Functionalized Dipicolinic Acid Derivatives as TALSPEAK-MME Stripping Agents

ABSTRACT

This work describes the results of an assessment of two derivatives of dipicolinic acid (DPA) as the actinide-selective stripping reagents in the combined HEH[EHP]/Cyanex-923 system, TALSPEAK-MME (mixed monofunctional extractants). One purpose of this investigation is to demonstrate probable advantages derived in phase-transfer kinetics by deploying dipicolinates as preorganized aminopolycarboxylate complexants in TALSPEAK-derived separation systems. The investigation is focused on the behavior of the lanthanides, Am, and selected transition metals (Zr, Mo, Pd, Ru, and Rh) in the extraction, solvent conditioning, and stripping steps. Solvent conditioning with glycine buffer solutions is shown to be effective for the removal of entrained HNO₃ while also managing Pd concentration prior to actinide stripping. The efficacy of the DPA derivative during the actinide-selective strip was assessed, focusing explicitly on the effects of pH and ligand concentration and evaluating the stripping kinetics. These ligands were shown to be highly selective for americium, producing in the TALSPEAK-MME platform separation factors comparable to commonly used actinide selective stripping agents for radiotracer Eu, Am, a trans-lanthanide series and selected transition metals. The stripping kinetics study revealed very rapid phase-transfer reactions, reaching equilibrium in less than 10 s on vigorous agitation. Further work will be required to address the possible contamination of the product by selected transition metals (such as Zr) during the stripping step.     

镓锗铜萃余液综合利用研究与应用

本文针对镓锗铜综合回收系统产出的萃余液,设计通过中和氧化除杂、锌粉置换除铜镉、有机试剂除钴镍、纯碱法生产碱式碳酸锌、高温煅烧生产活性氧化锌和一步法生产元明粉的生产工艺流程,有效的将镓锗铜萃余液分类分离富集,产出具有价值的富集渣和工业产品,进一步提升综合回收经济效益。     

中药口服液提取工艺的分析

对中药口服液提取工艺进行了简单的分析讨论。其中,重点对现有的中药口服液提取工艺方法进行了探讨,并由此思考了水提醇沉法的优化改进,仅供参考。     

Separation of aromatic components from light cycle oil by solvent extraction

To improve the versatility of light cycle oil (LCO), separation of aromatic compounds from LCO by solvent extraction was investigated. LCO was analyzed to identify 35 components: 19 aromatics and 16 alkanes. The batch liquid–liquid equilibrium extraction of LCO was performed using furfural, sulfolane, and methanol as extraction solvents. In each solvent, the aromatics present in LCO were selectively extracted relative to the alkanes. The separation selectivities of aromatics relative to alkanes were larger in sulfolane than in the other solvents. Among the aromatic components, di- and tricyclic compounds were selectively extracted relative to the monocyclic ones.     

咪唑类离子液体萃取分离高值废线路板浸出液中Au(III)的研究

以离子液体为新型萃取剂萃取稀贵金属具有萃取效率高、选择性强、清洁环保等优点，近年来不断被应用于湿法冶金领域，并取得一定研究成果。本文研究了咪唑类离子液体从高值废线路板浸出液中萃取Au(III)的行为。考察了萃取体系、萃取相比、萃取pH值、萃取时间对Au(III)的影响。结果表明，DBC+[BMIM][NTF2]萃取体系可实现室温下绿色、高效萃取Au(III)，对Au(III)选择性强，不与Ni(II)、Cu(II)等其他金属离子共萃。在pH值为0.5、O/A为1:2、萃取时间2min时，可与Au(III)形成稳定络合物，萃取率达到100%。采用1mol草酸对DBC+[BMIM][NTF2]含Au(III)萃取体系进行反萃，O/A为1:10，反萃时间10min时，可实现Au(III)从有机相中全部分离。该研究可为含Au(III)萃取溶液Au(III)与其余金属离子的分离提纯提供数据基础和理论指导。     

Simulation and exploration of cavitation process during microalgae oil extracting with ultrasonic-assisted for hydrogen production

Microalgae is promising to be used as feedstock resources for hydrogen production due to its high oil and grease contents. This promotes the development of extraction technology of microalgae oil. In this study, based on the Rayleigh-Plesset equation, the effects of temperature, pressure, ultrasonic power and frequency on the bubble motion of ethanol ultrasound cavitation are investigated. Subsequently, the effects of different process parameters on the extraction rate are studied using Schizochytrium sp. as raw material by stirring or ultrasonic-assisted extraction. And the composition of algae extraction oil is analyzed. The results show that the amplitude of cavitation bubbles increases with the increase of ultrasonic power and decrease of ultrasonic frequency. The extraction rate of algae oil reaches 93.76 ± 0.48% when the ultrasonic power is 150 W, the reaction time is 30 min, the temperature is 50 °C and the liquid-solid ratio is 10:1.     

Removal of Cu2+ from Water Using Liquid-Liquid Microchannel Extraction

The very good extraction selectivity of Cu²⁺ from water was demonstrated with a new microchannel equipment, by employing di-(2-ethylhexyl)phosphoric acid (D2EHPA) as an extractant and kerosene as a solvent. The effects of different experimental parameters on the extraction efficiency E, the volumetric mass transfer coefficient K_La, and the entrainment were experimentally investigated. The results showed that the extraction efficiency increased with increasing temperature, extractant concentration, phase ratio (organic/aqueous), and pH. The total flow rate, phase ratio, and pH were found to have a great effect on the mass transfer, whereas the temperature and the extractant concentration showed little effect.     

Separation of americium from complex radioactive mixtures using a BTPhen extraction chromatography resin

Extraction chromatography (EC) resins are widely used in analytical radiochemical separations, in particular for actinide separation. However, there is currently limited choice for separation of americium using EC, with DGA (N,N,N′,N′-tetra-n-octyldiglycolamide) resin being the preferred option. Here, we describe preparation and testing of a covalently-linked EC resin utilising a triazine soft N-donor (Me₄BTPhen) extractant for americium extraction. The resin was generated by conjugation of a Me₄BTPhen derivative with poly(vinylbenzyl) chloride to generate PVB–Me₄BTPhen. PVB–Me₄BTPhen was shown to extract americium from a complex matrix simulating nuclear forensic samples, and containing lanthanides, actinides and matrix elements with high Am (III) recovery (>90%) and low extraction of other elements, and provides an alternative to the currently used BTPhen liquid–liquid separation process for Am (III) extraction.     

抽采孔液态CO2预裂效果显微CT实验研究

为研究液态CO2预裂爆破后,煤体内裂隙发育情况,采用高精度微焦点显微CT系统,对预裂后不同区域的煤样进行CT扫描,并利用Photoshop进行孔裂隙占比统计学分析。研究结果显示,距预裂孔4 m处的煤体裂隙发育明显,孔裂隙占比增加了一倍,而在5 m处的煤体裂隙则发育较弱。表明抽采孔内采取液态C2预裂技术后,4 m范围内的煤体裂隙得到了充分发育,为瓦斯抽采提供了有利条件。     

High areal capacitance of FeOOH-carbon nanotube negative electrodes for asymmetric supercapacitors

The relatively low capacitance of negative electrodes, as compared to the capacitance of advanced positive electrodes, poses a serious problem, since this limits the development of asymmetric supercapacitor (SC) devices with a large voltage window and enhanced power-energy characteristics. We fabricate negative SC electrodes with a high capacitance that match the capacitance of advanced positive electrodes at similar active mass loadings, as high as 37?mg?cm^?2. Cyclic voltammetry, impedance spectroscopy, galvanostatic charge-discharge data and the power-energy characteristics of the asymmetric SC device exhibit good electrochemical performance for a voltage window of 1.6?V. Our approach involves the development and application of particle extraction through liquid-liquid interface (PELLI) methods, new extraction mechanisms and efficient extractors to synthesize α-FeOOH and β-FeOOH electrode materials. The use of PELLI allows agglomerate-free processing of powders, which facilitates their efficient mixing with multiwalled carbon nanotubes (MWCNT) and allows improved electrolyte access to the particle surface. Experiments to determine the properties of FeOOH-MWCNT composites provided insight into the influence of the electrode material and the structure of extractor molecules on the composite properties. The highest capacitance of 5.86?F?cm^?2 for negative electrodes and low impedance were achieved using α-FeOOH-MWCNT composites and a 16-phosphonohexadecanoic acid (PHDA) extractor. This extractor allows adsorption on particles, not only at the liquid-liquid interface, but also in the bulk aqueous phase and can potentially be used as a capping agent for particle synthesis and as an extractor in the PELLI method.