Nd, Sm의 추출율 및 분리계수가 증가하였으며, PC-88A 비누화도 40%인 조건에서 추출 후 수상의 초기 PH에 관계없이 평형 pH가 약 1.5 정도로 유지되는 것을 알 수 있었다. 그리고 PC-88A 비누화도가 증가함에 따라 Nd, Sm의 추출율이 크게 증가하였으며, 비누화도 40%인 조건에서 가장 높은 분리계수(${\beta}_{Sm,\;Nd}\;=\;10.8$)를 보여 주었다.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2711-2716
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• 2014

The high content of potassium in molasses limits its usage as a raw material for stock feed. Moreover, its high viscosity makes it difficult to develop an efficient removal process. In this study, ion exchange and solvent extraction experiments have been performed to investigate the removal of potassium from a mixture of molasses with water. Cationic exchange resins (AG50W-X8 and Diphonix) showed a high loading percentage of potassium but the occurrence of breakthrough in few bed volumes was a drawback to the industrial application. Among the cationic extractants (D2EHPA, PC 88A, Cyanex 272) tested in this study, saponified PC 88A was found to be the best extractant for the removal of potassium. Batch simulation studies on a three stage counter current extraction confirmed that 85% of potassium was removed from 50 wt % molasses solution in water by using saponifed PC 88A.

• Resources Recycling
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• v.13 no.2
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• pp.24-32
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• 2004

Solvent extraction equilibria of Gd with PC88A from chloride solutions were analyzed by considering chemical equilibria. phase equilibria, mass and charge balance equations. The following solvent extraction reaction and equilibrium constant were evaluated from the experimental data performed in this study. $Gd^{3+}$ $+2H_2$$A_2$,$or=GdA_3$HA.or+3 $H^{+}$ , K=3.3 A procedure was suggested to calculate the initial concentration of chloride ion from initial pH and initial concentration of Gd. By applying ionic equilibria, the distribution of Gd complexes with Gd and HCl concentration was obtained. The predicted distribution coefficients of Gd agreed well with the experimental results.

• Resources Recycling
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• v.22 no.5
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• pp.35-42
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• 2013

Solvent extraction experiments have been performed to investigate an optimum condition to separate Nd and Pr from chloride solutions using PC88A and D2EHPA. In our experimental ranges, the distribution coefficients of Nd were higher than those of Pr. In both of PC88A and D2EHPA extractant system, our results indicated that the increase in concentration ratio of extractant to metal had a great effect on the extraction and separation of the two metals. In extraction with saponified D2EHPA, the initial pH of the aqueous solution and saponification degree had some effect on the extraction of the two metals but little effect on the separation factor.

• Resources Recycling
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• v.28 no.1
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• pp.40-46
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• 2019

The solvent extraction of Tb(III) from hydrochloric acid solution was investigated by employing single organophosphorus (D2EHPA, PC88A and Cyanex 272), its mixture with Alamine 336 and ionic liquids with Aliquat 336. The equilibrium pH after the extraction with extractant mixtures and ionic liquids was higher than that by single extractants. Among the mixtures and ionic liquids, only the ionic liquid with Cyanex 272 and Aliquat 336 showed synergism to the extraction of Tb(III). The extraction percentage of Tb(III) by the extractant mixtures was lower than that by single extractant and the extraction order was in the following order : D2EHPA + Alamine 336 > PC88A + Alamine 336 > Cyanex 272 + Alamine 336. The extraction order of Tb(III) by the ionic liquids was Cyanex 272 + Aliqaut 336 > PC88A + Aliquat 336 > D2EHPA + Aliquat 336.