scholarly journals Selective Extraction of Platinum(IV) from the Simulated Secondary Resources Using Simple Secondary Amide and Urea Extractants

Separations ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 139
Author(s):  
Yuki Ueda ◽  
Shintaro Morisada ◽  
Hidetaka Kawakita ◽  
Keisuke Ohto
Keyword(s):  
Electrical Equipment ◽  
Selective Extraction ◽  
Extraction Process ◽  
Secondary Amide ◽  
Separation And Purification ◽  
Secondary Resources ◽  
Tertiary Amide ◽  
Third Phase ◽  
Simulated Effluent ◽  
Secondary Amides

The recycling of rare metals such as platinum (Pt) from secondary resources, such as waste electronic and electrical equipment and automotive catalysts, is an urgent global issue. In this study, simple secondary amides and urea, N-(2-ethylhexyl)acetamide, N-(2-ethylhexyl)octanamide, and 1-butyl-3-(2-ethylhexyl)urea, which selectively extract Pt(IV) from a simulated effluent containing numerous metal ions, such as in an actual hydrometallurgical process, were synthesized and achieved efficient Pt(IV) stripping using only water. Comparison of Pt(IV) extraction behavior with a tertiary amide without N–H moieties suggests that the secondary amides and urea extractants effectively use hydrogen bonding to the hexachloroplatinate anion by N–H moieties. Examining the conditions for the third phase formation revealed that the secondary amide extractant with the longest alkyl chain can be used in the extraction process for a long time without forming any third phase, despite its lower Pt(IV) extraction capacity. The practical trial with simple compounds developed in this study should contribute to the development of Pt separation and purification processes.

Hydride Reductions of 1H-Pyrrolo[2,1-c][1,4]-benzodiazepine-5,11-diones: Selective Reduction of Secondary Amides to Carbinolamines

1998 ◽  
Vol 51 (12) ◽  
pp. 1121 ◽  
Author(s):  
Andrew G. Katsifis ◽  
Meredith E. McPhee ◽  
Damon D. Ridley
Keyword(s):  
Selective Reduction ◽  
Secondary Amide ◽  
Tertiary Amide ◽  
Secondary Amides

For the syntheses of radiolabelled pyrrolo[1,4]benzodiazepine antitumour antibiotics we required a method in which the unstable carbinolamine functionality was introduced prior to the radiolabel. In turn this required the selective reduction of a secondary amide in the presence of, inter alia, a tertiary amide. We report methods which can be used to achieve this outcome in a series of 1H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11-diones.

scholarly journals Study on the Effect and Mechanism of Impurity Aluminum on the Solvent Extraction of Rare Earth Elements (Nd, Pr, La) by P204-P350 in Chloride Solution

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Wenjie Zhang ◽  
Xian Xie ◽  
Xiong Tong ◽  
Yunpeng Du ◽  
Qiang Song ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Organic Phase ◽  
Extraction Process ◽  
Industrial Applications ◽  
Separation And Purification ◽  
Aluminum Ion ◽  
Hydrochloric Acid Medium ◽  
Impurity Ion

Solvent extraction is the most widely used method for separation and purification of rare earth elements, and organic extractants such as di(2-ethylhexyl) phosphoric acid (P204) and di(1-methyl-heptyl) methyl phosphonate (P350) are most commonly used for industrial applications. However, the presence of impurity ions in the feed liquid during extraction can easily emulsify the extractant and affect the quality of rare earth products. Aluminum ion is the most common impurity ion in the feed liquid, and it is an important cause of emulsification of the extractant. In this study, the influence of aluminum ion was investigated on the extraction of light rare earth elements by the P204-P350 system in hydrochloric acid medium. The results show that Al3+ competes with light rare earths in the extraction process, reducing the overall extraction rate. In addition, the Al3+ stripping rate is low and there is continuous accumulation of Al3+ in the organic phase during the stripping process, affecting the extraction efficiency and even causing emulsification. The slope method and infrared detection were utilized to explore the formation of an extraction compound of Al3+ and the extractant P204-P350 that entered the organic phase as AlCl[(HA)2]2P350(o).

Efficient trace-scale extraction method of reactor produced 199Au adequate for nuclear medicine applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed F. Attallah ◽  
Ahmed M. Shahr El-Din ◽  
Mohamed A. Gizawy ◽  
Amal M. I. Ali
Keyword(s):  
Aqueous Media ◽  
Selective Extraction ◽  
Extraction Process ◽  
High Yield ◽  
High Recovery ◽  
Rapid Separation ◽  
Efficient Separation ◽  
Liquid Liquid Extraction ◽  
Cyanex 302 ◽  
Cyanex 923

Abstract Production of no carrier-added (NCA) 199Au through natPt(n, γ) reaction and subsequent purification using liquid-liquid extraction from other radioisotopes is studied in the context of theranostic application. Comparative separation of NCA 199Au after dissolution of activated Pt target using three Cyanex compounds (Cyanex-272, Cyanex-302 and Cyanex-923) is evaluated. The extraction process is optimized in terms of the type of extractant, the concentration of extractant, extraction time and aqueous media (HNO3, NH4OH). Among these extractants, the Cynaex-923 is efficient and promising for rapid separation and production of NCA 199Au from HNO3 by high extraction %. Selective extraction of 199Au from other Pt and Ir radioisotopes is observed. High recovery of 199Au was obtained in the case of Cyanex-923 using 0.05 M thiourea dissolved in HCl or 2 M NaOH. Our results find the Cyanex-923 as a promising extractant for efficient separation of 199Au from irradiated Pt target with high yield (99%).

scholarly journals Tantalum and Niobium Selective Extraction by Alkyl-Acetophenone

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 654 ◽  
Author(s):  
Moussa Toure ◽  
Guilhem Arrachart ◽  
Jean Duhamet ◽  
Stephane Pellet-Rostaing
Keyword(s):  
Extraction Efficiency ◽  
Methyl Isobutyl Ketone ◽  
Selective Extraction ◽  
Extraction Process ◽  
Liquid Extraction ◽  
Methyl Isobutyl ◽  
Isobutyl Ketone ◽  
Waste Solution ◽  
Liquid Liquid Extraction ◽  
D Values

A study has been carried out on Ta and Nb recovery by a liquid-liquid extraction process using 4-methylacetophenone (4-MAcPh) as the organic phase. The 4-MAcPh was compared to methyl isobutyl ketone (MIBK) with respect to extraction efficiencies (D values) at different concentrations of H2SO4 in the aqueous phase. The results showed a similar extraction of Nb for both solvents. However, for Ta, extraction efficiency is increased by a factor of 1.3 for 4-MAcPh. In addition, the MIBK solubilized completely after 6 mol∙L−1 of H2SO4 against only a loss of 0.14–4% for 4-MAcPh between 6 and 9 mol∙L−1 of H2SO4. The potential of 4-MAcPh has also been studied to selectively recover Ta from a model capacitor waste solution. The results showed a selectivity for Ta in the presence of impurities such as Ag, Fe, Ni and Mn. The 4-MAcPh also presents the advantage of having physicochemical properties adapted to its use in liquid-liquid extraction technologies such as mixer-settlers.

scholarly journals The ozonolysis of primary aliphatic amines in fine particles

2008 ◽  
Vol 8 (5) ◽  
pp. 1181-1194 ◽  
Author(s):  
J. Zahardis ◽  
S. Geddes ◽  
G. A. Petrucci
Keyword(s):  
Fine Particles ◽  
Reaction System ◽  
Tropospheric Chemistry ◽  
Ozone Exposure ◽  
Surface Barrier ◽  
Secondary Amide ◽  
Tertiary Amide ◽  
Aerosol Mass ◽  
Criegee Intermediates ◽  
Species Specific

Abstract. The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2– and NO3– ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3– (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10−3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

Recovery of Tea Polyphenols from Green Tea Waste by Liquid-Liquid Extraction

2011 ◽  
Vol 396-398 ◽  
pp. 1592-1595
Author(s):  
Zhong Jian Li ◽  
Zhe Wei ◽  
Wei Xiao ◽  
Jun Wang ◽  
Fu An Wu
Keyword(s):  
Distribution Coefficient ◽  
Green Tea ◽  
Ph Value ◽  
New Technology ◽  
Selective Extraction ◽  
Extraction Process ◽  
Tea Polyphenols ◽  
Extraction Temperature ◽  
Tea Waste ◽  
Equilibrium Data

Tea (Camellia sinensis L.) has became one of the most consumed beverages in the world in the past five thousand years, and tea polyphenols (TPs) are important organic acids widely used in chemical, pharmaceutical, food and other industries, which have been shown to exhibit various biological and pharmacological properties. In order to look for new technology of downstream process for TPs separation from green tea waste, selective extraction of TPs with 12 varieties of solvents were carried out, the distribution coefficient and equilibrium experiments at various temperatures were described by extraction isotherms model. The results indicated that the optimum solvent conditions were as follow: extractent was glyceryl triacetate, extraction temperature range was 20~30°C, pH value of crude TPs and reextractant were 3.17 and 9, respectively. Equilibrium data of TPs were successfully fitted to Henry isotherm, the distribution coefficient decreases with the increasing of the temperature, which showing an exothermic adsorption process. The data obtained is useful in the designing of solvent extraction process for the recovery of TPs from green tea waste.

Quercetin Molecularly Imprinted Polymers and its Application in the Separation and Analysis of Natural Products

2015 ◽  
Vol 1083 ◽  
pp. 46-50
Author(s):  
Rui Mei Liu ◽  
Lai Gui ◽  
Shi Feng Dai ◽  
Yan Ju Zhang ◽  
Zhi Gang Xu
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Selective Extraction ◽  
Medicinal Herbs ◽  
Chinese Medicinal Herbs ◽  
Separation And Purification ◽  
Preparation Methods ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Extraction And Purification ◽  
Effective Components

Molecularly imprinted polymers could selectively adsorb the target analytes from complex matrix. Chinese medicinal herbs had the characteristics of multi-component contents and complicated matrix. Molecularly imprinted polymers were very suitable for the selective extraction and purification of effective components in Chinese medicinal herbs. In this paper, the preparation methods of quercetin molecularly imprinted polymers and its applications in the separation and analysis of Chinese medicinal herbs were comprehensively reported. It would be a good reference for the selective separation and purification of quercetin in Chinese medicinal herbs.

scholarly journals Tantalum and Niobium Selective Extraction by Alkyl-Acetophenone

2018 ◽  
Author(s):  
Moussa Toure ◽  
Guilhem Arrachart ◽  
Jean Duhamet ◽  
Stephane Pellet-Rostaing
Keyword(s):  
Physicochemical Properties ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Extraction Efficiency ◽  
Selective Extraction ◽  
Extraction Process ◽  
Liquid Extraction ◽  
Waste Solution ◽  
Liquid Liquid Extraction ◽  
Kd Values

A study has been carried out on Ta and Nb recovery by liquid-liquid extraction process using 4-methylacetophenone (4-MAcPh) as organic phase. The 4-MAcPh was compared to methylisobutylketone (MIBK) with respect to extraction efficiencies (kD values) at different concentrations of H2SO4 in the aqueous phase. The results showed a similar extraction of Nb for both solvents. However, for Ta extraction efficiency is increased by a factor of 1.3 for 4-MAcPh. In addition, the MIBK solubilized completely after 6 mol L-1 of H2SO4 against only a loss of 0.14 to 4% for 4-MAcPh between 6 and 9 mol L-1 of H2SO4. The potential of 4-MAcPh has also been studied to selectively recover Ta from a model capacitor waste solution. The results showed a selectivity for Ta in the presence of impurities such as Fe, Ni, Mn. The 4-MAcPh also presents the advantage of having physicochemical properties adapted to its use in liquid-liquid extraction technologies such as mixer-settlers.

Selective Extraction of Palladium from Simulated Liquid Waste Solution by Emulsion Liquid Membrane Process using D2EHPA as a Mobile Carrier

2014 ◽  
Vol 69 (9) ◽  
Author(s):  
Norasikin Othman ◽  
Norul Fatiha Mohamed Noah ◽  
Norlisa Harruddin ◽  
Nurul Ashida Abdullah ◽  
Siti Khadijah Bachok
Keyword(s):  
Liquid Membrane ◽  
Liquid Waste ◽  
Precious Metals ◽  
Selective Extraction ◽  
Extraction Process ◽  
Extraction Time ◽  
Emulsion Liquid Membrane ◽  
Waste Solution ◽  
Mobile Carrier ◽  
Gold Silver

Liquid semiconductor waste has become a serious problem to the environment due to the toxicity of heavy metals in the wastewater. However the monetary value of precious metals such as gold, silver and palladium has become a great concern nowadays. Therefore this study is investigating the recovery of palladium by emulsion liquid membrane (ELM) process using di-(2-ethylhexyl) phosphoric acid (D2EHPA) as a carrier. The important parameters affecting the extraction of palladium such as concentrations of carrier and stripping agents, extraction time and treat ratio were investigate. This experiment was conducted using a mixer-settler in a batch system. The results showed that more than 90% of palladium was extracted using 0.05M D2EHPA, 0.1 M H2SO4 as a stripping agent, 5 minutes extraction time, and 1:3 treat ratio. However, the study on emulsion stability showed unstable results due to the leakage and swelling occurrence during the extraction process. As a conclusion, the research shows that ELM has the potential to extract palladium from simulated waste solution using D2EHPA as a mobile carrier.

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