Salt Lake Resources Research Articles

Photo-fenton catalysis degradation of 4-dodecylmorpholine by heterogeneous microprocessor Cu2O/SnO2

The increasing demand for potash has led to the increased use of 4-dodecyl morpholine (DMP), an important froth flotation agent for the extraction for potash extraction by “reverse flotation-cold crystallization”. As it is not easy to be stable and decompose in its natural state, it has seriously endangered the environment of salt lakes and the development of salt lake resources. The development of a safe and harmless catalytic system to accomplish the degradation and removal of DMP is urgent. Herein, A Cu2O/SnO2/PDA (CSP) nanoparticle with a synergistic effect of photocatalysis and Fenton-like catalysis was developed, and the CSP had a good photothermal conversion efficiency. Under 808 nm NIR irradiation, not only the catalyst activity was enhanced, but also the complexation rate of electron-hole pairs was reduced, which effectively increased the degradation efficiency of DMP (an increase of about 31.56 %). In addition, by analyzing the degradation products of DMP, the possible pathways of the DMP degradation process were proposed and, at the same time, the degradation catalytic system we used was proved to be safe and harmless. A new pathway is provided for the degradation and removal of DMP in the salt lake environment.

NaNO3-Promoted MgO-Based Adsorbents Prepared from Bischofite for CO2 Capture: Experimental and Density Functional Theory Study.

MgO has broad application potential in CO2 capture at intermedium temperatures. In this paper, the effects of NaNO3 doping on the properties of MgO prepared by using waste bischofite as the raw material were investigated to improve the performance of the CO2 capture. MgO-doped NaNO3 exhibited excellent CO2 capture performance at 320 °C with a maximum adsorption capacity of 36.62 wt %. MgO-doped NaNO3 has good cycling stability after 10 adsorption-desorption cycle experiments. In addition, CO2 adsorption on pure MgO and MgO-NaNO3 surfaces was investigated in accordance with density functional theory. Calculation results show that doping with NaNO3 allows more electrons to be transferred from the MgO substrate to the CO2 molecule. MgO-doped NaNO3 can lead to an increase in adsorption energy, resulting in a more stable structure after adsorption and thereby promoting adsorption. The result of this study provides an effective method for the comprehensive utilization of salt lake resources.

Influence of alkali metal ions (K+ and Na+) on the preparation of magnesium hydroxide hexagonal flakes.

Magnesium hydroxide (Mg(OH)2), as a green halogen-free flame retardant, has attracted significant attention in the field of flame retardant composite materials. In addition to conventional indicators such as purity and whiteness, Mg(OH)2 is required to take the form of regular hexagonal sheets to ensure the dispersion of composite materials. We use irregular large particles of Mg(OH)2 prepared by the magnesium factory in western Qinghai as raw materials to study the influence of alkali metal ions K+ and Na+ mainly present in salt lakes on the physicochemical properties of Mg(OH)2. The products were characterized via X-ray diffraction, scanning electron microscopy, automatic nitrogen physical adsorption apparatus, and other modern characterization techniques. Results show that alkali metal ions K+ and Na+ considerably influence the crystal surface polarity, particle size, and morphology of the prepared Mg(OH)2. The mechanism analysis shows that the presence of K+ and Na+ alters the dissolution, recrystallization, and growth characteristics of Mg(OH)2. This study provides theoretical support for the realization of high-performance Mg(OH)2 using salt lake resources and demonstrates the value for promoting the large-scale industrial application of the salt lake industry.

Layered Magnesium Phosphate as an Environmentally Friendly Solid Lubrication Additive: Morphology Control and Tribological Properties

To develop a new type of environmentally friendly solid lubricant and expand the high-value utilization of salt lake resources, we prepared a layered magnesium phosphate (MgHPO4·1.2H2O) eco-friendly lubricant using an improved green hydrothermal synthesis route in which particle size and morphology were controlled. The tribological properties of the layered magnesium phosphate samples as additives in PAO8 calcium-based grease were evaluated using an Optimol SRV-V oscillating reciprocating tester (hereafter referred to as SRV tester). Products exhibited excellent friction behavior when added to grease. When added at 3.0 wt %, the tribological properties of the grease were improved significantly; the highest operating load was raised from 400 to 600 N, the wear volume was decreased from 44.98 to 7.50 (10–4 mm3), and friction curves became more stable and smooth. A possible lubricating mechanism was proposed. Macro to micro analysis of rubbing surfaces showed that the MgP materials had a protective effect on the PAO8 calcium-based grease matrix, and lubricating films were clearly formed on the friction pair surface.

Isothermal Evaporations of the Brine from Tibet’s Laguocuo Salt Lake at 15 °C: Experiment and UNIQUAC Simulations

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.

Remote sensing inversion of the Zabuye Salt Lake in Tibet, China using LightGBM algorithm

The Zabuye Salt Lake in Tibet, China is the only salt lake in the world that contains natural crystalline lithium carbonate. The grade and spatial distribution of mineral resources are of great importance to the development and utilization of salt lake mineral resources. The use of remote sensing technology for salt lakes observations can overcome the disadvantages of traditional station observations, such as spatial discontinuity, high time consumption, and high labor costs. In addition, machine learning algorithms can efficiently analyze the information from remote sensing data. In this study, Landsat-8 remote sensing image data and the Light Gradient Boosting Machine (LightGBM) algorithm were used to perform inversions of the depth, salinity, and lithium concentration of the Zabuye Salt Lake. Moreover, the water volume, total salinity, and total lithium content of Zabuye Salt Lake in 2000 and 2017 were estimated, and the distribution of mineral resources and changes during the study period were analyzed. The results show that the water depth and volume of the entire lake increased sharply in 2017, resulting in a decrease in salinity and lithium concentration in the lake. Due to the inflow from the surrounding dry salterns, the South Lake experienced a relatively small change. Furthermore, the amount of lithium resources in North Lake decreased significantly in 2017 compared to 2000, possibly due to higher temperatures during the month of observation, which led to precipitation of lithium carbonate. Our study proves the feasibility and accuracy of the LightGBM machine learning algorithm for rapid inversion of salt lakes, which provides technical insight into remote sensing inversion of other mineral resources in salt lakes. Thus, the development of remote sensing technology in recent years can provide increasingly detailed assessments of salt lake resources in the future.

Application of Nanofiltration Membrane Based on Metal-Organic Frameworks (MOFs) in the Separation of Magnesium and Lithium from Salt Lakes

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.

Volumetric properties of the binary aqueous system lithium metaborate from 283.15 to 363.15 K and 101 kPa: Experimental and thermodynamic model

Volume properties of salt lake solution are of great significance in constructing the thermodynamic model of the salt lake brine system and promote the comprehensive utilization of salt lake resources. In this paper, LiBO2(aq) densities from 0.08083 to 0.75731 mol·kg−1 were determined experimentally at 5 K temperature intervals from 283.15 to 363.15 K and 101 kPa using a precise digital vibrating-tube densimeter. The apparent molar volume (Vϕ) and the thermal expansion coefficient (α) were derived based on the experimental data. The 3D diagrams of the apparent molar volume and the thermal expansion coefficient against molality and temperature were demonstrated. According to the Pitzer thermodynamic model of apparent molar volume of electrolyte, the Pitzer single-salt parameters βMX(0)ν, βMX(1)ν, βMX(2)ν,CMXν of LiB(OH)4 and their temperature-dependence coefficients (p = Co + C1lnT/298.15 + C2(T-298.15) + C3/(620-T) + C4/(T-227) were established for the first time. A comparison between the predictive and experimental data indicates that the experimental data and the parameters obtained in this work are reliable.

Impact of Regional Climate Change on the Development of Lithium Resources in Zabuye Salt Lake, Tibet

Climate change has important implication for the ecological environment and human social activities. The Qinghai-Tibet Plateau is a sensitive area for climate change, and the lakes on the Qinghai-Tibet Plateau are known as the “guardians” of climate change. However, there are few studies on the impact of climate variations on the exploitation of lithium resources in salt lakes. In this work, the collected data from Zabuye Salt Lake Observation Station and the experimental data of brine at different temperatures were employed as the research objects to investigate the relationship between regional climate change and lithium resources in salt lakes. The results indicated that Zabuye Salt Lake had abundant solar energy resources from 1991 to 2020 with the annual average sunshine duration of 3,122.4 h, the average annual evaporation of 2,579.07 mm/yr, and the annual average precipitation of 168.65 mm/yr. The average annual evaporation is around 15.3 times the average annual precipitation, owing to the short rainy season and the low rainfall. The phase diagram displayed that two lithium carbonate precipitation peaks clearly appeared at 25°C, and no obvious precipitation peak appeared at 15°C, indicating that a high-grade lithium carbonate mixed salt was prone to be formed at a higher temperature while lithium ions was more inclined to enrich in brine at a lower temperature. Therefore, Zabuye Salt Lake with the characteristics of low temperature, large temperature difference, less precipitation, strong radiation and large evaporation could be applied as unique lithium resources in the salt gradient solar pond, which would play a positive role in the development of salt lake resources.

Origin of the enrichment of B and alkali metal elements in the geothermal water in the Tibetan Plateau: Evidence from B and Sr isotopes

Geothermal fields distributed in the southern Tibet Plateau rifts such as Yangbajing - Dangxiong basin, and the Yaluzangbu suture are characterized by intensive hydrothermal activity and high enrichment of trace elements (e.g., Li, Rb, Cs, B and Br) in geothermal springs. However, the origin of these elements and their enrichment mechanisms in those geothermal waters remain unclear. This study presents data for the enriched elements, incompatible elements, and B and Sr isotopes, in the geothermal water in the Tibetan Plateau and compares them with some typical geothermal fields worldwide, in an attempt to provide new insights into the origin and mechanism of the enrichment of these trace elements. The results indicate that all geothermal water samples from the Tibetan Plateau show more negative δ11B values than those from local precipitation and rivers. Considering the wide existence of a high-conductivity zone in the middle or even upper-crust interpreted to correspond to re-melt magmatic fluids in the Tibet, the main sources of the typical chemical composition of geothermal waters in the Tibetan Plateau can be classified into two main types: residual magmatic fluids derived from crustal partial remelting and deep circulated groundwater modified by water–rock interactions. In particular, the possible source of magmatic fluids may play a more significant role for special geochemical compositions of geothermal water in the Tibet. Such resources are beneficial for the development and utilization of the geothermal water itself and also serve as a stable source for feeding the salt lake resources.

Dissolution enthalpies and the thermodynamic properties of sodium metaborates

The thermodynamic properties including enthalpy, entropy and Gibbs free energy are important parameters, which can provide a theoretical basis for utilizing salt lake resources. In addition, the dissolution equilibrium constant (K), activity coefficient (γ) and osmotic coefficient (Φ) of inorganic salt solution, especially for sodium borate, are critical and fundamental, but scarce owing to the difficulty to measure them. These data are not only important theoretical basis in analytical and physical chemistry, but also reliable information in determining chemical production processes. In this paper, the dissolution enthalpies (∆Hsθ) of sodium metaborate tetrahydrate (NaBO2·4H2O) and sodium metaborate dehydrate (NaBO2·2H2O) were determined using a microcalorimeter TAM IV. Based on our experimental data and the Pitzer electrolyte model, values of dissolution equilibrium constant (K, 8.7986 mol2·kg−2 for NaBO2·4H2O, 9.9560 mol2·kg−2 for NaBO2·2H2O), activity coefficient (γ, 0.2932), osmotic coefficient (Φ, 0.7999) of NaBO2 were measured with precision. According to the designed thermochemical cycle and the basic formula of thermodynamics, the standard enthalpy of formation (∆Hfθ), the standard entropy of formation (∆Sfθ), the standard Gibbs free energy (∆Gfθ), the standard enthalpy of dissolution (∆Hsθ), the standard entropy of dissolution (∆Ssθ), and the dissolution Gibbs free energy (∆Gsθ) of NaBO2·4H2O and NaBO2·2H2O at 298.15 K, which are not reported in the literature, were obtained with exactitude. These results indicate that the dissolution of both hydrates are all endothermic, spontaneous and entropy driven processes.

Phase Equilibria of the Brine Systems Containing Strontium and Calcium Ions

It is well known that the comprehensive utilization of the Salt Lake resources successfully must be guided corresponding to the aqueous phase equilibria and phase diagrams. Researches on the phase relationships of brine systems containing calcium and strontium ions are essential to promote the development for the relative resources discovered in China at recent years. In this paper, the phase equilibria of calcium-containing systems, strontium-containing systems and calcium-strontium coexisted brine systems around the world were reviewed. The problems existed recently and new trends in future were point out.

Solid-liquid Phase Equilibria of the Aqueous Systems Containing Lithium, Magnesium and Borate Ions

It is well known that the phase chemistry is of great importance in the fields of chemistry, chemical engineering, and the separation and purification of minerals from brine. To effectively employ the resources containing lithium, magnesium and borate, the study on phase equilibrium is essential to the comprehensive utilization of the Salt Lake resources. In this paper, progresses on phase equilibria of salt-water systems containing lithium, magnesium and borate were presented.

Phase Diagram of the Quaternary System KCl–MgCl2–NH4Cl–H2O at t = 60.00 °C and Their Application

Based on the requirement for the comprehensive exploitation and utilization of the salt lake resources magnesium chloride and potassium chloride, a new technology to produce KCl and ammonium carnallite (NH4Cl·MgCl2·6H2O) by using NH4Cl as salting-out agent to separate carnallite is proposed. The solubilities of quaternary system KCl–MgCl2–NH4Cl–H2O were measured by the isothermal method at t = 60.00 °C and the corresponding phase diagram was plotted and analyzed. The analysis of this phase diagram shows that there are seven saturation points and eight regions of crystallization. These eight regions of crystallization represent salts corresponding to KCl, NH4Cl, MgCl2·6H2O, (K1−n(NH4)n)Cl, ((NH4)nK1−n)Cl, (K1−n(NH4)n)Cl·MgCl2·6H2O, KCl·MgCl2·6H2O and NH4Cl·MgCl2·6H2O. According to the phase diagram analysis and calculations, ammonium carnallite (NH4Cl·MgCl2·6H2O) and KCl can be obtained using carnallite as raw materials and ammonium chloride as salting-out agent at t = 60.00 °C. The new technology shows the advantages of being easy to operate and having low energy consumption. The research on this quaternary phase diagram is the foundation for reasonable development of carnallite resources and comprehensive utilization of the salt lake brines.

Study on the Solid-Liquid Phase Equilibrium of the Calcium-Containing Brine System

It is well known that the comprehensive utilization of the salt lake resources successfully must be under the guide of the corresponding aqueous phase equilibria and phase diagrams. The researches on phase relationships of the calcium-containing brine system are essential to promote the comprehensive development and utilization of the relative salt lake resources discovered in our country at present years. In the paper, the progresses on the phase equilibrium of calcium-containing brine systems corresponding to sea water system, carbonate system, borate system and calcium-lithium coexisted system around the world were presented. The problems existed recently and the new trends in the future were also carried out.

Progress and Prospects of Salt Lake Research in China

AbstractChina has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride‐sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate (salt forming) have been identified. Five pan‐lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits: the atlas (1:2500000) of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of “Continental Potash Deposition Theory”; several new types of Mg‐borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti‐floatation‐cold crystallization method developed independently has improved the capacity of KCl production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K‐sulfate production Une, the biggest in the world, has been built in Lop Nor, and K‐sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, Le. brine preparation in winter‐cooling‐solarization‐isolation‐lithium deposition from salt gradient solar pond” the highest lithium production base at Zabuye Lake (4421 m), Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture (Salt land agriculture) has been established based on the mass growth of Dunaliella and other bacillus‐algae and the occurrence of various halophytes in saltmarsh and salt saline‐alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science “Salinology”.

Assessing China’s salt lake resources R&D based on bibliometrics analysis

The aim of this article is to assess China's RD several research groups have been formed to explore the mining of salt lake resources; Collaboration is mostly still confined to the domestic scene; cross-national collaboration has not yet started to grow. Finally, proposals are put forward for the formulation of an R&D strategy and for cultivating R&D groups.

New Thoughts of Comprehensive Development and Utilization of Salt Lake Resources in Qinghai Province

Qinghai Province has unique salt lake resources in China characterized by multicomponent,big storage,multi types and easy exploitation.These salt lake resources are concentrated in Qaidam Basin.

Establish Green Industry System, Improve the Comprehensive Utilization Level of Salt Lake Resources, and Create A New Pattern of Green Sustainable Development in Qaidam Basin

Acta Geologica Sinica - English EditionVolume 88, Issue s1 p. 439-439 Meeting Abstracts Establish Green Industry System, Improve the Comprehensive Utilization Level of Salt Lake Resources, and Create A New Pattern of Green Sustainable Development in Qaidam Basin Yuan XIE, Corresponding Author Yuan XIE Department of Science and Technology, Qinghai ProvinceCorresponding author. E-mail: xieyuan1961@163.comSearch for more papers by this author Yuan XIE, Corresponding Author Yuan XIE Department of Science and Technology, Qinghai ProvinceCorresponding author. E-mail: xieyuan1961@163.comSearch for more papers by this author First published: 12 December 2014 https://doi.org/10.1111/1755-6724.12280_13Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume88, Issues1Special Issue: Meeting Abstracts: The 12th International Conference on Salt Lake Research. July 14–18, Beijing, ChinaDecember 2014Pages 439-439 RelatedInformation

Progress and Prospects of Salt Lake Research in China

China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate(salt forming) have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits: the atlas(1:2500000) of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of Continental Potash Deposition Theory; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the correspond