Solvent Extraction Process Research Articles

Recovery of Rhodium by Solvent Extraction using N, N, N′, N′, N″, N″-Hexahexyl-nitrilotriacetamide and Electrodeposition

The development of solvent extraction and direct electrodeposition processes is crucial for reducing the volume of secondary waste. In this study, the extraction behavior of Rh(III) using N, N, N, N′, N′, N′-hexahexyl nitrilotriacetamide (NTAamide(C6)) was investigated with three different diluents that have relatively high dielectric constants. Slope analysis revealed that the extraction mechanism of Rh(III) is based on ion-pair extraction. The electrochemical behavior of the extracted Rh(III) complexes in each diluent was investigated using cyclic voltammetry. Rh(III) was reduced to Rh(0) through a three-electron transfer in the NTAamide(C6)/acetophenone, 1,2-dichloroethane, and 1-octanol systems. Moreover, the diffusion coefficient of the extracted Rh(III) complex was evaluated using semi-differential analysis. The electrodeposits were recovered through continuous solvent extraction and direct electrodeposition. The electrodeposits were identified as Rh metals by X-ray photoelectron spectroscopy and X-ray diffraction analyses.

Developing A Digital Twin of a TRUEX Extraction Process that Enables Non-proliferation and Safeguards Monitoring through Optical Spectroscopy and Machine Learning

Background The recycling of spent fuel can increase the longevity and decrease the waste footprint associated with the nuclear fuel cycle. However, nuclear fuel reprocessing introduces the risk of proliferation of fissile material. For example, the recycling of uranium (U) and plutonium (Pu) is generally accomplished via a solvent extraction process. The separation efficiency of the process is dependent on a variety of parameters such as acid concentration, organic to aqueous (O/A) volume ratio, number of separation stages, etc. A change in any of these parameters could result in different extraction conditions of fissile material and lead to a process upset with potential safeguards and proliferation concerns. Thus, the ability to monitor the solvent extraction process in real-time would enable the rapid identification and diagnosis of process upsets. Methods In this work, we discuss the development of a digital twin of a surrogate small-scale nuclear fuel reprocessing solvent extraction process utilizing online optical spectroscopic monitoring, machine learning (ML), and chemical modeling. A cascade of centrifugal contactors was employed with the TRUEX (TransUranic Extraction) solvent and surrogate minor actinides. Spectroscopic sensors were placed at strategic locations within the contactor bank and were used to predict TRUEX surrogate analyte concentrations at those locations. Results A solvent extraction digital twin consisting of the data acquisition, chemical model, and anomaly detection, provided expected concentrations at each contactor during normal operations. The digital twin demonstrated the ability to accurately simulate the extraction behavior under ideal conditions. Furthermore, the digital twin’s ML anomaly detection algorithm was shown to be successful in identifying several non-ideal process upset conditions.

A novel trialkyl phosphate – Ionic liquid mixture for an efficient separation of Lithium ion from its acidic feed solution

Separation of Lithium ion (Li+) using conventional non-crown type ligands through solvent extraction process is a challenging task and can only be feasible by tuning the organic phase with an additional polar environment. In this context, we have projected an extracting system containing a traditional trialkyl phosphate (T(alk)P): Tri-iso-amyl phosphate (TiAP) containing a minimal amount of ionic liquid (IL): [C4mpip][NTf2] (1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide) for the efficient extraction and separation of Li+ from its hydrochloric acid feed. The extraction performances pertaining various experimental parameters were realized to explore the solvent potentiality of TiAP/[C4mpip][NTf2] towards Li+ coordination. Involvement of two ligand molecules in extraction in presence of 10 % (v/v) IL diluent offers fast extraction kinetics and turns the extraction mechanism into a cation exchange pathway, which was further examined by using different classes of ILs in conjunction with TiAP for Li+ uptake. The selectivity of Li+ over other alkali (or alkaline earth) metal ions was investigated to highlight the affinity of the proposed IL system towards Li+. Extraction scenario in TiAP phase was compared with that in TBP phase containing same IL to bring out the efficacy of the proposed IL system. The stripping performance of Li+ from the loaded organic phase was studied using an acid solution to establish the sustainability of the proposed extraction process.

Implementation of an innovative hybrid process based on electrodeionization for nickel and cobalt separation from synthetic pregnant leach solution

ABSTRACT In this study, an innovative hybrid process was proposed and examined as an alternative for nickel/cobalt separation from a synthetic pregnant leach solution. The first step was carried out by employing electrodeionization of a feed solution containing 950 ppm of nickel and 100 ppm of cobalt after adding EDTA to form (Ni-EDTA)−2 complex to suppress migration of nickel cations toward cathodic compartment. This process increased nickel percentage from 90.47 to 97 in the diluted feed solution. This solution was then subjected to cation exchanging process to adsorb the remaining cobalt cations, leading to a nickel purity of 99.7 wt% with an overall recovery 71.1%. On the other hand, the cathode rinse solution of EDI process which contained a major portion of the cobalt cations underwent three stages of extraction process using cyanex 272, resulting in recovery of 65.5 wt% of cobalt with a purity of 100%. It was seen that six stages of solvent extraction process were needed to reach the same purity of cobalt cations by the traditional extraction method. These findings highlight the superior performance of the proposed hybrid process, which not only yielded a relatively high recovery ratio but also ensured excellent purity of nickel and cobalt.

Control of encapsulation efficiency and morphology of poly(lactide-co-glycolide) microparticles with a diafiltration-driven solvent extraction process

The removal of organic solvents during the preparation of biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microparticles by an O/W- solvent extraction/evaporation process was investigated and controlled by diafiltration. Emulsification and steady replacement of the aqueous phase were performed in parallel in a single-vessel setup. During the process, the solidification of the dispersed phase (drug:PLGA:solvent droplets) into microparticles was monitored with video-microscopy and focused beam reflectance measurement (FBRM) and the residual solvent content was analyzed with headspace gas chromatography (organic solvent) and coulometric Karl-Fischer titration (water). Microparticles containing dexamethasone or risperidone were characterized with regard to particle size, morphology, encapsulation efficiency and in-vitro release. Diafiltration-accelerated solvent extraction shortened the process time by accelerating solidification of dispersed phase but reduced the residual dichloromethane content only in combination with increased temperature. Increasing the diafiltration rate increased particle size, porosity, and the encapsulation efficiency of risperidone. The latter effect was particularly evident with increasing lipophilicity of PLGA. A slower and more uniform solidification of end-capped and increased lactide content PLGA grade was identified as the reason for an increased drug leaching. Accelerated solvent extraction by diafiltration did not affect the in-vitro release of risperidone from different PLGA grades. The initial burst release of dexamethasone was increased by diafiltration when encapsulated in concentrations above the percolation threshold. Both porosity and burst release could be reduced by increasing the process temperature during diafiltration. Residual water content was established as an indicator for porosity and correlated with the burst release of dexamethasone.

Carbon dioxide as a sustainable reagent in circular hydrometallurgy.

This review highlights the use of CO2 as a reagent in hydrometallurgy, with emphasis on the new concept of circular hydrometallurgy. It is shown how waste CO2 can be utilised in hydrometallurgical operations for pH control or regeneration of acids for leaching. Metal-rich raffinate solutions generated after removal of the valuable metals can serve as feedstocks for mineral carbonation, providing alternative avenues for CO2 sequestration. Furthermore, CO2 can also be used as a renewable feedstock for the production of chemical reagents that can find applications in hydrometallurgy as lixiviant, as precipitation reagent or for pH control. Mineral carbonation can be combined with chemical reactions involving metal complexation reagents, as well as with solvent extraction processes for the concurrent precipitation of metal carbonates and acid regeneration. An outlook for future research in the area is also presented.

Fast pyrolysis of paper sludge in a continuous stirred-tank reactor and liquid-liquid extraction of benzenoid aromatics from fast pyrolysis bio-liquid

Paper sludge is a solid waste in paper mills and is conventionally treated by, e.g., landfill, composting, and incineration. Paper sludge contains paper production fillers and lignocellulosic biomass, both of which can be recycled to recover circular minerals and produce bio-based fuels and chemicals by, e.g., thermochemical recycling technology namely fast pyrolysis, for circular bioeconomy. In this paper, three different paper sludge samples collected in The Netherlands and Spain were analyzed by thermogravimetric analysis, moisture analysis, ash analysis, CHNS elemental analysis, powder X-ray diffraction, and X-ray fluorescence spectrometry. Fast pyrolysis of paper sludge was carried out in a lab-scale continuous stirred tank reactor at 500 ± 10 °C with a paper sludge feeding rate of 1 kg h−1. The recovery of circular minerals, which are mainly calcium carbonate, is 87.1 ± 2.2 % (on mineral basis). The yields of fast pyrolysis bio-liquid and biochar are 49.2 ± 6.7 wt% (on biomass basis, equivalent to 23.7 ± 2.2 wt% on paper sludge basis) and 23.8 ± 8.3 wt% (on biomass basis). Fast pyrolysis bio-liquid is a diluted aqueous containing various oxygenates (major, including alcohols, acids, benzenoid aromatics, aldehydes, ketones, ethers, and esters) and hydrocarbons. Liquid-liquid extraction of the fast pyrolysis bio-liquid using CH3OH/H2O and SO2/H2O was further performed to obtain an improved bio-liquid with relatively high concentration of the desired bio-based chemicals (namely benzenoid aromatics with the concentration of 53.1–65.9 area%). Both SO2/H2O and CH3OH/H2O show high liquid-liquid extraction efficiency to concentrate the benzenoid aromatics for 3.4–11.0 times. This work shows the fast pyrolysis followed by liquid-liquid extraction for the valorization of paper sludge, of which the former has been recently demonstrated on a pilot-scale unit in industry. However, the latter still needs to be further developed by, e.g., focusing on the extraction solvent and continuous liquid-liquid extraction process integrated to fast pyrolysis.

Highly selective extraction of aluminum from chloride and sulfate solutions using a mixture of alkoxycarboxylic acid and tributyl phosphate

Four different solvent extraction systems are compared for aluminum (Al) separation in the presence of alkali metals, alkaline-earth metals, and transition metals. The octoxyacetic acid (OOA acid) is utilized as an Al extraction reagent for the first time, exhibiting high selectivity for Al. The impacts of the concentration of extractants, the equilibrium pH of the aqueous phase, and the concentration of phase modifier were studied systemically. The results indicate that the Al extraction efficiency using OOA/TBP (tributyl phosphate) system could reach 98.9 ± 0.63 % via a single-step solvent extraction process while maintaining negligible extraction for the other metal ions at the pH value of ∼ 4.2. Meanwhile, the separation factors (β) of Al over magnesium, calcium, manganese, cobalt and nickel reach the maximum values (βAl/Mg = 285157, βAl/Ca = 18275, βAl/Mn = 19271, βAl/Co = 10814, βAl/Ni = 5969). Slope analysis and infrared spectroscopic characterization confirm that the extraction of Al by the OOA/TBP system follows the cation exchange mechanism. The OOA/TBP solvent extraction system is promising for the efficient separation of Al, with potential applications in a wide range of practical scenarios.

Coupling Electrochemical Leaching with Solvent Extraction for Recycling Spent Lithium-Ion Batteries.

We propose coupling electrochemical leaching with solvent extraction to separate and recover Li and Co from spent lithium-ion batteries (LIBs). Electrochemical leaching occurs in the aqueous electrolyte for converting solid LiCoO2 into soluble Li+ and Co2+, in which electrons act as reductants to reduce Co(III) to Co(II). Simultaneously, solvent extraction occurs at the interface of aqueous and organic phases to separate Co2+ and Li+. By capturing and utilizing the protons from P507, leaching yields for both Co and Li exceed ∼7 times than acid leaching without solvent extraction. The extraction efficiency of Co2+ reaches 86% at 60 °C, 3.5 V, while simultaneously retaining the majority of Li+ in the H2SO4 solution. The total leaching amount was improved because the organic phase provides protons to help the leaching of Co2+, and the continuous extraction process of Co(II) maintains the low Co2+ concentration in the aqueous solution. The synergistic interaction between electrochemical leaching and solvent extraction processes significantly reduces the consumption of chemicals, enhances the utilization efficiency of protons, and simplifies the recovery process. The leaching kinetics of Li and Co both conforms well to the residue layer diffusion control model and the activation energy (Ea) values of the leaching for Li and Co are 4.03 and 7.80 kJ/mol, respectively. Lastly, the economic and environmental assessment of this process also demonstrates the advantages of this method in reducing inputs, lowering environmental pollution, and enhancing economic benefits.

Recovery of copper from ammonia–ammonium chloride leach liquor using sterically hindered beta-diketone

In this study, the recovery of copper from ammonia–ammonium chloride (NH3–NH4Cl) leach liquor using sterically hindered beta-diketone (β-diketones), a well-known extractant, was investigated. The experimental approach entails studying how various factors, including extraction time, concentration of the extractant, pH, phase ratio, and temperature, impact the effectiveness of copper extraction. The most favourable conditions for extracting copper from ammoniacal solutions containing 871.27 mg/L Cu2+, 1.75 mol/L NH3, and 0.5 mol/L NH4Cl were determined. Optimal copper extraction was achieved through a one-stage solvent extraction process at a phase ratio of 1 : 1, utilising sulphonated kerosene containing 0.25 mol/L of β-diketones. This extraction process lasted for 10 min and yielded a copper extraction efficiency of 75.10%. Additionally, a stripping ratio of 98.52% was achieved from the loaded organic phase through a one-stage stripping procedure at a phase ratio of 1 : 1, conducted at a temperature of 298 ± 0.5 K.

Formulation and evaluation of perfume from locally available flowers

The abstract should summarized the content of the formulation of perfume from flowers such as Rose, Crysanthemum, Plumeris, jasmine essential oil has been conducted. Essential oil from flowers was obtained by solvent exctraction. Perfume extraction is the extraction of aromatic compounds from raw materials,using methods such as solvent extraction’s essential oils are isolated from flowers. Which are the liquid and strong aromatic components and are a high concentrated oils extracted from aromatic flowers. Exctraction is a separation of aromatically active portion of flowers using selective solvent. In this formulation we use solvent extraction process. A literature search was performed to find flowers describing botanical name, genus, species, kingdom etc. The information used is from databases pubMed,Science direct and Goggle scholer. Evaluation test were performed such as Hedonic test, Sensory test, Spot test, Skin irritancy test. Based on result of quality evaluation it can be concluded that all flowers essential oil can be used as perfumery agent in perfume formulation and stable during the storage in room temperature.

Desiri Naturals: sustainable agriculture and eco-friendly business

Learning outcomes After completion of the case study, the students will be able to critically analyze the business model of Desiri Naturals, analyze the pricing strategy of Desiri Naturals, examine the importance of experiential marketing in the success of an environment-friendly business, identify the challenges faced by new entrepreneurs and evaluate the sustainability practices of Desiri Naturals. Case overview/synopsis This case study discusses the business model of an environmentally friendly business. The challenges and obstacles faced by entrepreneurs are illustrated in this case. The entrepreneurs’ vision to provide chemical-free food is highlighted and their business operations as a means to fulfill this vision are explained. Desiri used an age-old bull-driven method of oil extraction (Ghana). Challenges in pricing due to the availability of low-priced mass-produced edible oil using the solvent extraction process are presented in this case. The entrepreneurs faced the pricing dilemma at the inception of the business, as oil produced using the natural cold pressing method cost three times the selling pricing of solvent-extracted oil. Innovative methods of experiential marketing such as Ghana tourism are explained in this case. This case study also explains the sustainable and natural farming techniques propagated through its network of farmers. This case study provides insights into the scalability of this model and the scope for employment generation in rural India. The environmentally friendly practices followed by Desiri, such as the use of glass bottles and reusable steel containers for packaging oil are emphasized. Finally, this case presents the marketing and operational challenges faced by entrepreneurs in their quest to expand their operations. Complexity academic level This case study can be used by postgraduate and undergraduate students studying marketing, entrepreneurship, sustainability and operations management courses in commerce and business management streams. Supplementary materials Teaching notes are available for educators only. Subject code CSS8: Marketing.

Environmentally friendly non-saponification solvent extraction and separation process for RE(III) (RE = Eu, Gd and Tb) in acetic acid solution using HEHEHP/n-heptane

The key to achieving sustainable metal extraction development is to avoid the generation of high-salt wastewater from the source. Here, a new system for the extraction and separation of lanthanide elements Eu(III), Gd(III) and Tb(III) from the acetic acid solution using HEHEHP (2-ethylhexyl hydrogen-2-ethylhexylphosphonate) was studied. The corresponding parameters including contact time, HEHEHP concentration, concentrations of rare earth metal ions and acetic acid in the initial solution, aqueous/organic phase volume ratio (R(A/O)), and temperature were considered to optimize the conditions for the separation of different rare earth elements. The results showed that the separation coefficients of Tb(III)/Gd(III) and Gd(III)/Eu(III) in the acetic acid system were approximately 6.2 and 1.7, with HEHEHP of 0.15 mol/L and R(A/O) of 2:1, and the extraction efficiency of RE(III) reached approximately 73.1%, which was higher than that in the hydrochloric acid and sulfuric acid systems. The mechanism associated with the extraction reaction was evaluated and discussed by the maximum loading capacity method, chromatographic analysis, and FT-IR spectrometric analysis. The mechanism followed a cation exchange reaction and acetic acid did not participate in the extraction process. The feasibility of the separation of Tb(III) from Eu(III) and Gd(III)was also given in terms of the separation coefficients between different elements at different extraction conditions. Since saponification is not necessary in the acetic acid extraction system, it can considerably reduce wastewater discharge to the ecological environment from the source.

Experimental, numerical simulation and genetic algorithm as a hybrid method for the design of hydrogen peroxide separation via non-dispersive solvent extraction

This work employed a hybrid approach combining experiments, numerical simulation, and genetic algorithm (GA) to optimize the non-dispersive solvent extraction (NDSX) process of H2O2. A numerical simulation model with high accuracy was developed. The relative error between the simulation results and experimental data was controlled within 2.2 %. The results indicated the velocity of lumen side and temperature are the key factors affecting the extraction efficiency. The non-dominated sorting GA-II algorithm coupled with the numerical simulation was used to optimize the NDSX process. The Pareto optimal design of the NDSX process can be achieved within the water outlet concentration range of 13.44 to 550.2 kg m-3. Intensification factors of NDSX versus extraction towers are evaluated to be 17.9 and 13.2. In summary, this work provides a design framework for NDSX of H2O2, which is expected to simultaneously promote the mass transfer efficiency and safety of the H2O2 separation process.

Efficient Copper Extraction from Industrial Dilute Solutions Using Air-Assisted Solvent Extraction

ABSTRACT The growing demand for valuable metals in recent decades has heightened the economic significance of extracting them from dilute solutions. This research carefully assesses the extraction efficiency of the air-assisted solvent extraction (AASX) process for effectively recovering copper from industrial dilute solutions, such as the raffinate of the solvent extraction (SX) plant and heap leach solutions. The results clearly showed that increasing the frother dosage to 50 mg/L improved the Cu extraction from 83.5% to 90.2%, but increasing the frother dosage beyond 50 mg/L did not change this response significantly. Although varying the extractant concentration and silicone oil dosage in the studied range did not affect Cu extraction, it noticeably led to an increase in the barrier metals recovery. Furthermore, a nine-step AASX system was applied to comprehensively evaluate the extraction efficiency of Cu from dilute heap leach solution. Moreover, an impressive 95.1% of Cu recovery (from a solution containing 890 mg/L Cu, 12.32 g/L Fe, 2.64 g/L Zn, and 4.1 g/L Mn) was achieved with selectivity ratios of 149.6, 153.0, and 93.5, for Cu/Fe, Cu/Zn, Cu/Mn, respectively. It could be concluded that the AASX process is an efficient and promising method for extracting Cu from industrial dilute solutions derived from secondary resources, low-grade ores, and acid mine drainages.

Application of hydrophobic superparamagnetic nanoparticles in the solvent extraction of nickel aiming to accelerate phase disengagement

This study investigated the application of a magnetic organic phase containing hydrophobic superparamagnetic nanoparticles to accelerate phase disengagement in solvent extraction processes. For this purpose, stearate-modified magnetite nanoparticles were prepared, characterized, and dispersed in 20 vol.% D2EHPA extractant diluted in kerosene to obtain the intended organic phase. The magnetic solvent extraction process of nickel was conducted using the as-prepared magnetic organic phase containing varying concentrations of hydrophobic magnetite nanoparticles in a sulfate medium. The results implied significant decrements of up to four times in the aqueous/organic phase disengagement duration in an external magnetic field with 10 g.L−1 nanoparticles determined as the optimum concentration. Such magnetically accelerated separation was revealed to be the result of colliding and coalescing the size-heterogeneous magnetic organic droplets moving unevenly through the continuous aqueous solution in a separating system. It is also worth mentioning that applying magnetic solvent extraction did not affect the equilibrium extraction behavior of nickel by D2EHPA.

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.

Modeling of microfluidic solvent extraction: Evaluation of different flow regimes and cascade configurations

ABSTRACT Solvent extraction using a microfluidic platform is one of the process intensification tools. It may involve different two-phase flow regimes that have different physical and mass transfer characteristics. Therefore, this study focuses on the selection of a better flow regime, flow conditions and cascade configuration (cross or counter-current) using mathematical modeling for a typical high-throughput application (1000 L/day). The mathematical model is based on a plug flow model. The liquid–liquid system considered is a water–acetone–toluene system. The different flow regimes such as slug flow (SF), slug-droplet flow (SDF) and core-annular flow (CAF) in different cascade configurations are compared on the basis of parameters like specific extraction rate (SER), solvent extraction process effectiveness (SEPE) and modified merit index (MMI). Among the different flow regimes and cases studied, CAF is found to offer lesser parallel paths, total extraction length, total pressure drop and residence time. The best case of CAF has higher SER (3.6 times), SEPE (3.6 times) and MMI (21.8 times) than the best case of SF in both cascades. SDF shows the results between SF and CAF. For a specific flow regime, higher values of parameters are obtained at higher flow rates. Counter-current cascade is found to be better than cross-current cascade.

Exploration of polymer inclusion membrane for nickel recovery from waste printed circuit boards

In this study, the selective recovery of nickel ions from waste printed circuit boards (WPCBs) solution through polymer inclusion membranes (PIMs) containing 5-nonylsalicylaldoxime (ACORGA M5640) as extracting agent and polyvinyl chloride (PVC) as base polymer has been explored. The proposed method utilizes combined process of solvent extraction and PIMs route for the recovery of nickel. As a first step, the copper was solvent extracted using ACORGA M5640 by the previously developed method by our group and further the raffinate of first stage is utilized as feed phase for the nickel recovery. The consequence of carrier concentration on transportation of nickel, pH of feed solution and effect of acidity of stripping agent has also been investigated. The increase in carrier concentration increases the nickel removal efficiency from feed phase to strip phase. Moreover, the increase in concentration of strip phase also increases the nickel ion flux. 99.77 % nickel was selectively recovered from leach liquor using PIMs containing 50 % of ACORGA M5640. Further, PIMs stability and transport studies has been carried out to know the feasibility of its use in recycling of electronic waste.

Optimization of thorium solvent extraction process from feed solution with Cyanex 272 by response surface methodology (RSM)

Due to the limited reserves of uranium, the abundance of thorium compared to it and other advantages, the development of the thorium fuel cycle is of interest in different countries. The optimization of thorium extraction from a feed solution produced by Saghand ore with bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) on a laboratory scale was evaluated by response surface method. The operating variables include Cyanex 272 concentration of 0.001 to 0.2 mol/L, pH of 0 to 2, equilibrium time of 5 to 60 min and aqueous to organic phase ratio of 0.5 to 2.5 were conducted. The value of R2 = 0.9695 and an error of less than 4% indicate the validity of the model. Therefore, the model is in good agreement with the experimental results. It can be said that there are significant interactions between operational parameters, which vindicate different feedbacks of the system in different operational conditions. The results showed that the 4 mol/L sulfuric acid was a suitable agent for recovering thorium ions from the loaded organic phase. In optimum conditions, the thorium purity percentage and thorium stripping efficiency were obtained 98.99 and 94.12%, respectively.