Adsorption of lithium ions from aqueous solution by magnetic aluminum-based adsorbents

Yaru Qin; Tingfei Yang; Chenglong Shi; Bing Liu

doi:10.1371/journal.pone.0295269

Abstract

Magnetic aluminum-based adsorbents (MLDHs) were prepared with a coprecipitation method and used to separate lithium ions from the aqueous solutions. In static adsorption experiment, the adsorption capacity of MLDHs for lithium ions reached 8.22 mg/g. In a mixed solution of various metal ions, the adsorbents exhibited higher selectivity for lithium ions. Kinetic studies indicated that the adsorption process conformed to a pseudo-second-order model. The experimental data were fitted with nonlinear regression using commonly used adsorption isotherms. It was found that the adsorption isotherm process could be described by the Langmuir model. In addition, the thermodynamic parameters revealed that the adsorption of lithium was a spontaneous endothermic process.

Citation: Qin Y, Yang T, Shi C, Liu B (2023) Adsorption of lithium ions from aqueous solution by magnetic aluminum-based adsorbents. PLoS ONE 18(12): e0295269. https://doi.org/10.1371/journal.pone.0295269

Editor: Sivasankar Koppala, Saveetha Institute of Medical and Technical Sciences: Saveetha University, INDIA

Received: April 14, 2023; Accepted: November 17, 2023; Published: December 1, 2023

Copyright: © 2023 Qin et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript.

Funding: This work was supported by the Natural Science Foundation of Qinghai (grant number 2020-ZJ-953Q) (https://kjt.qinghai.gov.cn/). Yaru Qin was the recipient of the fund and the first author of this paper. Yaru Qin played an role in writing-original draft, visualization, validation, software, funding acquisition and formal analysis. There was no additional external funding received for this study.

Competing interests: The authors have declared that no competing interests exist.

1. Introduction

As an important strategic resource to reduce carbon emissions, lithium is known as "the metal that drives the world forward". Lithium and its compounds play an important role in many fields, such as new energy vehicles, glass, metallurgy, batteries, etc [1–6]. Lithium resources were mainly found in solid ores and salt lakes. The main problems of lithium extraction from ores were high energy consumption, high cost, and difficult tailings treatment. Since about 75% of lithium on land is stored in brine, lithium recovery from aqueous solutions has a significant advantage [7]. The main methods for lithium extraction from solution include evaporation and precipitation, solvent extraction, adsorption, and membrane separation [8–13]. Among them, the adsorption method has the advantages of high selectivity and simple operation, which is a promising method [14].

At present, the lithium adsorbents used to extract lithium ions mainly included titanium-based, manganese-based, and aluminum-based adsorbents [15, 16]. Titanium-based and manganese-based adsorbents exhibited excellent lithium adsorption properties, but under acidic conditions, the adsorbents were easily dissolved and lost and the adsorbent structure collapses, which limited their industrial applications [17–21]. Aluminum-based sorbents (LDHs) are the most widely studied inorganic adsorbents due to their stable cycle performance and easy preparation [22, 23]. Zhong et al [24, 25] prepared Li/Al-LDHs with a dimensional hexagonal plane, and investigated the effect of excessive lithium deintercalation on their adsorption performance. Experiments showed that the adsorption capacity of Li⁺ was 7.27 mg/g. It was confirmed that Li/Al-LDHs gradually transformed into gibbsite with excessive deintercalation, and the collapse intensity of the Li/Al-LDHs layered structure was positively correlated to excessive deintercalation intensity. When Fe(III) was doped into Li/Al-LDHs, it would enhance the stability of Li/Al-LDHs and reduce its solubility in nanocomposites [26]. The Li_xAl₂-LDH adsorbents were prepared by Lee et al [27]. The Li_xAl₂-LDH@SiO₂ nanostructure showed enhanced Li⁺ adsorption performance and high Li⁺ selectivity in mixed water resources of Mg²⁺, Na⁺, and K⁺ cations. They further proposed a new lithium deintercalation method [28]. The results indicated that lithium ions undergo topological reactions between amorphous Li-Al-O-OH and LiAl₂-LDH. A series of LDH adsorbents were synthesized and applied to extract lithium from geothermal brine. A Lithium recovery efficiency of approximately 91% was achieved [29].

In practical industrial applications, the synthesis of granular sorbents using organic binders was essential considering the difficulties in the separation and recovery of powdered aluminum-based adsorbents. However, the granulation process was tedious, the cost increased, and especially the adsorption performance decreased dramatically [30]. Kotsupalo et al. [31] prepared the granular LDHs using chlorinated polyvinyl chloride resin as a binder. The granular LDHs could selectively adsorb lithium ions from salt lake brine, however, the adsorption capacity of lithium ions decreased to 1.24 mg/g. Zhong et al. [32] developed a hybrid binder to granulate powdered LDHs into granular LDHs with applicable mechanical strength. The adsorption capacity of granular LDHs for lithium ions reached 4.92 mg/g at 303K. In order to avoid the decrease of LDHs adsorption capacity caused by the inefficient granulation process, a new strategy was designed by doping superparamagnetic nanoparticles (Fe₃O₄@SiO₂) in the LDHs to achieve rapid recovery of adsorbents with the help of a magnetic field.

In this paper, the magnetic aluminum-based adsorbents (MLDHs) were prepared by homogeneously doping silicon dioxide coated ferric tetroxide nanoparticles (Fe₃O₄@SiO₂) into the aluminum-based adsorbents. The adsorption performance of the MLDHs for Li⁺ in solution was investigated. The selectivity of the adsorbents to lithium ions in a mixed solution was verified. The mass transfer mechanism of the adsorption reaction was determined by kinetic models. In addition, the equilibrium data were analyzed using an isothermal model, resulting in thermodynamic parameters.

2. Experiments and methods

2.1 Materials and instruments

The chemicals, aluminum chloride hexahydrate (AR), potassium chloride (AR), monodispersed magnetite microspheres (AR), sodium chloride (AR), lithium hydroxide monohydrate (AR), magnesium chloride hexahydrate (AR), tetraethyl orthosilicate (AR), and lithium chloride (AR), were purchased from Aladdin Industrial Corporation (China). The temperature of the adsorption process was controlled by a water bath oscillator. The structure of MLDHs were characterized by an X-ray diffractometer (Rigaku Ultima IV) and scanning electron microscope (Zeiss Sigma 500). The concentrations of metal ions were determined with an inductively coupled plasma atomic emission spectrometer (Thermo Scientific ICAP-Pro).

2.2 Synthesis of MLDHs

The Fe₃O₄ particles (0.15 g) were dispersed into a mixed solvent of ethanol and water with a volume ratio of 4:1, and then ammonia (7 mL, 20% wt) was added to the solvent. Fe₃O₄@SiO₂ nanoparticles were prepared by adding ethyl silicate (TEOS) (4 mL) to the solution at room temperature and stirring for 10 h. Then, the Fe₃O₄@SiO₂ nanoparticles can be separated from the solution. The obtained nanoparticles were washed three times with ethanol and water, and dried at 333K for 10 h.

The aluminum trichloride hexahydrate (3.13 g) and lithium hydroxide monohydrate (0.27 g) were dissolved in deionized water to form a mixed solution. The 2.00 mol/L NaOH solution was added dropwise to the mixed solution, and the pH at the end of the reaction was controlled to be 6.5. The above mixed solution was stirred and reacted for 2 h to obtain a suspension. The suspension was centrifuged, and the solid obtained was washed thoroughly 5 times with deionized water, dried at 60°C to obtain LDHs.

The obtained Fe₃O₄@SiO₂ nanoparticles (0.2 g) were added into deionized water and dispersed by ultrasonic to form a suspension. Then, the LDHs (0.8 g) was added to the suspension, and the suspension was continued to disperse 30 min by ultrasonic. After filtration and drying, the final product MLDHs was obtained. Finally, the obtained solids were filtered and dried at 60°C overnight to gain the MLDHs. The synthesis strategy of MLDHs was described by the scheme in Fig 1.

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Fig 1. Schematic diagram of the preparation of MLDHs.

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2.3 Adsorption experiment

The adsorption behavior of the MLDHs for lithium ion in solution was studied by the static adsorption method. All adsorption studies were performed at 293 K, except for the experiments used to determine thermodynamic parameters at variable temperatures. A certain amount of MLDHs were weighed and placed in an aqueous solution containing lithium, which was shaken on an oscillator for a certain time and then separated from the liquid by an applied magnetic field. The solution before and after adsorption was taken out and diluted to measure the ion concentrations. The adsorption capacity q_e (mg/g), partition coefficient K_d (L/g) of lithium ions, and selectivity factor α were obtained from the following formulas: (1) (2) (3) where C₀ (mg/L) and C_e (mg/L) were the initial and residual lithium concentrations, respectively. The m (g) was the mass of the MLDHs and V (L) was the volume of the aqueous solution containing lithium. The subscript Me of α represents Na⁺, K⁺, Mg²⁺, and Ca²⁺.

3. Results and discussion

3.1 Characterization of MLDHs

The X-ray diffraction spectrum and characteristic peaks of Fe₃O₄, Fe₃O₄@SiO₂, LDHs and MLDHs were shown in Fig 2. As shown in Fig 2C and 2D, apparent peaks were observed at 30.35°, 35.54°, 43.29°, 53.61°, 57.14° and 62.68° degrees which correspond to (220), (311), (400), (422), (333) and (440) face centred cubic crystal orientation, respectively [33]. The spectra were in close agreement with JCPDS card No.79-0417. Since SiO₂ was in amorph structure, no SiO₂-related peaks were observed in the XRD pattern of Fe₃O₄@SiO₂ particles [34]. Representative diffraction peaks at 2θ = 11.51°, 20.44°, 23.14°, 36.09°, 40.66° and 63.18° can be clearly identified (Fig 2E). Compared with the XRD spectrum standard card (JCPDS No. 31–0700), it was known that MLDHs accorded with the chemical formula LiCl·2Al(OH)₃·xH₂O, and its XRD reflections indexed to the crystal plane of (003), (101), (006), (112), (115) and (300). However, most of these representative diffraction peaks were not observed in the diffraction patterns of MLDHs. Fig 2F displayed a new broad hump around 21.11°. The characteristic diffraction peak of MLDHs at 11.51° was attributed to the LDHs crystal phase, and the intensity was weak. The reason may be that Fe₃O₄@SiO₂ particles were dispersed in the interlayer of LDHs, which reduced the crystallinity of LDHs, resulting in its diffraction peaks not appearing in the diffraction pattern of MLDHs.

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Fig 2.

XRD patterns of (c) Fe₃O₄, (d) Fe₃O₄@SiO₂, (e) LDHs and (f) MLDHs. (a) JCPDS card of LDHs; (b) JCPDS card of Fe₃O₄.

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The SEM analysis of Fe₃O₄@SiO₂, LDHs, and MLDHs were illustrated in Fig 3. As shown in Fig 3A, the Fe₃O₄@SiO₂ particles had a sphere-like morphology and some of the particles were found to be in agglomerated form. The SEM image in Fig 3B demonstrated a legible layered structure of LDHs. As displayed in Fig 3C, numerous Fe₃O₄@SiO₂ particles can be observed dispersed on the surface of the LDHs. Fig 3D showed the morphology at the cross-section of the layered structure of LDHs. It can be observed from Fig 3D that Fe₃O₄@SiO₂ particles can be dispersed in the interlayer of LDHs and form many small pores in the adsorbent structure. The energy dispersive X-ray spectroscopy (EDS) of the MLDHs particles were depicted in Fig 4. The EDS spectrum demonstrated that Al, O, Fe and Si elements were presented in the structure of the MLDHs particles. The results of SEM and EDS analysis proved that Fe₃O₄@SiO₂ particles were successfully combined with LDHs to form MLDHs.

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Fig 3. The SEM images of Fe₃O₄@SiO₂, LDHs and MLDHs.

(a) Fe₃O₄@SiO₂; (b) LDHs; (c) and (d) MLDHs.

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Fig 4. The EDS analysis of MLDHs.

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3.2. Adsorption studies

3.2.1 Effect of pH on lithium adsorption.

Since aluminum hydroxide was a typical amphiphilic hydroxide, the solution acidity had a great influence on the stability of MLDHs. If the acidity of the solution was high, the adsorbent may decompose. However, the adsorbent will be converted to meta-aluminate when the acidity was low. The adsorption capacities of MLDHs were investigated by adding 0.2 g MLDHs into 15 mL pure lithium chloride solution.The initial Li⁺ concentration was 0.40 g/L and the Cl^- concentration was 2.04 g/L. Fig 5 showed the variation trend of adsorption capacity. When the acidity of the solution weakened, the adsorption capacity of MLDHs for lithium ions increased at first and then decreased gradually. At a pH of 5, the adsorption capacity of lithium ions reached a maximum. The structure of the adsorbent will be destroyed if the acidity of the aqueous solution is too high. In addition, there is competitive adsorption between H⁺ and Li⁺, which will lead to a decrease in adsorption capacity. The adsorption performance of LDHs was also investigated. It can be seen from Fig 5 that the adsorption process of MLDHs has a similar trend to that of LDHs. Under the same experimental conditions, the adsorption capacity of LDHs was slightly higher than that of MLDHs. In addition, it was found that pure Fe₃O₄@SiO₂ particles have no adsorption capacity for Li⁺, which indicated that LDHs were effective adsorption components in MLDHs. However, it was difficult to separate and recover powdered LDHs in application. If the powdered LDHs were granulated and formed by adding organic binder, the adsorption performance will decrease rapidly. The MLDHs had good adsorption capacity and can be recovered quickly under an external magnetic field. Considering the stability and adsorption capacity of the adsorbents, the pH value of the subsequent experimental solution was 5.

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Fig 5. Effect of pH on adsorption capacity.

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3.2.2 Effect of lithium ion equilibrium concentration on adsorption capacity.

The Fig 6 showed the effect of equilibrium concentration on lithium adsorption capacity. The initial Li⁺ concentration was varied from 0.05 g/L to 1.00 g/L, and the Cl^- concentration was varied from 0.26 g/L to 5.11 g/L. It can be seen from the adsorption capacity that the high lithium ions concentration exerted a positive influence on adsorption. At the fixed solid-liquid ratio, the adsorption capacity increased with the increase of Li⁺ concentrations. This was due to the fact that the lithium ion concentration difference was the main driving force for adsorption. When the concentration of lithium ions was high, it was beneficial for lithium ions to quickly occupy the adsorption sites, thus showing a high adsorption capacity. Therefore, in the actual adsorption process, the lithium-containing solution needed to be properly concentrated to increase the adsorption capacity.

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Fig 6. Effect of initial lithium ion concentration on adsorption capacity.

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3.3 Adsorption mechanism

Previous studies have shown that aluminum-based adsorbents have a two-dimensional layered structure, and the layers are connected by forces such as electrostatic interactions and hydrogen bonds [35, 36]. In the process of preparing aluminum-based adsorbents, the adsorbents are usually washed with deionized water to remove a fraction of Li⁺ in the structure and create vacancies in the adsorbent structure. These vacancies serve as the adsorption sites for lithium ions, and their size matches the lithium ions best, thus exhibiting a high selectivity for Li⁺ [37–39]. In addition, the hydration free energy of lithium ions was much lower than that of magnesium ions, and the adsorbents were more likely to combine with lithium ions, thereby achieving the purpose of separating lithium and magnesium [1]. The mechanism of adsorption and desorption of lithium by aluminum-based adsorbents could be described by the following Eq (4) [40].

(4)

The FTIR spectra in Fig 7 characterized the change of the absorption peak of the functional group of the MLDHs before and after adsorption. The broad absorption peak at 3475 cm^-1 could be considered as the stretching vibration of the O-H bond. The deformation vibration absorption peak of O-H was at 1638 cm^-1 caused by crystal water. The stretching vibrations of the Al-O₆ octahedron were identified as the absorption peaks at 750 cm^-1 and 540 cm^-1 [41]. The peak at 1096 cm^-1 corresponded to the asymmetric vibration of the Si-O-Si bond [42]. In addition, the peaks at 952 cm^-1 was assigned to the deformation vibration of Al-OH. The FTIR results showed that the position of the characteristic peaks of the MLDHs did not change after adsorption. However, the intensity of the band at 952 cm^-1 increased after adsorption, which reflected that the Cl⁻ intercalcation at interlayers affected the deformation vibration of -OH [24, 43].

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Fig 7. FTIR spectra of MLDHs.

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The XPS spectra of the MLDHs before and after adsorption were exhibited in Fig 8 to unravel the element distribution and surface state of MLDHs. As shown in Fig 8A, the Li1s, O1s, C1s, Cl2p, Si2p and Al2p peaks were observed in wide scan of XPS spectra of MLDHs. However, the Fe2p peak was not observed in the wide scan of XPS spectra, which may be caused by the coating of Fe₃O₄ particles by SiO₂. Before being used for lithium adsorption, only a fraction of Li⁺ need to be removed from the original structure of adsorbents. Therefore, the Li1s peak could be observed in the wide scan of XPS spectra of MLDHs before and after adsorption. Fig 8B and 8C showed the Al2p spectra resolutions of MLDHs before and after adsorption. The Al2p_3/2 binding energy transformed from 74.70 eV and 76.10 eV to 74.49 eV and 75.09 eV, respectively, which indicated that the Li⁺ entered into the crystal structure of adsorbents and affected the chemical environment around the Al-O in the adsorbents [24]. It can be found from Fig 8D and 8e that the binding energy of Cl2p also changed after adsorption, which indicated that the Cl^- entered into the structure of adsorbents in order to maintain the charge balance.

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Fig 8.

XPS spectra of MLDHs: (a) survey spectra, (b) Al2p spectra before adsorption, (c) Al2p spectra before adsorption, (d) Cl2p spectra before adsorption, (e) Cl2p spectra after adsorption.

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3.3.1 Adsorption kinetics.

The variation curve of adsorption capacity with contact time was shown in Fig 9. Obviously, the adsorption capacity of lithium ion changed rapidly with time. Specifically, The first 120 min corresponded to a rapid adsorption stage, which was mainly due to the sufficient amount of lithium ions that can be adsorbed and the adsorption materials can provide enough binding sites when the adsorbents reacted with lithium ions in the initial stage. As the contact time prolongs, the increasing rate of lithium ions adsorption capacity slowed down and finally tended to equilibrium. This was due to the gradual decrease in the available binding sites on the adsorbent material with increasing contact time. In the follow-up experiment, the oscillation time of the lithium ion adsorption experiment was determined to be 180 min.

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Fig 9. Effect of contact time on adsorption capacity.

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Two kinetic models were used to describe the lithium adsorption process. The pseudo-first-order model was a conventional method used to describe the adsorption of adsorbates from the liquid phase onto the solid phase, corresponding to the diffusion-controlled process [44, 45]. Ho and McKay had proposed the pseudo-second-order kinetic model which based on the assumption that the rate limiting step may be chemical sorption or chemisorption [46, 47]. The pseudo-first-order kinetic model can be represented by Eq (5), and Eq (6) described the pseudo-second-order kinetic model. It is helpful to further understand the mechanism of the adsorption process by fitting the adsorption kinetic data. (5) (6) where q_e and q_t represent the lithium adsorption capacity at equilibrium and time t, respectively. The K₂ (g/(mg·min)) and K₁ (min^-1) are both adsorption rate constants.

According to Eq (5) and Eq (6), the kinetic parameters of adsorption can be obtained by examining the linear relationship between ln (q_e-q_t) versus t and t/q_t versus t (Fig 10) and calculating their slope and intercept. Comparing the fitted correlation parameters R² of the two kinetic models from the data in Table 1, it could be seen that the correlation parameter of pseudo-second-order kinetic model fitting reached 0.9948, while the correlation parameter of pseudo-first-order kinetic model fitting was only 0.9182. Therefore, the sorption kinetics of lithium were more appropriately described by the pseudo-second-order model. It can be inferred that the adsorption of lithium by the MLDHs may be a chemisorption-dominated process rather than a simple physical diffusion process.

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Fig 10.

The fitting sorption data of MLDHs: (a) pseudo-first-order equation; (b) pseudo-second-order equation.

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Table 1. The fitting kinetic parameters.

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3.3.2 Adsorption isotherms.

In Fig 11, the adsorption isotherms of MLDHs measured at 293, 303, 313, 323 and 333 K revealed that the adsorption capacity of MLDHs had a positive correlation with the temperature and mildly increased with increasing temperature. Therefore, the adsorption process of lithium ions by MLDHs was endothermic.

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Fig 11. The Li⁺ adsorption isotherms of MLDHs under different temperatures.

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The adsorption process of solid adsorbent in solution was usually described by the Langmuir and Freundlich adsorption isotherm models. The Langmuir isothermal adsorption model was an ideal single-molecule layer adsorption model with an expression as in Eq (7). (7) where q_m (mg/g) and b (L/mg) are saturated adsorption capacity and Langmuir constant, respectively. The q_e (mg/g) and c_e (mg/L) are the lithium adsorption capacity and lithium concentration at equilibrium, respectively.

The Freundlich isotherm adsorption model was often used to describe the adsorption behavior on irregular surfaces and was expressed in Eq (8).

(8)

Where K_F was the Freundlich model constant.

Fig 12 showed the adsorption isotherms of MLDHs, and the fitted parameters were listed in Table 2. The fitting coefficient of the Langmuir model was 0.9626, which was higher than that of the Freundlich model. The Langmuir model may be more suitable for explaining the adsorption of lithium ions. Therefore, the adsorption of lithium ions by MLDHs behaved as monolayer adsorption, which was a chemical adsorption process.

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Fig 12.

Isothermal adsorption model, (a) langmuir model, (b) freundlich model.

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Table 2. Fitting parameters of the isothermal adsorption model (293 K).

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The temperature usually affected on the adsorption capacity of MLDHs. The adsorption thermodynamic data of lithium ion were obtained by investigating the adsorption effect of MLDHs for lithium ion at different temperatures. According to Eq (9) and Eq (10), the thermodynamic parameters ΔH⁰, ΔS⁰ and ΔG⁰ of the adsorption system can be calculated. A plot of lnK_d versus 1/T yields a straight line. The slope of this line is -ΔH⁰/R and the intercept is ΔS⁰/R. From Fig 13, ΔH⁰ and ΔS⁰ values can be obtained and listed in Table 3. It can be seen from Table 3 that ΔH⁰ was positive, which indicated that the adsorption of lithium ions by MLDHs was endothermic, and the increase in temperature was beneficial to improve the adsorption capacity of lithium ions. The value of ΔS⁰ obtained was 38.94 J·mol^-1·K^-1, which indicated that the adsorption process of lithium ions was an entropy-increasing process. The adsorption temperature varied from 293 K to 343 K, and the obtained ΔG⁰ values were all negative. Therefore, the adsorption process of lithium ions by MLDHs was spontaneous under practical conditions. In addition, it can be found that the value of ΔG⁰ decreased continuously with increasing temperature. The increasing temperature was beneficial to increase the adsorption capacity of MLDHs.

(9)

(10)

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Fig 13. Plot of lnK_d versus 1/T.

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Table 3. Adsorption thermodynamic parameters of MLDHs for lithium ion adsorption.

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3.4 Adsorption of lithium ions from multi-metal-ion solutions

The selectivity of MLDHs for lithium ion in brine solution was investigated. The brine was prepared in the laboratory and its composition was referred to the old brine of the Qarhan Salt Lake in China. The ion concentrations in simulated brine were as follows: Li⁺, 0.412 g·L⁻¹; Mg²⁺, 110.539 g·L⁻¹; K⁺, 0.474 g·L⁻¹; Na⁺, 1.316 g·L⁻¹; Ca²⁺, 0.0518 g·L⁻¹. In the experiment, 0.2 g MLDHs were added to 15 mL brine solution and shaken for 180 min. The adsorption capacity and separation factor (Me = Na⁺, K⁺, Ca²⁺ and Mg²⁺) were calculated. As can be seen from Fig 14, the MLDHs have a small adsorption capacity for other metal ions in the mixed metal ion solution. The corresponding and values were 23.52, 29.82, 42.34 and 101.97, respectively. The experimental results showed that the MLDHs had good selectivity for lithium ions. Due to the size-matched vacancies and ion memory effect of lithium ions, MLDHs exhibited high selectivity for lithium ions [48]. The adsorption capacity of several aluminum-based adsorbents was listed in Table 4. It can be found that the MLDHs in this work have a higher adsorption capacity compared to those reported in the literature.

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Fig 14. Adsorption amount of metal ion in solution by magnetic aluminum salt lithium adsorbent.

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Table 4. Comparison of Li/Al-LDHs adsorbents.

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3.5 Adsorption-desorption cycles

The adsorption properties of Li⁺ in solution by five adsorption-desorption cycles were studied to evaluate the stability and adsorption performance of MLDHs. The Li-loaded MLDHs were quickly washed with ice water (The ratio of the mass of MLDHs to the volume of water was 1 g/2 mL) to remove the residual brine remaining on the surface of the adsorbents, and dried at 60°C for 10 h. Then the Li⁺ in MLDHs was desorbed with deionized water at room temperature (The ratio of the mass of MLDHs to the volume of water was 1 g/50 mL), and shaken at 120 rpm for 6 h. The desorbed MLDHs were separated from the aqueous solution, dried at 60°C for 10 h, and used for the next adsorption cycle. The changing trend of Li⁺ adsorption capacities and mass ratio of Fe₃O₄@SiO₂ magnetic particles to LDHs in MLDHs were shown in Fig 15. The mass ratio of Fe₃O₄@SiO₂ magnetic particles to LDHs in MLDHs was 1:4 before adsorption. The MLDHs (0.2 g) was used in the adsorption-desorption cycle experiments, and the MLDHs solid was separated from the solution by a permanent magnet. The supernatant was collected and the unrecovered MLDHs particles were all dissolved by adding nitric acid. As control, 0.20 g MLDHs in 15 mL suspension was also dissolved by nitric acid. The Al³⁺ and Fe³⁺ concentrations in the solution were determined by ICP-OES, and the masses of Fe₃O₄@SiO₂ magnetic particles and LDHs lost to the solution in each adsorption-desorption cycle experiment were calculated. It was found from Fig 15 that the mass ratio of Fe₃O₄@SiO₂ magnetic particles to LDHs increased slightly with the increase of the number of adsorption-desorption cycles. Therefore, a small amount of LDHs was lost to the solution during the adsorption-desorption experiments. Since the LDHs were effective adsorption components in MLDHs, the adsorption capacity of MLDHs for Li⁺ also decreased slightly with the increase in the number of adsorption-desorption cycles. After five adsorption-desorption cycles, the adsorption capacity of magnetic aluminum-based lithium adsorbent decreased from 8.22 mg/g to 7.97mg/g, which maintained 96.96% of the initial adsorption capacity.

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Fig 15. Li⁺ adsorption capacities and mass ratio of Fe₃O₄@SiO₂ magnetic particles to LDHs changing with the number of adsorption-desorption cycles.

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The magnetic hysteresis loops of MLDHs before and after adsorption were further measured and compared with those of Fe₃O₄@SiO₂. Obviously, these hysteresis loops all present typical S-shaped curves in Fig 16. Since Fe₃O₄@SiO₂ nanoparticles were dispersed in the interlayer and surface of the aluminum-based adsorbents (LDHs), their saturation magnetizations were lower than that of pure Fe₃O₄@SiO₂. However, when the magnet was close to the aqueous solution, the MLDHs will rapidly gather towards the magnet, which made the MLDHs separate from the aqueous solution. In addition, it can be observed that the magnetic hysteresis loops of MLDHs coincide before and after adsorption, which indicated that MLDHs had good stability and less solution loss in the process of adsorption.

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Fig 16. The magnetic hysteresis loops of Fe₃O₄@SiO₂ and MLDHs.

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4. Conclusion

In this study, MLDHs were prepared and applied for the separation of lithium ions from aqueous solutions. The adsorption capacity of MLDHs for lithium ions reached 8.22 mg/g in the static adsorption experiment. In the mixed solution of various metal ions, the corresponding and values were 23.52, 29.82, 42.34 and 101.97, respectively. The experimental results show that the MLDHs have good selectivity for lithium ions. Kinetic studies indicated that the adsorption process conformed to a pseudo-second-order model. The Langmuir model may be more suitable for explaining the adsorption of lithium ions. The thermodynamic parameters revealed that the adsorption of lithium was a spontaneous endothermic process. In addition, the results of five adsorption-desorption cycles showed that MLDHs exhibited good stability and adsorption performance.

References

1. Sun Y, Wang Q, Wang YH, Yun RP, Xiang X. Recent advances in magnesium/lithium separation and lithium extraction technologies from salt lake brine. Separation and Purification Technology. 2021; 256: 117807.
- View Article
- Google Scholar
2. Zhang WF, Li SL, Zhou AJ, Song HY, Cui ZM, Du L. Recent advances and perspectives in lithium-sulfur pouch cells. Molecules. 2022; 26: 6341.
- View Article
- Google Scholar
3. Swain B. Recovery and recycling of lithium: A review. Separation and Purification Technology. 2017; 172: 388–403.
- View Article
- Google Scholar
4. Zhang CY, Mu YX, Zhao S, Zhang W, Wang YX. Lithium extraction from synthetic brine with high Mg²⁺/Li⁺ ratio using the polymer inclusion membrane. Desalination. 2020; 496: 114710.
- View Article
- Google Scholar
5. Tabelin CB, Dallas J, Casanova S, Pelech T, Bournival G, Saydam S, et al. Towards a low-carbon society: A review of lithium resource availability, challenges and innovations in mining, extraction and recycling, and future perspectives. Minerals Engineering. 2022; 163: 106743.
- View Article
- Google Scholar
6. Adak S, Cangi H, Yilmaz AS, Arifoğlu U. Development software program for extraction of photovoltaic cell equivalent circuit model parameters based on the Newton-Raphson method. Journal of Computational Electronics. 2023; 22: 413–422.
- View Article
- Google Scholar
7. Yu HW, Naidu G, Zhang CY, Wang C, Razmjou A, Han DS, et al. Metal-based adsorbents for lithium recovery from aqueous resources. Desalination. 2022; 539: 115951.
- View Article
- Google Scholar
8. Hou J, Zhang HC, Thornton AW, Hill AJ, Wang HT, Konstas K. Lithium extraction by emerging metal-organic framework-based membranes. Advanced Functional Materials. 2021; 31: 2105991.
- View Article
- Google Scholar
9. Shi CL, Li HX, Liu B, Qin YR, Song GX. Solvent extraction of lithium from aqueous solution using an ammonium ionic liquid. Journal of Molecular Liquids. 2020; 204: 112756.
- View Article
- Google Scholar
10. Li XiH, Mo YH, Qing WH, Shao SL, Tang CYY, Li JX. Membrane-based technologies for lithium recovery from water lithium resources: A review. Journal of Membrane Science. 2019; 591: 117317.
- View Article
- Google Scholar
11. Santos C, La Mantia F. Recent advances in reactor design and control for lithium recovery by means of electrochemical ion pumping. Current Opinion in Electrochemistry. 2022; 35: 101089.
- View Article
- Google Scholar
12. Zhang Y, Xu R, Wang Li, Sun W. Separation of magnesium from lithium in salt-lake brine through struvite precipitation. Minerals Engineering. 2022; 180: 107468.
- View Article
- Google Scholar
13. Su YF, Qian FR, Qian ZQ. Enhancing adsorption capacity and structural stability of Li1.6Mn1.6O4 adsorbents by anion/cation co-doping. RSC Advances. 2022; 12: 2150–2159. pmid:35425223
- View Article
- PubMed/NCBI
- Google Scholar
14. Luo QL, Dong MZ, Nie GL, Liu Z, Wu ZJ, Li J. Extraction of lithium from salt lake brines by granulated adsorbents. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2021; 628: 127256.
- View Article
- Google Scholar
15. Zhang LY, Zhou DL, Yao QQ, Zhou JB. Preparation of H2TiO3-lithium adsorbent by the sol-gel process and its adsorption performance. Applied Surface Science. 2016; 368: 82–87.
- View Article
- Google Scholar
16. Chen MM, Wu RY, Ju SG, Zhang XX, Xue F, Xing WH. Improved performance of Al-doped LiMn2O4 ion-sieves for Li+ adsorption. Microporous and Mesoporous Materials. 2018; 261: 29–34.
- View Article
- Google Scholar
17. Ji ZY, Yang FJ, Zhao YY, Liu J, Wang N, Yuan JS. Preparation of titanium-base lithium ionic sieve with sodium persulfate as eluent and its performance. Chemical Engineering Journal. 2017; 328: 768–775.
- View Article
- Google Scholar
18. Li XW, Chen LL, Chao YH, Chen W, Luo J, Xiong J, et al. Amorphous TiO2-derived large-capacity lithium ion sieve for lithium recovery. Chemical Engineering & Technology. 2020; 43: 1784–1791.
- View Article
- Google Scholar
19. Safari S, Lottermoser BG, Alessi DS. Metal oxide sorbents for the sustainable recovery of lithium from unconventional resources. Applied Materials Today. 2020; 19: 100638.
- View Article
- Google Scholar
20. Gu DL, Sun WJ, Han GF, Cui Q, Wang HY. Lithium ion sieve synthesized via an improved solid state method and adsorption performance for West Taijinar Salt Lake brine. Chemical Engineering Journal. 2018; 350: 474–483.
- View Article
- Google Scholar
21. Wang SL, Li P, Zhang X, Zheng SL, Zhang Y. Selective adsorption of lithium from high Mg-containing brines using HxTiO3 ion sieve. Hydrometallurgy. 2017; 174: 21–28.
- View Article
- Google Scholar
22. Heidari N, Momeni P. Selective adsorption of lithium ions from Urmia Lake onto aluminum hydroxide. Environmental Earth Sciences. 2017; 76: 551.
- View Article
- Google Scholar
23. Li YH, Chen XY, Liu XH, Zhao ZW, Liu CW. Extraction of lithium from brine solution by hydrolysis of activated aluminum powder. JOM. 2018; 70: 1449–1453.
- View Article
- Google Scholar
24. Zhong J, Lin S, Yu JG. Li⁺ adsorption performance and mechanism using lithium/aluminum layered double hydroxides in low grade brines. Desalination. 2021; 505: 114983.
- View Article
- Google Scholar
25. Zhong J, Lin S, Yu JG. Effects of excessive lithium deintercalation on Li+ adsorption performance and structural stability of lithium/aluminum layered double hydroxides. Journal of Colloid and Interface Science. 2020; 572: 107–113. pmid:32229342
- View Article
- PubMed/NCBI
- Google Scholar
26. Luo QL, Dong MZ, Li Q, Wu ZJ, Liu Z, Li J. Improve the durability of lithium adsorbent Li/Al-LDHs by Fe³⁺ substitution and nanocomposite of FeOOH. Minerals Engineering. 2022; 185: 107717.
- View Article
- Google Scholar
27. Lee Y, Cha JH, Jung DY. Selective lithium adsorption of silicon oxide coated lithium aluminum layered double hydroxide nanocrystals and their regeneration. Chemistry—An Asian Journal. 2021; 16: 974–980. pmid:33686783
- View Article
- PubMed/NCBI
- Google Scholar
28. Lee Y, Jung DY. Lithium intercalation and deintercalation of thermally decomposed LiAl₂-layered double hydroxides. Applied Clay Science. 2022; 228: 106631.
- View Article
- Google Scholar
29. Paranthaman MP, Li L, Luo JQ, Hoke T, Ucar H, Moyer BA, Harrison S. Recovery of lithium from geothermal brine with lithium-aluminum layered double hydroxide chloride sorbents. Environmental Science & Technology. 2017; 51: 13481–13486. pmid:29076733
- View Article
- PubMed/NCBI
- Google Scholar
30. Cai JG, Zhang YY, Pan BC, Zhang WM, Lv L, Zhang QX. Efficient defluoridation of water using reusable nanocrystalline layered double hydroxides impregnated polystyrene anion exchanger. Water Research. 2016; 102: 109–116. pmid:27337346
- View Article
- PubMed/NCBI
- Google Scholar
31. Kotsupalo NP, Ryabtsev AD, Poroshina IA, Kurakov AA, Mamylova EV, Menzheres LT, et al. Effect of structure on the sorption properties of chlorine-containing form of double aluminum lithium hydroxide. Russian Journal of Applied Chemistry. 2013; 86: 482–487.
- View Article
- Google Scholar
32. Zhong J, Lin S, Yu JG. Lithium recovery from ultrahigh Mg²⁺/Li⁺ ratio brine using a novel granulated Li/Al-LDHs adsorbent. Separation and Purification Technology. 2021; 256: 117780.
- View Article
- Google Scholar
33. Lavasani FS, Khalaj Z, Kabirifard H, Monajjemi M. Fabrication and characterization of the Fe3O4@SiO2-rGO nanocomposite: a catalyst for multi-component reactions. Physical Chemistry Chemical Physics. 2022; 25: 2821–2829.
- View Article
- Google Scholar
34. Yetim NK, Baysak FK, Koc MM, Nartop D. Characterization of magnetic Fe₃O₄@SiO₂ nanoparticles with fluorescent properties for potential multipurpose imaging and theranostic applications. Journal of Materials Science: Materials in Electronics. 2020; 31: 18278–18288.
- View Article
- Google Scholar
35. Wang Q, O’Hare D. Recent advances in the synthesis and application of layered double hydroxide (LDH) nanosheets. Chemical Reviews. 2012; 112: 4124–4155. pmid:22452296
- View Article
- PubMed/NCBI
- Google Scholar
36. Liu XH, Zhong ML, Chen XY, Zhao ZW. Separating lithium and magnesium in brine by aluminum-based materials. Hydrometallurgy. 2018; 176: 73–77.
- View Article
- Google Scholar
37. Kozlova SG, Gabuda SP, Isupov VP, Chupakhina LE. Using NMR in structural studies of aluminum hydroxide intercalation compounds with lithium salts. Journal of Structural Chemistry. 2003; 44: 198–205.
- View Article
- Google Scholar
38. Britto S, Kamath PV. Structure of bayerite-based lithium-aluminum layered double hydroxides (LDHs): observation of monoclinic symmetry. Inorganic Chemistry. 2009; 48: 11646–11654. pmid:19921786
- View Article
- PubMed/NCBI
- Google Scholar
39. Sun Y, Yun RP, Zang YF, Pu M. Highly efficient lithium recovery from pre-synthesized chlorine-ion-intercalated LiAl-layered double hydroxides via a mild solution chemistry process. Materials. 2019; 12: 1968. pmid:31248077
- View Article
- PubMed/NCBI
- Google Scholar
40. Goh KH, Lim TT, Dong Z. Application of layered double hydroxides for removal of oxyanions: A review. Water Research. 2008; 42: 1343–1368. pmid:18061644
- View Article
- PubMed/NCBI
- Google Scholar
41. Chen J, Lin S, Yu JG. High-selective cyclic adsorption and magnetic recovery performance of magnetic lithium-aluminum layered double hydroxides (MLDHs) in extracting Li+ from ultrahigh Mg/Li ratio brines. Separation and Purification Technology. 2021; 255: 117710.
- View Article
- Google Scholar
42. Sun J, Yu GL, Liu LL, Li ZF, Kan QB, Huo QS, et al. Core-shell structured Fe₃O₄@SiO₂ supported cobalt(ii) or copper(ii) acetylacetonate complexes: magnetically recoverable nanocatalysts for aerobic epoxidation of styrene. Catalysis Science & Technology, 2014, 4: 1246–1252.
- View Article
- Google Scholar
43. Wang DD, Zhu Q, Su YY, Li J, Wang AW, Xing ZP. Preparation of MgAlFe-LDHs as a deicer corrosion inhibitor to reduce corrosion of chloride ions in deicing salts. Ecotoxicology and Environmental Safety. 2019; 174: 164–174 pmid:30825739
- View Article
- PubMed/NCBI
- Google Scholar
44. Vasiliu S, Bunia I, Racovita S, Neagu V. Adsorption of cefotaxime sodium salt on polymer coated ion exchange resin microparticles: kinetics, equilibrium and thermodynamic studies. Carbohydrate Polymers. 2011, 85: 376–387.
- View Article
- Google Scholar
45. Simonin JP. On the comparison of pseudo-first order and pseudo-second order rate laws in the modeling of adsorption kinetics. Chemical Engineering Journal. 2016, 300: 254–263.
- View Article
- Google Scholar
46. Ho YS, McKay G. Pseudo-second order model for sorption processes. Process Biochemistry. 1999; 34: 451–465.
- View Article
- Google Scholar
47. Ho YS, McKay G. The kinetics of sorption of divalent metal ions onto sphagnum moss peat. Water Research. 2000; 34: 735–742.
- View Article
- Google Scholar
48. Isupov VP, Gabuda SP, Kozlova SG, Chupakhina LE. Structural mechanism of selective binding of lithium on a solid matrix of Al(OH)₃ from aqueous solutions. Journal of Structural Chemistry. 1998; 39: 362–366.
- View Article
- Google Scholar
49. Ryabtsev AD. Benefication technology for lithium-containing hydrogenic mineral products. Journal of Mining Science. 2005; 41: 573–582.
- View Article
- Google Scholar
50. Jiang HX, Zhang SY, Yang Y, Yu JG. Synergic and competitive adsorption of Li-Na-MgCl₂ onto lithium-aluminum hydroxides. Adsorption-journal of the International Adsorption Society. 2020; 26: 1039–1049.
- View Article
- Google Scholar
51. Chen J, Lin S, Yu JG. Quantitative effects of Fe₃O₄ nanoparticle content on Li⁺ adsorption and magnetic recovery performances of magnetic lithium-aluminum layered double hydroxides in ultrahigh Mg/Li ratio brines. Journal of Hazardous Materials. 2020; 388: 122101.
- View Article
- Google Scholar

[ref1] 1. Sun Y, Wang Q, Wang YH, Yun RP, Xiang X. Recent advances in magnesium/lithium separation and lithium extraction technologies from salt lake brine. Separation and Purification Technology. 2021; 256: 117807.
View Article
Google Scholar

[2] View Article

[3] Google Scholar

[ref2] 2. Zhang WF, Li SL, Zhou AJ, Song HY, Cui ZM, Du L. Recent advances and perspectives in lithium-sulfur pouch cells. Molecules. 2022; 26: 6341.
View Article
Google Scholar

[5] View Article

[6] Google Scholar

[ref3] 3. Swain B. Recovery and recycling of lithium: A review. Separation and Purification Technology. 2017; 172: 388–403.
View Article
Google Scholar

[8] View Article

[9] Google Scholar

[ref4] 4. Zhang CY, Mu YX, Zhao S, Zhang W, Wang YX. Lithium extraction from synthetic brine with high Mg²⁺/Li⁺ ratio using the polymer inclusion membrane. Desalination. 2020; 496: 114710.
View Article
Google Scholar

[11] View Article

[12] Google Scholar

[ref5] 5. Tabelin CB, Dallas J, Casanova S, Pelech T, Bournival G, Saydam S, et al. Towards a low-carbon society: A review of lithium resource availability, challenges and innovations in mining, extraction and recycling, and future perspectives. Minerals Engineering. 2022; 163: 106743.
View Article
Google Scholar

[14] View Article

[15] Google Scholar

[ref6] 6. Adak S, Cangi H, Yilmaz AS, Arifoğlu U. Development software program for extraction of photovoltaic cell equivalent circuit model parameters based on the Newton-Raphson method. Journal of Computational Electronics. 2023; 22: 413–422.
View Article
Google Scholar

[17] View Article

[18] Google Scholar

[ref7] 7. Yu HW, Naidu G, Zhang CY, Wang C, Razmjou A, Han DS, et al. Metal-based adsorbents for lithium recovery from aqueous resources. Desalination. 2022; 539: 115951.
View Article
Google Scholar

[20] View Article

[21] Google Scholar

[ref8] 8. Hou J, Zhang HC, Thornton AW, Hill AJ, Wang HT, Konstas K. Lithium extraction by emerging metal-organic framework-based membranes. Advanced Functional Materials. 2021; 31: 2105991.
View Article
Google Scholar

[23] View Article

[24] Google Scholar

[ref9] 9. Shi CL, Li HX, Liu B, Qin YR, Song GX. Solvent extraction of lithium from aqueous solution using an ammonium ionic liquid. Journal of Molecular Liquids. 2020; 204: 112756.
View Article
Google Scholar

[26] View Article

[27] Google Scholar

[ref10] 10. Li XiH, Mo YH, Qing WH, Shao SL, Tang CYY, Li JX. Membrane-based technologies for lithium recovery from water lithium resources: A review. Journal of Membrane Science. 2019; 591: 117317.
View Article
Google Scholar

[29] View Article

[30] Google Scholar

[ref11] 11. Santos C, La Mantia F. Recent advances in reactor design and control for lithium recovery by means of electrochemical ion pumping. Current Opinion in Electrochemistry. 2022; 35: 101089.
View Article
Google Scholar

[32] View Article

[33] Google Scholar

[ref12] 12. Zhang Y, Xu R, Wang Li, Sun W. Separation of magnesium from lithium in salt-lake brine through struvite precipitation. Minerals Engineering. 2022; 180: 107468.
View Article
Google Scholar

[35] View Article

[36] Google Scholar

[ref13] 13. Su YF, Qian FR, Qian ZQ. Enhancing adsorption capacity and structural stability of Li1.6Mn1.6O4 adsorbents by anion/cation co-doping. RSC Advances. 2022; 12: 2150–2159. pmid:35425223
View Article
PubMed/NCBI
Google Scholar

[38] View Article

[39] PubMed/NCBI

[40] Google Scholar

[ref14] 14. Luo QL, Dong MZ, Nie GL, Liu Z, Wu ZJ, Li J. Extraction of lithium from salt lake brines by granulated adsorbents. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2021; 628: 127256.
View Article
Google Scholar

[42] View Article

[43] Google Scholar

[ref15] 15. Zhang LY, Zhou DL, Yao QQ, Zhou JB. Preparation of H2TiO3-lithium adsorbent by the sol-gel process and its adsorption performance. Applied Surface Science. 2016; 368: 82–87.
View Article
Google Scholar

[45] View Article

[46] Google Scholar

[ref16] 16. Chen MM, Wu RY, Ju SG, Zhang XX, Xue F, Xing WH. Improved performance of Al-doped LiMn2O4 ion-sieves for Li+ adsorption. Microporous and Mesoporous Materials. 2018; 261: 29–34.
View Article
Google Scholar

[48] View Article

[49] Google Scholar

[ref17] 17. Ji ZY, Yang FJ, Zhao YY, Liu J, Wang N, Yuan JS. Preparation of titanium-base lithium ionic sieve with sodium persulfate as eluent and its performance. Chemical Engineering Journal. 2017; 328: 768–775.
View Article
Google Scholar

[51] View Article

[52] Google Scholar

[ref18] 18. Li XW, Chen LL, Chao YH, Chen W, Luo J, Xiong J, et al. Amorphous TiO2-derived large-capacity lithium ion sieve for lithium recovery. Chemical Engineering & Technology. 2020; 43: 1784–1791.
View Article
Google Scholar

[54] View Article

[55] Google Scholar

[ref19] 19. Safari S, Lottermoser BG, Alessi DS. Metal oxide sorbents for the sustainable recovery of lithium from unconventional resources. Applied Materials Today. 2020; 19: 100638.
View Article
Google Scholar

[57] View Article

[58] Google Scholar

[ref20] 20. Gu DL, Sun WJ, Han GF, Cui Q, Wang HY. Lithium ion sieve synthesized via an improved solid state method and adsorption performance for West Taijinar Salt Lake brine. Chemical Engineering Journal. 2018; 350: 474–483.
View Article
Google Scholar

[60] View Article

[61] Google Scholar

[ref21] 21. Wang SL, Li P, Zhang X, Zheng SL, Zhang Y. Selective adsorption of lithium from high Mg-containing brines using HxTiO3 ion sieve. Hydrometallurgy. 2017; 174: 21–28.
View Article
Google Scholar

[63] View Article

[64] Google Scholar

[ref22] 22. Heidari N, Momeni P. Selective adsorption of lithium ions from Urmia Lake onto aluminum hydroxide. Environmental Earth Sciences. 2017; 76: 551.
View Article
Google Scholar

[66] View Article

[67] Google Scholar

[ref23] 23. Li YH, Chen XY, Liu XH, Zhao ZW, Liu CW. Extraction of lithium from brine solution by hydrolysis of activated aluminum powder. JOM. 2018; 70: 1449–1453.
View Article
Google Scholar

[69] View Article

[70] Google Scholar

[ref24] 24. Zhong J, Lin S, Yu JG. Li⁺ adsorption performance and mechanism using lithium/aluminum layered double hydroxides in low grade brines. Desalination. 2021; 505: 114983.
View Article
Google Scholar

[72] View Article

[73] Google Scholar

[ref25] 25. Zhong J, Lin S, Yu JG. Effects of excessive lithium deintercalation on Li+ adsorption performance and structural stability of lithium/aluminum layered double hydroxides. Journal of Colloid and Interface Science. 2020; 572: 107–113. pmid:32229342
View Article
PubMed/NCBI
Google Scholar

[75] View Article

[76] PubMed/NCBI

[77] Google Scholar

[ref26] 26. Luo QL, Dong MZ, Li Q, Wu ZJ, Liu Z, Li J. Improve the durability of lithium adsorbent Li/Al-LDHs by Fe³⁺ substitution and nanocomposite of FeOOH. Minerals Engineering. 2022; 185: 107717.
View Article
Google Scholar

[79] View Article

[80] Google Scholar

[ref27] 27. Lee Y, Cha JH, Jung DY. Selective lithium adsorption of silicon oxide coated lithium aluminum layered double hydroxide nanocrystals and their regeneration. Chemistry—An Asian Journal. 2021; 16: 974–980. pmid:33686783
View Article
PubMed/NCBI
Google Scholar

[82] View Article

[83] PubMed/NCBI

[84] Google Scholar

[ref28] 28. Lee Y, Jung DY. Lithium intercalation and deintercalation of thermally decomposed LiAl₂-layered double hydroxides. Applied Clay Science. 2022; 228: 106631.
View Article
Google Scholar

[86] View Article

[87] Google Scholar

[ref29] 29. Paranthaman MP, Li L, Luo JQ, Hoke T, Ucar H, Moyer BA, Harrison S. Recovery of lithium from geothermal brine with lithium-aluminum layered double hydroxide chloride sorbents. Environmental Science & Technology. 2017; 51: 13481–13486. pmid:29076733
View Article
PubMed/NCBI
Google Scholar

[89] View Article

[90] PubMed/NCBI

[91] Google Scholar

[ref30] 30. Cai JG, Zhang YY, Pan BC, Zhang WM, Lv L, Zhang QX. Efficient defluoridation of water using reusable nanocrystalline layered double hydroxides impregnated polystyrene anion exchanger. Water Research. 2016; 102: 109–116. pmid:27337346
View Article
PubMed/NCBI
Google Scholar

[93] View Article

[94] PubMed/NCBI

[95] Google Scholar

[ref31] 31. Kotsupalo NP, Ryabtsev AD, Poroshina IA, Kurakov AA, Mamylova EV, Menzheres LT, et al. Effect of structure on the sorption properties of chlorine-containing form of double aluminum lithium hydroxide. Russian Journal of Applied Chemistry. 2013; 86: 482–487.
View Article
Google Scholar

[97] View Article

[98] Google Scholar

[ref32] 32. Zhong J, Lin S, Yu JG. Lithium recovery from ultrahigh Mg²⁺/Li⁺ ratio brine using a novel granulated Li/Al-LDHs adsorbent. Separation and Purification Technology. 2021; 256: 117780.
View Article
Google Scholar

[100] View Article

[101] Google Scholar

[ref33] 33. Lavasani FS, Khalaj Z, Kabirifard H, Monajjemi M. Fabrication and characterization of the Fe3O4@SiO2-rGO nanocomposite: a catalyst for multi-component reactions. Physical Chemistry Chemical Physics. 2022; 25: 2821–2829.
View Article
Google Scholar

[103] View Article

[104] Google Scholar

[ref34] 34. Yetim NK, Baysak FK, Koc MM, Nartop D. Characterization of magnetic Fe₃O₄@SiO₂ nanoparticles with fluorescent properties for potential multipurpose imaging and theranostic applications. Journal of Materials Science: Materials in Electronics. 2020; 31: 18278–18288.
View Article
Google Scholar

[106] View Article

[107] Google Scholar

[ref35] 35. Wang Q, O’Hare D. Recent advances in the synthesis and application of layered double hydroxide (LDH) nanosheets. Chemical Reviews. 2012; 112: 4124–4155. pmid:22452296
View Article
PubMed/NCBI
Google Scholar

[109] View Article

[110] PubMed/NCBI

[111] Google Scholar

[ref36] 36. Liu XH, Zhong ML, Chen XY, Zhao ZW. Separating lithium and magnesium in brine by aluminum-based materials. Hydrometallurgy. 2018; 176: 73–77.
View Article
Google Scholar

[113] View Article

[114] Google Scholar

[ref37] 37. Kozlova SG, Gabuda SP, Isupov VP, Chupakhina LE. Using NMR in structural studies of aluminum hydroxide intercalation compounds with lithium salts. Journal of Structural Chemistry. 2003; 44: 198–205.
View Article
Google Scholar

[116] View Article

[117] Google Scholar

[ref38] 38. Britto S, Kamath PV. Structure of bayerite-based lithium-aluminum layered double hydroxides (LDHs): observation of monoclinic symmetry. Inorganic Chemistry. 2009; 48: 11646–11654. pmid:19921786
View Article
PubMed/NCBI
Google Scholar

[119] View Article

[120] PubMed/NCBI

[121] Google Scholar

[ref39] 39. Sun Y, Yun RP, Zang YF, Pu M. Highly efficient lithium recovery from pre-synthesized chlorine-ion-intercalated LiAl-layered double hydroxides via a mild solution chemistry process. Materials. 2019; 12: 1968. pmid:31248077
View Article
PubMed/NCBI
Google Scholar

[123] View Article

[124] PubMed/NCBI

[125] Google Scholar

[ref40] 40. Goh KH, Lim TT, Dong Z. Application of layered double hydroxides for removal of oxyanions: A review. Water Research. 2008; 42: 1343–1368. pmid:18061644
View Article
PubMed/NCBI
Google Scholar

[127] View Article

[128] PubMed/NCBI

[129] Google Scholar

[ref41] 41. Chen J, Lin S, Yu JG. High-selective cyclic adsorption and magnetic recovery performance of magnetic lithium-aluminum layered double hydroxides (MLDHs) in extracting Li+ from ultrahigh Mg/Li ratio brines. Separation and Purification Technology. 2021; 255: 117710.
View Article
Google Scholar

[131] View Article

[132] Google Scholar

[ref42] 42. Sun J, Yu GL, Liu LL, Li ZF, Kan QB, Huo QS, et al. Core-shell structured Fe₃O₄@SiO₂ supported cobalt(ii) or copper(ii) acetylacetonate complexes: magnetically recoverable nanocatalysts for aerobic epoxidation of styrene. Catalysis Science & Technology, 2014, 4: 1246–1252.
View Article
Google Scholar

[134] View Article

[135] Google Scholar

[ref43] 43. Wang DD, Zhu Q, Su YY, Li J, Wang AW, Xing ZP. Preparation of MgAlFe-LDHs as a deicer corrosion inhibitor to reduce corrosion of chloride ions in deicing salts. Ecotoxicology and Environmental Safety. 2019; 174: 164–174 pmid:30825739
View Article
PubMed/NCBI
Google Scholar

[137] View Article

[138] PubMed/NCBI

[139] Google Scholar

[ref44] 44. Vasiliu S, Bunia I, Racovita S, Neagu V. Adsorption of cefotaxime sodium salt on polymer coated ion exchange resin microparticles: kinetics, equilibrium and thermodynamic studies. Carbohydrate Polymers. 2011, 85: 376–387.
View Article
Google Scholar

[141] View Article

[142] Google Scholar

[ref45] 45. Simonin JP. On the comparison of pseudo-first order and pseudo-second order rate laws in the modeling of adsorption kinetics. Chemical Engineering Journal. 2016, 300: 254–263.
View Article
Google Scholar

[144] View Article

[145] Google Scholar

[ref46] 46. Ho YS, McKay G. Pseudo-second order model for sorption processes. Process Biochemistry. 1999; 34: 451–465.
View Article
Google Scholar

[147] View Article

[148] Google Scholar

[ref47] 47. Ho YS, McKay G. The kinetics of sorption of divalent metal ions onto sphagnum moss peat. Water Research. 2000; 34: 735–742.
View Article
Google Scholar

[150] View Article

[151] Google Scholar

[ref48] 48. Isupov VP, Gabuda SP, Kozlova SG, Chupakhina LE. Structural mechanism of selective binding of lithium on a solid matrix of Al(OH)₃ from aqueous solutions. Journal of Structural Chemistry. 1998; 39: 362–366.
View Article
Google Scholar

[153] View Article

[154] Google Scholar

[ref49] 49. Ryabtsev AD. Benefication technology for lithium-containing hydrogenic mineral products. Journal of Mining Science. 2005; 41: 573–582.
View Article
Google Scholar

[156] View Article

[157] Google Scholar

[ref50] 50. Jiang HX, Zhang SY, Yang Y, Yu JG. Synergic and competitive adsorption of Li-Na-MgCl₂ onto lithium-aluminum hydroxides. Adsorption-journal of the International Adsorption Society. 2020; 26: 1039–1049.
View Article
Google Scholar

[159] View Article

[160] Google Scholar

[ref51] 51. Chen J, Lin S, Yu JG. Quantitative effects of Fe₃O₄ nanoparticle content on Li⁺ adsorption and magnetic recovery performances of magnetic lithium-aluminum layered double hydroxides in ultrahigh Mg/Li ratio brines. Journal of Hazardous Materials. 2020; 388: 122101.
View Article
Google Scholar

[162] View Article

[163] Google Scholar

Figures

Abstract

1. Introduction

2. Experiments and methods

2.1 Materials and instruments

2.2 Synthesis of MLDHs

2.3 Adsorption experiment

3. Results and discussion

3.1 Characterization of MLDHs

3.2. Adsorption studies

3.2.1 Effect of pH on lithium adsorption.

3.2.2 Effect of lithium ion equilibrium concentration on adsorption capacity.

3.3 Adsorption mechanism

3.3.1 Adsorption kinetics.

3.3.2 Adsorption isotherms.

3.4 Adsorption of lithium ions from multi-metal-ion solutions

3.5 Adsorption-desorption cycles

4. Conclusion

References