scholarly journals Tantalum Recycling by Solvent Extraction: Chloride Is Better than Fluoride

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 346 ◽  
Author(s):  
Luke M. M. Kinsman ◽  
Rosa A. M. Crevecoeur ◽  
Amrita Singh-Morgan ◽  
Bryne T. Ngwenya ◽  
Carole A. Morrison ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Aqueous Phase ◽  
Electronic Waste ◽  
Secondary Source ◽  
Alternative Route ◽  
Primary Amide ◽  
Acid Halide ◽  
Subsequent Separation ◽  
Better Than

The recycling of tantalum (Ta) is becoming increasingly important due to the criticality of its supply from a conflict mineral. It is used extensively in modern electronics, such as in capacitors, and so electronic waste is a potentially valuable secondary source of this metal. However, the recycling of Ta is difficult, not least because of the challenges of its leaching and subsequent separation from other metals. In this work, we show that Ta(V) halides, such as TaCl5 and TaF5, which can potentially be accessed from Ta metal upon acid halide leaching, can be recovered by solvent extraction using a simple primary amide reagent. The need for high halide concentrations in the aqueous phase implies the formation of the hexahalide salts [TaX6]− (X = F, Cl) and that an anion-swing mechanism operates. While extraction of the fluorides is poor (up to 45%), excellent extraction under chloride conditions is found (>99%) and presents an alternative route to Ta recycling.

scholarly journals Aspergillus piperis A/5 from plum-distilling waste compost produces a complex of antifungal metabolites active against the phytopathogen Pythium aphanidermatum

2016 ◽  
Vol 68 (2) ◽  
pp. 279-289 ◽  
Author(s):  
Jelena Jovicic-Petrovic ◽  
Sanja Jeremic ◽  
Ivan Vuckovic ◽  
Sandra Vojnovic ◽  
Aleksandra Bulajic ◽  
...  
Keyword(s):  
Citric Acid ◽  
Solvent Extraction ◽  
Antifungal Activity ◽  
Aqueous Phase ◽  
Plant Pathogens ◽  
Complex Mixture ◽  
Pythium Aphanidermatum ◽  
Disease Suppression ◽  
Antifungal Metabolites ◽  
Culture Extract

Adding compost to soil can result in plant disease suppression through the mechanisms of antagonistic action of compost microflora against plant pathogens. The aim of the study was to select effective antagonists of Pythium aphanidermatum from compost, to assess the effect of its extracellular metabolites on the plant pathogen, and to characterize antifungal metabolites. The fungal isolate selected by a confrontation test was identified as Aspergillus piperis A/5 on the basis of morphological features and the internal transcribed spacer (ITS) region, ?-tubulin and calmodulin partial sequences. Liquid chromatography-mass spectroscopy (LC-MS) analysis showed that gluconic and citric acid were the most abundant in the organic culture extract. However, the main antifungal activity was contained in the aqueous phase remaining after the organic solvent extraction. The presence of considerable amounts of proteins in both the crude culture extract as well as the aqueous phase remaining after solvent extraction was confirmed by SDS-PAGE. Isolated Aspergillus piperis A/5 exhibits strong antifungal activity against the phytopathogen Pythium aphanidermatum. It secretes a complex mixture of metabolites consisting of small molecules, including gluconic acid, citric acid and itaconic acid derivatives, but the most potent antifungal activity was associated with proteins resistant to heat and organic solvents. Our findings about the activity and characterization of antagonistic strain metabolites contribute to the understanding of the mechanism of interaction of antifungal metabolites as well as fungal-fungal interaction. The obtained results provide a basis for further application development in agriculture and food processing.

LTCC 3D FLOW FOCALIZATION DEVICE FOR LIQUID-LIQUID PARTIAL SOLVENT EXTRACTION

2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000111-000117
Author(s):  
Houari Cobas Gomez ◽  
Jéssica Gonçalves da Silva ◽  
Jocasta Mileski Machado ◽  
Bianca Oliveira Agio ◽  
Francisco Jorge Soares de Oliveira ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Aqueous Phase ◽  
Microfluidic Device ◽  
Flow Rate ◽  
Extraction Efficiency ◽  
Channel Length ◽  
Main Channel ◽  
Process Variables ◽  
3D Flow ◽  
Acetone Concentration

Abstract The present work shows a ceramics microfluidic device for partial solvent extraction scheme. The technology used for device fabrication was Low Temperature Cofired Ceramics (LTCC) which allows us for complex and chemical resistant 3D microfluidic devices. The proposed system aims to partially extract the solvent present in a mixture containing aqueous and organic phases. This scheme uses a 3D flow focalization in order to improve the solvent diffusion into the external aqueous phase. The device is composed by three different parts, the input channels distribution, the main channel and the output channels distribution. The designed input channels distribution ensures a centered 3D focalized solvent stream along the main channel. The focalized solvent mixes with the surrounding water thanks to diffusion. Projected output channels take the central fluid out separately from the surrounding. Thus the device has two different outputs, one for the focalized fluid and another one for the waste fluid, which is the aqueous phase plus solvent. For a device concept proof, acetone and water were used as organic and aqueous phases, respectively. COMSOL Multiphysics was used for device microfluidics and chemical transport simulation. The extraction efficiency was the variable used as indicator for device performance validation. The flow rate ratio between phases, total flow rate, main channel length and focalized stream channel output hydraulic diameter (ODH) were used as process variables for simulation purposes. A factorial experimental planning was used in order to analyze the extraction efficiency taking into account process variables effects. From simulation results it was determined main channel length and ODH as the variables with stronger effect on extraction efficiency. Obtained simulated efficiencies were as high as 80.6%. Considering previous results observations a microfluidic device was fabricated with a main channel length of 21,4 mm and ODH of 214,63 μm. Gas chromatography was used to measured acetone concentration in outputs samples and from here the extraction efficiency. Experimental results were in agreement with simulation, returning extraction efficiencies in the order of 80.8% ± 2.2%.

scholarly journals Ultrasound-Assisted Deep Eutectic Solvent Extraction of Anthocyanins from Blueberry Wine Residues: Optimization, Identification, and HepG2 Antitumor Activity

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5456
Author(s):  
Hongkun Xue ◽  
Jiaqi Tan ◽  
Qian Li ◽  
Jintian Tang ◽  
Xu Cai
Keyword(s):  
Solvent Extraction ◽  
Antitumor Activity ◽  
Deep Eutectic Solvent ◽  
Extraction Process ◽  
Ultrasonic Power ◽  
Extraction Temperature ◽  
Brewing Process ◽  
Ultrasound Assisted ◽  
Optimum Extraction ◽  
Better Than

Blueberry wine residues produced during the wine-brewing process contain abundant anthocyanins and other bioactive compounds. To extract anthocyanins from blueberry wine residues more efficiently, a novel procedure of ultrasound-assisted deep eutectic solvent extraction (UADESE) was proposed in this work. The extraction process was optimized by response surface methodology coupled with genetic algorithm. The optimum extraction parameters to achieve the highest yield of anthocyanins (9.32 ± 0.08 mg/g) from blueberry wine residues by UADESE were obtained at water content of 29%, ultrasonic power of 380 W, extraction temperature of 55 °C, and extraction time of 40 min. The AB-8 macroporous resin combined with Sephadex LH-20 techniques was used to purify the crude extract (CE) obtained under optimum extraction conditions and analyze the anthocyanins composition by HPLC-ESI-MS/MS. The cyanidin-3-rutinoside with purity of 92.81% was obtained. The HepG2 antitumor activity of CE was better than that of the purified anthocyanins component. Moreover, CE could increase the intracellular reactive oxygen species levels and the apoptosis, and arrest HepG2 cells in the S phases. These findings provided an effective and feasible method for anthocyanins extraction, and reduced the environmental burden of this waste.

Thermodynamics of Solvent Extraction of Perrhenate with N235 at High Concentration

2010 ◽  
Vol 150-151 ◽  
pp. 890-894
Author(s):  
Ke Xu Jiang ◽  
Da Wei Fang ◽  
Han Wang ◽  
Bao Xin Wang ◽  
Ying Xiong ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Aqueous Phase ◽  
Supporting Electrolyte ◽  
Extraction Process ◽  
Extraction System ◽  
Thermodynamic Quantities ◽  
High Concentration ◽  
Extraction Constants ◽  
Solvent Extraction System

In solvent extraction system of perrhenate with the extractant of N235 at high concentration, the equilibrium molalities of ReO4- were measured at ionic strengths from 0.2 to 2.0 mol.kg-1 in the aqueous phase containing Na2SO4 as the supporting electrolyte from 278.15K to 303.15K. The standard extraction constants K0 at various temperatures were obtained. Thermodynamic quantities for the extraction process were also calculated.

THE SOLVENT EXTRACTION OF PROTACTINIUM

1956 ◽  
Vol 34 (3) ◽  
pp. 284-292 ◽  
Author(s):  
A. Goble ◽  
J. Golden ◽  
A. G. Maddock
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Aqueous Phase ◽  
Hydrogen Ion ◽  
Nitrate Complex ◽  
Constant Concentration ◽  
Extraction Coefficient ◽  
Ion Concentrations

The variation of the experimental extraction coefficient for protactinium upon dilution of the solvent ketone with benzene has been determined for aqueous solutions at constant concentration of hydrochloric acid. The bromo complex has been shown to be far less readily extracted. The effects on the extraction of the nitrate complex by amyl acetate, of the nitric acid, of the nitrate and hydrogen ion concentrations in the aqueous phase, as well as of the dilution of the solvent with benzene, have been explored. The existence of a slow reaction in the extraction has been demonstrated. It is concluded that chloride solutions are the more reliable for the isolation of protactinium from concentrates.

scholarly journals Determination of protein loss during aqueous and phase partition fixation using formalin and glutaraldehyde.

1984 ◽  
Vol 32 (10) ◽  
pp. 1107-1112 ◽  
Author(s):  
E T Mays ◽  
R C Feldhoff ◽  
G S Nettleton
Keyword(s):  
Organic Solvent ◽  
Aqueous Phase ◽  
Protein Loss ◽  
Protein Retention ◽  
Phase Partition ◽  
Better Than

In phase partition fixation tissue is immersed in an organic solvent at equilibrium with an aqueous phase containing a fixing agent. By using radioisotope labeling techniques the effects of phase partition fixation on protein retention during fixation of tissue with formalin and glutaraldehyde have been determined and compared with those of standard aqueous fixation using these fixatives. It has been shown that retention of protein in tissue during phase partition fixation was as good or better than during aqueous fixation. Improved retention provides further evidence that phase partition fixation may be a useful alternative to aqueous fixation.

scholarly journals Rare Earth Extraction using Solvent Extraction: Which Factor Has the Most Significant Impact?

2020 ◽  
Vol 7 (2) ◽  
pp. 86-93
Author(s):  
Nurul Ain Ismail
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Factorial Design ◽  
Aqueous Phase ◽  
Extraction Process ◽  
Phase Ratio ◽  
Feed Composition ◽  
Five Factors ◽  
Acid Type ◽  
Rare Earth Extraction

Using a two-level factorial design, a study was undertaken to change the parameters impacting the recovery of rare earth from rare earth mixture. The experimental design was used to screen and identify the major contributing aspects to rare earth recovery. The experiment aims to isolate samarium from a mixture of samarium, europium, and gadolinium. Factors involved consist of pH (pH 1 and pH 6), acid type (nitric acid and hydrochloric acid) and concentration (1.0M and 5.0M), mixing duration (30 min and 120 min), feed composition (20% samarium and 80% samarium), type of diluent (hexane and chloroform), temperature (room temperature and 60°C) and organic to aqueous phase ratio (1:1 and 2:1). The results showed that the samarium recovery was in the range of 0.98% to 90.88%. Based on analysis variance (ANOVA), five factors significantly affect the samarium recovery out of eight factors explored. The five factors according to the most significant order are pH> feed composition> organic to aqueous phase ratio>acid concentration>acid type>mixing duration>type of diluent> temperature.  Statistical analysis shows that the linear model is significant, with the value of R2 is 0.9886. Based on the statistical data, five significant variables influence the separation of samarium. This research shows that two-level factorial design can anticipate significant variables impacting rare earth separation, particularly samarium, in the solvent extraction process.

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