Extraction Of Rare Earth Metals Research Articles

Influence of ionic radius on the degree of extraction of rare earth metals during sorption by the interpolymer system AMBERLITE IR-120 –AВ-17-8

Studies have been carried out on the sorption of rare earth metal ions in solution using the interpolymer system Amberlite IR-120:AB-17-8. The purpose of the work is to search for conditions for maximum sorption of rare earth elements (Dy, Tb, Gd, Eu and Sm) from aqueous solutions using the effect of remote interaction of ion exchange resins. Methodology. The residual concentrations of rare earth ions were determined using an Optima 8300DV Duo inductively coupled plasma spectrometer. Results. The best sorption characteristics were determined by the interpolymer system at a ratio of 3:3. The residual concentration of rare earth elements in the solution was: Dy – 4.64 mg/l, Tb – 4.16 mg/l, Gd – 4.21 mg/l, Eu – 4.16 mg/l, Sm – 4.56 mg/l. The variations in the ionic radius of the ions chosen for the study are Dy3+<Tb3+<Gd3+<Eu3+<Sm3+. The degree of sorption of interpolymer system increased with increasing ionic radius of the metals. For dysprosium with the smallest ionic radius, the degree of sorption was η – 52%, and for terbium, gadolinium and europium it increased to η – 58%. For individual Amberlite IR-120 (6:0), the degree of sorption of terbium ions was 47%. Conclusion. The results of the study showed that the interpolymer system with a ratio of 3:3 has the best sorption activity. It has been established that the degree of sorption of interpolymer pairs increases with increasing order of the ionic radius of metals (Tb3+< Gd3+< Eu3+).

Use of Rare Earth Metals in Renewable Energy: Opportunities and Risks

The results of research on the use of rare earth metals for the development of a low-carbon economy are presented. Directions for the use of rare earth metals for the development of solar and wind energy are shown. Characteristics are given and information is given on the volumes of extraction of rare earth metals in the context of the main countries. The opportunities associated with the use of rare earth metals for the development of renewable energy in the context of low-carbon development are identified, as well as the environmental and social risks associated with the extraction and transportation of ore to processing plants. Using the example of the development of the Tomtor rare earth metal deposit in the Arctic zone of the Republic of Sakha (Yakutia).

LiNO3-assisted electrochemical extraction of metallic Sm from a molecular liquid-based electrolyte

Developing efficient, green, and cost-effective methods for extracting rare earth (RE) metals is essential to accelerate breakthroughs in critical technologies in the field of RE-based functional materials. In this study, a low-cost aprotic polar molecular liquid, N,N-Dimethylformamide (DMF), was used for electrowinning metallic Sm with upstream SmCl3 as the raw material, inspired by previous applications of diverse specialised ionic liquids for the electrochemical recovery of RE metals. Cyclic voltammetry and electrodeposition experiments demonstrated that metallic Sm cannot be obtained from the binary DMF-SmCl3 system, but can be electrodeposited with LiNO3. Therefore, the mechanism underlying the observed electrochemical behaviour is elucidated and discussed in detail. Sm and Sm–Co metallic elements were successfully electrodeposited on an Al substrate at a relatively high current density, characterised, and evaluated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Moreover, a unique two-step method involving electrodeposition and direct smelting is prospectively described for the continuous preparation of bulk RE-containing alloys to stabilise highly active RE elements. Therefore, this study provides valuable insights into practical solvometallurgical processes for RE metal extraction, refinement, and recycling.

Exploring the Aggregation Behavior of Extractant Molecules in Ionic Liquids: A Coupled Polarizable Molecular Dynamics and SAXS Study.

This study presents a comprehensive investigation of the aggregation behavior of a malonamide extractant molecule (N,N'-dimethyl,N,N'-dioctylhexylethoxymalonamide (DMDOHEMA)) in three different solvents, including two piperidinium- and (trifluoromethylsulfonyl)imide-based ionic liquids (1-ethyl-1-butylpiperidinium bis(trifluoromethylsulfonyl)imide ([EBPip+][NTf2-]) and 1-ethyl-1-octylpiperidinium bis(trifluoromethylsulfonyl)imide ([EOPip+][NTf2-])) and n-dodecane. By combining polarizable molecular dynamics simulations and small-angle X-ray scattering experiments, we extensively investigated the arrangement of supramolecular assemblies of the extractant molecules. Our results showed that the insertion of the alkyl chains of the extractant molecules into the apolar domain of [EOPip+][NTf2-] has a significant impact on the aggregation behavior of the extractant molecules, leading to the formation of smaller aggregates having a higher dispersion compared to other solvents. These findings provide new insights into the physicochemical properties of this type of system and are crucial in designing more effective solvents for rare earth metal extraction.

Reserves and extraction of rare earth metals and elements as a key factor in the renewable energy sector development at the the world economy transformation current stage

The use of renewable energy sources, which are experiencing a period of rapid development, is one of the stages of the current energy transition, as the world community tries to ensure a future with zero CO2 emissions and to achieve energy independence and security. At the same time, for output of the wide range of products for the renewable energy sector, as well as for the development of energy depot systems, it is necessary to use rare earth elements and metals in production. The results of the analysis of data on reserves, production and calculated values of the resource availability coefficient of rare earth elements and metals shows that at the existing level of production, the proven reserves of cobalt will last for ≈ 50 years, lithium– for ≈ 200 years and rare earth elements – for ≈ 450 years, respectively, which leads to a limitation of the global transition speed to renewable energy sources and makes it necessary to look for new technical solutions.

Comparison of extraction abilities of deep eutectic solvents and aqueous acid solutions for extraction of rare earths and transition metals

In recent years, deep eutectic solvents have attracted increasing interest as effective extractants for the separation of both organic substances and metals from various objects. Acid-based deep eutectic solvents are most often used as extractants for the extraction of metals. In this work, for the first time, the extraction efficiency of transition metals and rare earth elements (Y, Zr, Nb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf and Ta) from mining tailings and Na, K, Ca, Mg, Cu, Fe, Mn, Pb, Ba, Ni and Sr from biodiesel samples using acidic deep eutectic solvents and saturated aqueous solutions of the same acids (malonic, malic, tartaric and citric) is compared. For this, deep eutectic solvents based on acids and their aqueous saturated solutions were prepared and studied. The prepared mixtures were analyzed by IR spectroscopy to confirm the formation of eutectic solvents. Properties such as the density and viscosity of the resulting mixtures were also investigated, as this can be of key importance for the efficiency of metal extraction. The extraction of rare earth metals from mining tailings took a long time (up to several days), while the extraction of metals from fuel took no more than 30 min. Atomic emission spectral methods were used as an analysis method. It is shown that the extraction efficiency with aqueous solutions is better than that with eutectic solvents, which casts doubt on the need for deep eutectic solvents use in this area.

ЭКСТРАКЦИОННЫЕ И КОМПЛЕКСООБРАЗУЮЩИЕ СВОЙСТВА ФОСФОРИЛКЕТОНОВ ПО ОТНОШЕНИЮ К АКТИНИДАМ И ЛАНТАНИДАМ

The paper summarizes the results of studies of the complexing properties of phosphoryl ketones with respect to actinides and lanthanides, which makes it possible to identify the most effective and selective ligand of the phosphoryl ketones class, namely 5-(diphenylphosphoryl)hexan-3-one. Using this ligand, the possibility of efficient extraction of rare earth metals, as well as uranium(VI) and thorium(IV) from phosphogypsumleaching solutions within a single stage technological extraction process was demonstrated and the efficiency of using 5-(diphenylphosphoryl)hexan-3-one as extractant with commercially available TBP and TOPO was performed.

Group Extraction of the Rare-Earth Elements by Alkyl Phosphine Oxides of the Hexyl–Octyl Series

Samples of monoalkyl and mixed-alkyl phosphine oxides of the hexyl–octyl series were synthesized previously by the Grignard method. Here, the group extraction of rare-earth metals contained simultaneously in their nitrate solutions has been studied using then-synthesized alkyl phosphine oxides. Extraction isotherms for the recovery of the total of lanthanides, scandium, and thorium from nitrate solutions have been obtained. Trihexyl phosphine oxide (THPO) exhibits the highest efficiency under these conditions. Trioctyl phosphine oxide (TOPO) exhibits the best selectivity to heavy-group lanthanides, which makes it useful for the recovery of the heavy-group lanthanide fraction. In addition, scandium and thorium were extracted completely, which in turn indicates the usefulness of phosphine oxides for their extraction. The separation factors have been determined for the entire lanthanides series.

Extraction of Rare Earth Metals from Sulfuric Acid Media by Hydrazides of α- Branched Tertiary Carboxylic Acids

Extraction of Rare Earth Metals from Sulfuric Acid Media by Hydrazides of α- Branched Tertiary Carboxylic Acids

Coordination-enhanced extraction of rare earth metals from waste polishing powder and facile preparation of a mesoporous Ce-La oxide

Efficient and environmental-friendly recycling of rare earth polishing powder waste (REPPW) is imperative not only to ecological well-being but also to sustainability of critical rare earth resources. However, the low leaching efficiency of rare earth elements in mild acidic conditions and complicated synthesis procedure of high-end products hindered industrial recycling of REPPW. Herein, an ascorbic acid-H2SO4 system with mild conditions, i.e., ascorbic acid concentration = 0.042 mol/dm3, H2SO4 concentration = 1 mol/dm3, liquid to solid ratio = 20 cm3/g and temperature = 353 K, is proposed for leaching REPPW, in which the leaching ratios of Ce and La reached 96.79 % and 93.81 %, respectively. The coordination stability constants of Ce3+-ascorbic acid, i.e., β1 = 106.88 and β2 = 1013.03, were determined by pH-potentiometry, which revealed that the enhanced Ce3+ dissolution in this mild leaching system was attributed to Ce3+-ascorbic acid coordination. Subsequently, a high-purity, mesoporous Ce-La oxide cube was synthesized from the leaching solution by a facile chemical precipitation method at atmospheric pressure and temperature. The product had a composition of 78.07 wt% CeO2 and 21.93 wt% La2O3, and its average pore diameter was 7.30 nm. Its reducibility was 1.52 times higher than the theoretical value, suggesting a high potential for catalyzing redox reactions. This work proposes an efficient and value-added process for recycling REPPW, which helps to enlighten the sustainable utilization of secondary rare earth resources.

Low Temperature Electrochemical Extraction of Rare Earth Metals From Lignite Coal: An Environmentally Benign and Energy Efficient Method

Rare earth elements (REEs) extraction via conventional technologies is exceedingly energy and environmentally intensive. New efficient and sustainable technologies for REE extraction from primary and secondary resources would be extremely beneficial. This research demonstrated a novel low-temperature electrochemical extraction process for extracting REEs from lignite coal ash (LCA) solutions. The LCA contained 17 different REEs with a concentration ranging from 13 to 1645 ppm. The LCA solution mixed with ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate (BMITF) was used for extracting REEs at different electrochemical potentials. The ICP-MS analysis confirmed an overall 26% REEs recovery from the LCA solution with 16 out of the 17 REEs successfully extracted from the LCA solution. This study shows an environmentally benign and energy-efficient REE extraction process that is suitable for coal and coal byproducts.

Coordination-Enhanced Extraction of Rare Earth Metals from Waste Polishing Powder and Facile Preparation of Mesoporous Ce0.8la0.2o1.9

Coordination-Enhanced Extraction of Rare Earth Metals from Waste Polishing Powder and Facile Preparation of Mesoporous Ce0.8la0.2o1.9

Recycling and disposal of gypsum-containing waste generated in the production of citric acid

The cycle of citric acid production with the formation of gypsum-containing waste was considered and options for processing and utilization of citrogypsum were proposed. The methods obtained include: the use of citrogypsum in the production of building materials, the extraction of rare earth metals, as well as the creation of a high-quality organic-mineral fertilizer, during the creation of which it is possible to reduce the negative effect not only from the accumulation of citrogypsum, but also from manure stored in the filtration fields. In the future, the resulting fertilizer can be used for reclamation of technologically disturbed territories.

Assessment of mass transfer coefficients in extraction stages of La(III) and Ce(III) ions by using rotating Scheibel column with regular packing structure

The extraction of rare earth metals is critical due to their applicability in the industry. Because of this subject’s importance, the Scheibel column with the regular packing structure was investigated in the extraction process of lanthanum and cerium ions. Mass transfer coefficients identified the column performance in the transport stage of La(III) and Ce(III) from the aqueous phase to the organic phase. The variations in operating conditions were investigated to optimize the extraction of two ions. The backflow model (BFM), axial dispersion model (ADM), and forward mixing model (FMM) were investigated to evaluate the mass transfer performance in the column. The result showed that the description of the volumetric overall mass transfer coefficient with the forward mixing model is more significant than the two other models. The FMM model was evaluated by the function of droplet size and droplet residence time and the concentration profiles fitting technique. The medium of average absolute relative error obtained by the FMM model is ~ 4.45% and ~ 18.40% (lanthanum extraction) and ~ 10.75% and ~ 14.99% (cerium extraction) for the continuous and dispersed phase, respectively. It indicated that the applied model has a remarkable accuracy for the description of mass transfer performance. The result showed that the rotor’s speed has the most notable effects on the extraction conditions.

Direct Electrochemical Extraction of Sm from SmCl3 in a Molecular Liquid Solvent Supported By LiNO3

Low-temperature electrochemical extraction of rare earth metals from their corresponding chlorides in ionic liquids has long been a scientific challenge. In this study, a new class of task-specific ionic liquids (ILs) containing Li elements, i.e. Li-containing solvate ionic liquids ([Li(DMI)n]3+NO3 —, 0.15 M LiNO3 dissolved in DMI (1,3-Dimethy-l-2-imidazolidinone)), is developed and used for metallic Sm electrodeposition from SmCl3. To elucidate the electrochemical deposition mechanism, the ionic component of the DMI/LiNO3 system was characterized by a range of instrumental analysis techniques (including 7Li NMR, UV-vis) and theoretical calculations. Cyclic voltammetry was used to explore the electrochemical behavior of Sm-containing species in the ionic liquid. Finally, metallic Sm was successfully obtained using constant potential deposition on high purity Al substrates which was confirmed by XPS and SEM. Li-containing solvate ILs have immense potential in green electrometallurgy because of their higher tunability and similar properties to ILs.

Adsorption methods for the extraction and seperation of rare earth elements. Review

Rare earth elements play an important role in the production, energy, and high technology. Due to the rapid development of industry, the demand for rare earth metals is rising every day. Therefore, it is necessary to improve the extraction of rare earth metals from various sources to meet the demand for these elements. Currently, pyro- and hydrometallurgical technologies are used to extract rare earth metals from an ore and other secondary sources (industrial wastewater, acid drainage mines, etc.). Hydrometallurgical technologies include precipitation, extraction, adsorption, and ion exchange methods. Adsorption is one of the most effective methods for the extraction and separation of rare earth elements. Adsorption methods are highly selectivity to metal ions and have low emissions. However, not all adsorbents are effective in producing the same metal ions. This study provides an overview of the different adsorbents that can be used to extract rare earth elements from aquatic systems. Hydrogels and molecular polymers have been found to be cost-effective methods for high-grade rare earth metals. Further research is needed to ensure the performance of these systems.

Extraction of Rare Earth Metals by Solid-Phase Extractants from Phosphoric Acid Solution

Nowadays, solving the problem of rational, integrated use of the mined raw materials, the transition to waste-free technologies for its processing is a crucial task. The sulfuric acid technology used for the processing of apatite concentrates on a large industrial scale does not provide the associated extraction of accompanying valuable components—rare earth metals (REM). During apatite concentrate processing, rare-earth metals are affected by the technology-related dispersion, being distributed between the insoluble leaching residue and phosphoric acid solution sent to the production of fertilizers. The necessity of a cost-effective method development for the extraction of rare earth metals is quite obvious already in connection with the indicated significance of the problem. Phosphoric acid solutions that simulate the composition of industrial phosphoric acid solutions of the following composition 4.5 mol/L H3PO4, 0.19 mol/L H2SO4 and 0.10–0.12% REM were selected as the object of research. The extraction of rare earth metals was carried out using polymers containing a fixed layer of an extractant—di-2-ethylhexylphosphoric acid (D2EHPA). Fixed layer was obtained by impregnation-saturation (solvent-impregnated resin (SIR)) or by the introduction of an extractant at the stage of polymer matrix synthesis (extractant-resin extraction (ERE)). The work determined the thermodynamic and technological characteristics of the solid-phase extraction of rare earth elements from phosphoric acid solutions with polymers impregnated with D2EHPA and containing a rigidly fixed extractant in a styrene-divinylbenzene resin matrix. The possibility of effective multiple use of polymeric resins containing D2EHPA, regenerated with a solution of 1 mol/L sodium citrate, was revealed.

Polityka surowcowa w wymiarze metali ziem rzadkich. Rwanda – studium przypadku

The primary goal of a state's raw material policy is to ensure its raw material security. Due to the progressing technological development, rare earth metals play an increasingly important role. For several years, they have become the subject of a political game between the countries that play a dominant role in their market, i.e., the People's Republic of China and the United States. The other countries where the discussed groups of metals are mined were left on the sidelines of the discussion. The aim of the research undertaken in this article is to show the role of rare earth metals in creating raw material security on the example of Rwanda. It is home to some of the largest deposits of niobium and tantalum, key elements used in electronics, in aviation industry, and in the manufacturing of medical equipment. The main result of the research carried out is as follows: extraction of rare earth metals constitutes one of the foundations of the Rwandan economy. In recent years, there has been a significant professionalization of mining practices, bearing in mind the environment, health, and safety. It was also established that the factors that pose the most important threat to Rwanda's raw material policy include the current, uneasy situation on the border with the Democratic Republic of Congo, where the largest deposits of the metals in question are located, and the negative effects of the global Sars-Cov-2 pandemic.

Analytic assessment and systematization of technologies for rare earth metals extraction from industrial waste

Analytic assessment and systematization of technologies for rare earth metals extraction from industrial waste

Malonamide-Functionalized Ionic Liquid for Recovery of Rare-Earth Metals from End-Of-Life Products (Lamp Phosphors)

A novel functionalized ionic liquid, namely, malonamide-functionalized ionic liquid (MFIL) was synthesized and evaluated for the liquid–liquid extraction of rare-earth metals (REMs), transition, and other base metals from a hydrochloric acid medium. Theoretical calculations coupled with FT-IR studies were used to establish the mode of complexation between metal ions and the extracting moiety of MFIL. Uptake studies with multimetal feed solutions showed very good selectivity for REMs over other transition and base metals. Quantitative back extraction of REMs from loaded MFIL was accomplished using an acidic solution. MFIL showed preferential uptake of REMs over base and transition metals typically found in lamp phosphors.