Academic communication
-
ISL made a major breakthrough in the research on the key technology of clean production of electrosynthesis of sodium dichromate
Recently, the "Key Technology of Electrosynthesis Sodium Dichromate Closed Cycle Process and 50,000 Tons Industrialization" project undertaken by the research team of Dong Yaping and Feng Haitao of ISl was successfully commissioned in Qinghai Bohong Chemical Technology Co., Ltd. in Ganhe Industrial Park, Qinghai Province. A crystalline product of sodium dichromate dihydrate with good crystal morphology was obtained, and the main content of the product was greater than or equal to 99.7%, which reached the standard of superior industrial sodium dichromate. This marks a breakthrough in the research on the key technology of the green cycle new process for the electrosynthesis of sodium dichromate by ISL, and also indicates that Qinghai Bohong Chemical Technology Co., Ltd. has entered the ranks of international advanced enterprises in the production of chromium salt.
The chromium chemical industry has an irreplaceable special position in China’s economic and social development. Chromium chemical products based on sodium dichromate, chromic anhydride, chromium trioxide, chromium sulfate, chromium oxychloride and metallic chromium are closely related to 15% of the commodities in the national economy, are used in leather, printing and dyeing, medicine, anticorrosion, electroplating. However, the high pollution, difficult management and long-term destructive problems in the production of basic chromium salt products are the fatal hidden dangers for the survival and development of chromium chemical companies. The "source governance" of chromium chemical production is a fundamental measure to solve the "bottleneck" of chromium salt production.
With the strong support of Qinghai Provincial Department of Science and Technology and the Chinese Academy of Sciences, the research team of Dong Yaping and Feng Haitao of Qinghai Salt Lake Research Institute have been systematically studying the electrochemical preparation of chromium salt technology since 2007 on the basis of preliminary research. The project solved the closed loop process of electrosynthesis of sodium dichromate, makes full use of the by-product sodium hydroxide, hydrogen and oxygen to meet the requirements of zero emission, established a test method for accurately detecting the types and contents of trace ions in raw materials and products, solved the problems of tolerance and efficiency of anode and ion exchange membrane materials; establish real-time monitoring of important process parameters and interlock control mechanism. It has laid a solid technical foundation for the successful implementation of the "Key Technology of Electrosynthesis of Sodium Dichromate Closed Cycle Process and Industrialization of 50,000 Tons". At the same time, the research team continues to deepen the research and development of the series of chromium salt products prepared by electrochemical methods, and establishes long-term, stable and effective cooperative relations with chromium salt companies, and gradually promotes and applies the series of chromium salt process technologies developed in recent years. On the basis of the technology of preparing sodium dichromate by the electrochemical method, a complete set of chromium salt cleaner production technology based on electrochemical method has been successfully developed, including the electrochemical ferric oxide preparation of sodium chromate and the co-production of chromium trioxide and ferric oxide. Membrane electrosynthesis of sodium dichromate and ion membrane electrosynthesis of chromic anhydride.
Install ion membrane
Automatic control center
Group photo of the main members of the research team
. .2021-01-27 -
New progress has been made in research on the correlation between Asian monsoon and westerly Holocene evolution by ISL
On December 24, 2020, the international academic journal "Gondwana Research" (Gondwana Research) published the title "Correlation and anti-correlation of the Asian summer monsoon and westerlies during the Holocene". Related research). This achievement was jointly completed by Dr. Li Yun and Dr. Han Li from Qinghai Salt Lake Institute, Professor Liu Xingqi from Capital Normal University, researcher Song Yougui from Institute of Earth Environment, Chinese Academy of Sciences, and Dr. Wang Yixuan from Qinghai Salt Lake Institute.
Research on the correlation between westerly winds and Asian monsoons during the Holocene has received extensive attention in recent years, but there are still controversies. For this reason, this article has reconstructed the changes in precipitation since the Holocene in the northeastern part of the Qinghai-Tibet Plateau by investigating the loess and lake sediments in the northeastern part of the Qinghai-Tibet Plateau, and compared it with the records of other northern Chinese lakes, and found that they have good similarities. Therefore, we believe that the reconstructed precipitation changes can represent the history of Asian monsoon changes during the Holocene. These Asian monsoon records have an inverse correlation with the history of westerly wind changes studied by previous studies on the Holocene suborbital scale, but there is a positive correlation on the millennium scale. On this basis, we analyzed the results of the Trace21 simulation experiment and found that the seasonal variation of solar radiation (precession) is the reason for their anti-correlation on the suborbital scale, which is consistent with the results of previous studies. However, on the millennium scale, the North Atlantic Thermohaline Circulation (AMOC) is the reason for their positive correlation. The main contribution of our research results is that during the Holocene westerly winds and Asian monsoons have different correlations on different time scales (suborbital and millennial time scales), which refines and perfects the modal relationship between the Holocene westerly and monsoons.
Comparison of Asian monsoon and westerly indexes during the Holocene based on paleoclimate records and simulated data
. .2021-01-26 -
The basic theory and application research results of magnetic magnesium hydroxide prepared by ISL are evaluated as the leading in China
ISL and Jiangsu aitek flame retardant materials Co., Ltd. jointly carried out "key technology research on preparation of magnesium hydroxide crystal plane oriented magnetic core-shell nano materials", "key technology research on magnetic core-shell technology preparation of high-purity ultra-fine and special morphology high dispersion magnesium hydroxide flame retardant" and "preparation of functional modification and excellent performance of low smoke and halogen-free flame retardant". The key technologies of preparing magnetic core-shell nanomaterials with crystal face orientation and magnetic high-purity superfine and high dispersion magnesium hydroxide flame retardant with special morphology have been broken through, and FeFe2O4&CoFe2O4with uniform particle size, regular morphology and excellent magnetic properties were prepared, and magnetic nanoparticles and FeFe2O4@Mg(OH)2 & CoFe2O4 @ Mg(OH)2 composites were prepared.
This achievement breaks through the key technology of continuous production of high-end magnetic magnesium hydroxide flame retardant integrating synthesis and high-efficiency modification, solves the bottleneck of key technologies and core equipment such as particle size distribution, morphology, specific surface area, purity, whiteness and filtration of magnesium hydroxide, and makes the preparation technology and product index comparable with foreign monopoly enterprises. In the United States, magnetic magnesium hydroxide has become a multifunctional product, expanding the application field of high value-added magnesium hydroxide. The structure-activity relationship between the structure of the coupling agent and the properties of the modified powder and the action mechanism of the surface modified magnesium hydroxide powder were preliminarily constructed. The influence factors of the structure, pyrolysis and surface chemical characteristics of magnesium hydroxide on the properties of flame-retardant polymer materials were investigated. It provides a new idea and strategy for the preparation of different flame-retardant polymer materials and the selection of surface modifiers. The key technology for the preparation of magnetic magnesium hydroxide flame retardant polymer composites has been broken through, the technical level and development level in the field of magnesium hydroxide flame retardant polymer materials have been improved, and the development of environmentally friendly flame-retardant polymer composites has been promoted.
This work was supported by the special project of achievement transformation of Qinghai Provincial Science and Technology Department, and was recognized as "domestic leading level" in the project acceptance and evaluation of scientific and technological achievements organized by Qinghai science and technology department
Magnetite FeFe2O4 (rust) vs. CoFe2O4 Nanoparticles
The reaction mechanism and magnetic recovery of Fe3O4@Mg(OH)2 composite materials for copper recovery from copper-containing wastewater
The meeting venue
. .2020-11-25 -
New progress has been made in the research and development of key technologies for the engineering of salt lake magnesium-based supramolecular layered functional materials (LDHs)
On September 28, the Qinghai Provincial Department of Science and Technology organized experts to accept the special scientific and technological achievement transformation project "High-efficiency and high-value utilization of magnesium resources in salt lakes-Application and demonstration of key engineering technologies for magnesium-based supramolecular structure layered functional materials (LDHs)" which was undertaken by ISL.
The expert group believes that in view of the occurrence of magnesium resources and environmental characteristics in the old brine after the potassium extraction east of the Chaerhan Salt Lake Railway, through Yantian precision control process nucleation-crystallization isolation, program temperature control dynamic crystallization and other technologies, the project team has prepared high-purity, high-value-added magnesium-based functional material products. The prepared material can be used for ultraviolet barrier and gas barrier film materials, showing excellent performance, improving the solid phase product dispersibility of magnesium-based functional material products, saving water and reducing consumption, and establishing an efficient and high-value utilization of salt lake magnesium resources.
Through the implementation of this project, 9 invention patents were applied, 9 SCI papers were published, 2 doctoral students and 4 master students were trained
100-ton pilot demonstration line
Salt field
.2020-10-12 -
The effect of Mg2+ doping on the adsorption performance of H1.6Mn1.6O4 lithium ion sieve studied by ISL
The structure of liquid water is highly complex and diverse. The structure of liquid water has become a world-famous problem. In 2005, "Science" published 125 scientific problems for the next 25 years. The 21st question was "What is the structure of water?" 96% of water in nature exists in the form of various salt solutions. Compared with the pure water structure, the solution structure includes not only the bulk water structure but also the solvated ion structure and ion association structure. Therefore, the structure of the solution is far more complex than that of pure water. The solution structure is often "inherited" into its descendant crystals, which determines the purity, size and morphology of the precipitated crystals, and further affects the purity and particle size of the product. Some discoveries of mother liquor structure often lead directly to some major high-tech inventions. At present, most domestic research on solution structure is based on computer simulation, and there are not many reports on direct experimental measurement.
The team of Associate Professor Zhou Yongquan from ISL, has built the first domestic solution structure X-ray scattering research platform that can realize the reflection of the flat sample cell and the cylindrical geometric transmission in the experimental research of the solution structure, and developed the solution structure X-ray scattering data analysis Software package (XNSA). In terms of solution structure computational chemistry, the research team built a special high-performance computing cluster for solution chemistry, combining quantum chemistry ab initio (ab initio), ab initio molecular dynamics (AIMD) and classical molecular dynamics (MD) with experimental research, can achieve mutual complementation and mutual verification. In terms of the application of large-scale scientific devices, the research team took the lead in researching liquid structures on synchrotron radiation sources and spallation neutron sources in China. In recent years, the team has used X-ray, neutron scattering and computational chemistry methods to study the structural information of complex multi-component, low-scattering solution samples represented by borate solutions, and has made some important progress. More than 50 SCI journal papers. has been published.The research team has achieved synchronization with the world's top expert teams in solution structure experimental methods and data analysis methods, and has achieved surpassing and leading in some fields such as data analysis software development, calculation simulation and experimental results.
Recently, the team of Associate Professor Zhou Yongquan wrote an article "Application of X-ray and Neutron Scattering in the Study of Solution Structure" in "Salt Lake Research". This article introduces the experiment of using X-ray and neutron scattering to study the structure of the solution (the reflection method of the flat sample cell and the cylindrical geometric transmission method) and the method of data analysis (theoretical model calculation based on the Debye scattering model and reverse Monte Carlo).At the same time, this article reviews the application of X-ray and neutron scattering in the research of pure water structure, borate aqueous solution structure and "dihydrogen bond" in solution by the research team in recent years. The problems of X-ray and neutron scattering in the solution structure are briefly described, and the development direction of the solution structure research is put forward. For details, please see "Salt Lake Research" Issue 3 of 2020-Salt Lake Chemical Special Issue "Research Highlights": 1-17 pages.
Research on X-ray and Neutron Scattering of Solution Structure
.2020-09-02 -
ISL summarized the application and preparation research progress of magnesium-based hydrotalcite
China has abundant salt lake resources, rich in lithium, potassium, sodium, magnesium, boron, bromine and other resources. Among them, magnesium reserves reach billions of tons, accounting for more than 70% of the country's magnesium resources. Every 1 ton of potassium or lithium produced will produce hundreds of tons of magnesium by-products. The by-product magnesium salts have low added value and are dumped in large quantities. This not only severely restricts the exploitation of lithium and potassium resources, but also causes the waste of salt lake resources. As the country's requirements for environmental protection increase, as well as the continuous emphasis on comprehensive utilization of resources and balanced mining of mineral resources, the development of magnesium has gradually attracted attention. The preparation of magnesium-based functional materials with high added value is an effective means to realize high-value utilization of magnesium resources and balanced exploitation and comprehensive utilization of salt lake resources.
Magnesium-based hydrotalcite is a type of layered material, which is formed by the accumulation of interlayer anions and positively charged layers. It has the properties of layer metal ion, interlayer guest anion type and quantity adjustable, and material size and shape adjustable. The special structure gives it rich properties and wide applications. As a kind of important magnesium-based functional materials, magnesium-based LDHs and their derivatives have important applications in industrial catalysis, plastics, rubber, biology, environment, textiles and other fields.
The research team of Professor Deng Xiaochuan and Dr. Fan Faying from Qinghai Institute of Salt Lakes, Chinese Academy of Sciences systematically reviewed the properties, preparation methods and existing problems of magnesium-based hydrotalcite. In addition, its application and characteristics as functional additives of polymer materials, flame retardants, heat stabilizers, ultraviolet shielding agents, adsorbents, catalysts, preservatives, and drug slow-release agents are introduced. The future development direction and application prospects of magnesium-based hydrotalcite are also prospected, which provides a certain reference for the future application of salt lake magnesium resources. For details, please see "Salt Lake Research" Issue 3, 2020-"Research Highlights" of the Special Issue of Salt Lake Chemical Industry: Pages 18-27.
Application of magnesium-based hydrotalcite and its derivatives
.2020-08-30 -
The effect of Mg2+ doping on the adsorption performance of H1.6Mn1.6O4 lithium ion sieve studied by ISL
Because of its unique properties, lithium and its compounds are widely used in chemical engineering, energy, medicine, metallurgy, etc., and are known as the strategic elements of the 21st century. Lithium resources mainly exist in solid mines and lithium-containing liquid resources (salt lake brine, sea water, geothermal water, etc.). With the decreasing amount of solid resources, the importance of comprehensive development and utilization of brine lithium resources has become increasingly prominent. At present, the main methods for extracting lithium from liquid lithium resources are solvent extraction, membrane, adsorption, etc. Different methods are suitable for specific salt lake brines. Among them, the adsorption method is suitable for the separation of low-grade lithium resources from salt lake brines with high magnesium-to-lithium ratio and potassium extraction tailings. Spinel-type lithium manganese oxide has a unique pore structure, large specific surface area, and high selectivity to lithium. It has a good application prospect as an adsorbent for extracting lithium from a solution.
At present, the most studied lithium manganese oxide compounds are LiMn2O4, Li4Mn5O12 and Li1.6Mn1.6O4. Compared with the former two, Li1.6Mn1.6O4 has the highest theoretical adsorption capacity, but its dissolution loss rate is still far from the actual application. Element doping is an effective method for manganese oxide compounds to improve stability and reduce the rate of dissolution loss. Therefore, how to effectively reduce the dissolution rate of materials while ensuring the adsorption capacity has attracted the interest of many researchers. The current doping work mainly focuses on the replacement of Mn at the 16d site in the Li1.6Mn1.6O4 crystal lattice by transition metals, and there is very little doping of Li1.6Mn1.6O4 crystals with alkali metals and alkaline earth metals. Since the actual lithium ion exchange capacity is only about 60% of the theoretical exchange capacity, the reason may be that part of the lithium acts as a supporting framework. In order to reduce its resistance to dissolution, doping and substitution of lithium ion sites that are difficult to exchange, and the influence of doping and substitution on the structural stability need to be investigated experimentally and theoretically.
At present, there has been a lack of research on the cation skeleton spinel structure composed of alkali metals and transition metals, the doping sites of alkaline earth metal ions and the effect on performance. ISL inorganic separation and inorganic materials group synthesized Mg2+ doped spinel Li1.6Mn1.6O4 (LMO) by hydrothermal method. After demolding, Mg2+ doped spinel lithium ion sieve H1.6Mn1.6O4 (HMO) was obtained. The adsorption results of Li+ show that the adsorption capacity of HMO is similar to that of the matrix ion sieve, and Mg2+ doped HMO has better recycling performance. Compared with the undoped r-LMO after Mg2+ doping, the Mn dissolution loss is reduced by 18.5%. Theoretical studies have shown that Mg2+ replaces Li+ at the 16d site of the bulk phase. The Mg-O bond is stronger than the Li-O bond, which enhances the structural stability of the material; at the same time, after Mg2+ doping, it reduces the charge density near the 16d site. The average valence of Mn is improved, and the dissolution loss of Mn is reduced. This study provides an idea for improving the dissolution resistance of lithium ion sieves: different sites have different properties of lithium. In addition to the 16d site Li+, the higher density 8a site lithium can also be structurally modified to adjust the local charge distribution to achieve. The purpose of stabilizing the framework structure and improving the resistance to dissolution. For details, please see "Research Highlights": 1-14, No. 2 Chemistry Special Issue of "Salt Lake Research" in 2020.
Optimized structure of replacing different Li sites with Mg
.2020-08-22 -
ISL proposed a new method for green preparation of magnesium oxide and magnesium phosphate cement
Magnesium phosphate cement (MPC) has the characteristics of negative temperature curing, fast setting and hardening, high strength, strong bonding ability, low shrinkage rate and biological activity. It has attracted widespread attention in the fields of rapid/emergency repair of existing structures, nuclear waste and heavy metal solidification, bone repair and 3D printing.
Low-activity magnesium oxide is the key raw material for preparing MPC. The low-activity magnesia for preparing MPC is mainly dead burnt magnesia sintered at 1500~1800℃ for 5~10h. The current process for producing dead burnt magnesia has high energy consumption and low equipment turnover efficiency, resulting in high energy consumption and high cost for preparing MPC. Moreover, the acid-base reaction rate between the commercially available dead burnt magnesia and the phosphate solution is relatively fast. When preparing MPC, it is necessary to add a B-containing retarder to slow down the solidification rate of the slurry in order to obtain sufficient operating time. But on the one hand, the B-containing retarder reduces the early performance of MPC, on the other hand, the B-containing retarder is expensive, which further increases the cost of MPC, which is not conducive to popularization and application.
In response to this scientific problem, the team of associate researcher Li Ying from ISL prepared low-activity magnesium oxide by calcining light burnt magnesia powder and brucite at ≤1200℃, using common elements such as B, Na, K and Cl's sintering effect. The experiment measured the physical characteristics of low-activity magnesium oxide such as particle size, specific surface area, porosity, chemical composition, mineral composition and morphology, as well as the setting time, hydration products, microstructure, and compressive strength of MPC prepared by low-activity magnesium oxide , volume stability and other setting and hardening properties, and analyzed the effect of sintering temperature on the physical and chemical properties of low-activity magnesium oxide and the setting and hardening properties of MPC. Compared with the prior art, the sintering effect of salt lake co-existing elements can reduce the sintering temperature of magnesium oxide from 1500 to 1800°C to below 1200°C, which is conducive to the realization of low energy consumption and low-cost green preparation of low-activity magnesium oxide and MPC. Promote the promotion and application of MPC. For details, please see "Research Highlights" in the second issue of chemistry special issue of "Salt Lake Research" in 2020: 15-25.
Morphology of sintered magnesia
Compressive strength of MPC prepared by sintering magnesium oxide
.2020-08-20 -
Exploration of the soil black carbon distribution and rustic exchange characteristics in the salt lake area of the Qaidam Basin by ISL
Black carbon generally refers to an impure carbon-containing mixture produced by incomplete combustion of fossil fuels or biomass. It has special physical and chemical properties and exhibits different environmental geochemical behaviors and environmental effects in different environmental media. Studies have shown that about 80% to 90% of the black carbon produced by combustion or oxidation remains directly in the soil, becoming an important part of soil organic matter, and the rest is released into the atmosphere. After a series of natural effects, black carbon will eventually be deposited and preserved in soil and other media in different proportions. Black carbon is widely distributed in the atmosphere, soil, sediment, ice and snow, and has become one of the hotspots in the fields of soil science, atmospheric science, geochemistry, environmental science and ecology at home and abroad.
Black carbon is an important part of the atmospheric aerosol, and it is the most absorbing component of the aerosol in the atmosphere. Aerosol black carbon is closely related to global warming, crop yield reduction, atmospheric persistent organic pollutants, etc. It may have a negative impact on terrestrial and aquatic ecosystems, and has attracted widespread attention. In addition, black carbon is highly chemically inert and porous, and can absorb organic pollutants and heavy metals in the soil, but it will affect the degradation rate of organic pollutants. Black carbon can also change soil fertility and structure, and affect soil microbial communities and ecological environment. Therefore, in-depth and comprehensive study of the temporal and spatial distribution of black carbon in soil and its impact on the physical and chemical properties of soil, to clarify its environmental and ecological effects, which has important scientific significance for soil pollution remediation and sustainable agricultural development.
In response to the above scientific issues, the team of Professor Wu Jun of the Qinghai Salt Lake Institute conducted a key investigation on the distribution characteristics of black carbon in the soil and the exchange characteristics of black carbon in the salt lake area of ？？the Qaidam Basin. The results show that: 1) The soil black carbon content and aerosol content in the salt lake area of ？？the Qaidam Basin are relatively high, indicating that the massive exploitation of salt lake resources and industrial production activities may be an important factor that causes a large amount of black carbon emissions in the study area. In addition, the existence of "plateau effect" may also cause the increase of soil black carbon content in the study area; 2) The range of soil black carbon δ13CBC value in the salt lake area of Qaidam Basin ranges from -25.33‰ to -23.46‰, which may reveal that the source of soil black carbon in the study area may be jointly affected by C3 plants and fossil fuel sources; 3) Although the results of studies on the exchange behavior of soil total black carbon and soot components black carbon and aerosol black carbon at the rustic interface are different using different KOA values, there are indeed obvious and frequent black carbon rustic exchanges behavior in this area. These results will provide basic data for the study of black carbon geochemical behavior in the Qinghai-Tibet Plateau. For details, please refer to "Research Highlights" of the first issue of the geosciences in the "Salt Lake Research" in 2020: 1-10.
The aerosol black carbon content in the salt lake area of Qaidam Basin
2020-05-05 -
ISL Completed the Second Investigation of the Kekexili Region
ISL has undertaken the task of the Salt Lake Special in the Second Comprehensive Scientific Investigation of the Tibetan Plateau. According to the arrangement of the scientific research tasks, on December 21, 2019, Associate Professor Xu Jianxin led the scientific research team to begin a systematic scientific investigation of the main lakes in the Kekesili area. A total of 10 members of the scientific expedition entered the Kekexili area from Wudaoliang and Erdaogou in Qinghai Province. The scientific expedition lasted for 22 days. The expedition members overcame all difficulties in the extreme environment of high altitude, extreme cold, and hypoxia in the Kekexili area, and successfully completed the scientific expedition. This scientific expedition totaled more than 5,600 kilometers.
This scientific expedition mainly surveyed 14 large and medium-sized lakes in the Kekesili area, including Gouluohu Lake, Trash Lake, Ulan Wula Lake, Mingjing Lake, Xijin Ulan Lake, Zhuonai Lake, Taiyang Lake, Lexian Wudan Lake, Kokosiri Lake, Koko Lake, Kusai Lake, Hedingor Lake, Xinsheng Lake, and Xiaoyan Lake. The physical and chemical parameters of lake water (including: pH, dissolved oxygen, conductivity, salinity, redox potential, atmospheric pressure, water temperature and other indicators) were measured in the wild; the samples of lake water and some lake bottom sediments were collected, the samples were collected from loose sediments, sedimentary and volcanic rocks and boiling springs on the lake shore. This expedition also collected for the first time microbiological samples of lake water in extreme environments.
It can be found from the obtained lake water salinity value that the lake water body in this area has a tendency to desalination. This is consistent with the changes in snow and ice melting and precipitation that have increased significantly in recent years due to the warm and humid climate of the Tibetan Plateau. At the same time, the expedition team also found that the lake water area of Kusai Lake, Heddingnor Lake, and Xinsheng Lake was significantly increased due to the leakage of Zhuonai Lake, and the three lakes were almost connected together. The eco-environmental effects brought about by such changing trends in the Kekesili Salt Lake still need further monitoring and analysis.
Compared with the results of the Basic Special Project of Ministry of Science and Technology “Special Survey of Changes in China’s Salt Lake Resources” undertaken by ISL five years ago, this survey also obtained some of the latest data on changes in lakes in the Kekesili area. This has a very positive effect on understanding the changes in modern salt lakes with no (or less) human intervention in the context of climate change.
The expedition team members took a group photo
Determining of various parameters in lake water
Collecting sediment samples from the bottom of Wudan Lake in Lexian
2020-04-10