1789 results about "Hydroxide" patented technology

The invention provides a preparation method of a nickel-based composite oxygen evolution anode for alkalescent electrolyte. According to the invention, nickel-based alloy is used as substrates, two same substrates are respectively used as a working electrode and an auxiliary electrode, two-electrode system electrochemical oxidation reduction treatment at room temperature is carried out in a mixed solution of phosphate, carbonate and chloride, and two reconstructed nickel-based composite oxygen evolution electrodes are obtained at the same time. In the electrochemical oxidation process, nickel ions and other metal (Fe, Co, Cr and Mn) ions are dissolved out from the nickel-based alloy under the etching assistance of chloride ions; in the electrochemical reduction process, water on the electrode is reduced to form hydroxyl. Under continuous oxidation reduction, substance reconstruction is carried out to generate a composite catalyst layer of phosphate, carbonate and hydroxide of nickel and other metals, so that not only can the oxygen evolution activity be improved, but also metal dissolution and corrosion passivation when the catalyst is used in a weakly alkaline solution can be inhibited, and the durability of the electrode is greatly improved.

The invention relates to the field of electro-catalytic materials, and particularly discloses a layered transition metal hydroxide catalyst as well as a macro-quantity preparation method and application thereof. According to the method, the nanoparticles are formed through solvent difference induction, the nanoparticles are adsorbed on the foamed nickel substrate, formation of the layered transition metal hydroxide on the foamed nickel substrate is promoted, the layered transition metal hydroxide is prepared through a heterogeneous nucleation mechanism, and compared with a traditional homogeneous nucleation process, disordered aggregation of the nanoparticles can be effectively prevented; the preparation method has the advantages of high dispersity and uniform structure, the preparation method does not depend on conditions such as high temperature and high pressure, the equipment cost, energy consumption and safety risk can be reduced, and the method has universality and environmental friendliness and can be applied to macroscopic preparation of the catalyst with good uniformity.

The invention belongs to the technical field of catalysts, and particularly relates to a general preparation method and application of amino acid intercalated layered hydroxide. According to the catalyst material, the nickel-iron layered hydroxide is optimized through amino acid intercalation, aromatic amino acid is anchored between layers of the nickel-iron layered hydroxide through a one-step hydrothermal method, dissolution of metal ions is inhibited, the catalyst structure is stabilized, an interlayer electronic structure is regulated and controlled, and reaction kinetics is accelerated. According to the invention, the improvement method of the organic-inorganic hybrid catalyst is perfected, and a new thought is provided for the development of the nickel-iron layered hydroxide catalyst.

The invention discloses a lanthanum-doped CuMgAl catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts. The preparation method of the lanthanum-doped CuMgAl catalyst comprises the following steps: adding a copper salt, a magnesium salt, an aluminum salt and a lanthanum salt into water to obtain a first solution; adding a precipitator into water to obtain a second solution; adding the second solution into the first solution to adjust the pH value to 10.5 to obtain a mixed solution, stirring the mixed solution to generate a co-precipitation reaction, after the reaction is completed, carrying out aging treatment to promote growth and structure ordering of layered double hydroxide crystals, and then carrying out calcination treatment to convert a layered double hydroxide precursor into an oxide, thereby obtaining the layered double hydroxide. And the lanthanum-doped CuMgAl catalyst is obtained. The lanthanum-doped CuMgAl catalyst prepared by the preparation method disclosed by the invention has excellent activity and stability.

The invention relates to the technical field of vaccine adjuvants, and particularly discloses a preparation method of a nanoscale aluminum hydroxide adjuvant based on organic metal alkoxide hydrolysis. Aluminum isopropoxide is used as a precursor, and a hydrolysis interface is directionally regulated and controlled through a compound surfactant; a staged hydrolysis process is adopted, and a kinetic equation is met; and the surface is modified by a KH-550 coupling agent. According to the preparation method disclosed by the invention, boehmite phase crystallization, nanoscale uniformity and high antigen adsorption stability are synchronously realized at low temperature through alcoholate hydrolysis bond energy reconstruction, surface activity compounding interface regulation and control and staged kinetic control, and the bottlenecks of high temperature, high energy consumption and non-uniform particle size of a traditional process are overturned; and a novel industrial scheme with low consumption and high efficiency is provided for vaccine adjuvants.

The invention belongs to the field of corrosion and protection, and discloses a preparation method of an intelligent coating with multistage self-repairing capability. According to the method, a core-shell structure nano container with a metal organic framework (MOF) compound as a core and layered double hydroxide (LDH) as a shell is prepared, different functional objects are respectively loaded in the core and the shell by adopting a step-by-step in-situ loading method, and graded release of the functional objects is realized by utilizing pH responsiveness of the MOF and corrosive ion responsiveness of the LDH; the nano container is added into an organic coating as a filler to construct an intelligent coating with multi-stage self-repairing capability. The problems of passive protection and uncontrollable corrosion inhibitor release of a traditional anti-corrosion coating are solved, the coating can repair corrosion defects in time according to needs, the long-acting corrosion resistance is remarkably improved, the preparation process is simple, the condition is mild, and the coating is suitable for metal protection of high-end equipment and other complex service environments.

The invention discloses polyphenylene sulfide resin and a preparation method thereof. The weight-average molecular weight of the polyphenylene sulfide resin is 20000-50000, the molar ratio of a sulfydryl terminal group to a chlorine terminal group is 1-9, and the content of the chlorine terminal group is 15-60 [mu] mol / g. In the preparation method of the polyphenylene sulfide resin, a sulfur source, an alkali metal hydroxide and a dihalogen aromatic compound are taken as raw materials and subjected to a polymerization reaction in N-methyl pyrrolidone, and self-blocking is performed by accurately controlling the adding time of the dihalogen aromatic compound, so that controllable adjustment of an active end group is realized. The polyphenylene sulfide resin provided by the invention has excellent processability, and has excellent reactivity with silane coupling agents such as gamma-aminopropyltriethoxysilane and the like.

The invention discloses a porous CoFe hydrotalcite nano material as well as a preparation method and application thereof, and relates to the field of nano materials. The porous CoFe hydrotalcite nano-material is of a porous layered double hydroxide nano-structure, and the aperture of the porous CoFe hydrotalcite nano-material ranges from 2 nm to 10 nm. The porous CoFe hydrotalcite nano material is prepared through a microwave hydrothermal synthesis method, the preparation method is simple, easy to operate and environmentally friendly, and industrial production can be achieved. The porous CoFe hydrotalcite nano material prepared by the method is stable in structure, has photocatalytic activity and peroxidase-like activity, can effectively catalyze and generate various reactive oxygen free radicals under the illumination condition, realizes efficient synergistic killing of bacteria, and has a good antibacterial effect.

The invention relates to a composite powder explosion suppressant for suppressing aluminum hydride explosion and a preparation method of the composite powder explosion suppressant, belongs to the technical field of explosion suppressants, and solves the problems of single action mechanism, high required explosion suppression concentration, low efficiency and the like of a traditional explosion suppressant. According to the solution, the composite powder explosion suppressant for suppressing aluminum hydride explosion is prepared through raw material pretreatment, powder mixing and drying in sequence, and the composite powder explosion suppressant is prepared from the following components in parts by mass: 10.2 to 30.2 parts of melamine cyanurate, 20.4 to 40.6 parts of monopotassium phosphate, 15.2 to 25.2 parts of potassium bicarbonate, 8.4 to 13.2 parts of aluminum hydroxide, 6.8 to 11.1 parts of zinc borate, 5.0 to 9.0 parts of fumed silica and 2.0 to 5.3 parts of calcium silicate. The explosion suppressant can act on different combustion areas and combustion stages in the aluminum hydride explosion process, the physical and chemical explosion suppression effects of all the components of the explosion suppressant are fully exerted, and meanwhile, efficient explosion suppression of aluminum hydride explosion can be achieved through the synergistic effect of all the components.

The invention relates to a high-dispersity magnesium hydroxide flame retardant as well as a preparation method and application thereof. The flame retardant comprises a magnesium hydroxide crystal and a multifunctional composite group which is modified on the surface of the magnesium hydroxide crystal and is used for improving the flame retardant property, wherein the magnesium hydroxide crystal accounts for 90-98% by mass, and the multifunctional composite group accounts for 2-10% by mass; the multifunctional composite group is composed of an organosilicon group, an olefin group, a nitrogen-containing group, a hydrophilic group and a hydrophobic group. A magnesium hydroxide crude product is subjected to surface modification treatment by adopting the weakly hydrophobic and strongly hydrophobic modifiers, and wet modification and dry modification processes are combined, so that the distribution narrowness (span) of the flame retardant is improved, the dispersion effect and the compatibility of the material are further improved, and the overall flame retardant property of the material is remarkably improved; meanwhile, the mechanical property of the filling material is maintained or enhanced, and an innovative solution is provided for developing an efficient and environment-friendly polymer flame-retardant material.

The invention relates to the technical field of novel environment-friendly materials, in particular to a ZnO / ZnFe2O4 desulfurization adsorbent with a stable porous structure and a preparation method of the ZnO / ZnFe2O4 desulfurization adsorbent with the stable porous structure, and the preparation method of the ZnO / ZnFe2O4 desulfurization adsorbent with the stable porous structure comprises the following steps: step 1, preparing a zinc-iron salt mixed solution; preparing an alkaline mixed solution; step 2, dropwise adding the alkaline mixed solution prepared in the step 1 into the zinc-iron salt mixed solution while stirring, and adjusting the pH value to 9-10; then carrying out a water bath reaction to obtain a zinc iron-double metal hydroxide; 3, the zinc iron-bimetal hydroxide prepared in the step 2 is subjected to high-temperature calcination, and the ZnO / ZnFe2O4 desulfurization adsorbent with the stable porous structure is obtained.The zinc iron-bimetal hydroxide (ZnFe-LDH) serves as a raw material, under the high-temperature calcination condition, the ZnFe-LDH is decomposed to generate ZnO and Fe2O3, then the ZnO and the Fe2O3 are further subjected to a solid-phase reaction to generate ZnFe2O4 (excessive ZnO), and the ZnO / ZnFe2O4 desulfurization adsorbent with the stable porous structure is obtained. And finally, the ZnO / ZnFe2O4 desulfurization composite adsorption material is prepared.

Provided is a cation exchange membrane in which when a hydroxide aqueous solution showing strong alkalinity is produced by using an electrodialyzer, significant swelling in the cation exchange membrane in contact with the hydroxide aqueous solution is suppressed, destruction of a cation exchange resin due to polyvalent cations contained as impurities in a raw material inorganic salt is suppressed, and the capacity of the cation exchange membrane is hardly lowered.　This cation exchange membrane is characterized by having an electric resistance of 2.0-5.0 (Ω∙cm2), as measured at 25ºC in 0.5 mol / L of a NaCl aqueous solution, and a dimensional change rate of at most 1.2%.

The invention discloses a preparation process of a rare earth precipitation resistant electrophoretic coating for an automobile body. The preparation process comprises the following steps: S1, preparing a stable solution; s2, preparing a rare earth chelating solution; adding lanthanum lactate into the stable solution for multiple times, and adding ammonium ceric sulfate for multiple times after the lanthanum lactate is completely dissolved; s3, preparing a resin base solution; s4, preparing mixed slurry; s5, adding a solvent and an auxiliary agent; a five-membered ring chelate with thermodynamic stability is formed by carboxyl, hydroxyl and rare earth elements in sodium citrate, rare earth ions can be tightly wrapped through strong coordination bonds, namely, empty orbits of the rare earth ions and lone pair electrons of a chelating agent form coordination bonds, so that the rare earth ions cannot be dissociated in a system, and the rare earth ions are prevented from being dissociated in the system. And a path of generating hydroxide precipitates by free rare earth ions is thoroughly blocked, so that rare earth elements are effectively ensured to be uniformly distributed in the electrophoretic paint, and the surface of a raw material treated by a subsequent electrophoresis process is more uniform.

The present invention relates to a bimetallic layered hydroxide / phytic acid synergistic flame-retardant nylon 6 composite material and its preparation method and application, belonging to the technical field of flame retardant material synthesis. The composite material is prepared from nylon 6, bimetallic layered hydroxide and phytic acid. Wherein, the phosphate functional group in the phytic acid can chelate with the metal ion in the bimetallic layered hydroxide, thereby forming a novel flame retardant. When combustion occurs, the layered structure and thermal decomposition products such as metal oxides, metal phosphates, and carbon-containing aromatic network structure substances in the flame retardant help to suppress the release of smoke and toxic gases, and the release of metal ions and phosphorus-containing free radicals helps to suppress the spread of fire. Compared with pure nylon 6, the peak heat release rate and total heat release rate of the composite material are greatly reduced, the limiting oxygen index is greatly increased, and the vertical combustion test reaches V-0 level. At the same time, the raw material sources in the preparation method of the composite material are abundant, the operation is simple, and it is suitable for scaled-up production.

The invention relates to a method for recovering lithium and fluorine from aluminum electrolysis hazardous waste, which comprises the following steps: firstly, mixing organic polyol and alkaline hydroxide according to a molar ratio of 1: (0.5-2) to obtain a eutectic solvent; heating the eutectic solvent to 80-150 DEG C, and adding a proper amount of raw material fine powder and calcium oxide for reaction leaching; carbonating and filtering the leachate to obtain lithium carbonate; washing the leaching residues with an acetic acid solution to obtain a calcium fluoride product; the concentration of fluorine ions in the leachate is smaller than or equal to 200 ppm, and the purity of calcium fluoride is larger than or equal to 90%; the leaching rate of lithium in the method is greater than 85%; the slag feeding rate of fluorine is greater than 95%; and no hydrogen fluoride gas is generated in the method. According to the method, a non-toxic and biodegradable eutectic solvent is adopted as a leaching agent, and efficient leaching of lithium and fluorine in the aluminum electrolysis dangerous waste materials is achieved; calcium oxide is used as a precipitating agent, free fluorine is promoted to be precipitated and recycled as calcium fluoride, the whole process meets the requirement of green metallurgy, and the win-win situation of resources and the environment is achieved.

The invention discloses a method for preparing hafnium oxide from hafnium oxalate feed liquid through an oxidation precipitation method, and belongs to the technical field of hydrometallurgy. The specific method comprises the following steps: adding an oxidizing agent into hafnium oxalate feed liquid to destroy oxalate ions in hafnium oxalate so as to enable hafnium to form hydroxide precipitates; and separating the generated white precipitate, and roasting at high temperature to obtain hafnium oxide. The strong oxidant used in the method is low in cost, high in precipitation efficiency, green, environmentally friendly, free of large pollution to equipment and the environment and wide in application range. The method is simple in process, does not involve a complex process flow, does not need precise equipment, avoids a large amount of alkali liquor required by metal ion precipitation, is simpler in process flow, higher in efficiency and lower in cost, avoids the generation of a large amount of wastewater, and is very environment-friendly. And meanwhile, the process is wide in application range and suitable for various oxalic acid metal feed liquid.

The invention discloses a diabase tailing geopolymer cementing material and a preparation method thereof, and belongs to the technical field of building materials. The diabase tailing geopolymer cementing material provided by the invention is prepared from the following components in parts by mass: 80 to 120 parts of diabase tailings, 10 to 20 parts of sodium hydroxide, 80 to 120 parts of water glass, 10 to 20 parts of aluminum hydroxide, 1 to 3 parts of a water reducing agent and 2 to 11 parts of a stabilizing material, the geopolymer cementing material is prepared from the solid waste diabase tailings, harmful solvents, heavy metals and radioactive substances are not added, waste can be turned into wealth, the preparation process is simple, the cost is low, the energy consumption is small, and an effective way is provided for comprehensive utilization of the diabase tailings.

The invention discloses a method for comprehensively recycling electrolytic aluminum carbon residues, and relates to the technical field of comprehensive recycling of waste materials. The method for comprehensively recycling the electrolytic aluminum carbon residues comprises the following steps of: breaking the carbon residues into 0.1-1cm particles by a hammer, carrying out wet ball milling under the condition of adding a flotation agent, and separating carbon powder on the upper layer and gray regenerated cryolite on the bottom layer of slurry through flotation equipment, wherein the fineness is 40-100 meshes, and the carbon content is less than 1%; the preparation method comprises the following steps: adding water into cryolite to prepare slurry, adding calcium oxide or calcium hydroxide, heating, stirring and reacting for 1-3 hours, and carrying out filter pressing to obtain filtrate and filter residues which are calcium fluoride and a sodium metaaluminate solution; the purity of the calcium fluoride powder is greater than 85%; and introducing hydrochloric acid into the filtrate, stirring and adjusting the pH to 7-9 to obtain aluminum hydroxide slurry, filtering and washing to obtain aluminum hydroxide, and drying to obtain the aluminum hydroxide with the purity of more than 95%.

A method of adsorbing a dye from an aqueous solution including contacting a composition with the aqueous solution. At least a portion of the dye adsorbs to the composition. The composition includes biochar, cellulose nanocrystals, and a layered double hydroxide (LDH). The LDH includes Cu and Fe. Particles of the LDH and the biochar at least partially cover an outer surface of the cellulose nanocrystals.

The invention discloses a method for extracting copper fine powder by flotation of copper-containing ore, which belongs to the technical field of mineral processing, and comprises the following steps: after copper-containing raw ore is crushed, ground and classified by a cyclone, overflow enters flotation, and settled sand is returned for regrinding; sodium carbonate is added into graded overflow to adjust the pH, a sodium hexametaphosphate-polyacrylamide composite dispersant is added, and copper sulfate is added and stirred after low-temperature microwave heating; gradient flotation is conducted, specifically, copper sulfide is roughly selected, the pH is adjusted, an amino-sulfonic acid group synergistic modified layered double metal hydroxide / cobalt ferrite composite collecting agent is added, and rough concentrate 1 is obtained through high-frequency pulse air inflation flotation; copper oxide roughing is conducted, clear water is supplemented to adjust the pH, and a collecting agent is supplemented to obtain rough concentrate 2; scavenging is performed for three times, a collecting agent is added for flotation, and concentrate returns to the previous stage; the rough concentrates are combined, and magnetic impurities are removed through high-gradient magnetic separation to obtain magnetic concentrates; and carrying out microbiological leaching on tailings to recover copper. The composite collecting agent is prepared through layered double hydroxide carrier synthesis, amino modification, sulfonic acid group grafting and cobalt ferrite anchoring.

The invention provides a ternary synergistic flame retardant suitable for a polylactic acid composite material and a preparation method thereof. The ternary synergistic flame retardant comprises ternary components of magnesium hydroxide, zinc oxide and titanium dioxide, the ternary component is subjected to surface modification through a silane coupling agent solution containing an epoxy group, the mass ratio of magnesium hydroxide to zinc oxide to titanium dioxide is 4: 1.5: 1-5: 2: 1, and the ternary component is used for maintaining the mechanical property of polylactic acid and achieving the synergistic effect of flame retardance and smoke suppression at the same time. According to the polylactic acid composite material prepared by the invention, the limit oxygen index is increased to 28.85% from 19.91%, the increase amplitude is about 45%, and the UL-94 V-0 grade is reached; the maximum smoke density is reduced from 287 to 198, the reduction amplitude is about 31%, and the flame retardant efficiency of the material and the visibility in the combustion process are remarkably improved. The addition amount of the ternary synergistic flame retardant is controlled in a range of 15-25%, an excellent flame retardant effect can be obtained, the addition amount is greatly reduced compared with that of a single magnesium hydroxide system (generally, the addition amount needs to be larger than or equal to 40%), and the mechanical property loss caused by high filling is effectively avoided.

The application discloses an improved electrolytic synthesis method of 3,6-dichloropicolinic acid, which comprises the following steps: adopting a diaphragm electrolytic cell, taking an aqueous solution containing 3,4,5,6-tetrachloropicolinic acid and a certain flow of CO2 gas as a cathode liquid, taking an aqueous solution of alkali metal hydroxide as an anode liquid, taking silver as a cathode, and taking a nickel-based material as an anode to carry out an electrolytic reaction, and obtaining 3,6-dichloropicolinic acid after the electrolytic reaction is completed. In the electrolytic process, the anode is separated from the cathode, so that corrosion is avoided; meanwhile, the CO2 gas is introduced to effectively control the occurrence of a hydroxylation side reaction, the molar yield of a hydroxyl byproduct is reduced from 20% to 35% to 2% to 8%, the molar yield of 3,6-dichloropicolinic acid is increased from 45% to 50% to above 80%, and the highest can reach 92.2%.

The invention belongs to the technical field of inorganic chemical material preparation, and discloses a high-selectivity crystallization and impurity migration inhibition method of high-purity magnesium hydroxide. The method comprises the following steps: a phenylphosphonic acid surface modifier is introduced in the initial stage of crystallization, molecules of the phenylphosphonic acid surface modifier selectively occupy high-activity Mg < 2 + > sites of a magnesium hydroxide crystal face through bidentate coordination, and a molecular-level interface barrier with steric hindrance and electrostatic repulsion effects is formed, so that a Ca < 2 + > migration path is specifically blocked, and Mg < 2 + > crystallization is not influenced. The preparation method of the high-purity magnesium hydroxide is high in selectivity, high in efficiency, low in cost and environmentally friendly, the interface adsorption behavior of calcium ions is accurately intervened in the initial stage of crystallization through a molecular level surface engineering means, the technical bottleneck that impurity migration and lattice doping are difficult to control in a traditional process is fundamentally solved, and the preparation method is suitable for industrial production. And a brand new technical path is provided for green manufacturing of high-performance inorganic functional materials.

The preparation method of the low-sodium-oxide Bayer-process micro-powder aluminum hydroxide comprises the following steps: adding a seed crystal into a Bayer-process sodium aluminate solution to carry out a first-stage decomposition reaction so as to induce the generation and growth of an aluminum hydroxide crystal nucleus in the Bayer-process sodium aluminate solution; adding a sodium aluminate fine solution into the material subjected to the first-stage decomposition reaction for multiple times to perform a second-stage decomposition reaction so as to promote lattice reconstruction of the aluminum hydroxide crystal nucleus and removal of sodium ions in the sodium aluminate solution; carrying out solid-liquid separation on the material after the second-stage decomposition reaction to obtain a solid material; and washing and drying the solid material to obtain the micro-powder aluminum hydroxide. Through the synergistic effect of seed crystal induced crystallization, segmented decomposition reaction, temperature control, solid-liquid separation, washing and the like, the residual amount of sodium oxide is reduced from multiple links, and efficient preparation of the low-sodium-oxide micro-powder aluminum hydroxide is achieved.

The invention provides application of a modified adsorption material in removal of perfluorinated compounds and a preparation method of the modified adsorption material. According to the method, the to-be-treated water body containing the perfluorinated compound is mixed with the modified adsorption material, and the obtained mixed to-be-treated water body is treated by regulating and controlling reaction conditions, so that PFAS is removed, and the purified water body is obtained. The method disclosed by the invention is a process for treating PFAS based on layered bimetallic hydroxide efficient adsorption, and the method is relatively low in energy consumption and relatively low in process treatment cost; wherein the layered bimetal hydroxide material is a modified layered bimetal hydroxide material, the PFAS treatment capacity is remarkably improved, and the layered bimetal hydroxide material has a good application prospect in the field of wastewater treatment.

The invention discloses a catalyst Cr, Co-Ni (OH) 2 (at) NF based on a nickel base. The catalyst is prepared by taking foamed nickel (NF) as a carrier and doping Cr and Co elements, has efficient urea oxidation reaction (UOR) performance, and can be used for hydrogen production by electrolysis of water and urea pollution treatment. The preparation method comprises the following steps: soaking nickel foam in an HCl solution, soaking the nickel foam in a nickel salt solution with a specific concentration for reaction to generate nickel-based hydroxide, and soaking the nickel-based hydroxide in a solution containing chromic nitrate and cobalt potassium cyanide for reaction to finally generate the catalyst doped with Cr and Co. The catalyst shows low overpotential and good stability in a 1M KOH + 0.33 M urea solution, the overpotential of an anode for hydrogen production through electrolysis of water is remarkably reduced, and meanwhile efficient degradation of urea is achieved.

The application discloses a preparation method of low-chlorine magnesium oxide. The method comprises the following steps: adding high-chlorine magnesium hydroxide slurry into an electrolytic cell, adding an anode liquid into an anode chamber, adding a cathode liquid into a cathode chamber, and adding a reinforcing agent into the high-chlorine magnesium hydroxide slurry. A direct current electric field is applied between the anode and the cathode by using a pulse power source to remove chlorine. Under the action of the electric field, the negative-charged chlorine ions move to the anode chamber by electromigration, and the chlorine moves to the cathode chamber by electrodialysis in the form of chlorides or other soluble ions, so as to reduce the concentration of the chlorine ions in the high-chlorine magnesium hydroxide slurry. After the chlorine is removed, the magnesium hydroxide is filtered and calcined to obtain the low-chlorine magnesium oxide. The method has the advantages that the high-energy-consumption processes such as ball milling and calcining in the traditional chlorine removal process of magnesium hydroxide are avoided, the harm of the chlorine ions to the equipment is reduced, the chlorine ions in the magnesium hydroxide are removed only by electromigration and electrodialysis, and the green and efficient preparation of the low-chlorine magnesium oxide is realized.

The application belongs to the technical field of dechlorination carrier and specifically provides a preparation method of a dechlorination active carrier, which comprises the following steps: 1) polyoxyethylene-polyoxypropylene block copolymer and modified protein solution are dissolved in deionized water, then cobalt nitrate, aluminum lactate and 2-aldehyde benzene boronic acid are added and stirred uniformly, reaction is carried out at 110-130 DEG C, centrifugation and drying are carried out to obtain a precursor; 2) tetrabutylphosphonium hydroxide and sodium aluminate are added into deionized water, TEOS and the precursor are added after mixing, stirring is carried out, crystallization is carried out at 165-175 DEG C, centrifugation and washing are carried out, and the obtained solid is dried and calcined to obtain the dechlorination active carrier. The carrier prepared by the application has the advantage of good dechlorination effect.

The invention discloses a preparation method and application of a sodium-ion battery positive electrode material, and relates to the technical field of sodium-ion batteries, and the preparation method comprises the following steps: (1) dissolving a compound containing a Cr element in water, adding the solution into a reaction kettle, gradually dropwise adding a NaOH solution, after the reaction is completed, gradually adding a chitosan hydrochloride aqueous solution into the reaction kettle according to a certain ratio, and stirring to obtain a mixed solution; after reacting for a certain time, filtering, washing and drying to obtain chitosan-coated chromium hydroxide Cr (OH) 3 (at) CS; (2) blending the Cr (OH) 3 (at) CS prepared in the step (1) with a sodium source according to a certain molar ratio, sintering the mixture under protective gas, and then grinding and sieving to obtain a carbon-coated sodium chromite positive electrode material NaCrO2 (at) C; the sodium-ion battery has good electrochemical performance and cycle performance, and the sustainable development of the sodium-ion battery industry is promoted.

The invention provides a method for extracting tantalum and niobium from tungsten tailings, and belongs to the technical field of rare metal recovery, and the method comprises the following steps: adding a reducing agent, a fluxing agent, a covering agent and a slag former into the tungsten tailings, and heating and smelting under the protection of inert gas to obtain an alloy ingot; the alloy ingot is crushed and then leached through hydrochloric acid, and acid leaching residues containing tantalum, niobium and tungsten are obtained; the acid leaching residues are subjected to alkaline leaching, and alkaline leaching residues containing tantalum and niobium are obtained; the alkaline leaching residues are leached through hydrofluoric acid and sulfuric acid, and decomposition liquid is obtained; and extracting and separating the decomposition liquid to obtain tantalum hydroxide and niobium hydroxide, and respectively calcining the tantalum hydroxide and niobium hydroxide to obtain tantalum oxide and niobium oxide. The method is simple in technological process, convenient to operate, low in cost and suitable for industrial production, tantalum and niobium can be efficiently extracted from tungsten tailings, and good economic benefits and environmental benefits are achieved.