• Resources Recycling
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• v.26 no.3
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• pp.26-31
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• 2017

LIX 63 showed a selectivity for the extraction of Pd(II) over other PGMs, such as Pt(IV), Ir(IV) and Rh(III) from 6 M HCl solution. Moreover, HCl solution has significant effect on the oxidation-reduction reaction between Ir(IV) and LIX 63. Therefore, the applicability of employing LIX 63 for the separation of the 4 PGMs was investigated from 3 M HCl solution. From 3 M HCl solution, only Pd(II) was selectively extracted by LIX 63 and its extraction percentage was higher than from 6 M HCl solution. Extraction of the Pd(II) free raffinate with TBP led to the selective extraction of Pt(IV). After oxidation of Ir(III) with $NaClO_3$ to Ir(IV), extraction of the Pt(IV) free raffinate with Aliquat 336 selectively extracted Ir(IV). For each extraction step, optimum stripping conditions were obtained. By this process, it was possible to separate the 4 PGMs by solvent extraction from 3 M HCl solution.

• Resources Recycling
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• v.23 no.2
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• pp.37-45
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• 2014

Solvent extraction experiments have been performed to separate Nd and Pr from chloride leaching solution of monazite sand using single Cyanex272 and mixed extractants as PC88A+Cyanex272 and PC88A+TBP. For this purpose, the effect of the concentration of extractants 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. In Cyanex272 system, our results indicated that concentration of extractant and initial pH did not affect distribution coefficients, but separation factor was increased with increasing initial pH. In binary extractant system, distribution coefficients were lower than those of single PC88A system, whereas separation factor was similar in both mixed and single extractant system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.6015-6022
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• 2013

It has been known that there are large amount of nitric acid and valuable metals, copper in the plating waste solution of automobile wheel. As nitric acid and valuable metals are high price and toxic, they should be recovered for economics and environment. Plating waste was extracted with TBP diluted with kerosene. The concentration of nitric acid in aqueous phase was analyzed by titration method by NaOH solution (0.1~1.0N) and the amount of metals by ICP-MS and ICP-AES. The concentration of copper in plating waste were 76,850 mg/L. The concentration of nitric acid in plating waste was 1.02 M. After three step extraction was performed with 50% TBP, each organic phase was stripped three times with distilled water to obtain 48.1% of nitric acid. Purity of final nitric acid was over 99.9% by ICP analysis. After recovery of nitric acid, copper was extracted with various solvent extractors like PC 88A, D2EPHA, LIX 84 and ISE 106. Among these extractors, 92% of copper was recovered by ISE 106 after 1st extraction and 30% $H_2SO_4$ stripping. Copper ion was reduced with $N_2H_4$ to make metal powders, respectively.

• Resources Recycling
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• v.27 no.3
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• pp.93-99
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• 2018

Effective extraction of platinum group elements by dissolving waste platinum scrap from the display industry and solvent extraction, was studied. The extracted platinum solution was prepared as a precursor solution for diesel automotive exhaust gas purification catalyst and its catalytic activity was tested. The behavior of aqueous species of platinum was investigated through solution chemistry and based on the existence and behavior of these chemical species, the possibility of extraction and separation was established. By dissolving waste scrap by electrochemical method, the dissolution time of scrap was shortened and the extraction efficiency was increased. Through separation and removal of rhodium component, solvent extraction by TBP, and stripping by hydrochloric acid, Pt-Chloride-$H_2O$ solution was prepared. And then, an platinum amine complex solution through amination reaction with this solution as a raw material was prepared. The possibility of producing high-value platinum compounds from platinum group waste scrap was investigated by preparing platinum amine complex solution and then examining the catalytic activity with this amine precursor on the combustion reaction of carbon black.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.743-749
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• 1996

A new static contractor using capillary phenomena induced by a highly packed fiber bundle was developed for the solvent extraction. When two immiscible phases being cocurrently and forcedly fed into the packed fiber bundle, the contactor brings about a very large liquid-liquid contact area for mass transfer within a small definite space without any turbulence and drop phenomena. In order to test the characteristics and stability of the static contractor system, continuous extraction experiments of TBP-uranyl ion-nitric acid system were done and compared with the batch extraction experiment of the same chemical system. The performance of the static contractor were the same as that of the ideal batch extractor with the same extraction condition. For the increase of the extraction yield by the contactor, the increase of organic flow rate was required at a fixed aqueous flow rate, and a certain residence time of the aqueous phase flow within the contactor system had to be maintained to meet the performance of the batch system of the same phase ratio. The residence time in the case of TBP-uranyl ion-nitric acid system was about 1.9 minutes. This system was confirmed to be effective and stable enough for purposes of the kinetic study of solvent extraction as well as the mutual separation and purification of ordinary materials because of good reproducibility and the stable and large static liquid-liquid contact area.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.06a
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• pp.110-111
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• 2006

• Clean Technology
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• v.23 no.4
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• pp.393-400
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• 2017

In this study, we have developed a process for separating and recovering Ni and Fe in solution through a new solvent instead of TBP and Alamine336, which are solvents used in the conventional solvent extraction method. Experimental conditions were optimized through lab test and a $10L\;h^{-1}$ pilot plant was constructed for commercialization. In addition, the process data for mass production were obtained through pilot experiment and it was confirmed that there is no problem in product quality that can be used through the corrosion test of ferric chloride.

• Korean Journal of Metals and Materials
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• v.47 no.6
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• pp.349-355
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• 2009

In the solvent extraction of Ru(IV) with Alamine336, it was found that Ru took part in the reaction as $RuCl_{6}_^{2-}$ in the HCl concentration range of 1 to 5 M. Interaction parameter between hydrogen ion and $RuCl_{6}_^{2-}$ was estimated by applying Bromley equation to the extraction data. From the mixed solutions of Pd(II) and Ru(IV), the distribution coefficients of Pd were found to be higher than those of Ru in the experimental ranges. Separation factor between Pd and Ru rapidly increased with the decrease of Alamine336 concentration. About 60% of the Ru from the mixed solutions was extracted by TBP at 8.3 M HCl, while Pd was not extracted in the HCl concentration range of 1.6 to 8.3 M.

• Resources Recycling
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• v.1 no.1
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• pp.23-28
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• 1992

The process for recovery of acids and valuable metals such as nickel and chromium from the stainless-steel pickling acids has been developed vased on the use of solvent extraction technique. Until now, several processes for the treatment of waste acids were already developed in such countries as Japan, Swden and Canada. Those methods are, however, forcussed on the recovery of acids from them discarding the metals included in them as the hydroxides sludge. In the present work, the recovery of nickel and chromium in addition to nitric acid and hydrofluoric acid has been aimed so as to recycle them to the stainless-steel pickling lines and also to minimize the amount of sludge generated during the treatment of waste acids. The establishment of the process to recover the acids has been carried out based on the solvent extraction with TBP. The iron was eliminated from the waste solutions by precipitating in the form of hydroxide through the adjustment of pH with calcined limestone and the selective extration of chromium and nickel from the resultant solutions has been conducted by using D2EHPA as extractant.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.245-249
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• 1980

Uranium (Ⅵ) was extracted from dilute aqueous solutions of uranyl nitrate with acetylacetone and tri-n-butyl phosphate in n-dodecane. Synergistic effect was observed with the mixed reagents above pH 1. The species extracted are the 1:2:1 and the 1:2:2 uranyl-AA-TBP complexes. The extraction constants for these reactions have been determined.