Stripping Stages Research Articles

Closed-Loop Process of Extracting and Separating Zinc Impurities from Industrial Cobalt Products—Pilot Test Study

The cobalt-containing products of an enterprise were selected as the object of this study. The separation effect of Cyanex 272 on Zn and Co was studied through a pilot test. The results showed that Cyanex 272 had a high extraction rate for Zn at pH 3–3.4, up to 99.8%. The extracted Zn2+ was enriched in the organic phase, and the Zn2+ in the organic phase was extracted back into the aqueous phase in the stripping stage by adding strong acid. Addition amounts of strong acid of 50 g·L−1, 80 g·L−1, and 100 g·L−1 were set. The results showed that the addition amounts of 80 g·L−1 and 100 g·L−1 could significantly reduce the pH of the back-extraction solution and effectively enrich Zn2+ in the solution. There was a large amount of Zn2+ in the back-extraction solution, which could be used twice to prepare zinc carbonate products through neutralization and precipitation. By comparing the extraction effect, economic cost, and resource loss under different strong acid addition amounts, it was found that the 80 g·L−1 strong acid addition amount was more suitable for the actual production process. This study provides data support and practical evidence for the selection of industrial extraction process parameters for Zn2+ separation in actual cobalt products.

Iron removal and valuable metal recovery from spent lithium-ion batteries (LIBs) using solvent extraction after bioleaching

Our study investigated the feasibility of solvent extraction for the separation of impurities, specifically aluminum (Al), copper (Cu), and iron (Fe) from simulated leachate with similar composition to real pregnant leach solution (PLS) obtained after the bioleaching of spent lithium-ion batteries (LIBs). The Fe2+ in the Fe-rich PLS was oxidized to Fe3+ by addition of H2O2. Subsequently, Fe3+, Al3+, Cu2+, and Mn2+ were extracted at pH 4.0 using 20 % di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant. At this pH, 99.99 % of Al3+ and Fe3+, 93 % of Cu2+, and 83 % of Mn2+ were successfully extracted. Co-extracted Co2+ was recovered through a two-stages scrubbing process, where it was replaced with Mn2+ using a MnSO4 solution at an O/A ratio of 1:1. Finally, Al3+, Cu2+, and Mn2+ were stripped with 5 M H2SO4, and 99 % Fe3+ was separated by stripping with 100 % aqua regia. Our study presents an approach for effectively separating valuable metals and impurities, particularly Fe, by optimizing the extraction, scrubbing, and stripping stages of solvent extraction for PLS treatment. Moreover, this study emphasizes the need for further research on the pre-separation of Fe and the development of novel extractants and solvents to enhance the treatment of Fe-rich PLS after bioleaching.

Separation of Pd from Pt and Rh by solvent extraction method from waste solution

The paper investigated the possibility of extractive separation of palladium from platinum and rhodium with ionic liquid Cyphos IL 101. A technological solution obtained by dissolving waste materials was used as the test material. Based on the experiments performed, it was found that a 10% (v/v) solution of the Cyphos IL 101 ionic liquid in toluene allows the extraction of both Pd and Pt with an efficiency of 99% from the initial solution when extraction is carried out at the pH 0.5, vorg:vaq phase ratio 1:1 and contact time of 15 min. Moreover, the research proved that it is possible to separate Pd from Pt at the stripping stage using a 0.1 mol/dm3 thiourea solution while maintaining a high selectivity coefficient.

Highly efficient and eco-friendly process for selective recovery of copper from waste printed circuit boards via pyrolysis and ammoniacal solvoleaching

This study proposes a process combining pyrolysis and ammoniacal solvoleaching to selectively recover Cu from waste printed circuit boards (WPCBs). Optimal pyrolysis conditions were determined by investigating parameters such as temperature, heating rate, N2 flow rate, holding time and particle size. Under the conditions: 500 °C temperature, 20 °C/min heating rate, 0.3 L/min N2 flow rate, 10 min time and +9.50 mm particle size, ∼25% of weight loss was obtained. The pyrolyzed mass underwent further physical separation process involving impact crushing, magnetic- and gravity separations to enrich metals into a concentrate. Copper in the resulting concentrate was selectively extracted using a one-stage ammoniacal leaching and solvent extraction process (ammoniacal solvoleaching), employing an oxime-based organic extractant, LIX 84-I with a small volume of NH4OH. Ammoniacal solvoleaching was optimized by considering parameters such as stirring speed, time, LIX 84-I concentration, volume of aqueous ammonia, temperature and pulp density. Under the following conditions: 500 rpm, 0.3/0.3/10 (g/mL/mL) of sample/NH4OH/LIX 84-I (0.8 M), 3 h time and 25 °C temperature, quantitative Cu dissolution was achieved after two-stage solvoleaching. Cu solvoleaching followed the Avrami model, with an activation energy of 28.95 kJ/mol in the temperature range 15–45 °C (298–318 K) for the mixed control mechanism. LIX 84-I could be recycled without loss of extraction performance. Cu concentration was further enriched during stripping stage using H2SO4. A flowsheet for the sustainable metal recovery from WPCBs was developed.

Adsorption and transport of acid dye through polymer inclusion membrane with Aliquat 336 and TBP

Colour is typically the initial pollutant identified in wastewater. Membrane separation represents a novel approach to separation processes, with expectations of supplanting many traditional separation systems. The aim of this study is to investigate polymer inclusion membranes (PIMs) consisting of tri octyl methyl ammonium chloride as the carrier, tributylphosphate as the modifier, poly-vinyl chloride as the base polymer and 2-Nitro phenyl pentyl ether as the plasticizer for removing an acid dye (Red Erionyl A-3G) from aqueous solution. The dye adsorption on the membrane surface and its transition to the stripping phase was achieved by placing the membrane between two glass cells. Changing the stripping solution ensured both adsorption on the membrane surface and the transfer of all the dye to the stripping stage. Using a mixture of 0.8 M salicylic acid and 0.8 M NaOH, along with stirring at 1000 rpm during the stripping phase, extraction efficiency reached 98% in the feed phase and 53% in the stripping phase. When 1 M NaOH solution was employed as the stripping solution, the membrane absorbed all the dye within 10 minutes, but there was no transition to the stripping phase. The membrane has a durability of 2 days.Graphical abstract

Optimized carbon extraction replicas for transmission electron microscopy of nanoprecipitates in microalloyed low-carbon steels

Nanoprecipitates play a decisive role in strengthening of microalloyed low-carbon steels. The direct carbon extraction replica (CER) method is a promising way to extract the nanoprecipitates from the surrounding iron matrix for a detailed characterization of their structure and chemistry using electron microscopy. Better results can generally be obtained by electron microscopy when the magnetic matrix is removed. However, there are challenges in the preparation of relatively thin CERs, especially during stripping and cleaning stages of the procedure. In this contribution, a systematic study of different parameters associated with the direct CER preparation method was performed on a vanadium-microalloyed low-carbon model steel to improve the replication procedure. Relatively low nanoscale surface kurtosis of the iron matrix with respect to the thickness of the deposited carbon layer was found to be important for successful replications from different crystallographic planes of the matrix during the stripping stage. Furthermore, modified water-based stripping and cleaning solutions were introduced that minimized wrinkling, coalescence, and disintegration of ∼8 nm thick CERs. These results are supported by (scanning) transmission electron microscopy observations, which showed successful extraction of V-rich nanoprecipitates in a size range of 1–50 nm from both the ferritic and bainitic microstructures. The modified method improves the common direct CER preparation procedure and can be used to study precipitates in a wide range of microalloyed low-carbon steels.

СНИЖЕНИЕ ЩЕЛОЧНЫХ И СУЛЬФИДНЫХ СТОКОВ ЗА СЧЕТ ОПТИМИЗА-ЦИИ СТАДИИ ОТДУВКИ СЕРОВОДОРОДА ПРИ ГИДРООЧИСТКЕ БЕНЗИНА КАТАЛИТИЧЕСКОГО КРЕКИНГА

At oil refining and petrochemical industry enterprises, one of the main environmental problems is as-sociated with the need to neutralize or dispose of waste alkaline solutions and aqueous process con-densates contaminated with sulfur compounds, which make up sulfur-alkaline wastewater. This paper addresses the issue of reducing alkali consumption and reducing sulfur-alkali wastewater by optimiz-ing the stages of hydrogen sulfide stripping and alkalization during the hydrotreating of catalytic cracking gasoline

Demonstration of Mixer-Settlers Runs for Separation of Uranium and Neptunium by TBP Vis-a-Vis DHOA Under a Legacy Waste Condition

ABSTRACT Separation of neptunium from an acidic feed containing 0.063 mol/L uranium in 3 mol/L HNO3 was demonstrated in counter-current extraction in mixer-settlers with TBP (tri-n-butyl phosphate) and DHOA (N,N’-dihexyl octanamide) as the organic extractants. With a feed solution of 0.063 mol/L uranium (in the absence of neptunium) and at an organic to aqueous phase ratio (O/A) = 1, >99.9% uranium could be extracted into the organic phase in 6 stages with the raffinate containing <10−5 mol/L of uranium. The extraction results with TBP and DHOA were comparable. However, stripping of uranium with 0.01 mol/L HNO3 from the loaded organic phase was better with DHOA vis-a-vis TBP phase. From the DHOA phase, loaded with 0.063 mol/L uranium, the entire metal ion could be stripped in 6 stages at an O/A = 1. However, ca. 17% uranium remained in the TBP phase even after 6 stages of stripping. With these preliminary results, the extraction of neptunium was systematically studied in mixer-settlers from feed containing uranium, and from simulated high level liquid waste. Our results of neptunium extraction in the presence of 0.021 mol/L uranium yielded excellent result. Similarly, the extraction of neptunium from simulated high level liquid waste was also demonstrated with good extraction efficiency.

Process intensification of metal solvent extraction studies using a miniaturized solvent extraction plant

This study examines the potential of a miniaturized solvent extraction plant (MSXP) to improve the efficiency and reproducibility of laboratory and pilot-scale metallurgical studies that typically require extended testing periods. The MSXP has been designed to replace conventional solvent extraction (SX) apparatus and aims to reduce start-up time, time to reach equilibrium, and overall test time. Two copper solvent extraction (Cu-SX) research campaigns were conducted to test the functionality, ease of operation, modularity, and reproducibility of the MSXP. The first campaign quantified the extraction efficiency and net copper transfer, while the second campaign operated the MSXP in a semicontinuous countercurrent flow configuration with three extraction and two stripping stages. The main variables studied in the first campaign are the number of stages (1-3), volumetric flow rates (O/A, 1-3), and organic phase residence time in the micro-contactor (0.7-2.4 min). The results demonstrate that the MSXP can work with very low stage efficiencies (48%), while achieving high copper recoveries (> 90%). At the stripping circuit level, we show that the MSXP can operate at superior stage efficiencies (> 100%), with low copper recoveries (30%–55%). The reproducibility evaluation also demonstrates high statistical confidence (< 6% CV) in the obtained process values. The MSXP offers great flexibility in net copper transfer and can be used to benchmark and emulate a wide range of Cu-SX systems. Experimental Cu-SX campaigns can be run in about 60 min while investing roughly US$1.4/h on reagents, which is significantly lower compared to typical campaigns that can last from days to weeks to reach reliable research outcomes and require about US$62/h for reagents. The potential of MSXP extends to more elaborate solvent extraction systems, specifically those designed to purify energy-critical elements like lithium, nickel, cobalt, or rare-earth elements. This study demonstrates the promise of process intensification approaches for improving the efficiency of laboratory and pilot-scale SX studies, which can help in reducing time, reagents, and energy consumption while improving the reproducibility of results.

Recovery of Strategic Metals from Waste Printed Circuit Boards with Deep Eutectic Solvents and Ionic Liquids

The recycling of metals from waste printed circuit boards (WPCBs) has been presented as a solid–liquid extraction process using two deep eutectic solvents (DESs) and four ionic liquids (ILs). The extraction and separation of Cu(II), Ag(I), and other metals, such as Al(III), Fe(II), and Zn(II), from the solid WPCBs (after the physical, mechanical, and thermal pre-treatments) with different solvents are demonstrated. Two popular DESs were used to recover valuable metal ions: (1) choline chloride + malonic acid, 1:1, and (2) choline chloride + ethylene glycol, 1:2. The extraction efficiencies of DES 1 after two extraction and two stripping stages were only 15.7 wt% for Cu(II) and 17.6 wt% for Ag(I). The obtained results were compared with those obtained with four newly synthetized ILs as follows: didecyldimethylammonium propionate ([N10,10,1,1][C2H5COO]), didecylmethylammonium hydrogen sulphate ([N10,10,1,H][HSO4]), didecyldimethylammonium dihydrogen phosphate ([N10,10,1,1][H2PO4]), and tetrabutylphosphonium dihydrogen phosphate ([P4,4,4,4][H2PO4]). Various additives, such as didecyldimethyl ammonium chloride surfactant, DDACl; hydrogen peroxide, H2O2; trichloroisocyanuric acid, TCCA; and glycine or pentapotassium bis(peroxymonosulphate) bis(sulphate), PHM, were used with ILs during the extraction process. The solvent concentration, quantity of additivities, extraction temperature, pH, and solid/liquid, as well as organic/water ratios, and the selectivity and distribution ratios were described for all of the systems. The utilization of DESs and the new ILs with different additives presented in this work can serve as potential alternative extractants. This will help to compare these extractants, additives, extraction efficiency, temperature, and time of extraction with those of others with different formulas and procedures. The metal ion content in aqueous and stripped organic solutions was determined by the ICP-MS or ICP-OES methods. The obtained results all show that solvent extraction can successfully replace traditional hydrometallurgical and pyrometallurgical methods in new technologies for the extraction of metal ions from a secondary electronic waste, WPCBs.

Recovery of lithium resources from salt lake brines using a novel low dissolution loss extractant of DEHEHP with FeCl3

Lithium is becoming one of the most eye-catching metal elements in modern industry, mainly because of its crucial role in manufacturing lithium-ion batteries. The demand for lithium in the new energy market is burgeoning significantly, while enormous lithium resources reserved in salt lakes in northwest China are not exploited effectively, due to the high Mg/Li mass ratio. Although the TBP extraction system has been applied in lithium extraction from salt lake brines, there are still some problems to be solved, such as its high solubility, easy degradation, and so on. In this work, a novel low dissolution loss extraction system was developed, with DEHEHP and FeCl3 serving as extractant and co-extractant, respectively. A real brine from Da Qaidam Lake was used to prove its practicality and effectiveness. After studying the detailed conditions of each process, a whole countercurrent process was performed, including eight stages of extraction, two stages of scrubbing, three stages of stripping, and regeneration. It was found that 99.4% of Li+ was successfully recovered from the brine, and the stripping liquor contained 22.74 g/L Li+, 0.51 g/L Mg2+, and 3.16 g/L B. The concentration of Li+ increased approximately 20-fold while the Mg/Li mass ratio decreased by a factor of 3900, from real brine to stripping liquor. High-purity (>98.5%) lithium carbonate products were prepared from the stripping liquor by precipitation. The dissolution loss of the organic phase in the raffinate was only 22.5 ppm, much lower than published works. Finally, the mechanism of extraction and co-extraction were systematically studied and the structure of the complex formed during extraction was revealed as LiFeCl4·2DEHEHP.

Simulation study of reactive distillation process for synthesis of dimethyl maleate

Abstract Conventional dimethyl maleate (DMM) synthesis relies on the use of sulfuric acid as a catalyst which requires water washing and produces a large amount of wastewater that harms the environment. The use of this method is expensive since it involves numerous processes such as neutralization of sulfuric acid, washing with water, distillation etc. and the yield of dimethyl maleate is not very high. Reactive distillation integrates the two important industrial processes such as reaction and distillation into a single unit which shortens the overall process, reduces capital and operating costs, and maintains the reaction in a forward direction to enhance the conversion of maleic anhydride by continuously removing of the products. In this work, simulation study based on experimental investigation of reactive distillation process for the synthesis of dimethyl maleate was carried out using Aspen Plus V11. DZH strong cation exchange resin was used as catalyst for esterification reaction of maleic anhydride with methanol. A reactive section of column was packed with Katapak SP type packing loaded with DZH catalyst while non-reactive sections consist of wire gauze packing. In order to describe a reactive distillation process for synthesis of dimethyl maleate, RAD-FRAC equilibrium stage model was employed. The NRTL activity model and RK equation of state model were selected to describe vapor-liquid equilibrium of the system. The reliability of the developed simulated model was verified by validating the simulation results with the experimental ones. The effect of various design and operating parameters on the conversion of maleic anhydride and purity of dimethyl maleate has been studied. It was found that the optimal condition for RD, were as follow: total number of theoretical stages 17, rectifying stages 3, reactive stages 7, stripping stages 5, reflux ratio 0.25, operating pressure 0.1 MPa, reboiler duty 250 Cal/Sec, feed mole ratio 1:5. Under optimized condition the water formed as a results of esterification reaction was constantly removed from the reactive section of the column to maintain reaction balance, the conversion of maleic anhydride was 99.95 %, purity of dimethyl maleate achieved was 0.997 and the reactive distillation process was feasible to produce dimethyl maleate without any wastewater.

Recovery of pure lithium phosphate from sulfuric acid leaching solutions of spent LiFePO4 batteries by solvent extraction and chemical precipitation

With the increasing use of electric vehicles, the demand for lithium iron phosphate batteries (LiFePO4) has risen sharply. Therefore, the recycling of metals from these batteries at the end of their life is necessary. In this study, a hydrometallurgical process for the recovery of lithium phosphate from spent LiFePO4 batteries was developed. The effects of the parameters on the recovery process, consisting of leaching, solvent extraction, and precipitation were investigated. The addition of H2O2 to the H2SO4 solution was ineffective for the selective leaching of Li(I) over iron. The results showed that Li(I) and iron were completely dissolved by 1.5 mol/L H2SO4, 100 g/L pulp density at 25 ?C for 60 min at 300 rpm. After oxidation of Fe(II) in the leaching solution by addition of H2O2, Fe(III) was completely separated from the solution by five steps of cross-flow extraction with 1.0 mol/L D2EHPA at room temperature. The loaded Fe(III) was successfully separated by four steps of cross-current stripping with 50% (v/v) aqua regia solution. Finally, most Li(I) was recovered by precipitation of lithium phosphate from the iron-free raffinate by maintaining the pH of the solution at 11 and the temperature at 95 ?C for 30 min. The optimum conditions for the complete dissolution of LiFePO4 batteries by sulfuric acid solution and for the separation of iron and lithium ions from the leaching solutions were determined. A hydrometallurgical process was proposed for the recovery of pure lithium phosphate from spent LiFePO4 batteries.

Localization of Defects on PCBs with Diverse Acquisitions

The Printed Circuit Board (PCB) accommodates various Integrated Circuit (IC) components arranged in a specific layout of bond pads, lines, and tracks. Throughout the manufacturing process, irregularities or defects often occur during drilling, etching, stripping, and other stages, impacting the performance and functionality of the circuit board. Many of these defects are related to soldering pads and copper balance, identifying them through manual inspection is time-consuming and error-prone. This necessitates the use of Automated Optical Inspection (AOI). Practices like template matching often require two identical PCBs, which are compared using mathematical algorithms to detect differences. However, they are not resilient to viewpoint variations and non-rigid deformations. The current inspection process primarily focuses on rectifying PCB images captured with tilts ranging from 0 to 84 using homography principles. This correction process operates within a maximum run time of 7.96 s. The adjusted images then undergo analysis via a pattern-matching unit, where the system receives images of the same PCB pattern, each exhibiting different defects. Structural information mapping is performed using various spatial-domain feature-based matching algorithms. When evaluated using SSI and MSE metrics, the model achieved high matching percentages of 99.67%, 99.75%, and 99.30%, and low error rates of 0.343%, 0.358%, and 0.721% for three different types of PCB designs considered. Additionally, the model excels in precisely identifying the location of defects in the PCB images without using bounding boxes, in accordance with the description of the co-images through a segmentation approach. Overall, the proposed system effectively corrects skew, accurately detects abnormalities and outperforms traditional assessment systems.

Ram-pressure induced radial inflows of gas to the galaxy centre

AbstractRam-pressure stripping (RPS) is a process known to remove gas from satellite galaxies. Recent observational studies have found an increased ratio of active galactic nuclei (AGN) among the population of RPS galaxies compared to regular galaxies in the field. To test whether ram pressure (RP) can trigger an AGN, we perform a suite of hydrodynamical wind-tunnel simulations of a massive (Mstar = 1011Mȯ) galaxy, with inclusion of star formation, stellar feedback and high resolution up to 39 pc. We find that RP increases the inflow of gas to the galaxy centre, which in turn can result in the enhanced BH accretion, as measured by the Bondi-Hoyle model. We also estimate pressure of outflows from our accretion rates and show that AGN feedback would play an important role on the early stages of stripping, while RP itself is not so strong.

Cobalt/nickel purification by solvent extraction with ionic liquids in millifluidic reactors: From single-channel to numbered-up configuration with solvent recycle

This work describes the continuous separation of cobalt and nickel by solvent extraction in a numbered-up millifluidic system (1 mm ID) using Cyphos IL 101 (C101) as extractant, which is recycled. A dilution of 50 vol% C101 in p-cymene was chosen as the optimal trade-off between extraction performance and hydrodynamic properties of the solvent. The effects of channel length (20–100 cm), flow rate (1–2.5 mL min−1) and temperature (20–70 °C) were investigated on the extraction, scrubbing and stripping performance in a single-channel system. Subsequently, the developed manifold structure (five parallel reactors) was benchmarked against the single-channel system, which displayed a maldistribution of only 1% and performed equally well as the single-channel system. Then, a continuous separation process of one extraction and two countercurrent stripping stages was executed for 6 h with the proven manifold. A cobalt and nickel purity of, respectively, 99.7 and 97.7 % were achieved at a rate of 5 mL min−1. Stable slug flow was observed in the entire system throughout the operating period.

Sequential Recovery of Critical Metals from Leached Liquor of Processed Spent Lithium-Ion Batteries

The processing and extraction of critical metals from black mass is important to battery recycling. Separation and recovery of critical metals (Co, Ni, Li, and Mn) from other metal impurities must yield purified metal salts, while avoiding substantial losses of critical metals. Solvent extraction in batch experiments were conducted using mixed metal sulphates obtained from the leach liquor obtained from spent and shredded lithium-ion batteries. Selective extraction of Mn2+, Fe3+, Al3+ and Cu2+ from simulated and real leached mixed metals solution was carried out using di-2-ethylhexylphophoric acid (D2EPHA) and Cyanex-272 at varying pH. Further experiments with the preferred extractant (D2EPHA) were performed under different conditions: changing the concentration of extractant, organic to aqueous ratio, and varying the diluents. At optimum conditions (40% v/v D2EPHA in kerosene, pH 2.5, O:A = 1:1, 25 °C, and 20 min), 85% Mn2+, 98% Al3+, 100% Fe3+, and 43% Cu2+ were extracted with losses of only trace amounts (&lt;5.0%) of Co2+, Ni2+, and Li+. The order of extraction efficiency for the diluents was found to be kerosene &gt; Exxal-10 &gt;&gt;&gt; dichloromethane (CH2Cl2) &gt; toluene. Four stages of stripping of metals loaded on D2EPHA were performed as co-extracted metal impurities were selectively stripped, and a purified MnSO4 solution was produced. Spent extractant was regenerated after Fe3+ and Al3+ were completely stripped using 1.0 M oxalic acid (C2H2O4).

End-to-end machine-learning for high-gravity ammonia stripping: Bridging the gap between scientific research and user-friendly applications

The removal and recovery of ammonia from wastewater are critical processes for achieving global environmental sustainability and promoting circular economic development. High-gravity technology is an advanced solution to achieve ammonia stripping from wastewater. This study used machine-learning (ML) techniques to provide more comprehensive insights on various influencing factors, including the operating parameters, wastewater characteristics, and design parameters of rotating packed beds. Bayesian auto-optimization combined with a boosting algorithm effectively overcame the challenges of modeling complex datasets with small sample sizes, multidimensional data, missing values, and skewed distributions. Accurate ML based predictive models for the ammonia removal efficiency (η) and mass transfer coefficient (KLa) were developed, the performance on the training set was R2 = 0.98 and R2 = 0.89, and on the testing set was R2 = 0.98 and R2 = 0.82. The developed model revealed that the stripping stage and gas-liquid ratio were the most influential features for predicting η, whereas the liquid flow and high-gravity factor were the most important features for predicting KLa. The well-trained model was then deployed in an online software application that could provide both predictive and auto-update functions for operators and managers, ensuring that practitioners could use the model. The end-to-end machine-learning approach used in this study—that is, covering data collection, model development, and application—could improve the availability of research results, providing valuable references for the further advancement of technology in the field of environmental.

Organic phase modification of YW100 extraction system: Extraction of germanium using YW100 + D2EHPA + N235

In this study, germanium was selectively extracted using an organic phase containing 3% C7-9 hydroxamic acid (YW100), 15% Di(2-ethylhexyl)phosphoric acid (D2EHPA), 35% Tri(octyl-decyl) amine (N235), and 47% kerosene from the Ge-slag sulfuric acid leaching solution. Then, the solution was stripped by the 1 mol/L NH4F solution to obtain a germanium extraction ratio of 99.4% and a stripping ratio of 96.2% after three extraction and stripping stages. The total organic carbon (TOC) was used to characterize the total organic matter amount in the raffinate. Compared to the “YW100 + D2EHPA” extraction system, the “YW100 + D2EHPA + N235” extraction system reduced 80% of the water solubility loss of YW100 and improved the phase separation performance. In addition, the mechanisms of germanium extraction and phase separation improvement were studied. The coordination number of YW100 and germanium is 3, while the coordination number of D2EHPA is 1.

Ram Pressure Stripping in the EAGLE Simulation

Ram pressure stripping of satellite galaxies is thought to be a ubiquitous process in galaxy clusters, and a growing number of observations reveal satellites at different stages of stripping. However, in order to determine the fate of any individual galaxy, we turn to predictions from either simulations or analytic models. It is not well determined whether simulations and analytic models agree in their predictions, nor the causes of disagreement. Here we investigate ram pressure stripping in the reference EAGLE hydrodynamical cosmological simulation, and compare the results to predictions from analytic models. We track the evolution of galaxies with stellar mass M * > 109 M ⊙ and initial bound gas mass M gas > 109 M ⊙ that fall into galaxy clusters (M 200c > 1014 M ⊙) between z = 0.27 and z = 0. We divide each galaxy into its neutral gas disk and hot ionized gas halo and compare the evolution of the stripped gas fraction in the simulation to that predicted by analytic formulations for the two gas phases, as well as to a toy model that computes the motions of gas particles under the combined effects of gravity and a spatially uniform ram pressure. We find that the analytic models generally underpredict the stripping rate of neutral gas and overpredict that of ionized gas, with significant scatter between the model and simulation stripping timescales. This is due to opposing physical effects: the enhancement of ram pressure stripping by stellar feedback, and the suppression of stripping by the compaction of galactic gas.