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Rajesh Kumar Jyothi,김혜림,김준수,정경우,이진영 대한금속·재료학회 2018 대한금속·재료학회지 Vol.56 No.10
The present paper deals with liquid-liquid extraction studies and the possible separation of light rare earths (LREs) from chloride solutions. Aromatic diluents such as benzene, toluene and xylene were tested for LREs extraction and possible separation from chloride solutions. Bis(2,4,4-triethylpentyl)phosphinic acid (trade name Cyanex® 272) was used as an extractant and dissolved in the diluents. Various experimental parameters such as time effect, influence of pH, extractant concentration variation and maximum loading capacity of the target LREs to Cyanex® 272 were examined. Finally, the separation potential of each of the other LREs was calculated, and a suitable diluent system was proposed. The highest separation factors were found using the present systems.
Rare Earths Recovery from Waste Permanent Magnets (WPMs) by Hydrometallurgical Methods
( Rajesh Kumar Jyothi ),( Jin-young Lee ),( Kyeong Woo Chung ),( Jong Hyuk Jeon ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-
Rare earths are a series of 17 elements (the lanthanides, yttrium, and scandium) which are key components in the current lifestyle. Those metals have multiple applications in different areas especially in the electrical and electronics fields alongside being key materials for green energy production. To recover rare earths from primary (ores) and secondary sources (scraps, spent magnets, etc.) the economically sound and most convenient technology involves liquid- liquid extraction. Several countries, such as South Korea, lack of primary sources of these important metals, therefore they must recur to recycling -or importation (fluctuating depending on the market supply and demand)- to fulfill the demand necessary for their growing high-tech industries, dedicated primarily to the manufacture of electrical and electronic items used in the daily life. In addition, after electronic and industrial goods are used they must be discarded usually in landfills, which in small countries with high population density is a great economic, social and environmental burden. The countries with the highest population densities according to the economic co-operation and development (OECD) organization records (year 2012) are South Korea, The Netherlands, Belgium, Israel, Japan, UK, Germany, Luxemburg, Italy and Switzerland (http://www.un.org/en/development/desa/population/publications/trends/wpp2012. The market trade of rare earths is a monopoly controlled by China, followed by a small supply from India, Australia, Malaysia, Brazil, USA and Russia. China’s monopoly of the RE trade can be seen as detrimental for the free economy of these goods having applications widely in the metallurgy, permanent magnets, electronics, fabrication of household items, glass, alloys, petroleum refining catalysts, among others. The major rare earth consuming industrial products are magnets 26%, metal alloys 19%, polishing 16.5%, catalysts 15%, glass/phosphors 6% and ceramics/others 5.5%, which shows the necessity of an industrial and economically feasible process to recover REEs from waste or secondary resources. The Department of Energy in the United States recognize four elements as critical due to their multiple industrial applications: neodymium, praseodymium, dysprosium and terbium. When talking about green economy, the first option that must be considered is the minimization of the consumption of the elements or the minimization of waste production. The second option to be considered is the reuse, recycling and recovery of the waste produced in the fabrication process of consumer products. Finally, the least favored option is the disposal of waste, which must overcome the landfill challenge. By reusing and recycling rare earth elements from secondary sources the national demand of these metals can be reached without consuming primary resources and having and environmental friendly process.
( Jyothi Rajesh Kumar ),( Chul Joo Kim ),( Ho Sung Yoon ),( Dong Jun Kang ),( Jin Young Lee ) 대한금속재료학회(구 대한금속학회) 2015 대한금속·재료학회지 Vol.53 No.8
In the present study, extraction and separation possibilities have been established for boron and lithium from Uyuni salar brine. Diols were shown to be effective extraction reagents for boron. The present scientific study was developed with 2, 2, 4-trimethyl-1, 3-pentanediol (TPD) as an extractant system. For fixing the diluent system, various diluents were tested and it was found that chloroform is a better diluent for boron extraction. Further, experimental studies on the extraction equilibrium time, pH influence, and phase ratio effects on boron extraction were conducted and the conditions for boron recovery and lithium separation were optimized. The McCabe Thiele diagram was established to optimize the number of extraction stages for boron extraction. Finally, stripping studies of boron from the loaded organic phase using various salts were performed. Received October 31, 2014)
( Jyothi Rajesh Kumar ),( In-hyeok Choi ),( Jin-young Lee ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.4
The present experimental study proposed two ionic liquids (ILs) namely [Aliquat 336] [HSO<sub>4</sub>] (prepared and characterized at our laboratory) and Cyphos 101 IL (supplied by Cytec Company) dissolved in two different diluents such as DCM (di-chloro-methane) and toluene applied for PMs extraction. The first IL [Aliquat 336] [HSO<sub>4</sub>] prepared and confirmed the formation of final product by using FT-IR and TGA studies. The primary experiment in solvent extraction processing is kinetic effect; 0 to 30 time varied for PMs by using two ILs and confirmed the optimized extraction equilibrium time. This study was conducted for PMs (Pt, Rh and Cu) extraction and separation from each other by using proposed ILs. This is the primary study of the utilizing green solvents such as ILs as an extractant system for Pt, Rh and Cu extraction and possible separation.
Rare Earths Extraction, Separation, and Recovery from Phosphoric Acid Media
Reddy, Bontha Ramachandra,Kumar, Jyothi Rajesh MARCEL DEKKER JOURNALS 2016 SOLVENT EXTRACTION AND ION EXCHANGE Vol.34 No.3
<P>Rare earths (REs) recovery and processing becomes most important all over the globe due to their versatile applications in modern life. The present general article discusses REs extraction and possible separation and recovery methods from phosphoric acid media. Leaching studies are discussed followed by two extraction techniques: solvent extraction and solid-liquid extraction. Various extractants such as TOPS 99 (or) D2EHPA, Cyanex 272, PC 88A were tested for REs extraction and separation. Three resins, Tulsion T-PAR, CH-96, and CH-93, as well as impregnated TOPS 99 were utilized for solid-liquid extraction studies.</P>
Liquid-Liquid Extraction General Principles - A Review
이진영,Lee, Jin-Young,Kumar, Jyothi Rajesh The Korean Institute of Resources Recycling 2009 資源 리싸이클링 Vol.18 No.6
본 총설은 용매추출(또는 액-액 추출)에 대한 일반적인 원리와 추출제별 용매추출 공정의 기초 원리를 소개하고 있다. 용매추출은 서로 섞이지 않는 두 상(phase)간에 화합물이 한 상(phase)에서 다른 상으로 이동하는 현상을 이용하는 공정이다. 초기에는 분석화학 분야에서 용매추출의 간편성, 신속성 및 넓은 적용성 때문에 많이 사용되었으며, 분액깔데기와 같은 간단한 도구로 수분내에 추출실험을 완료할 수 있다는 장점이 있다. The present review paper deals the liquid-liquid extraction (LLE) general principles and the basic fundamentals, general process of LLE followed by the importance of LLE reagents. LLE is a process of transferring a chemical compound from one liquid phase to a second liquid phase, immiscible with the first. In analytical chemistry, this method enjoys a favored position among separation techniques because of its simplicity, speed and wide scope. By utilizing apparatus no more complicated than a separatory funnel and requiring several minutes at most to perform, extraction procedures offer much to the analytical chemist.