Solvent Extraction Process Research Articles

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.

Enhancing bacterial inhibition in beetroot beverages: The potent combination of sappan heartwood extracts via accelerated solvent extraction and pulsed electric field methods

This study aimed to investigate the potential of sappan heartwood extract as an inhibitor of foodborne pathogenic bacteria in beetroot juice. The extract was obtained using an accelerated solvent extraction process (using an ethanol/water solvent mixture (3:1 w/w) at 120 °C and 1500 psi for 5 min), yielding 10.04 g per 73.6 g of dried sappan heartwood powder, with a percentage yield of 13.64 and 2.69 % brazilin. The extract was combined with pulsed electric fields (PEF) at different strengths and tested against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus), and Salmonella typhimurium (S. typhimurium). Results showed that the combination of sappan heartwood extract and PEF at 15 kV/cm and concentrations of 3.91, 5.86, and 11.73 mg/mL effectively reduced the total plate count and coliform bacteria count, and completely eliminated B. cereus and S. typhimurium during 7 days of storage at 4 °C. Furthermore, this combination was found to be more efficient in bacterial elimination compared to thermal pasteurization and potassium sorbate addition. These findings suggest that sappan heartwood extract can be used as a natural antimicrobial agent in food products, especially in beetroot juice, where regulatory standards restrict the addition of preservatives. Using sappan heartwood extract in combination with PEF is highly effective in killing foodborne pathogens, reducing the risk of consumer harm and ensuring food safety.

Extraction Strategies from Black Alloy Leachate: A Comparative Study of Solvent Extractants

Recycling spent lithium-ion batteries (LIBs) is crucial to prevent environmental pollution and recover valuable metals. Traditional methods for recycling spent LIBs include hydrometallurgy and pyrometallurgy. Among these methods, solvent extraction can selectively extract valuable metals in spent LIB leachate. Meanwhile, spent LIBs that underwent pyrometallurgical treatment generate a so-called ‘black alloy’ of Ni, Co, Cu, and so on. These elements in the black alloy need to be separated by solvent extraction and there have been few studies on extracting valuable metals from black alloy. Therefore, it is necessary to examine the extraction behavior of elements in black alloy and optimize the solvent extraction process to recover valuable metals. In this paper, four types of organic extractants are used to extract metals from simulated black alloy leachate: di-(2ethylhexyl) phosphoric acid (D2EHPA), bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC88A), and neodecanoic acid (Versatic acid 10). Based on the pH isotherms, D2EHPA would be the most reasonable for Mn extraction and impurity removal. Cyanex 272 would be more suitable for Co separation than PC88A, and Versatic acid 10 is preferred for Cu extraction over other metals. In conclusion, the optimal combination of extractants is suggested for the recovery of valuable metals.

Improved Extraction of Crocin and Comprehensive Evaluation of its Physicochemical, Biological, and Functional Properties

Crocin, as a valuable metabolite of saffron, encompasses numerous nutritional, pharmacological, and medicinal properties suitable for different applications. This study aimed to effectively extract crocin compounds with high yield and quality from saffron stigma and comprehensively investigate their various physicochemical and functional properties. To this end, the modified solvent extraction method was used for crocin extraction and its different functional and physicochemical properties were investigated using various characterization techniques. The functional and biological properties of the resultant crocins in terms of antioxidant activity, antibacterial potency, anti-tyrosinase property, and cytotoxicity were investigated. According to the results, a high extraction yield and purity for extracted samples (19.6% and 13.4% production yield and 78% and 98.4% purity in the first and second crystallization steps, respectively) were obtained using the green, environmentally friendly, and sustainable crystallization method. The coloring index, bitterness, and aromatic power of the extracted crocin were comparable with the standard crocin. Morphological, structural, and thermal properties of the extracted crocin from different analytical methods confirmed its preserved composition and structure through the solvent extraction process. Moreover, a desired antioxidant activity by the DPPH, superoxide, hydroxyl radical scavenging, and reducing power assays were observed for resultant crocin products. In the antibacterial and cytotoxicity assays, a 5 mg/mL minimum inhibitory concentration (against Gram-positive and Gram-negative bacteria) and more than 95% cell viability (toward the NIH 3T3 cell line) were recorded, respectively. A potent anti-tyrosinase activity (IC50 = 73.93 μg/mL) with a significant reduction in the melanin production of the B16F10 cell line also was noticed for the obtained crocin products.

The Extraction Using Deep Eutectic Solvents and Evaluation of Tea Saponin.

Tea saponins have high surface-active and biological activities and are widely used in chemicals, food, pharmaceuticals, and pesticides. Tea saponins are usually extracted using ethanol or water, but both methods have their disadvantages, including a negative impact on the environment, high energy consumption, and low purity. In this study, we explored an effective process for extracting tea saponins from tea meal using deep eutectic solvents combined with ultrasonic extraction and enzymatic techniques. The experimental results showed that a high extraction efficiency of 20.93 ± 0.48% could be achieved in 20 min using an ultrasonic power of 40% and a binary DES consisting of betaine and ethylene glycol (with a molar ratio of 1:3) at a material-liquid ratio of 1:35 and that the purity of the tea saponins after purification by a large-pore adsorption resin reached 95.94%, which was higher than that of commercially available standard tea saponin samples. In addition, the extracted tea saponins were evaluated for their antioxidant and bacteriostatic activities using chemical and biological methods; the results showed that the tea saponins extracted using these methods possessed antioxidant properties and displayed significant antibacterial activity. Therefore, the present study developed a method for using deep eutectic solvents as an environmentally friendly technological solution for obtaining high-purity tea saponins from tea meal oil. This is expected to replace the current organic solvent and water extraction process and has great potential for industrial development and a number of possible applications.

Valorization of Sour Cherry Kernels: Extraction of Polyphenols Using Natural Deep Eutectic Solvents (NADESs).

The objective of this research was to optimize the natural deep eutectic solvent (NADES) extraction process from sour cherry kernels (Prunus cerasus L.). For polyphenol isolation, conventional solid-liquid extraction was employed using different concentrations of ethanol (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 96%), as well as the innovative NADES extraction technique. In the initial phase of the research, a screening of 10 different NADESs was conducted, while extraction was carried out under constant parameters (50 °C, 1:20 w/w, 60 min). NADES 4, composed of lactic acid and glucose in a molar ratio of 5:1, exhibited the highest efficiency in the polyphenol isolation. In the subsequent phase of the research, response surface methodology (RSM) was utilized to optimize the extraction process. Three independent variables, namely temperature, extraction time, and solid-liquid (S/L) ratio, were examined at three different levels. The extracted samples were analyzed for total phenol (TP) and antioxidant activity using the DPPH, ABTS, and FRAP assays. ANOVA and descriptive statistics (R2 and CV) were performed to fit the applied model. According to RSM, the optimal extraction conditions were determined as follows: temperature of 70 °C, extraction time of 161 min, and S/L ratio of 1:25 w/w.

Microwave enhanced demulsification of metal ion extraction emulsions: From permittivity modeling to proof of concept for solvent extraction processes

The demulsification by microwaves of liquid-liquid systems for metal recycling was experimentally and numerically investigated. Strongly ionic aqueous phases with high conductivities and typical organic phases, both representative of industrial ones, were used. Experimental microwave demulsification was achieved in both the W/O and O/W systems at the laboratory scale showing the rapidity and the efficiency of the process. The dielectric properties of these representative emulsions were measured and modeled using the permittivities measured in the separate phases and the phase fractions. Taking into account the direction of the emulsion, permittivities were predicted over a wide range of frequencies, along with microwave penetration depths in the whole range of phase fractions. Numerical simulations of the electric field distribution and penetration depths calculations at several frequencies demonstrated that microwave heating is relevant and possible in both W/O and O/W dense packed emulsions, which should rapidly lead to demulsification, including on a large industrial scale.

Physicochemical properties of extraction solvents for the advanced recycling of spent nuclear fuel

A comprehensive understanding of solvent physicochemical properties is essential to developing advanced solvent extraction processes, such as Advanced PUREX (Plutonium Uranium Reduction Extraction) and GANEX (Group Actinide Extraction), that can safely and efficiently recycle spent nuclear fuel. The densities, viscosities and surface tensions of binary mixtures of tributyl phosphate (TBP) (0.92–3.66 M) in n-dodecane and N,N-di (2-ethyl hexyl)isobutyramide (DEHiBA) (0.69–2.78 M) in n-dodecane were measured at atmospheric pressure from 278.15 to 333.15 K. Through these measurements, empirical expressions to predict the density and viscosity at any molar composition of these solvents within the studied temperature range were constructed and shown to be in good correlation with all experimental data across the studied variables. The relationship between temperature and viscosity of pure TBP and DEHiBA can be described by the Arrhenius equation for viscosity in the temperature range studied. Surface tension measurements (air-liquid interface) were obtained for varying extractant concentrations between 278.15 and 333.15 K, which showed that DEHiBA acts as a surfactant when mixed with n-dodecane whilst TBP exhibits a higher surface tension than n-dodecane.

Hollow drop bubbles: A preliminary study of simplified prototype for improving copper(II) extraction with ACORGA® M5640 using coated bubble swarm

There are two well-defined processes for the types of copper ores. One for the processing of copper sulfides and another for the processing of the copper oxides. There are similarities between the two, particularly in the preparation stage of the run of mine (ROM) such as the crushing. However, significant differences exist in how to concentrate the elements of interest. Flotation is the most used concentration process to separate copper sulfide minerals from other minerals using air bubbles. For oxides, after the dissolution of copper, the solvent extraction (SX) process is the preferred path using two immiscible liquids to separate the copper.A line of investigation for solvent extraction is the use of a bubble coated with solvent to extract the metal of interest from the aqueous solution, some devices have been built and tested for this purpose using different principles to generate a coated bubble swarm. However, those equipments have been tested on laboratory and have not been scaled up to an industry level.The Hollow Drop (HD) concept was born from the idea of building a device to generate coated bubbles in a continuous swarm that could be scalable to an industry level. In this paper two columns were built and operated: a proof-of-concept column and a scale-up attempt for the extraction of Cu(II) fom an aqueous solution of 2.5 g L−1 using ACORGA® M5640 (25% v/v) in the Kerosene.The results show that we could generate a bubble swarm and conduct the solvent extraction process at a 97% recovery using our proposed coated bubble generator. However, in our scaled prototype test only a 70% recovery was achieved, which shows that our column is working but the scaling-up needs more investigation regarding the dimensions and flows of the process.

Quantifying pore structure heterogeneity of shale samples after solvent extraction following anhydrous and hydrous pyrolysis

Heterogeneity is an important pore structure characteristic of shale formations that can impact reservoir transport properties. To better understand the heterogeneity intrinsic to the shale pore structure, gas adsorption and multifractal theory were combined to analyze data from artificially matured shale samples under both anhydrous and hydrous pyrolysis conditions. We compared two sets of samples: one that was kept intact (not treated with organic solvent), and the other set that was treated with an organic solvent to remove any liquid petroleum that was produced during the pyrolysis process. The results revealed differences in the pore structure parameters of the aliquots under these two pyrolysis conditions as well as treated vs. intact. Furthermore, at the same pyrolysis temperature, the disparity in surface area and pore volume before and after extraction of petroleum was found to be greater with anhydrous compared to hydrous pyrolysis conditions. Regardless of the pyrolysis conditions, when the pyrolysis temperature is under 400 °C, pore structural heterogeneity following extraction of petroleum is often small compared to the situation when yield is still present in the pores. As a result, the movable oil under both maturity routes can increase pore structure heterogeneity. Considering the results, when analyzing shale adsorption data for pore structure heterogeneity, experimental design would have an impact on the final outcome and data interpretation. This is the first study that investigates the effect of the movable oil and solvent extraction process on pore structure heterogeneity in relation to the thermal evolution of shale in the presence and absence of water.

Effective recovery of Ni and Cu from low-grade nickel sulfide concentrate: Process kinetics and preparation of Ni80Cu20O material

In this work, NaCl was used to synchronously extract metal from a low-grade nickel sulfide concentrate. Optimized process parameters were determined as follows: particle size 80–96 μm, temperature 400 °C, time 100 min, and NaCl dosage 100 %. The transformation mechanism of mineral phase was clarified using the means of XRD, SEM and EDS. The roasting process contained solid–solid and gas–solid reactions, and the valuable metal was effectively extracted by the combined action of sulfation of sodium sulfate and chlorination of chlorine gas. The kinetic study of the roasting process showed that the transformation of metals depends on the diffusion control between solid and solid phases. The reaction activation energies of valuable metal were calculated to be 9.15 kJ/mol for Ni, 11.14 kJ/mol for Cu, and 12.72 kJ/mol for Co. Nickel and copper were recovered from the leaching solution by purification and solvent extraction process to prepare Ni80Cu20O material. The Ni80Cu20O electrode material prepared at calcination temperature of 400 °C has excellent electrochemical performance. A new process of recovering metals from minerals to prepare Ni80Cu20O cathode material was established, which was proved to be a clean and promising technology.

A new approach to monitoring solvent extraction processes for the nuclear industry

As part of an initiative to steward research, development, and innovation into the nuclear fuel cycle, Idaho National Laboratory is building the Beartooth test bed. Beartooth will include a cascade of centrifugal contactors, glove box lines, and solidification and dissolution equipment to aid in the progression of novel separation techniques and to provide hands-on opportunities to early-career separation engineers. Beartooth will incorporate novel monitoring techniques using sensors and machine learning algorithms to inform process operators of separation conditions. This research is examining unconventional monitoring technologies such as incorporating acoustic microphones, vibration sensors, infrared cameras, red-green-blue color sensors, among others into nuclear separation processes. Research is ongoing in the use of machine learning methods to detect faults and alert operators of typical and anomalous events. Results from this research have the potential to impact safeguards-by-design efforts and real-time decision making. This overview will detail preliminary measurement results from acoustic, vibration, and color sensors.

High-efficiency stepwise recovery of gallium and rare earths from NdFeB waste by a hydrometallurgical process

NdFeB waste serves not only as a crucial resource for the recovery of rare earth elements (REEs) but also as an underutilized source of gallium (Ga). In this work, to simultaneously extract REEs and Ga from NdFeB waste, an efficient and novel method was developed, which involved the process of leaching, reduction, solvent extraction, precipitation, and calcination. Initially, the Pr, Nd, and Ga were co-leached with 5 mol/L HCl and liquid-solid ratio (mL/g) of 5:1 at 90 °C for 150 min, resulting in the leaching rate of Pr, Nd, and Ga were 98 %, 99 %, and 98 %, respectively. Secondly, to mitigate the interference of Fe (III) on the extraction process, Fe (III) was reduced to Fe (II) completely using Fe powder for 10 min, given that the excess iron powder factor was 1.2. Then, the tributyl phosphate (TBP) was chosen as the extractant for Ga due to its high selectivity. Under the optimal conditions, three-stage counter-current extraction achieved an extraction efficiency of 99 % for Ga, with the addition of 10 % isodecanol to eliminate the third phase. The gallium was completely stripped by water at a phase ratio (O/A) of 2:1. Subsequently, di-2-ethylhexylphosphoric acid was selected as the Pr and Nd extractant because of its high separation ability between REEs and Fe (II). The extraction efficiency of Pr and Nd achieved more than 99 % through three-stage counter-current extraction and the entire stripping of Pr and Nd was realized by 1.8 mol/L HCl. Additionally, a significant amount of Fe (II) in the raffinate was treated via adding oxalic acid to obtain FeC2O4 ⋅ 2H2O. Finally, the Ga2O3 and Nd2O3 (PrO2) were prepared from the stripping solution. According to the whole process, the yield of Ga, Pr, and Nd was 93.4 %, 97 %, and 98 %, with the purity of Ga2O3 and Nd2O3 (PrO2) being 98.6 % and 98.4 %, respectively. The results suggested that the stepwise recovery of REEs and Ga from NdFeB waste can be achieved.

Contamination of Water by Heavy Metals and Treatment Methods – A Review

Water is an indispensable need for the survival of living ecosystems. Industrialization and urbanization gifted a sophisticated life as well as a polluted environment. Water is getting polluted by various means like human activities, industries, and sewage. One of the serious issues around the globe in the upcoming days is heavy metal pollution. A voluminous amount of heavy metals are let into the environment from various sources like agricultural, industry, sewage, and mining. It causes adverse effects on the environment and human beings when the heavy metals concentration is beyond the expected permissible limit. Innovative processes are developing day by day for the operational deletion of heavy metals. This review article provides a consolidated report of the treatment techniques used for heavy metals removal of with excellent efficiency like precipitation, ion-exchange process, adsorption, solvent extraction, electrocoagulation and membrane processes.

Study of the synthetic silica functionalization effect on wettability of oxidized polypropylene film by plasma discharge

AbstractThis work describes the effect of functionalized silica, treated with organosilane (γ‐methacryloxypropyltrimethoxysilane), on the wettability loss of polypropylene (PP) film when exposed to surface oxidization treatment by atmospheric air plasma. The observed wettability loss results from the spontaneous process within the polymer matrix, which reduces surface energy, causing oxidized polymer molecules to move toward the bulk of the film. The effect of silica's functionalization on the initial wettability of oxidized PP film and its loss on storage time is measured by contact angle. Elemental analysis of the modified silica, employing acid catalytic processes, reveals the highest functionalization yield. Silicon nuclear magnetic resonance shows that the post‐condensation process negatively affects structures formed by the organosilane, eliminating three‐dimensional bonds and reverting it to its original and hydrolyzed state. The solvent extraction process and elemental analysis confirm that the concentration of organosilane in the chemically bonded layer, which was around 9 wt%, is not influenced by the post‐condensation treatment. Notably, silica functionalized with the highest concentration of organosilane has significantly improved initial wettability when oxidative treatment occurs within a shorter residence time (30 s), which achieved a contact angle of 53.8° against 59.1° for the film with untreated silica. However, the wettability loss rate of the materials remains unaffected by the presence of functionalized silica.

Flexible Wood‐Based X‐Ray Scintillator Film Using Lead‐Free Cs3Cu2I5 Perovskite Nanoparticles

The prevalent use of unsustainable polymers in current X‐ray scintillators poses a significant environmental concern. The advancement of biodegradable X‐ray scintillators holds promise in mitigating escalating environmental issues tied to electronic or medical waste and carbon footprints. Herein, a biodegradable and flexible X‐ray scintillation film is presented employing lead‐free 0D Cs3Cu2I5 perovskite nanoparticles integrated into densified‐delignified wood (Cs3Cu2I5@D‐Wood). The Cs3Cu2I5@D‐Wood film demonstrates precise and detailed X‐ray imaging capabilities, achieving a high spatial resolution of 10 line pairs per millimeter (lp·mm−1). To minimize the environmental impact associated with disposal, metal and halide ions (e.g., Cs+, Cu+, I−) from Cs3Cu2I5@D‐Wood can be easily retrieved by a simple solvent extraction process. The approach showcases the potential of biodegradable wood‐based X‐ray scintillation screens as alternatives to conventional, plastic‐based screens. This offers a significant contribution to environmental sustainability by reducing electronic or medical waste.

Influence of the extraction process on the chemical composition and oxidation state of baobab (Adansonia digitata L.) seed oil

Baobab oil is nowadays highly prized by local populations as well as the cosmetic industry. It is a rare oil due to the low oil content of the seeds of the baobab fruit (Adansonia digitata L.). To obtain this oil, the collected seeds were cleaned and ground into powder. Then, the extraction was done by pressing and solvent. The aim of this study is to assess the impact of the extraction method on the composition of baobab oil. According to the results obtained, the solvent extraction process has an influence on the fatty acid composition, especially for oleic (36.42 vs 37.40) % and linoleic (26.85 vs 25.21) % acids. We note a significant difference in the total sterol in favor of the solvent extraction process (370.02 mg.100.g-1 for the oil obtained by pressing against 458.14 mg.100.g-1 for the oil obtained by solvent). Solvent extraction drastically reduces total tocopherols from 1562.4 mg.kg-1 to 547.6 mg.kg-1. The chlorophyll content decreases slightly. However, the carotenoid content increases slightly with solvent extraction. According to the results obtained, the soxhlet solvent extraction process has an effect on the chemical composition of the oil. The heat contributes to the oxidation of the oil and the reduction of sensitive elements such as tocopherols.

Insight into the interaction between zirconium dibutyl phosphate complex and diluents: An experimental and computational study

In solvent extraction processes, there are challenges caused by the formation of the third phase or interfacial precipitation. The branched alkanes have been used as diluents to disrupt the third-phase formation, while there is little study about the effect of diluents on the appearance of precipitation. Here, we report the inhibiting effect of the novel hyperbranched alkane diluent (HAD) on the formation of zirconium-dibutyl phosphate (Zr-DBP) precipitation and investigate the formation mechanism by the density functional theory (DFT) theory. The extraction experiments show that HAD as the diluent has a remarkable inhibiting ability to form Zr-DBP precipitation, compared with n-dodecane and kerosene. The spectra show no noticeable difference in the composition and structures of the precipitations formed in the three diluents. The energetics from the DFT calculations suggest the P-OH and P=O ligands on one HDBP molecule can bridge two Zr-DBP complexes into a dimer and then aggregate into the precipitation. Besides, the interactions between diluent-diluent molecules play a significant role in precipitation formation. The straight-chain n-dodecanes have a strong intermolecular dispersion force and tend to attract each other but not the Zr-DBP complex. However, the branched alkanes with weak intermolecular interactions have a better dispersive capacity for Zr-DBP complexes, due to the much higher dispersion force of diluent-complex interaction than that of the diluent-diluent interaction. This work provides a new insight into the formation of interfacial crud from the interactions between solutes and diluents of the organic phase in solvent extraction.

Conversion of Lithium Chloride into Lithium Hydroxide Using a Two-Step Solvent Extraction Process in an Agitated Kühni Column

A significant consequence of the green transition is the growing demand of lithium-ion batteries (LIBs), as they are essential for electrical vehicles. In turn, the demand for the raw materials that are needed to produce LIBs is increasing. A common LIB cathode type for electrical cars is lithium nickel manganese cobalt oxide (NMC). Since cobalt is currently considered as a critical raw material, nickel-rich NMC cathodes are now designed with lower cobalt contents. The synthesis of these new NMC types requires LiOH instead of Li2CO3, which was used for Co-richer NMC materials in the past. Most production routes of LiOH start from Li2CO3 or Li2SO4. However, LiCl could also be a potential precursor for LiOH, as it could be obtained from various lithium sources. A two-step solvent extraction process (SX) was developed for direct conversion of LiCl into LiOH, using a phenol (butylhydroxytoluene or BHT) and a mixture of quaternary ammonium chlorides (Aliquat 336) in an aliphatic diluent (Shellsol D70) as the solvent. The SX process was validated in counter-current mode using a rotary agitated Kühni extraction column. The use of a column instead of mixer-settlers reduced the CO2 uptake by the final product (LiOH), which prevented the partial conversion of LiOH to Li2CO3. A total of 75 L of LiCl feed solution was processed in the Kühni column to obtain a solution of LiOH with a final purity of more than 99.95%, at a yield of 96%.Graphical

Innovative pilot-scale process for sustainable rare earth oxide production from coal byproducts: A comprehensive environmental impact assessment

This study developed a pilot-scale process feeding with two different materials resulting from a column leaching process and acid mine drainage (AMD) streams to recover rare earth elements (REEs). A life cycle assessment (LCA) study was done to evaluate the environmental impacts of rare earth production from deleterious material in the form of highly contaminated leachate (HCL) and low-contaminated leachate (LCL). The results indicate that the main contributors to environmental categories that produce RE-hydroxide stages are NaOH and electricity. Also, oxalic acid, Na2CO3, and hydrochloric acid significantly contribute to the production stage of individual rare earth oxides (REOs), including solvent extraction (SX) and precipitation steps. The HCL route has higher environmental impacts than LCL due to higher chemical/energy and H2SO4 usage, so 468 and 292 kg of carbon dioxide are generated to produce 1 t of individual REOs from HCL and LCL routes, respectively. Moreover, the carbon dioxide emitted from the process, including the RE-hydroxide production, SX, and REOs production, is less than 10 t CO2. A sensitivity analysis was also performed to assess the changeability of the environmental footprints of the main inputs in the SX process, as the main stage has a higher contribution to the whole process. This LCA study is the first step toward understanding the environmental influence of new processing methods to produce REEs from coal by-products through a developed pilot-scale process.