A new calcification process in seaweed chemical industry was studied using Ca（OH）₂ as the calcifying agent.A composite of CaCl₂ and Ca（OH）₂ was used as calcifying agent for sodium alginate instead of traditional CaCl₂ .The deter-mined double-calcium calcification process conditions were：per liter of sodium alginate glue（alginate sodium mass concen-tration was 2.5 g/L）,the adding amount of 5%（mass fraction） CaCl₂ solution was 29.0 mL,the adding amount of 5%（mass fraction） Ca（OH）₂ solution was 13.75 mL and the amount-of-substance ratio of CaCl₂ to Ca（OH）₂ in the composite calcify-ing agent was 1.19:1.Compared with the traditional process,the new calcification process did not change the yield of sodium alginate significantly,but decreased the viscosity of the obtained sodium alginate slightly from 275.1 mPa·s to 241.3 mPa·s.The adding amount of CaCl₂ was reduced by more than 40%,and the amount of total calcium ions added was reduced by 19%.The double-calcium calcification process realized the reuse of calcification wastewater,in which the mass concentration of calcium was reduced from 483 mg/L to about 20 mg/L and the electrical conductivity was reduced from 6.84 mS/cm to 4.28 mS/cm after decalcification treatment.The treated calcification wastewater reused as process water did not significantly affect the yield and viscosity of the sodium alginate product.The new process is simple in operation,not only effectively reducing the introduction of ions in the calcification wastewater,but also realizing low-cost decalcification treatment,and the decalcified wastewater would be able to be reused as process water that provides a feasible way to reduce the water consumption in the seaweed chemical industry.

Improving the efficiency of technological innovation in phosphorus chemical industry is of great significance to the healthy,orderly and green sustainable development of phosphorus chemical industry.With 27 listed enterprises of phospho-rous chemical industry in different provinces of China as the research objects,the evaluation system of technological innova-tion efficiency was constructed,the input-output data of enterprises in 2018 were collected,and the overall and internal analysis of technological innovation efficiency was carried out based on DEA model.The results showed that：the overall technological innovation efficiency of listed enterprises in China was 0.372,which did not meet the DEA effective standard; low pure technological efficiency or low scale efficiency was the main reason for the non DEA effective technological innovation efficiency of enterprises; close to 3/4 of listed enterprises in phosphorus chemical industry had the decline of scale return of technological innovation investment; 45% of enterprises were not DEA efficient due to redundant R&D funding and 50% of enterprises were not DEA efficient due to insufficient output.Finally,combined with the research conclusion,the countermeasures and suggestions to improve the technological innovation efficiency of phosphorus chemical industry were put forward.

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.

Lithium is a kind of non-renewable strategic mineral as well as the indispensable raw material for the development of modern industry.Based on the analysis of the characteristic,deposit type,distribution,reserve,yield,demand,security and the industry structure of the lithium resources in China,the problems in Chinese lithium industry at present were pointed out.According to the above problems,some countermeasures and suggestions to promote healthy and sustainable development of lithium industry,such as increasing mineral exploration,enhancing international cooperation,optimizing the industrial structure,efficient use of resources,paying attention to environmental protection,building ecological mining industry and so on,were put forward.

Photocatalysis technology is a new green environmental protection technology with resource saving,environmental friendliness and great application prospect in the field of organic pollutant treatment.As a typical semiconductor photocatalyst,TiO₂ is favored by people for its good photoactivity,good stability,non-toxic to human health,low cost,mild reaction conditions and no secondary pollution etc..However,its wide band gap and higher recombination rate of photogenerated electronhole pair limit its large-scale application,which are technical problems to be solved.The catalytic mechanism of TiO₂ was explained.The limitations of traditional TiO₂ were analyzed.And the modification methods and principles for improving the catalytic activity of TiO₂,such as ion doping,surface deposition of precious metals,surface photosensitization,semiconductor composite,load and other methods,were introduced.At last the future research and development direction of TiO₂ photocatalyst were discussed.

Metal oxides are a class of ionic compounds composed of metal cations and oxygen anions.The metal positive ions and oxygen negative ions are arranged into various crystal structures by ion bonding, showing unique physical properties.However, metal oxides are limited in potential application by their wide band gaps, low photon quantum yields and photoelectric conversion efficiencies, high probability of recombination of photo-generated electrons and holes, low gas response speed and negative effects of valence band and conduction band on the electron transfer performance.The research progress of several typical doped metal oxides, such as zinc oxide, titanium dioxide, iron oxide and rare earth oxides is reviewed.The effects of metal doping on the optical, electrical, magnetic and sensing properties of these typical metal oxides is analyzed and their potential application fields and research status are introduced.The future development direction and topics needing attention are put forward.

Alumina precursors synthesized by neutralization method,hydrothermal method,alcoholic aluminium method and aluminium powder-hydrochloric acid reflux method were used as raw materials to prepare spherical alumina carriers which are marked as ZH、SR、ST and SOL respectively.The samples were characterized by strength tester,XRF,BET,SEM and NH₃-TPD,etc.The effect of the alumina support on the performance of Pt-Sn-K/Al₂O₃ catalysts in the dehydrogenation of propane was investigated.The results showed that the alumina precursors synthesized by different methods have been used to prepared spherical alumina supports with high strength.Especially the alumina supports prepared by hydrothermal method and alcoholic aluminium method also had large pore volume and moderate specific surface area.The preparation methods of precursors had greater influence on the acidity of catalysts,while neutralization catalyst was mainly weak-medium-strong acid center and other catalysts were mainly weak acid center,and the order of acidity was ZH-CAT>SOL-CAT>ST-CAT>SR-CAT.The evaluation results showed that the supports prepared by alcoholic aluminium method and hydrothermal method had good performance for propane dehydrogenation catalyst,which was equivalent to or even superior to the industrial catalyst.

The monodispersed pure vaterite microspheres were synthesized by disperse bubbling carbonization using the reaction system of CaCl₂-NH₃-H₂O and characterized by SEM,FE-SEM,TEM and XRD.The effects of several factors such as the initial pH,final pH,initial reaction temperature and flow rate of CO₂ gas on the morphology and particle size of products were investigated.The formation mechanism of vaterite microspheres was also discussed.The experiment results demonstrate that much more CO₂ bubbles with uniform size are produced by dispersed bubbling carbonization which can increase the supersaturation of CO₂ in solution compared with the direct bubbling carbonization.It is helpful to prepare monodisperse vaterite microspheres with high purity.Low initial temperature and high flow rate of CO₂ gas also improve the produce of vaterite.The optimum conditions are as follows: initial pH of 10.0,final pH of 7.0,flow rate of CO₂ gas of 1 L/min.

Based on the patent database of Incopat,the sodium industry′s important patentees,major technology research and development teams,key technology navigation and technology composition etc.was analyzed from the perspective of patents from 1972 to 2020.The development status and characteristics of all aspects of sodium industry in Qinghai,in China and in globe were summarized.It was suggested that the future development of sodium industry in Qinghai should take advantage of the great historical opportunity of One Belt and One Road by exploring the international market of sodium industry,promoting the comprehensive utilization of salt lake resources,strengthening the patent layout,introducing high-end talents and improving the ability to transform patented technological achievements.

At present,commercial lithium ion batteries（LIBs） mostly use organic liquid electrolyte,which is flammable,explosive,leaky and other security risks.The use of solid electrolyte instead of organic liquid electrolyte could effectively improve the safety of batteries.The solid electrolyte for Li-ion battery can be divided into inorganic electrolyte and organic（polymer） electrolyte.Inorganic solid electrolyte has good adaptability to high temperature or other corrosive environment,which is suitable for rigid battery in extreme working environment;polymer solid electrolyte has obvious advantages in flexibility and processability,which is suitable for flexible battery and other fields,but these materials still have problems to be solved.Inorganic-organic complex is expected to integrate the advantages of the two materials,learn from each other and improve the comprehensive performance and practical value of solid electrolyte.

The continuous ion exchange technology was used to extract lithium from the salt lake brine with adsorption method.Aiming at the tailing brine system from Yiliping Salt Lake in Qinghai,a continuous ion exchange adsorption process was developed to extract lithium.The effect of operating parameters on the lithium extraction performance of the continuous ion exchange system was studied.In addition,the long-term stability evaluation was carried out under optimized process conditions.Results showed that,when the stepping rotation period was 20 min,the brine feed flow was 3.2 BV/h,the rinsing water volume was 2.9 BV/h,the desorption water volume was 9.3 BV/h and the desorption temperature range was at 15~25 ℃,a lithium recovery of above 98.5%,a Mg/Li mass concentration ratio of about 3 and a lithium mass concentration of about 1.1 g/L were stably obtained in the performance of the qualified solution with the continuous ion exchange system.

Rare earth is an important material for new energy.It has many irreplaceable uses in the development of modern industry.The rare earth resources in the world are rich,but the distribution is not balanced.Nearly 93.11% of the proven rare earth reserves are concentrated in a few countries such as the United States,Australia,Russia,Vietnam,Brazil and China.As one of the most important strategic advantages of mineral resources in China,rare earth is distributed all over the country.The rare earth deposits are mainly of alkaline carbonatite type,granite type,placer type and weathering shell ion adsorption type in genesis,they are mainly distributed in six metallogenic provinces such as northern margin of north China block,Daxinganling of Inner Mongolia,upper Yangtze,lower Yangtze,south China and Sanjiang etc..By analyzing the type of rare earth deposits resource,distribution characteristics,and combined with the new progress of exploration and exploitation of rare earth ore in China,it is proposed that it is necessary to strengthen the research on the theory and exploration technology of rare earth mineralization,to research and development of rare earth high-end materials and application technologies,to coordinate the rational development and utilization of rare earth resources and ecological environmental protection,to establishing a sustainable national strategic reserve system of rare earth resources.

A series of sheet-like Bi/BiVO₄ composite photocatalysts with different Bi contents were synthesized using solvo-thermal method.The prepared catalysts were characterized by using X-ray diffraction（XRD）,X-ray photoelectron spectro-scopy（XPS）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,ultraviolet-visible diffuse reflec-tion spectroscopy（UV-Vis DRS）,inductively coupled plasma optical emission spectroscopy（ICP-OES）,nitrogen adsorp-tion-desorption analysis and photocurrent response measurements.The photocatalytic performance of the sample was assessed by photodecomposition of methylene blue（MB） under xenon lamp irradiation.The results showed that the photocatalytic ac-tivity of BiVO₄ was enhanced significantly with Bi self-doping.Finally,the photocatalytic reaction mechanism of Bi/BiVO₄ composite was discussed by free radical capture experiments.

The calcium carbonate structure was studied by infrared（IR） spectroscopy.There were calcium carbonate CO₃asymmetrical stretch vibrationmode（ν）,calcium carbonate CO₃ symmetrical stretching vibration mode（ν）,calcium carbonate CO₃ out-of-plane bending vibration mode（r） and calcium carbonate CO₃ in-plane bending vibration mode（β）.Temperature-dependent infrared（TD-IR） spectroscopy was also used to study the thermal stability of calci-um carbonate.In the temperature range of 293~393 K,the infrared absorption intensity and frequency of the main functional groups of calcium carbonate had some changes.Two-dimensional infrared（2D-IR） spectroscopy of the calcium carbonate（ν,r and β） were studied to the frequency information of the absorption peak change.The key roles of third-step IR spectroscopy in the analysis of structure and thermal stability of the important inorganic salt（calcium carbonate） were demonstrated.

The carbonization method of lithium carbonate is characterized by its high reaction efficiency and simple process.It has become the mainstream process for battery-grade lithium carbonate production.However,in the process of preparing battery-grade lithium carbonate by carbonization method and with salt lake lithium concentrate as raw material,there are still problems such as low carbon dioxide utilization in the carbonization process,poor removal of impurities in the carbonized liquid and low lithium yield.With salt lake lithium concentrate as raw material,process optimization experiments were carried out from three main links：carbonization,purification and pyrolysis,that is,changing from atmospheric carbonization to pressurized carbonization,and using a combination of chemical purification and ion exchange resin adsorption to remove carbonization.Impurities in the liquid were changed from conventional pyrolysis to pressure pyrolysis,which can increase the carbon dioxide utilization rate in the carbonization processed to 87.4%,the removal rate of calcium and magnesium in the purification processed to 97.92% and 96.09%,and the direct yield of lithium in the whole processed to 82.27%.

Since the explosive growth of new energy vehicles in 2015,the demand for lithium has increased rapidly in the world.Therefore,it is of great significance to accelerate the development of lithium resources. Lithium resources in China are quite abundant,mainly existing in lithium ore and salt lake brine,and salt lake brine is the main source. With the significant advantages of low energy consumption and low cost,lithium extraction from brine has become an important direction for obtaining lithium resources in the future. The existing methods of extracting lithium from brine were summarized,and the extraction method,adsorption method,membrane separation method and electrochemical method that currently being studied were expounded emphafically.At present,FeCl₃-diluent is still used as extraction system in most extraction methods.The types of extractants and diluents were studied primarily.In the adsorption method,adsorbents are the key to the experiment.In recent years,aluminum-based adsorbents and ionic sieve adsorbents have become the focus of research,How to granulate and how to reduce the dissolution loss rate will become the main research direction in the future.In membrane separation,the key of the two methods is to improve the adsorption capacity,and nanofiltration and electrodialysis in membrane separation method are relatively mature.As for electrochemical lithium extraction,researchers proposed to use different adsorbents as electrode materials to significantly improve the lithium extraction effect.The rise of electrochemical lithium extraction method provides a new idea for lithium extraction from brine.

Metal-organic frameworks（MOFs） are a class of porous materials formed by self-assembly of metal ions（or clus-ters） with organic ligands^[1] MOFs have extremely developed pore structure,and their specific surface area and pore volume are far superior to other porous materials.The feature of organic/inorganic hybridization has also given infinite structural and functional tunability to MOFs that other materials（such as zeolite and activated carbon,etc.） do not possess^[2].In addition,MOFs have persistent pores and cavitation that remove the guest molecules while the host framework remains intact,which makes MOFs exceptionally chemically and physically stable.Based on these characteristics,MOFs have many applications in many fields^[3-4],such as catalysis^[5],H₂ storage^[6],CO₂ capture^[7],drug delivery^[8],pollutants adsorption^[9],biomedical imaging^[10] and so on.The commercialization of MOFs has become a hot spot.Many applications of MOFs are related to sustainable development and “green materials”,but the synthesis process of MOFs itself also needs to consider sustainability and environ-mental impacts.The environmental challenges facing metal organic chemistry are unique because they link the hazards of metalions and organic ligands,and most of the synthesis process requires a lot of energy.This review mainly introduces the green and sustainable synthesis of metal-organic framework materials,which are mainly divided into four aspects：1）using safer or biocompatible ligands;2）using greener,low-cost metal sources;3）development of green solvents;4）solvent-free synthesis.

The doped CeO₂-based material is an ideal electrolyte material for medium-low temperature solid oxide fuel cells（SOFC）.Firstly,the relationship between the structure and properties of doped CeO₂-based electrolytes was described.Then,the effects of metal ion doping on the crystal structure and electronic structure of CeO₂-based electrolytes were introduced. The effects of single-element doping and two-element doping on the properties of CeO₂-based electrolytes were mainly revie-wed.By analysis,the results showed that：comparing with single-doping of alkaline earth elements,the single-doping of rare earth metal elements significantly improved the conductivity of CeO₂-based electrolytes,but the raw material cost of rare earth oxides was much higher than that of rare earth oxides.CeO₂-based electrolytes doping with two-element presented more oxygen vacancy disorder and less oxygen ion mobility activation energy than the single-element doping,so two-element doping had more advantages in improving the ionic conductivity of the CeO₂-based electrolyte.The doping rules and relationship be-tween the structure and properties of CeO₂-based electrolyte materials was summarized,in order to play a guiding role in the preparation of CeO₂-based electrolytes with better performance.

Preparing hydrogen peroxide by anthraquinone process,which started by introducing and researching foreign tech-nology in 1958 in China.After researching,testing,practicing,technological improving,expanding production scale and so on,it had achieved rich production experience at present.The development process of hydrogen peroxide production in China was introduced.The development course,technology progress and its far-reaching significance for production development of anthraquinone process were also introduced in detail.Technical improvement of hydrogen peroxide production by anthra-quinone process such as the hydrogenation catalyst from the use of Raney nickel to palladium,the structure of hydrogenation tower,the equipment and process of oxidation process,the improvement of working liquid solvent and institute measures of production and safety etc.,was emphasized.The current status of production and technological progress of hydrogen peroxide were presented.The development trend in the future was prospected and the existing problems were put forward.

Mixed matrix membranes（MMMs） is a kind of membrane material of combining the characteristics of inorganic fillers and organic matrices has been widely concerned because of its good permeability and separation performance.The inor-ganic fillers,such as SiO₂ nanoparticle spheres,zeolite molecular sieves,metal-organic framework （MOF）,graphene oxide （GO）and carbon nanotubes（CNT） are all widely applied in the preparation of MMMs,but issues of poor dispersion,poor compati-bility and existence of interface defects often lead to poor gas separation performance.The factors that improve the gas separa-tion performance of MMMs through surface functional modification,covalent cross-linking,multiple fillers and size and mor-phology controlling in recent years were summarized and decomposed.The development trend of MMMs in the future was also prospected.