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Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This is an article in the field of mining engineering. In view of the concentration and enrichment of lithium ions in old halide in Qerhan Salt Lake, the expansion experiment of the multi-stage precision control process of old halide enrichment was completed by means of evaporation crystallization and step separation. The enrichment law of lithium and boron during evaporation was studied. The concentration of lithium ions reached more than 1 g/L, and high quality hydrochloromagnite was obtained. The material balance of the evaporation process of the salt pan was carried out, and the actual halogen yield and lithium yield of each phase of salt extraction were obtained, as well as the production capacity of the sun salt pan and the area distribution ratio of each level of the salt pan, which can provide reliable data support for the comprehensive development and utilization of potassium old brine extraction in Qerhan Salt Lake in the future.

As global demand for renewable energy and electric vehicles increases, the need for lithium has surged significantly. Extracting lithium from salt lake brine has become a cutting-edge technology in lithium resource production. In this study, two-dimensional (2D) GO/MXene composite membranes were fabricated using pressure-assisted filtration with a polyethyleneimine (PEI) coating, resulting in positively charged PEI-GO/MXene membranes. These innovative membranes, taking advantage of the synergistic effects of interlayer channel sieving and the Donnan effect, demonstrated excellent performance in Mg2+/Li+ separation with a mass ratio of 20 (Mg2+ rejection = 85.3%, Li+ rejection = 16.7%, SLi,Mg = 5.7) in simulated saline lake brine. Testing on actual salt lake brine in Tibet, China, confirmed the composite membrane's potential for effective Mg2+/Li+ separation. In the actual brine test with high concentration, Mg2+/Li+ after membrane separation is 2.2, which indicates that the membrane can significantly reduce the concentration of Mg2+ in the brine. Additionally, the PEI-GO/MXene composite membrane demonstrated strong anti-swelling properties and effective divalent ion rejection. This research presents an innovative approach to advance the development of 2D membranes for the selective removal of Mg2+ and Li+ from salt lake brine. [ABSTRACT FROM AUTHOR]

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The natural environment in the high-altitude regions of Northwest China is extremely harsh, characterized by numerous salt lakes. The high concentrations of chloride salts, sulfates, and alkali metal ions in these areas can induce alkali–silica reactions (ASRs) in concrete. These reactions generate harmful gel within the concrete, causing expansion and cracking, which significantly impacts the durability of concrete structures. This study investigates the evolution of the mechanical properties in high-performance concrete (HPC) under long-term ASR by incorporating different admixtures and varying the equivalent alkali content. A three-dimensional random aggregate mesoscopic model was used to simulate static compression tests under various operational conditions. Non-destructive testing methods were utilized to determine the expansion rate, internal, and surface damage variables of the concrete. The experimental results indicate that the 10-year expansion rate differs from the 1-year rate by approximately 1%, and under long-term ASR mitigation measures, the internal damage in the HPC is minimal, though the surface damage is more severe. As the equivalent alkali content increases, the compressive strength of the concrete cubes decreases, initially rising before falling by 5–15% over time. The HPC with only air-entraining agent added exhibited better mechanical performance than the HPC with both air-entraining and corrosion inhibitors added, with the poorest performance observed in the HPC with only a corrosion inhibitor. A relationship was established between the surface and internal damage variables, with the surface damage initially increasing rapidly before stabilizing as the internal damage rose. Numerical simulations effectively describe the damage behavior of HPC under static uniaxial compression. Comparisons with actual failure morphologies revealed that, in the cube compression tests, crack propagation directly penetrated both coarse and fine aggregates rather than circumventing them. The simulations closely matched the experimental outcomes, demonstrating their accuracy in modeling experiments. This study discusses the compressive mechanical properties of concrete under prolonged ASR through a combination of experimental and simulation approaches. It also delves into the impact of surface damage on the overall mechanical performance and failure modes of concrete. The findings provide experimental and simulation support for the concrete structures in regions with high alkali contents. [ABSTRACT FROM AUTHOR]

Effects of brine corrosion and Alkali-Silicate Reaction (ASR) on High Performance Concrete (HPC) incorporating ASR inhibition measures were investigated. The study involved developing HPC with ASR inhibition measures and exposing it to brine corrosion for a period of 10 years to investigate the compressive strength and mesoscopic mechanical properties within the Interfacial Transition Zone (ITZ) of coarse and fine aggregate in HPC. The results reveal that the microhardness of the ITZ surrounding alkali-active fine aggregate is the lowest due to the synergistic influence of ASR and brine corrosion. Additionally, the correlation between macroscopic and mesoscopic mechanical properties was established and macroscopic parameters for mortar and ITZ were derived. These parameters were subsequently used in the numerical computation of a three-dimensional mesoscopic mechanical model depicting the compressive strength of HPC cubes. The numerical simulation of the concrete mesoscopic mechanical model revealed that HPC with ASR inhibition measures, after prolonged exposure to salt lake brine corrosion, manifests mesoscopic mechanical characteristics in compressive failure within cube specimens. The propagation of cracks directly through the coarse aggregate results in a distinctive splitting failure pattern for the HPC specimens.

In recent years, with the rapid development of the global lithium battery industry, the demand for lithium as a raw material is also increasing. There are abundant lithium resources in salt lake brine, however, the concentration of lithium is very low and the composition is complex. The development of highly efficient separation technology to extract lithium resources from brine has important economic value and strategic significance. The solvent extraction method has the advantages of large processing capacity, high extraction efficiency, excellent selectivity and easy operation on a large scale, resulting in promising industial application. This paper summarized the separation of lithium resources from salt lakes using various solvent extraction reagents in the last five years, including β-diketones, organophosphorus extractants, macrocyclic receptors, 4-phosphorylpyrazolone, ionic liquids and deep eutectic solvents. The mechanism, application scenarios, advantages and disadvantages of these extractants were systematically summarized. In view of the problems of the extraction system, the intensification technology of the extraction process was further introduced, such as membrane extraction intensification and electric field intensification. Finally, we gave the suggestions for the studies improvement of the extractants and prospected the development of extractants in the future. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The durability of concrete is critical for the service life of concrete structures, and it is influenced by various factors. This paper investigates the impact of the relative humidity (RH) of the curing environment on the durability of five different concrete types. The aim is to determine a suitable approach for designing concrete that is well-suited for use in the salt lake region of Inner Mongolia. The concrete types comprise ordinary Portland cement (OPC), high-strength expansive concrete (HSEC), high-strength expansive concrete incorporating silica fume, fly ash, and blast furnace slag (HSEC-SFB), steel fiber-reinforced high-strength expansive concrete (SFRHSEC), and high elastic modulus polyethylene fiber-reinforced high-strength expansive concrete (HFRHSEC). All these concrete types underwent a 180-day curing process at three distinct relative humidities (RH = 30%, 50%, and 95%) before being subjected to freeze–thaw cycles in the Inner Mongolia salt lake brine. The curing environment with a 95% RH is referred to as the standard condition. The experimental results reveal that the durability of OPC and HSEC decreases significantly with increasing relative humidity. In comparison with the control sample cured in 95% RH, the maximum freeze–thaw cycles for concrete cured in lower RHs are only 31% to 76% for OPC and 66% to 77% for HSEC. However, the sensitivity of the durability of HSEC-SFB, SFRHSEC, and HFRHSEC to variations in RH in the curing environment diminishes. In comparison with the corresponding reference value, the maximum freeze–thaw cycles for samples cured in dry conditions increase by 14% to 17% for HSEC-SFB and 21% for SFRHSEC. Specifically, the service life of HFRHSEC cured in a low RH is 25% to 46% higher than the reference value. The durability of HSEC-SFB, SFRHSEC, and HFRHSEC has been proven to be appropriate for structures located in the salt lake region of Inner Mongolia. [ABSTRACT FROM AUTHOR]

The research on comprehensive utilization of salt lake resources is integrated into the experimental teaching of inorganic chemistry and chemical analysis as practical application cases, and the basic knowledge of inorganic and analytical chemistry, such as crude salt purification, soda ash preparation and alkali purity determination, is combined with the industrial application of salt lake brine, and comprehensive evaluation is carried out through students’ independent design of experimental schemes, completion of experimental operations and comprehensive inspection of various indexes of the schemes. It makes students more deeply understand and know the application of professional knowledge in practical production and life, and enhances students’ interest in learning. At the same time, ideological and political elements are integrated into the course, and students’ scientific literacy, innovative spirit, team spirit and social responsibility are cultivated. [ABSTRACT FROM AUTHOR]

To address the increasing demand for lithium, the recovery of lithium from salt lake brines has garnered significant attention. Techniques have been developed; however, these approaches exhibit drawbacks such as high energy consumption, excessive freshwater usage, and substantial dissolution losses, presenting environmental concerns. This review discusses the application and characteristics of four extractant systems used in solvent extraction: organophosphates, ionic liquids, crown ethers, and β-diketones. Furthermore, we present the optimization of organophosphate systems to make them more environmentally friendly. Optimization encompasses four key aspects: synergistic extractants, coextractants, diluents, and main extractants. Solvent extraction is a simple, cost-effective, and environmentally benign technique for lithium extraction from brine. Modifying the structure of these extractants can reduce dissolution rates and improve extraction efficiencies. [ABSTRACT FROM AUTHOR]

This article reviews the mechanism of Li+ de-intercalation and intercalation in manganese-based lithium ion-sieve, titanium-based lithium ion-sieven and aluminum-based adsorbent. The lithium extraction mechanism and the factors affecting the adsorption effect; some problems in lithium ion sieve materials are summarized, and the future research focus and development direction of lithium ion sieves are prospected. [ABSTRACT FROM AUTHOR]

Novel Li/Al‐LDHs with high layer charges (HCLDHs) were synthesized in the light of the inter‐layer effect on Li+ adsorption. Compared with conventional low‐charge Li/Al‐LDHs (LCLDHs), HCLDHs exhibited a distinct micromorphology characterized by a preferential growth orientation along the c‐axis and a significantly reduced lateral diameter. Adsorption experiments showed that HCLDHs possessed superior Li+ adsorption performance in various brines, specifically with a Li+ adsorption capacity of 9.72 mg/g in Qarhan old brine, surpassing that of LCLDHs by 2 mg/g. All‐around characterizations and finite element analysis calculations uncovered that the reduced lateral dimensions facilitated the exposure of more accessible Li+ adsorption sites, while the high positive charge of the host layers decreased the electrostatic repulsion toward Li+ by attracting anions and increased the surrounding ionic strength. Surface photovoltage (SPV) and x‐ray absorption fine structure (XAFS) further proved the structural stability of HCLDHs, which ensured the maintenance of a high Li+ adsorption capacity during adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

As global demand for renewable energy and electric vehicles increases, the need for lithium has surged significantly. Extracting lithium from salt lake brine has become a cutting-edge technology in lithium resource production. In this study, two-dimensional (2D) GO/MXene composite membranes were fabricated using pressure-assisted filtration with a polyethyleneimine (PEI) coating, resulting in positively charged PEI-GO/MXene membranes. These innovative membranes, taking advantage of the synergistic effects of interlayer channel sieving and the Donnan effect, demonstrated excellent performance in Mg2+/Li+ separation with a mass ratio of 20 (Mg2+ rejection = 85.3%, Li+ rejection = 16.7%, SLi,Mg = 5.7) in simulated saline lake brine. Testing on actual salt lake brine in Tibet, China, confirmed the composite membrane’s potential for effective Mg2+/Li+ separation. In the actual brine test with high concentration, Mg2+/Li+ after membrane separation is 2.2, which indicates that the membrane can significantly reduce the concentration of Mg2+ in the brine. Additionally, the PEI-GO/MXene composite membrane demonstrated strong anti-swelling properties and effective divalent ion rejection. This research presents an innovative approach to advance the development of 2D membranes for the selective removal of Mg2+ and Li+ from salt lake brine.

The natural environment in the high-altitude regions of Northwest China is extremely harsh, characterized by numerous salt lakes. The high concentrations of chloride salts, sulfates, and alkali metal ions in these areas can induce alkali–silica reactions (ASRs) in concrete. These reactions generate harmful gel within the concrete, causing expansion and cracking, which significantly impacts the durability of concrete structures. This study investigates the evolution of the mechanical properties in high-performance concrete (HPC) under long-term ASR by incorporating different admixtures and varying the equivalent alkali content. A three-dimensional random aggregate mesoscopic model was used to simulate static compression tests under various operational conditions. Non-destructive testing methods were utilized to determine the expansion rate, internal, and surface damage variables of the concrete. The experimental results indicate that the 10-year expansion rate differs from the 1-year rate by approximately 1%, and under long-term ASR mitigation measures, the internal damage in the HPC is minimal, though the surface damage is more severe. As the equivalent alkali content increases, the compressive strength of the concrete cubes decreases, initially rising before falling by 5–15% over time. The HPC with only air-entraining agent added exhibited better mechanical performance than the HPC with both air-entraining and corrosion inhibitors added, with the poorest performance observed in the HPC with only a corrosion inhibitor. A relationship was established between the surface and internal damage variables, with the surface damage initially increasing rapidly before stabilizing as the internal damage rose. Numerical simulations effectively describe the damage behavior of HPC under static uniaxial compression. Comparisons with actual failure morphologies revealed that, in the cube compression tests, crack propagation directly penetrated both coarse and fine aggregates rather than circumventing them. The simulations closely matched the experimental outcomes, demonstrating their accuracy in modeling experiments. This study discusses the compressive mechanical properties of concrete under prolonged ASR through a combination of experimental and simulation approaches. It also delves into the impact of surface damage on the overall mechanical performance and failure modes of concrete. The findings provide experimental and simulation support for the concrete structures in regions with high alkali contents.

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the different concentration and high salinity of salt in salt lake brine, it is difficult to determine accurately by conventional analysis methods. By investigating the addition amount of cation exchange resin, the exchange time of cation exchange resin, the influence of pH value on exchange efficiency, and the correction of internal standard elements, the determination of metasilicate in salt lake brine by cation exchange resin separation and inductively coupled plasma emission spectrometry was established. In this method, salt lake brine is diluted five times, 6 g cation exchange resin is added, and the static exchange is 1. 5 h. After removing a large number of cations in the brine, Si 251. 611 nm is selected as the analytical spectral line, and Y 371. 030 nm spectral line is used as the internal standard for signal drift correction. The content of metasilicic acid in the brine is determined by inductively coupled plasma emission spectrometer. The calibration curve is tested under the optimum conditions, and the linear range of the calibration curve is 0. 50--200 mg/L, and the linear relationship of the regression equation obtained is good (rj^ 0. 9994). The detection limit of this method is 0. 16 mg/L, the relative standard deviation (RSD, w = 12) is 1. 8%--4. 6%, and the recovery of standard addition is 96. 3%--102%. At the same time, UV-visible spectrophotometry is used to compare the content of metasilicic acid, and there is no significant difference between the two test results, indicating that the method has good accuracy. Through this method, the content of metasilicic acid in salt lake brine can be determined quickly and accurately, providing reliable data support for improving the comprehensive utilization of salt lake resources. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the mechanism of lithium extraction with β‐diketones was investigated by resolving the reaction mechanism, thermodynamic property, and molecular interaction through density functional theory approach. Before the selective extraction of lithium, the β‐diketones had tautomerism with the product of enol. The enol structure was unsteady in alkaline environment so that Li+ can be selectively extracted by taking the place of hydroxyl hydrogen. Meanwhile, the synergistic effect of TOPO intensified the extraction ability by the generation of strong electrostatic. Based on the calculated Gibbs energy changes, the parameters of extraction efficiency and separation factor were analyzed and they had qualitative consistence with the experimental results. Meanwhile, it was determined that the electron‐withdrawing effect of the subsistent group in the β‐diketones had a critical influence on the extraction separation performance. Besides, the theoretical model predicted successfully the transition of extraction complex from hydrophilicity to lipophilicity after the combination with synergistic reagent. [ABSTRACT FROM AUTHOR]

Lithium recovery is imperative to accommodate the increase in lithium demand. Salt lake brine contains a large amount of lithium and is one of the most important sources of lithium metal. In this study, Li2CO3, MnO2, and TiO2 particles were mixed, and the precursor of a manganese–titanium mixed ion sieve (M-T-LIS) was prepared by a high-temperature solid-phase method. M-T-LISs were obtained by DL-malic acid pickling. The adsorption experiment results noted single-layer chemical adsorption and maximum lithium adsorption of 32.32 mg/g. From the Brunauer–Emmett–Teller and scanning electron microscopy results, the M-T-LIS provided adsorption sites after DL-malic acid pickling. In addition, X-ray photoelectron spectroscopy and Fourier transform infrared results showed the ion exchange mechanism of the M-T-LIS adsorption. From the results of the Li+ desorption experiment and recoverability experiment, DL-malic acid was used to desorb Li+ from the M-T-LIS with a desorption rate of more than 90%. During the fifth cycle, the Li+ adsorption capacity of the M-T-LIS was more than 20 mg/g (25.90 mg/g), and the recovery efficiency was higher than 80% (81.42%). According to the selectivity experiment, the M-T-LIS had good selectivity for Li+ (adsorption capacity of 25.85 mg/g in the artificial salt lake brine), which indicates its good application potential. [ABSTRACT FROM AUTHOR]

The original composition of Laguocuo Salt Lake was found in the mirabilite area of the 15 °C isothermal phase diagrams of the Li+, Na+, K+//Cl−, SO42−-H2O system. Four phases comprise the isothermal evaporation procedure. The first stage is the unsaturated stage except for carbonate. The second stage is made up of sodium chloride, mirabilite, and borax precipitate simultaneously, where the halogenation rate is 31.58%, and the water loss rate is 68.32%. The penultimate step is the lithium salt precipitation section, where primarily NaCl, Na2SO4·10H2O, and Li2SO4·3Na2SO4·12H2O are formed, where the water loss rate is 91.38%, the halogenation rate is 7.42%, and the salt precipitation rate is 1.20%. The final stage is the eutectoid stage of lithium and potassium salts, where primarily NaCl, Li2SO4·3Na2SO4·12H2O, and 3K2SO4·Na2SO4 precipitate simultaneously. The rates of water loss, halogenation, and salt precipitation are 93.60%, 5.73%, and 0.67%, respectively. NaCl, Li2SO4·3Na2SO4·12H2O, and 3K2SO4·Na2SO4 were all precipitated through dispersion precipitation of borax with the evaporation process following precipitation. The UNIQUAC model was employed to predict the isothermal evaporation at 15 °C. The theoretical calculation and the experimental were in good agreement. The present work can offer a fundamental theoretical framework for the development and use of Laguocuo Salt Lake resources at 15 °C. [ABSTRACT FROM AUTHOR]

The research shows that the original compositions of the brine of Lhaguo Tso Salt Lake in Tibet is located in the mirabilite region of isothermal phase diagram of the Li+, Na+, K+//Cl–, SO42–-H2O quinary system at 0°C, and the isothermal evaporation process is divided into four stages. The first section is the unsaturated section except for carbonate, the second section is the sodium salt section, the third section is the potassium salt section, the last section is the lithium salt section. Among them, the sodium chloride and the potassium chloride will be precipitated with the evaporation process after precipitation, the borax is precipitated gradually, and the lithium salt is precipitated in various forms. This study can provide a basic theoretical basis for the development and utilization of salt lake resources under low temperature conditions. [ABSTRACT FROM AUTHOR]

Lithium extraction from salt lake brine with a high mass ratio of Mg/Li by counter-current method using TBP-DIBK extraction system was investigated in this study. In the extraction process, TBP and DIBK acted as extractant, kerosene was used as diluent, and FeCl3 was used as co-extractant. The operation conditions of extraction, scrubbing, stripping, and regeneration were investigated. In this study, 5.5 mol/L LiCl + 0.5 mol/L HCl was used as a scrubbing solution for purifying products, and 6 mol/L HCl solution was used as a stripping agent to transfer Li+ from organic phase to aqueous phase. Furthermore, 2 mol/L NaOH and saturated MgCl2 were used as the regeneration agent to remove H+ from organic phase. The counter-current extraction experiments of 3-1-1-3 stages were carried out. After 10 cycles, the lithium extraction efficiency reached 99.90%; the separation factor of Li/Mg, Li/K, Li/Na, and Li/Ca was 5.215 × 104, 2.159 × 103, 3.659 × 102, and 3.104 × 102, respectively. The results indicated that the TBP-DIBK extraction system was effective at extracting lithium from salt lake brine with a high mass ratio of Mg/Li. Furthermore, the study of extraction thermodynamics suggested that lithium extraction was an exothermic process and that lower temperature promoted lithium extraction. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• The activity coefficients of the NaCl in the NaCl–Na 2 B 4 O 7 –H 2 O solutions at 288.2 K and 318.2 K were determined by cell potential method. • Single salt parameters of Na 2 B 4 O 7 and mixed ion parameters of the ternary system NaCl–Na 2 B 4 O 7 –H 2 O were fitted using the Pitzer model. • Other thermodynamic properties of NaCl–Na 2 B 4 O 7 –H 2 O solution were calculated. • The solubility data of NaCl–Na 2 B 4 O 7 –H 2 O at 288.2 K and 318.2 K were calculated, and the results were more in line with the experimental values. • Design of a preliminary boron extraction process from brine of Zabuye Salt Lake using phase diagrams. Zabuye Salt Lake is rich in boron resources, and the separation and precipitation process of boron from the brines can be developed by investigating the activity coefficients and phase equilibria of the ternary subsystem { y NaCl + (1− y)Na 2 B 4 O 7 }(aq) at 288.2 K and 318.2 K. In this work, the mean activity coefficients of NaCl in { y NaCl + (1− y)Na 2 B 4 O 7 }(aq) systems were determined by using the cell potentials and Nernst equation. The unreported single salt parameters β N a 2 B 4 O 5 (O H) 4 0 , β N a 2 B 4 O 5 (O H) 4 1 and C N a 2 B 4 O 5 (O H) 4 Φ of Na 2 B 4 O 7 and the mixed salt parameters θ C l , B 4 O 5 (O H) 4 and ψ N a , C l , B 4 O 5 (O H) 4 were determined by using activity coefficients and the Pitzer model. The obtained parameters are used to calculate other thermodynamic properties. Furthermore, phase equilibria of the ternary subsystem { y NaCl + (1− y)Na 2 B 4 O 7 }(aq) at 288.2 K and 318.2 K are measured experimentally. Subsequently, the solubility data of the ternary subsystem { y NaCl + (1− y)Na 2 B 4 O 7 }(aq) were theoretically predicted by the Pitzer model. The calculated results agree well with the experimental results, indicating that the obtained parameters are reliable. These key thermodynamic data for the development of boron-rich brine resources were provided. Based on the phase diagram of the ternary system, a separation process for borates was designed in this work. [ABSTRACT FROM AUTHOR]

The demand for lithium and its compounds is increasing by years, but separating lithium ions from brines are challenging. A novel material of Peach gum Carbon Quantum dots (PG-CQDs) lithium ion sieve was prepared by using a simple precipitation method and heat treatment. The molecular formula of the adsorbent compound was H 2.05 Mn 1.86 C 0.43 O 4 and the maximum adsorption capacity reached 34.6 mg/g, approximately twice that of the unmodified adsorbent, with a separation factor of 293.2–11434 in brine with a high Mg/Li ratio. Experimental and theoretical analyses indicated that he presence of Mn-O-C bonds in the adsorbent and that CQDs increase the pore structure of the lithium ion sieve and that the crystallisation of the original material changes, leading to an increase in BET surface area, proton number and adsorption capacity. The outstanding material can be massively used in lithium ions extraction in complex water system and carbon quantum dots doping Li+ sieve have potential application value for extracting lithium ions. [Display omitted] • A modified Li+ adsorbent PG-CQDs@HMS was obtained by co-precipitation. • Li+ adsorption capacity of PG-CQDs@HMS can reach to 34.6 mg/g. • PG-CQDs@HMS show a high Li+ selectivity with α Me Li of 293.2–11434 in brine. • CQDs increase the pore structure of the lithium ion sieve due to Mn-O-C bonds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quantify fouling mechanism of NF in brine via adsorption kinetics and AFM analyses. • GO-modified membranes show enhanced anti-fouling for lithium extraction from brine. • Brine Mg/Li mass ratio reduced by 98.4 % with GO-modified NF membrane filtration. Nanofiltration (NF) is a promising method in lithium extraction from salt lake brine with a high Mg2+/Li+ mass ratio. However, membrane fouling challenges its applicability and productivity. This study incorporated graphene oxide (GO) into the polyamide (PA) selective layer of NF membranes to enhance anti-fouling properties and improve lithium extraction from brine. Membrane structure analyses revealed that 0.002 wt% and 0.01 wt% GO facilitated the interfacial polymerization reaction. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) results indicated that the PA selective layers in the GO-0.002 % and GO-0.01 % membranes were denser, smoother, and thinner. In contrast, the addition of 0.05 wt% GO resulted in the Turing structures on the membrane surface. Adsorption kinetics indicated pollutant adhesion in the following order: GO-0.05 % > GO-0 % > GO-0.002 % > GO-0.01 %, which was attributed to calcium-carboxyl complexation, as directly measured by AFM and consistent with carboxyl density. The GO-0.002 % and GO-0.01 % NF membranes demonstrated excellent anti-fouling properties in brines, with lower initial fouling rates and higher flux recovery after cleaning, underscoring the significant role of calcium-carboxyl complexation in membrane fouling. The retention of Mg2+ increased to 95 %, while that of Li+ decreased to below −28 % for GO-0.002 % and GO-0.01 % membranes, indicating promising potential for Mg and Li separation. This study provides valuable insights into developing NF membranes with high Mg/Li selectivity and anti-fouling capabilities for lithium extraction from salt lake brine. [ABSTRACT FROM AUTHOR]

[Display omitted] • The porous structure facilitates Li+ diffusion and optimizes electron transfer. • The porous adsorbent has higher electrochemical activity and reaction intensity. • The porous adsorbent has a faster adsorption capacity and higher adsorption kinetics. Efficient and selective electrochemical lithium adsorption from liquid resources is crucial for sustainable lithium extraction and purification. However, the sluggish Li+ diffusion kinetics often lag behind electron transfer rates, hindering the overall adsorption efficiency in capacity and kinetics. This work addresses this challenge by introducing a tunable porous spherical architecture in H 1.6 Mn 1.6 O 4 adsorbent particles. The Li+ diffusion coefficient (D Li+) enhanced from 1.32 × 10-12 cm2/s to 3.61 × 10-12 cm2/s, the solution resistance (R s) decreased from 28.88 ohm to 25.30 ohm, the charge transfer resistance (R ct) decreased from 31.04 ohm to 30.40 ohm, and the desolvation activation energy (E a) reduced from 10.81 kJ/mol to 9.81 kJ/mol. Consequently, the optimized porous spherical H 1.6 Mn 1.6 O 4 demonstrates superior adsorption capacity and adsorption kinetics, exceeding 24.23 mg/g at 180 min, which is 1.26 times that of the dense spherical counterpart (19.28 mg/g). The simulation calculations of Li+ diffusion highlight the pivotal role of the porous structure in accelerating internal Li+ diffusion, thereby significantly contributing to the enhanced overall adsorption efficiency of H 1.6 Mn 1.6 O 4. This work emphasizes the significance of synergistically optimizing ion diffusion channels and electron transfer paths for enhancing electrochemical processes and provides a path for constructing similar pore structures in various ion–electron-related applications. [ABSTRACT FROM AUTHOR]

The development of granular adsorbents with high adsorption capability and high cycle stability is of great significance for the application in efficiently extracting lithium from salt lake brine. Herein, the structure of granular aluminum-based adsorbents was regulated by adding water-soluble polymer PEG. The results showed that the molecular weight of PEG was closely related to the pore structure and surface hydrophilicity of the granular adsorbents. With the decrease of the molecular weight of PEG, the specific surface area, the average surface pore size, and the hydrophilicity of granular adsorbents increase. The optimized adsorbent PSF-PEG600@AD formed a complex pore structure with surface macropores and internal mesopores as well as excellent hydrophilicity. The mechanical strength and wear resistance are enhanced. This unique porous structure and surface hydrophilicity enable PSF-PEG600@AD rapid adsorption equilibrium in the old brine of Qarhan salt lake with a Mg/Li ratio of 323 within 4 h. The adsorption capacity remains as high as 99.02 % after 10 static adsorption-desorption cycles, showing excellent cyclic stability. This study guides a direction in preparing high-performance granular adsorbents with adjustable pore structure and surface properties. • The porosity and hydrophilicity of adsorbents simultaneously optimized • Complex pore structure with surface macropores and internal mesopores • Enhanced lithium recovery efficiency from ultrahigh Mg/Li ratio brine • High suitability and stability for recovering lithium from brine exhibited [ABSTRACT FROM AUTHOR]

Nanofiltration (NF) membranes have been used extensively for lithium extraction pretreatment from salt lake brine. However, the separation of lithium from divalent cations by NF membranes under high salinity conditions is technically challenging. Here, Salton Sea geothermal brine, a promising lithium enriched resource in the U.S., was used to conduct comprehensive experiments to evaluate NF as a potential pretreatment approach under different feed salinity and pH levels. Among the 3 most popular commercial membranes (NF270, DL, and NF90), poor rejection, low Li/Mg selectivity (1∼2), and low flux (28∼42 L m−2 h−1, LMH) were found at 30 bars at higher salinity. With the feed concentration being diluted from 200 g/L to 20 g/L, the rejection of divalent ions (68.5∼79.1 %) and flux (75∼135 LMH) improved significantly. pH only influenced the selectivity when the feed concentration was low. Our molecular dynamics simulation confirmed that the hydrogen bond dynamics at high salinities reduced the water mobility, while the salt mobility deterioration was found to be relatively insignificant. Therefore, the rejection was decreased at high feed salinity. These are critical findings to be considered if NF is employed to pretreat brine for lithium extraction. A preliminary economic assessment was conducted using combined NF and crystallization to recover Li from geothermal brine. With enormous high content of calcium in the Salton Sea geothermal brine, we suggest placing crystallization upstream of NF to remove most of divalent cations. Then, the treated brine required to be diluted to a range of 18∼30 g/L followed by three-stages of NF that can achieve the final molar Li/Mg and Li/Ca ratios upward 99. [Display omitted] • We evaluated NF as a lithium extraction pretreatment from geothermal brine under various feed salinity and pH levels. • We observed low Li/Mg selectivity at high salinity and pH affected the selectivity only at low feed concentrations. • Molecular dynamics showed hydrogen bond dynamics at high salinity reduced the water mobility of NF membranes. • Economic assessment suggested that brine needed to be pretreated before NF stage. [ABSTRACT FROM AUTHOR]

Cesium is an important strategic resource, and solvent extraction is the most frequently used technology for its extraction from various minerals and brines. However, this common method faces operational and cost problems owing to large alkali consumption. A synergistic extraction system consisting of 4- tert -butyl-2-(α-methylbenzyl) phenol (t-BAMBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was designed and used to extract Cs+ from an alkali-free solution. The effects of variables such as: (i) pH, (ii) concentration of t-BAMBP and D2EHPA, (iii) temperature, (iv) Cs+ concentration, and (v) coexisting cations, on the Cs+ extraction performance of the synergistic system were investigated. The most suitable organic phase composition was 1.0 mol/L t-BAMBP and 0.1 mol/L D2EHPA in kerosene, and the synergistic coefficient was up to 57 at 25 °C and an organic/aqueous phase volume ratio of 1/1. The extraction sequence of cations using the t-BAMBP–D2EHPA synergistic system followed the descending order Cs+ > Rb+ > Ca2+ > K+ > Li+ > Mg2+ > Na+. The chemical formula of the extracted species was determined as [CsA(HA)(ROH) 2 ] using the slope method. The Cs+ extraction process is an exothermic reaction with an enthalpy (ΔH o ) of −55.3 kJ mol−1, confirmed by the thermodynamic study. After three-stage countercurrent extraction, the extraction efficiency of Cs+ was 92.6%, demonstrating excellent selectivity from coexisting cations. The t-BAMBP–D2EHPA synergistic system showed outstanding economic and environmental advantages and a good application prospect to develop a conceptual process flowsheet for extraction with this system and stripping with HCl to separate cesium salt from salt-lake brine. • A novel Cs+ extraction system without alkali consumption was proposed. • The novel extraction system showed excellent selectivity for Cs+ between co-exiting cations. • >92% Cs+ could be extracted from natural salt lake brine with low Cs+ concentration and complex components. • The Cs+ extraction showed advantages in a short process with favorable economics and environmental protection. [ABSTRACT FROM AUTHOR]

Boron selective resin is a crucial material used for extracting boron from salt lake brine, but the adsorption capacity of resin remains to be improved. In this work, a boron selective resin with high adsorption capacity was created by modifying branched poly (ethylene imine) (PEI) on chloromethyl polystyrene resin, followed by reacting with D-(+)-gluconic acid δ-lactone. The influence of surface hydroxyl content on adsorption capacity of the resin was investigated by varying molecular weights of PEI during modification. The adsorption mechanism of boric acid was explored by changing pH and composition of solution, and by analyzing the adsorption thermodynamic and kinetic behaviors. Furthermore, the selectivity of resin was assessed by the effects of coexisting ions on the adsorption rate of boric acid. The results show that PEI modification effectively increases the content of hydroxyl on the surface of the resin so as to enhance the adsorption capacity of the resin towards boric acid up to 39.4 mg/g. Also, the adsorption rate can still reach up to 75 % even in the presence of 400 times coexisting ion, showing a good selectivity. Furthermore, the adsorption of boric acid is primarily driven by boronate affinity rather than an anion exchange in alkaline solution. Finally, the dynamic extraction of boric acid was carried out, and gives an enrichment factor of up to 39.6 on fixed bed, demonstrating a potential of the resin in the field of boron extraction. [Display omitted] • PEI-mediated dihydroxy-functionalized resin possesses much higher adsorption capacity to boric acid. • Adsorption of boric acid is driven by boronate affinity rather than an anion exchange. • Relationship between adsorption capacity and molecular weight of PEI is explored. • The resin exhibits excellent selectivity and dynamic extraction ability. [ABSTRACT FROM AUTHOR]

The lithium resources in Tibet's salt lake account for more than 31 % of China's total, featuring a low magnesium-to-lithium ratio with its carbonate-type salt lakes representing a unique resource of the region. When extracting lithium from low-magnesium salt lakes (carbonate-type salt lakes) using a β-diketone system, it is common practice to add alkaline reagents at the front end to precipitate and remove magnesium. This study utilizes the LIX54/TRPO-ADD-1 system for the co-extraction of lithium and magnesium from the brine of the Jiezechaka salt lake, employing CO 2 for stepwise stripping to separate lithium and magnesium, using a weak acid instead of a strong acid for stripping to avoid impacting Tibet's fragile ecological environment. By controlling the pH with varying amounts of CO 2 , an extraction efficiency of 92.54 % for lithium at pH=8.5 and an A/O = 1:5, and complete stripping of magnesium from the loaded organic phase at pH=7 with an A/O = 1:3.2 over three theoretical stages was achieved. This new process omits the front-end magnesium precipitation step, offering a new avenue for the separation of lithium and magnesium in salt lakes and the resource utilization of magnesium. • Using the LIX54/TRPO extraction system to achieve co-extraction of lithium and magnesium. • Implementing stepwise stripping with CO 2. • Establishing a new extraction system to utilize lithium and magnesium resources from low-magnesium salt lake brine. [ABSTRACT FROM AUTHOR]

With the increasing demand for lithium, the shortage of resources has become increasingly apparent. In order to conserve resources and to improve recovery, the extraction of lithium from salt lakes has become mandatory for sustainable development. Porous metal-organic framework (MOF) materials have attracted extensive attention due to their high/tunable porosity, pore function, multiple pore structures/compositions, and open metal sites. Moreover, MOFs combine the advantages of other porous materials and have a wide range of applications, which have received significant interest from the scientific community. Therefore, the selection of MOFs materials, the optimization of preparation methods, and the research of lithium separators are key directions to improve the total yield of lithium resources in salt lakes in China. This study aims to improve the comprehensive utilization of resources after lithium extraction and strengthen the engineering technology research of lithium extraction from salt lakes. This study can help to achieve the goal of efficient, integrated, and sustainable utilization of salt lake resources. An attempt has been made to summarize the types and preparation methods of MOFs materials, as well as the separation mechanism of MOFs nanofiltration membranes, with reference to its application in lithium extraction from salt lake brine. Finally, the future development of MOFs nanofiltration membranes for lithium extraction from salt lakes is also proposed. [ABSTRACT FROM AUTHOR]

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In this work, Li preintercalated λ-Li x MnO 2 with tunable lithium content is synthesized, which exhibited excellent electrochemical performance and dual-mode electrochemical storage behavior. Double-layer capacitive and diffusion-controlled Faradaic processes play a role in the charge-discharge process, leading to an enhanced lithium selective adsorption capacity. When employed in hybrid capacitive deionization (HCDI), the λ-Li 1.5 MnO 2 obtains a Li + adsorption capacity of 33.68 mg g -1 in 32.74 mg L -1 Li + ion solution and low energy consumption of 0.19 Wh g -1 . Moreover, the λ-Li 1.5 MnO 2 electrode exhibited outstanding cycling stability, with a significant capacity retention rate of 80% and a manganese mass dissolution rate of 1.2% over 100 intercalation/deintercalation cycles. λ-Li 1.5 MnO 2 achieved outstanding lithium selectivity with a separation factor ≈32.7 at a Mg 2+ /Li + molar ratio of 30 in synthetic brine. Importantly, λ-Li 1.5 MnO 2 achieved a high Li + adsorption capacity and good selectivity in Lop Nor, the low-grade original brine of the XieLi salt flats, making it a candidate electrode for lithium extraction from low-grade original brine. The pre-intercalation strategy offers a viable option for rationalizing other intercalation electrode materials for electrochemical lithium extraction from low-grade original brine., (© 2024 Wiley‐VCH GmbH.)

Taking Xitaijinel Salt Lake brine as the research object，the TBP ionic liquid lithium extraction system was selected. TBP was used as the extraction agent, and 1 butyl 3 methylimidazolium hexafluorophosphate([BMIM] PF6) was used as the co extraction agent to study the effects of coexisting ions in brine on Li+ extraction. The results show that Mg2+ has a synergistic extraction effect on Li+，K+ and Na+ can inhibit the extraction of Li+, and B, pH and anion species show trace effect on the extraction of Li+. [ABSTRACT FROM AUTHOR]

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The tributyl phosphate (TBP)/FeCl 3 system has been widely used for lithium extraction from high‑magnesium salt lakes. However, at high TBP concentrations, the Li/Mg selectivity is significantly lower. This study revealed that at high TBP concentrations, TBP alone extracted Mg2+ to form MgCl 2 ·6TBP as the main product, thus affecting the extraction efficiency of Li+. On this basis, a neutral phosphate with long carbon chains, trioctyl phosphate (TOP), was used to replace TBP. The separation capacity and extraction mechanism of the TOP/FeCl 3 system were studied, and density functional theory (DFT) calculations were employed to model the cationic complexes of the TOP and TBP systems. The results showed that in the presence of FeCl 3 , the extraction efficiency of Li+ (E Li) reached 91 %, and the Li/Mg separation factor (β Li/Mg) was 5688. In contrast, in the TBP/FeCl 3 system with the same concentration, the E Li and β Li/Mg values were much lower at 74 % and 239, respectively. Furthermore, the TOP complex of Li+ had shorter Li − O bond lengths and a more negative binding energy, while that formed with Mg2+ had longer Mg − O bond lengths and the smallest HOMO–LUMO gap, indicating that TOP bonded more stably with Li+ and was less prone to Mg2+ extraction than TBP. [Display omitted] • TBP alone extracted MgCl 2 via solvation to form MgCl 2 ·6TBP. • TOP alone could not extract MgCl 2. • The Li/Mg separation factor reached 5668. • The structures of the formed complexes were modelled by DFT. [ABSTRACT FROM AUTHOR]

A great challenge is to develop suitable techniques to extract Li+ resources from low-grade salt-lake brines with high Mg/Li ratios. In this study, an efficient ternary extraction system has been constructed using tributyl phosphate (TBP) and crown ether (CE) as the extractant and sodium bistrifluoromethylsulfonimide (NaNTf 2) as the auxiliary extractant to extract Li+. Results showed that the single-stage E Li % and SF Li-Mg were up to 74.1 % and 757, respectively, when the O/A was 1, 0.02 mol/l Li+ and 0.232 mol/l Mg2+. It is noteworthy that the elution of Li+ was also as high as 100 % at an O/A volume ratio of 5, when 0.5 mol/l HCl was used as the counter-extractant to recovery Li+. The NMR and FTIR analysis and molecular dynamics (MD) and density functional theory (DFT) revealed that the exceptional performance of the three-component extraction system was attributed to the optimal matching between the diameter of Li+ and the cavity size of the CE, as well as the strong affinity exhibited by CE, TBP, and NTf 2 − towards Li+. Specifically, the 2TBP-LiNTf 2 -CE-LiNTf 2 complex structure with the highest binding energy displayed the most structure. In summary, this work paves the way for the recovery of Li+ from low-grade salt-lake brine. [Display omitted] • The green ternary extraction system was constructed with TBP, CE and NaNTf 2. • The E Li % and SF Li-Mg of TBP-CE-NaNTf 2 were up to 74.1 % and 757, respectively. • The NTf 2 − readily forms the complexes with Li+ and TBP, CE. • The structure with 2TBP-LiNTf 2 -CE-LiNTf 2 is the most stable. • TBP and CE are more easily combined with NTf 2 − rather than Cl− to extract Li+. [ABSTRACT FROM AUTHOR]

Copyright of Mining & Metallurgy (10057854) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • λ-MnO 2 is in-situ deposited on 3D rGO matrix with high conductivity and uniformity. • The electrochemical performance of λ-MnO 2 /rGO with 3D network is much enhanced. • λ-MnO 2 /rGO electrode is highly selective to Li+ adsorption in CDI device. • High adsorption amount with good selectivity is achieved in synthetic brine. Faced with the strong demand of clean energy, development of lithium source is becoming exceedingly vital. Spinel-type manganese oxide (λ-MnO 2) is a typical lithium ion sieve material. Herein, the conductive three-dimensional (3D) lithium ion sieve electrode material was fabricated by in-situ growth of λ-MnO 2 on 3D reduced graphene oxide (3D-rGO) matrix for Li extraction by capacitive deionization (CDI). The λ-MnO 2 modified rGO (λ-MnO 2 /rGO) retained the 3D network structure with uniform distribution of λ-MnO 2 nanosheets on rGO. Electrochemical characterization demonstrated its high conductivity and fast lithium ion diffusion rate. By adjusting the rGO concentration, λ-MnO 2 activity was improved significantly. With λ-MnO 2 /rGO as a positive electrode (activated carbon as negative electrode), the corresponding CDI system was successfully applied for the selective extraction of Li+. The final rGO content in the λ-MnO 2 /rGO was attained by thermogravity analysis. With the appropriate rGO content (15.5%), the obtained λ-MnO 2 /rGO electrode achieved the optimal Li+ adsorption amount. The corresponding λ-MnO 2 /rGO-based CDI cell showed good selectivity and high cycle stability. When applied to the extraction of lithium from synthetic salt lake brine, the electrode also obtained high Li+ adsorption amount with good selectivity. [ABSTRACT FROM AUTHOR]

The Qaidam Basin on the Qinghai-Tibet Plateau is well endowed with a variety of critical metals, such as Li and Rb. However, little is known about the distribution, source, and enrichment mechanisms of these elements. In this paper, we present results of systematic geochemical and H-O-B isotopic analyses of brines in the Tertiary and Quaternary sediments of the Qaidam basin. The results reveal that the paleobrines from oil-bearing anticlines at Dafengshan, Nanyishan, Youquanzi, Jiandingshan, and Jianshishan are significantly enriched in Li and Rb, whose contents are 81.1–128.9 mg L−1 and 4.5–29.2 mg L−1, respectively, reaching levels of economic significance. High Rb contents (up to 12.5 mg L−1) and well-endowment of Li also characterize the Dongtai, Xitai, Yiliping, and Senie salt lakes in the Qaidam Basin. The Tertiary paleobrine average in δD and δ18O at −40.7‰ and 2.84‰, respectively. The paleobrine with the highest Li and Rb has δD and δ18O values close to magmatic water. The δ11B values are lower than those of river water but close to those of geothermal fluids, suggesting that replenishment by deep magmatic hydrothermal fluid is most likely the key mechanism for the anomalous enrichment of these elements in the paleobrines, though evaporation and water-rock reactions have contributed to the critical metal mineralization. The anomalous enrichment of Li and Rb in modern salt lake brines is closely related to the input of volcanic geothermal water. The relatively high Li and Rb contents of intercrystalline brines in salt lakes of the western Qaidam Basin and the increase of Li and Rb contents with increasing depth were caused by upwelling of local paleobrines along the fault zones. [ABSTRACT FROM AUTHOR]

A novel boron flotation agent (N-2-hydroxyoctadecyl-N-Methylglucamine, NHO-NMDG) was fabricated using 1,2-epoxyoctadecane and N-methyl-D-glucamine. The obtained collector possesses both collecting and foaming properties and it was characterized by nuclear magnetic resonance, mass spectrometry, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy methods. The flotation performance for boron removal from the salt lake brine has been studied. The flotation experiments indicated a highly effective removal of boron from the salt lake brine. The boron removal rate in the Da Qaidam brine could reach 67.08% by NHO-NMDG. The mechanism analysis shows that the meglumine group in the bifunctional flotation agent can be complexed with boron, and the long-chain alkyl group can attach to the surface of the bubble and enter into the bubble layer, so as to separate boron from the aqueous solution. [ABSTRACT FROM AUTHOR]

The original composition of Laguocuo Salt Lake was found in the mirabilite area of the 15 °C isothermal phase diagrams of the Li+, Na+, K+//Cl−, SO42−-H2O system. Four phases comprise the isothermal evaporation procedure. The first stage is the unsaturated stage except for carbonate. The second stage is made up of sodium chloride, mirabilite, and borax precipitate simultaneously, where the halogenation rate is 31.58%, and the water loss rate is 68.32%. The penultimate step is the lithium salt precipitation section, where primarily NaCl, Na2SO4·10H2O, and Li2SO4·3Na2SO4·12H2O are formed, where the water loss rate is 91.38%, the halogenation rate is 7.42%, and the salt precipitation rate is 1.20%. The final stage is the eutectoid stage of lithium and potassium salts, where primarily NaCl, Li2SO4·3Na2SO4·12H2O, and 3K2SO4·Na2SO4 precipitate simultaneously. The rates of water loss, halogenation, and salt precipitation are 93.60%, 5.73%, and 0.67%, respectively. NaCl, Li2SO4·3Na2SO4·12H2O, and 3K2SO4·Na2SO4 were all precipitated through dispersion precipitation of borax with the evaporation process following precipitation. The UNIQUAC model was employed to predict the isothermal evaporation at 15 °C. The theoretical calculation and the experimental were in good agreement. The present work can offer a fundamental theoretical framework for the development and use of Laguocuo Salt Lake resources at 15 °C.

Tributy 1 phosphate(TBP)-FeCls system was used as extractant lor extraction and separation ol lithium from an Argentine salt lake brine ol high lithium content and mixed chloride and sullate salts alter boron extraction. The ellects ol Fe/Li molar ratio, TBP concentration, diluent type, phase ratio O/A, organic additive type and concentration were investigated, the process parameters were optimized, and the distribution behaviors ol lithium in the extraction two-phase system and the separation among lithium Irom magnesium, sodium and potassium were analyzed. When the organic phase lormation is 65 % TBP-5 % methyl-isobutyl ketone(MIBK) -30% 260 井 solvent oil, the molar ratio of Fe/Li is 1. 5: 1, the phase ratio 0/A is 2; 1, and the mixing time is 5 min, the single-stage extraction yield ol lithium is more than 79% at room temperature, whereas the extraction yields ol magnesium, sodium and potassium are only 5. 24%, 8. 57% and 0. 88%, respectively. The separation coefficients of lithium and magnesium, sodium and potassium reach 62,37 and 388 respectively. TBP exhibits good selectivity lor lithium and the addition ol MIBK can improve the phase separation and lithium extraction performance. Magnesium, sodium and potassium entrained and co extracted into the organic phase can be removed by washing with dilute hydrochloric acid solution ol lithium chloride. The organic phase loaded with lithium can be stripped with 7 mol/L HC1 solution to obtain lithium-rich solution. [ABSTRACT FROM AUTHOR]