With the proposal of “dual carbon” goal，the application of lithium in the field of new energy materials has received great attention，and the demand for lithium has shown explosive growth.The world's lithium resources are mainly composed of ore lithium and salt lake lithium.Salt lake lithium has become the focus of future lithium resource development because of its large reserves， and therefore the sulfate type salt lake， which accounts for the largest proportion，has become the focus.Due to the significant difference in the composition of salt lake，and the special properties of sulfate type salt lake，lithium has multiple crystalline forms in the evaporation stage of saltpan and causes losses，which increases the difficulty of effective enrichment of lithium.The results of evaporation experiment of lithium-rich sulfate salt lakes were summarized，the law of crystallization salt evolution during evaporation based on the phase diagram was analyzed and summarized，with a focuses on the concentrated state of lithium and the crystalline form of lithium，providing reference for the development of lithium resources in sulfate salt lakes.

Fe₂P is a common by-product during the generation of lithium iron phosphate（LiFePO₄，LFP），and its effect on the electrochemical performance of LFP has not been thoroughly studied so far.The effect of adding different proportions of Fe₂P into LFP by ball milling method on the electrochemical performance of LFP cathode materials was explored.The results showed that after doping Fe₂P，the crystal structure of LFP material remained unchanged，the particle morphology was highly organized，and the distribution of major elements was uniform.Additionally，the ion and electron conductivity of LFP material were improved to varying degrees.Especially，when the Fe₂P doping amount was 0.5%（mass fraction），the first discharge specific capacity reached 158.2 mA·h/g and 148.5 mA·h/g at 0.1C and 0.5C magnification，which were 8.90% and 7.2% higher than pure LFP，respectively.The difference in redox peak potential in CV curve（ΔE） was only 0.264 V，indicating that the introduction of Fe₂P was beneficial for improving the polarization of LFP materials，and the high overlap of the first three CV curves indicated that the material had a high degree of reversibility.The charge transfer resistance（R_ct） was only 41.56 Ω，which was 76.49% lower than pure LFP.The diffusion coefficient of lithium ions was 8.20×10^-9 cm²/s，which was 89.4% higher than pure LFP.At the same time，the improvement on rate capability and cycling performance was significant.

Olivine LiFePO₄ is one of the most widely used cathode materials for lithium-ion batteries,with characteristics of low cost,high safety,environment-friendly,long cycle life and stable operating voltage.In recent years,with the breakthrough of CTP technology and blade battery technology,its commercialization progress has been greatly improved.However,LiFePO₄ has the defects of poor electronic conductivity and low ion diffusion coefficient,which seriously limits the electrochemical capacity of lithium-ion battery.It is of great significance to study on the preparation process and performance enhancement of LiFePO₄. In this paper,the differences of performance and development status of LiFePO₄ and other cathode materials for lithium-ion batteries were compared.The modification methods of preparation and strengthening of LiFePO₄ cathode materials and related research progress and challenges were systematically summarized,and the future development direction and research ideas were put forward.

The current development status of membrane technology for CO₂ removal from natural gas was reviewed.Firstly，the technical characteristics and application situations of various processes for removing CO₂ from natural gas were compared.Compared with other separation methods，the membrane separation method has the advantages of less investment，small footprint，and low energy consumption.The principle of membrane separation，membrane materials，development status of membrane modules，and technical units of membrane technology to remove CO₂ from natural gas were introduced.The process technology unit was further divided into pretreatment unit and membrane separation unit：the pretreatment unit was selected to different removal methods to combine according to the components of the produced raw material gas；the raw material gas was entered the membrane separation unit after passing through the pretreatment unit.According to the actual working conditions，considering the hydrocarbon recovery rate，land occupation，energy consumption，investment and other factors，the membrane decarbonization separation process was reasonably designed.Then，the domestic and foreign application cases for the removal of CO₂ from natural gas by membrane methods were introduced.At present，there were many application cases of foreign membrane methods to remove CO₂ from natural gas，while there were few domestic application cases.Therefore，it was necessary to increase the domestic membrane method to remove CO₂ from natural gas industrial applications.Finally，the development direction of CO₂ removal technology by natural gas membrane method was prospected.The research and development of membrane materials with independent intellectual property rights and maintaining high performance and long?term stability under actual complex working conditions is the focus of future membrane separation technology development.A coupled integrated combined process was that combining two or more single CO₂ removal technologies，such as membrane separation+chemical absorption，membrane separation+temperature swing adsorption，etc.This coupled integrated combined process would provide new directions for the future decarbonization process technological developments.

The growth of uranium dendrites is a potential threat factor that leads to accidental short circuit in the electrolytic refining unit of spent fuel reprocessing，and at the same time，it will incline a lot of molten salt in the uranium product，which will affect the purity of the product.In order to better understand the microscopic mechanism of uranium dendrite growth and grasp the control method of cathode deposition morphology，an electrodeposition model of uranium in cathode was established based on the phase field method.The dependence of topography parameters such as bottom deposition width，main dendrite height and total deposition area on the change of flow field velocity was studied.It was found that the introduction of external flow field could reduce the bottom deposition width of uranium dendrites by 37.18%，the main dendrite height was lowered by 30.5%，and the total deposition area was decreased by 49.3%.The results showed that the applied flow field could inhibit the growth of uranium dendrites and improve the morphology of uranium deposition，but at the same time，the broken dendrites would be redissolved into the molten salt system，and the efficiency of uranium electrolytic refining would be reduced.In addition，through the analysis of the phase diagram of uranium dendrite morphology under the coupling effect of deposition conditions such as flow field，electrolytic voltage and initial concentration，it could be seen that in the actual electrolytic refining process，a higher initial concentration and a lower electrolytic voltage should be selected as far as possible on the basis of ensuring the efficiency of electrolytic refining，and a reasonable flow field velocity should be set to obtain an ideal uranium dendrite deposition morphology.

Bimetallic-organic frameworks materials（BMOFs） have been widely studied in many fields of catalysis，biosensing，energy storage due to their large specific surface areas，high porosities，synergistic effects，controllable components and morphologies，and easily design and synthesis，etc.The preparation of BMOFs with several common methods were reviewed.Their designed and controllable morphologies were introduced.The stability of the composition and morphology before and after modification was discussed.The application performance and advantages of BMOFs in the fields of catalysis，sensing and energy storage were briefly described.The results showed that the large specific surface areas，the synergistic effects of bimetals，the controllable multi-components and morphologies of BMOFs were favor to the improvement of porosities，active sites，electron transfer rates and properties.And the challenges and problems were analyzed，such as low electrical conductivity，synthesis method，and insufficient maturity in precise design and regulation.Finally，the prospects based upon the above shortcomings of BMOF were proposed.

The recent research on modified lithium iron phosphate（LiFePO₄） materials as lithium-ion electronic cathode materials was reviewed.Although LiFePO₄ were considered to be the most promising cathode materials for lithium-ion power batteries due to their good stability，high safety and environmental friendliness，their inherent low electronic conductivity and lithium-ion diffusion coefficient deteriorated their electrochemical performance.The study on modification to improve their electrochemical performance was reviewed in this paper.The effects of four modification strategies including elemental doping，surface carbon coating，particle nanosizing and materials compositing on the electrochemical performance of LiFePO₄ were analyzed.Then，the advantages and disadvantages of these four modification strategies were discussed.The analysis showed that the four modification strategies could effectively improve the Li-ion diffusion kinetics and electronic conductivity，but the surface carbon coating and particle nanosizing would conversely reduce the tap density of the materials，resulting in low energy density.Finally，the research direction to solve the existing problems was proposed that it would be a feasible method to develop a modification strategy with coexistence of battery and capacitive properties.

Nickel-based phosphorus compounds have been shown to have good hydrogen evolution ability in electrolytic water because of their hydrogen-like electronic structure and excellent stability.Because its intrinsic activity is insufficient，the conductivity is not high and the stability is poor，so practical application of monometallic phosphide is limited.The preparation methods of nickel-based phosphide composites with novel structure，excellent performance and high stability were reviewed.The research results of regulating the electronic structure and microstructure of electrode materials，promoting long-term electrolytic stability，increasing specific surface area and improving electrical conductivity through heteroatom doping，morphology regulation，combination of self-supporting materials and new composite materials（carbon nanotubes，graphene，graphyne，MXene） were summarized and analyzed.It provided the research direction for exploring new nickel-based phosphide composite materials with high catalytic activity and stable structure.

MgAl-layered double hydroxides（MgAl-LDH） were synthesized using a separate nucleation and aging steps（SNAS） method，and high-iron low-calcium portland cement（iron phase mass fraction of 19.6%） was prepared by limestone，standstone and iron ore powder.The effects of MgAl-LDH content on the chloride curing ability，mechanical properties and microstructure of high-iron low-calcium cement were studied by X-ray diffraction（XRD），thermogravimetric（TG），scanning electron microscopy（SEM），and chemical analysis methods.The results showed that MgAl-LDH could improve the mechanical properties and chemical curing ability of chloride ions.When MgAl-LDH content was 3%（mass fraction），compared with the blank group，the chloride ion curing rate at 7 d was increased by 46.4%，and the compressive strength at 3，7 d and 28 d was increased by 27.5%，34.6% and 17.1%，respectively.The microscopic tests showed that MgAl-LDH could promote the early hydration of high-iron low-calcium cement to generate more hydration products，and promote the densification of cement structure to a certain extent.And it could promote the reaction of hydration products and chloride ions to form Friedel's salt，and improve the chemical curing amount of chloride ions.

The performance of lithium-ion battery cathode materials is the development bottleneck of lithium battery technology.Recently，alumina（Al₂O₃） coated cathode materials have been widely studied in order to improve the cycle life，thermal stability and multiplier properties of lithium-ion batteries.The Al₂O₃ coatings were divided into three different forms of namely rough，ultra-thin and thick coatings.The role of Al₂O₃ surface coatings in improving cathode material performance was briefly discussed，such as HF scavenger，physical protective barrier，increasing lithium ion diffusion rate，improving thermal stability of cathode material，reacting with LiPF₆ to form electrolyte additive LiPO₂F₂ and inhibiting Jahn-Teller effect，etc.The surface modification methods were introduced，including impregnation method，precipitation method，dry coating process，sputtering method and atomic layer deposition method，etc.and its influence on the cathode materials of lithium cobaltite（LiCoO₂），lithium manganite（LiMn₂O₄），lithium iron phosphate（LiFePO₄） and ternary material（Li-Ni-Co-Mn-O）.At last，the development trend of Al₂O₃ surface coating and atomic layer deposition technology was prospected.

Hierarchical titanium silicalite-1（h-TS-1） was synthesized by sol-gel method with cetyltrimethyl-ammonium bromide（CTAB） as mesopores template.Structural features of the h-TS-1 were characterized by transmission electron microscope（TEM）,X-ray diffraction（XRD）,N₂ adsorption-desorption,ultraviolet-visible diffuse reflectance spectroscopy（DR UV-vis） and Fourier transform infrared spectroscopy（FT-IR）.Catalytic performance of the h-TS-1 was investigated by the direct hydroxylation of benzene and phenol,using H₂O₂ as oxidant under mild conditions.The results indicated that the h-TS-1 not only possessed the same MFI topology and ideal crystal form as TS-1,but also had microporous and mesoporous structure,of which the average pore size was 2.67 nm.Compared with TS-1,the catalytic activity of h-TS-1 had been improved significantly.Furthermore,the h-TS-1 had a great capacity of reutilization.

The application of solid electrolyte instead of flammable liquid electrolyte can effectively solve the safety issues of lithium-ion batteries nowadays.However，the solid-solid contact of electrodes/electrolytes in solid state batteries usually lead to large interfacial impedance，resulting in high polarization.The polyvinylidene difluoride（PVDF） based solid electrolyte was used as cathode and anode interface buffer layer，which effectively solved the problem of high impedance of titanium-aluminum-lithium phosphate solid electrolyte with electrode，reducing the positive interface impedance from 1 716 Ω/cm² to 213 Ω/cm².At the anode interface，PVDF provided a good elastic support，so that the interfacial impedance was reduced from 1 135 Ω/cm² to 109 Ω/cm².In addition，the direct current polarization of lithium symmetric battery showed that the stability of the anode interface was significantly improved after PVDF modification.Finally，the lithium cobalt oxide/lithium pouch battery was assembled.With PVDF modification on both cathode and anode interface，the energy density of the battery reached to 336 W·h/kg.The capacity retention rate was increased from 30.7% to 83.3% after 300 cycles at 1C.

In order to reveal the flocculation effect of different flocculants on abandoned drilling mud，the method of breaking flocculation was used to treat the abandoned coalbed methane drilling mud with high water content and complex composition，which was taken from Shanxi Province.The effect of flocculant type，flocculant amount，and other factors on the flocculation performance of the abandoned drilling mud was analyzed.The flocculation mechanism was explored by scanning electron microscopy（SEM）.The results showed that the dosage of aluminum sulfate with 2 000 mg/L had the best flocculation effect，and the dosage of non-ionic polyacrylamide（NPAM） with 10 mg/L had the best co-treatment effect.The liquid phase chromaticity，COD_Cr，suspended matter content and water content of mud cake after treatment were 20 times，61.98，32.50 mg/L and 78.64% respectively.The electric neutralization of aluminum sulfate could produce good synergistic effect with the bridge trapping of NPAM，which could significantly accelerate the flocculation settlement of particles in the mud，increasing the volume of volume of flocculation and the degree of porosity，so as to reduce the content of pollutants in liquid phase and the moisture content of mud cake.The results of this study could provide useful guidance and theoretical basis for the flocculation treatment of waste drilling mud.

Ultrafine magnesium hydroxide（MH） was prepared by two-way precipitation method using sodium hydroxide as precipitant and anhydrous magnesium chloride as raw material.In the preparation process，silicon polyether was introduced to organicize the surface of magnesium hydroxide.The effects of the addition method of silicon polyether，the addition amount of silicon polyether，the reaction temperature and the stirring speed on the filtration performance of magnesium hydroxide slurry were investigated.The contact angle，particle size，surface structure and thermal stability of magnesium hydroxide powder were characterized by contact angle tester，nano particle size and Zeta potential analyzer，Fourier transform infrared spectrometer and synchronous thermal analyzer.The results showed that the addition method of silicon polyether was to add silicon polyether in sodium hydroxide solution［Mg（OH）₂-Ⅱ］.The addition amount of silicon polyether was 3 g per 100 g MH，the reaction temperature was 60 °C，and the stirring speed was 800 r/min.The filtration performance of magnesium hydroxide slurry was the best，and the fastest filtration speed was 4.79×10^-4 m/s.The contact angle results showed that the contact angle of magnesium hydroxide prepared under the optimal conditions was more than 6 times higher than that of unmodified magnesium hydroxide.FT-IR analysis proved that the silicone polyether was successfully adsorbed on the surface of magnesium hydroxide.Thermal analysis showed that the thermal stability of modified magnesium hydroxide was significantly improved.

To effectively suppress Jahn-Teller effect of spinel lithium manganate and improve the problem of rapid capacity decay during high-rate charge discharge cycles，the LiNi_0.05Mn_1.95O₄ samples were successfully prepared by using a molten salt combustion method and different calcination temperatures.The experiment results demonstrated that the crystal structure of LiMn₂O₄ did not change under Ni-doping and different calcination temperatures.With the rise of calcination temperature，the crystallinity and particle size of the samples were increased continuously.Besides，the particle sizes were gradually increased from nanoscales to submicron scales.The optimal calcination temperature of 650 ℃ delivered excellent electrochemical performance.The initial discharge specific capacity at 5C and the capacity retention rate after 500 cycles were 100.8 mA·h/g and 80.0%，respectively.At a higher rate of 10C，the capacity of 500 cycles only attenuated by 7.5%.The dynamic performance test results indicated that it had a large lithium-ion diffusion coefficient of 3.26×10^-16 cm²/s and a smaller apparent activation energy of 25.67 kJ/mol.Ni doping and different calcination temperatures inhibited the Jahn-Teller effect of LiMn₂O₄ materials，thereby promoted the rate performance and cycle life of LiMn₂O₄ materials.

Fly Ash is the maximum solid waste pollution source in China，its high-value application can not only turn waste into treasure，but also it is an important technical and economic policy in China's economic construction.It is an important means to solve the contradiction between power production pollution and resource shortage in China.The preparation of fly ash ceramsite has great significance for the resource utilization of fly ash.The preparation methods and research progress of fly ash ceramsite at home and abroad were reviewed，and the technology and mechanism of preparation of fly ash ceramsite by calcination and non-calcination methods were analyzed in detail.The market application fields and adopted standards of fly ash ceramsite were introduced，the problems and solutions in the process of comprehensive utilization were put forward，and the development trend in the future was prospected.

Taking the application of self-cleaning materials in the photovoltaic industry as an example,the application development process,principles and main problems of nano-SiO₂ and nano-TiO₂ were summarized,which were commonly used as film materials for self-cleaning of solar cell glasses.And the main reason for the difficulty in commercial application of nanoTiO₂ self-cleaning film materials was analyzed.Combined with the author′s relevant research work,the research and development progress on nano-graphene self-cleaning anti-reflection film materials was introduced,and it was recommended to strengthen the self-cleaning film materials of nano-graphene in photovoltaic,textile,sewage treatment and other industries.It was believed that nano-graphene was the black material that promoted the upgrading of self-cleaning technology.With the continuous updating of preparation methods and technologies of nano-graphene composite materials,nano-graphene would be more widely used in the field of self-cleaning.

Lithium resources are important national strategic resources,which are widely used in many fields such as new energy vehicles,electronic products,and energy storage.China is rich in lithium resources.Among them,salt lake brine lithium resources are mainly distributed in Qinghai and Tibet.However,due to factors such as the low grade of salt lake brine itself,low extraction efficiency of lithium salt and limited production capacity,it has not been effectively developed,resulting in a serious dependence on foreign lithium products.Therefore,in order to ensure the continuous and safe supply of lithium resources in China,it is of great significance to break through the lithium extraction technology from salt lakes and explore more green,efficient and low-cost extraction technologies for the utilization of lithium resources in salt lake brines.The general situation of lithium resources in salt lakes,the characteristics of salt lake brine,and the latest research progress of efficient separation and extraction of lithium resources were systematically introduced.Finally,the research focus of lithium resources separation and extraction technology was prospected.

The amount of waste salt in China is large，the source is wide and difficult to be treated，so it is of great significance to study the recycling and disposal of waste salt.The sources，classification and properties of chemical waste salt were summarized，and the current treatment and disposal policies and problems of waste salt were listed.The disposal technology and research progress of waste salt in pesticide，medicine，printing and dyeing，coal chemical industry and epoxy resin five high-yield industries were discussed.In order to provide some reference for the recycling of waste salt in related industries，the new ideas of classifying resource utilization according to different industries，improving the removal rate of organic matter and conversion efficiency of chemical reaction，and realizing source emission reduction and raw material recovery and reuse were put forward.

To solve the problem of low utilization rate of flue gas desulphurization gypsum（FGD gypsum） and improve its added-value utilization，calcined gypsum was prepared by calcining FGD gypsum added with potassium aluminum sulfate（KAS，mass ratio of 0，0.3%，0.6%，1.0%） at atmospheric pressure.The effects of calcination temperature and KAS content on the properties and the morphology of calcined gypsum were mainly studied.The results showed that the proper calcination temperature could improve the properties of calcined gypsum.However，excessive temperature could generate more cracks on the surface of calcined gypsum，and the properties were subsequently decreased.The addition of appropriate amount of KAS not only improved the crystallinity of calcined gypsum，but also promoted the growth of new phase dihydrate gypsum（DH） along the b-axis after hydration，delayed the growth along the c-axis，and significantly reduced the length-diameter ratio of DH crystals，which could promote the densification of gypsum sclerotium，resulting in the increase of strength.As 0.3% KAS was added into FGD gypsum and calcined at 170 ℃ for 2 h，the performance of the prepared calcined gypsum was the best.The initial and final setting time was 11.5 min and 14 min，respectively，the 2 h flexural and compressive strength were 3.40 MPa and 9.23 MPa，respectively，and the dried flexural and compressive strengths were 6.70 MPa and 21.82 MPa，respectively，which met the 3.0 grade requirements of the GB/T 9776—2022 “Calcined Gypsum”.Compared with the blank group，the 2 h flexural strength was increased by 26% and the 2 h compressive strength was increased by 40%.