1760 results about "Carbonate sodium" patented technology

The invention discloses a method for preparing a composite positive electrode material by using a waste battery, and belongs to the technical field of battery recovery. The method comprises the following steps: discharging, disassembling and sorting a waste lithium iron phosphate battery to obtain a positive plate, carrying out water treatment, separating from an aluminum foil to obtain a waste lithium iron phosphate sheet, adding sodium hypochlorite, tetraethoxysilane, deionized water and hydrochloric acid, stirring to obtain SiO2-coated iron phosphate precipitate particles and a lithium-containing solution, adding sodium hydroxide into the lithium-containing solution to adjust the pH value, and carrying out solid-liquid separation to obtain the lithium-ion battery cathode material. Adding sodium carbonate, heating and drying to obtain lithium carbonate precipitate. And adding a carbon source and alcohol into the SiO2-coated iron phosphate precipitate particles and lithium carbonate, carrying out ball milling, taking out, drying, and calcining in a protective atmosphere to obtain the positive electrode composite material. Compared with the prior art, according to the prepared positive electrode composite material, material particles contain a lithium silicate network, so that the specific discharge capacity of a battery material is effectively improved. The method is simple in process and suitable for comprehensive utilization of waste batteries.

The invention provides an MHP precipitation method based on a compound alkali precipitator and application of the MHP precipitation method, and the MHP precipitation method comprises the following steps: mixing laterite-nickel ore iron and aluminum removed liquid and a compound alkali solution for precipitation reaction to obtain cobalt nickel hydroxide slurry; the compound alkali in the compound alkali solution comprises a mixture of sodium carbonate and sodium hydroxide; and carrying out post-treatment on the cobalt nickel hydroxide slurry, and separating to obtain the MHP. According to the method, a sodium hydroxide and sodium carbonate compounded system is used as a precipitator, the MHP is prepared under the cooperation of sodium carbonate and sodium hydroxide, the content of manganese in the obtained MHP is remarkably reduced, the content of nickel and cobalt in the MHP is increased, the method has important significance for reducing the cost for preparing crystals through subsequent MHP refining, meanwhile, the reaction rate is more controllable, the obtained MHP is better in filtering performance, and the method is suitable for industrial production. The water content is lower.

The invention discloses a method for preparing a manganese iron phosphate precursor by recycling waste lithium manganese iron phosphate, and belongs to the technical field of lithium ion batteries. The invention provides a method for preparing a manganese iron phosphate precursor by recycling waste lithium manganese iron phosphate, which comprises the following steps: by taking waste lithium manganese iron phosphate battery powder as a raw material, carrying out acid dissolution and filtration to remove graphite and part of impurities; adjusting the pH value of the filtrate to obtain a lithium-ion-rich solution and a ferromanganese precipitate, and adding sodium carbonate into the lithium-ion-rich solution for concentration and crystallization to obtain battery-grade lithium carbonate; carrying out acid dissolution on the ferromanganese precipitate, removing copper and aluminum impurities in the solution, adjusting the ratio of ferromanganese to phosphorus, and mixing with liquid caustic soda in a nitrogen atmosphere to obtain a ferromanganese phosphate precursor; according to the method, the problems of incomplete recovery and insufficient impurity removal of the manganese iron phosphate lithium battery are solved, the battery-grade lithium carbonate and the manganese iron phosphate precursor are prepared during recovery, the value of the recovered product is improved, and the production requirement of the lithium ion battery is met.

The invention provides a method for efficiently synthesizing basic nickel carbonate, and belongs to the technical field of chemical preparation. Comprising the following steps: (1) preparing a mixed solution of sodium carbonate and sodium hydroxide; (2) under low-temperature and high-speed stirring conditions, dropwise adding a nickel salt solution into the mixed solution, adding a competitive adsorbent, adjusting the pH value of the solution, then heating, continuing stirring reaction, separating the competitive adsorbent by a magnet, centrifuging, washing and collecting prepared primary basic nickel carbonate; and (3) recrystallizing the primary basic nickel carbonate in an ethanol water solution, and drying to obtain the basic nickel carbonate. According to the preparation method disclosed by the invention, the content of impurity ions in the product is reduced, so that the high-purity basic nickel carbonate can be prepared, the synthesis efficiency is high, the production cost is relatively low, the method is green and environment-friendly, the competitive adsorbent can also be repeatedly utilized and recycled, the production cost is reduced, and the method has a wide application prospect.

According to the invention, biomass rice hull ash and a sodium hydroxide solution are reacted to obtain water glass and carbon mud. And reacting the water glass with CO2 generated by calcining the limestone to produce a white carbon black product and a mixed waste liquid of sodium carbonate and sodium bicarbonate. Meanwhile, quick lime obtained by calcining limestone is digested and then reacts with sodium carbonate and sodium bicarbonate mixed waste liquid to generate a light calcium carbonate product and dilute sodium hydroxide waste liquid. And finally, the dilute sodium hydroxide waste liquid is concentrated and reused for water glass production, so that the waste liquid is recycled, and a complete process closed loop is formed. According to the process method disclosed by the invention, two leading-edge innovative processes, namely production of white carbon black by renewable resource biomass rice hull ash and production of white carbon black by a carbonization method, are organically combined and are coupled with production of light calcium carbonate by a limestone calcination process, so that the problem that a large amount of sodium sulfate-containing wastewater is discharged in a traditional process is solved; meanwhile, the carbon footprint of white carbon black and calcium carbonate products is greatly reduced.

The invention discloses a method for recovering lithium, nickel cobalt manganese composite hydroxide and aluminum copper powder from a waste ternary lithium ion battery pole piece. The method comprises the following steps: treating waste pole pieces of a ternary plant or a mixture of positive and negative pole pieces by using a Fenton technology, leaching by using a mixed ferric salt solution, and filtering to obtain lithium-containing leachate and slag; adjusting the pH value of the leachate, oxidizing and filtering to obtain a purified solution and ferric hydroxide precipitate, and adding the purified solution and a lithium hydroxide solution into a reactor for coprecipitation to obtain a deeply purified solution and the nickel-cobalt-manganese composite hydroxide. And dissolving the ferric hydroxide precipitate with dilute acid, adding a reducing agent to generate a ferrous salt solution, and returning the ferrous salt solution for Fenton reaction and leaching reaction. And adding the sodium carbonate saturated solution into the deep purification solution, and crystallizing and precipitating to obtain the battery-grade lithium carbonate. And performing hydrodynamic screening on the leaching residues to obtain an aluminum-copper mixture and graphite residues, and performing grinding and specific gravity separation on the aluminum-copper mixture to obtain high-purity aluminum powder and copper powder. According to the method, the iron salt is directly leached from the pole piece, the used iron salt can be recycled, and the method is suitable for large-scale recovery of the waste ternary lithium ion battery.

The invention relates to the technical field of fabrics, and discloses a preparation method of a high-elastic anti-wrinkle blended fabric, which comprises the following steps: adding sodium carbonate, an organosilicon quaternary ammonium salt triazine finishing agent and a cotton / spandex blended fabric into water, soaking, then soaking and rolling twice, washing, and then pre-drying and baking to obtain the high-elastic anti-wrinkle blended fabric. The finishing agent contains cyanuric chloride groups, active chlorine atoms of the cyanuric chloride groups can react with hydroxyl groups of the cotton fabric, so that the finishing agent is connected to the surface of the blended fabric through stable chemical bonds, meanwhile, the finishing agent contains a large number of amido bonds, and the amido bonds and carbamate groups of spandex fabric form hydrogen bond interaction, so that the finishing agent can be used for finishing the cotton fabric. The finishing agent can be firmly attached to the surface of the blended fabric and has good washing resistance, the finishing agent is not prone to falling off after multiple times of washing, and the fabric still has high wrinkle recovery angle, moisture regain and good hand feeling and keeps good wrinkle resistance, hydrophilic performance and soft and elastic hand feeling.

The invention provides a reformate dechlorinating agent and a preparation method thereof. The reformate dechlorinating agent comprises an active component, a carrier and a binder, wherein the active component is sodium carbonate and / or sodium bicarbonate, and the carrier comprises alumina powder and alkali-washed waste FER molecular sieves; the specific surface area of the dechlorinating agent for the reformate is 60-150m < 2 > / g, and the average pore size is 10.5-18.5 nm. The problems that in the prior art, the waste FER molecular sieves are not fully recycled, and a dechlorinating agent which is low in cost and good in dechlorinating effect is lacked are effectively solved.

The invention provides a lithium precipitation mother liquor lithium recovery method based on countercurrent centrifugal extraction. The method comprises the following steps: S1, pretreating a lithium precipitation mother liquor to obtain a lithium-containing pre-extraction solution; s2, conveying the lithium-containing pre-extraction liquid to a centrifugal extraction system, fully mixing the lithium-containing pre-extraction liquid with an organic phase, and sequentially carrying out multi-stage countercurrent centrifugal extraction; performing phase splitting to obtain raffinate and a lithium-loaded organic phase; s3, the lithium-loaded organic phase enters a washing section to be subjected to multi-stage countercurrent centrifugal washing; s4, performing multi-stage countercurrent centrifugal reverse extraction on the washed lithium-loaded organic phase to obtain a lithium-rich solution; and S5, synthesizing the lithium-rich solution and a sodium carbonate solution to obtain the battery-grade lithium carbonate. The lithium recovery method has the characteristics of rapidness, high efficiency, low equipment investment, small occupied area, less extraction agent consumption and short process flow.

The invention relates to the technical field of precious metal recovery, in particular to a precious metal recovery method which comprises the following steps: I, crushing a waste catalyst, blending the waste catalyst with sodium carbonate according to the weight ratio of 1: (0.5-1.2), and roasting at 700-1000 DEG C for 0.5-3 hours to obtain a roasted product; and II, dispersing the roasted product and sodium hydroxide in the weight ratio of (0.2-0.5): 1 in water at the temperature of 50-90 DEG C, stirring at the rotating speed of 80-320 r / min for 5-20 min for leaching, filtering while hot after leaching is finished, and collecting, washing and drying filter residues to obtain the recovered noble metal. According to the recycling method, the precious metal is efficiently recycled from the high-carbon-content catalyst by accurately controlling parameters of all the steps, and compared with a traditional recycling method, the recycling rate is remarkably increased, the influence on the environment is reduced, and meanwhile the production cost is reduced.

The invention discloses polyether-ether-ketone resin with adjustable molecular weight distribution as well as a synthesis method and application of the polyether-ether-ketone resin. The synthesis method comprises the following steps: preparing polyether-ether-ketone resin in the presence of carbonate and / or bicarbonate of alkali metal; wherein the carbonate and / or bicarbonate of the alkali metal comprises sodium carbonate and potassium carbonate, and the sodium carbonate has gradient particle size distribution. According to the invention, sodium carbonate with specific particle size distribution is used to regulate and control the reaction rate to be stable and continuous, so that the molecular weight distribution of the polymer presents a narrower distribution form. Therefore, the molecular structure is uniform, the molecular form is uniform, the physical and chemical properties, including mechanical strength, thermal stability and chemical stability, of the material can be improved, and particularly, the thermal stability of the material is improved most remarkably.

The invention belongs to the technical field of desiliconized fly ash, and particularly relates to a high-alumina-silica-ratio material capable of replacing bauxite as well as a preparation method and application of the high-alumina-silica-ratio material. The preparation method comprises the following steps: S1, crushing coal gangue, and grinding the crushed coal gangue until the particle size is less than 40 meshes to obtain a ground material; s2, mixing the ground material and a catalyst according to a weight ratio of 100: (1-2), roasting, and cooling to obtain activated coal gangue; the catalyst comprises sodium carbonate, calcium oxide and aluminum oxide in a weight ratio of 1: (0.3-0.5): (1.4-1.6); s3, mixing a sodium hydroxide solution, the activated coal gangue and a surfactant, and reacting at 50-90 DEG C for 1-6 hours to obtain desiliconized slurry; and S4, filtering the desiliconized slurry, collecting a solid phase, washing with water, and drying to obtain desiliconized fly ash, namely the high alumina-silica ratio material capable of replacing bauxite. The method is high in desiliconization rate.

The invention relates to the technical field of purification of organic chemicals, in particular to an aroma purification method of leaf alcohol. Comprising the following steps: preparing a methanesulfonic acid magnetic catalyst; esterification of leaf alcohol; and alcoholysis and fractionation of the esterification solution. According to the method, acetic acid is used for esterification of leaf alcohol, then clear water and a sodium carbonate solution are used for washing, the clear water can effectively remove some water-soluble impurities and acidic byproducts, and the sodium carbonate solution not only can neutralize residual acidic substances, but also can promote siloxane impurities in initial leaf alcohol to be hydrolyzed and then taken away by a water phase, so that the content of the siloxane impurities in the leaf alcohol is reduced; in the subsequent process of producing leaf alcohol through alcoholysis of the organic phase I, pure water and ethanol, silyl ether impurities are hydrolyzed in a high-temperature and strong-alkali environment, products are dissolved in waste liquid to be removed, olefine aldehyde impurities with the boiling point lower than that of leaf alcohol are removed through azeotropic fractionation with ethanol, in conclusion, the impurities in the finished product leaf alcohol can be effectively reduced, and the yield of the finished product leaf alcohol is increased. And the prepared finished product leaf alcohol is high in purity and pure in fragrance.

The invention discloses a wear-resistant and mildew-proof ceramic tile which comprises a green body and a glaze layer attached to the green body, and the wear-resistant and mildew-proof ceramic tile is obtained by coating the surface of the green body with a modified interface agent and then glazing, wherein the glaze layer is prepared from the following raw materials in parts by weight: 40 to 50 parts of silicon dioxide, 30 to 35 parts of aluminum oxide, 15 to 20 parts of modified titanium dioxide, 6 to 10 parts of barium carbonate, 6 to 10 parts of mullite, 5 to 8 parts of silver-loaded zirconium phosphate, 4 to 8 parts of potassium carbonate, 4 to 8 parts of sodium carbonate, 3 to 7 parts of limestone, 3 to 5 parts of sodium borate, 2 to 4 parts of zinc oxide and 0.5 to 1 part of sodium tripolyphosphate. According to the ceramic tile, the modified interface agent with specific composition is introduced between the ceramic tile green body and the glaze layer, modified titanium dioxide and inorganic components (such as aluminum phosphate, aluminum acetylacetonate and tetrapropyl zirconate) in the interface agent form oxides in the sintering process, and the interface bonding strength is remarkably enhanced through physical occlusion; and the long-term wear resistance and mildew resistance of the ceramic tile glaze layer are improved.

The invention discloses a high-entropy layered double hydroxide with a strong strain effect and a preparation method of the high-entropy layered double hydroxide. The preparation method comprises the following steps: firstly, preparing ferric salt, cobalt salt, nickel salt, copper salt and zinc salt into a mixed aqueous solution of five metal salts; preparing sodium hydroxide and sodium carbonate into an alkali source aqueous solution; then mixing and stirring the mixed aqueous solution of the five metal salts and the alkali source aqueous solution to gradually form yellowish-brown precipitates, then transferring the yellowish-brown precipitates into a polytetrafluoroethylene reaction kettle, and further reacting in a drying oven; and finally, carrying out centrifugal separation, deionized water and absolute ethyl alcohol washing and freeze drying on the fully reacted precipitate to obtain brown powdery solid, namely the high-entropy layered double hydroxide. The high-entropy layered double hydroxide can be used for advanced oxidation catalytic degradation of tetracycline antibiotic wastewater, the strong strain effect of the high-entropy layered double hydroxide enhances the benefit of activating peroxymonosulfate to generate active free radicals, the efficiency of degrading water pollutants is improved, and the high-entropy layered double hydroxide has good application prospects.

The invention provides a method for recycling a waste lithium iron phosphate battery positive electrode material based on organic solvent soaking. The method comprises the following steps: mixing waste lithium iron phosphate positive electrode material powder and a crown ether chelating type co-dissolving agent to obtain a leaching solution; hydrogen peroxide is added into the leachate, the pH is adjusted, a diammonium hydrogen phosphate solution is added, and iron phosphate and filtrate containing lithium ions are obtained; adding sodium carbonate into the filtrate containing lithium ions, and adjusting the pH value to obtain lithium carbonate; mixing the iron phosphate with a phosphoric acid solution to obtain purified iron phosphate; and mixing the purified iron phosphate, lithium carbonate and acetylene black to obtain the regenerated lithium iron phosphate positive electrode material. According to the method for recycling the positive electrode material of the waste lithium iron phosphate battery based on soaking of the organic solvent, the leaching rate of the lithium element is effectively increased, the selectivity to other metal ions is low, and the regenerated positive electrode material of the lithium iron phosphate battery has relatively high discharge capacity and good cycling stability.

The invention relates to the technical field, in particular to an ultralight foamed ceramic hollow sphere prepared from iron lepidolite tailings and a preparation method and application of the ultralight foamed ceramic hollow sphere. The foamed ceramic hollow sphere is prepared from the following raw materials: iron lepidolite tailings, silicon carbide, bentonite, sodium carbonate and potassium carbonate; in percentage by mass, the content of the iron lepidolite tailings is 90 to 96.4 percent; the content of the silicon carbide is 0.1-1%; the iron lepidolite tailings are prepared from the following components in percentage by mass: 77 to 80 percent of SiO2, 10 to 13 percent of Al2O3, 1.3 to 1.6 percent of Fe2O3 and 0.1 to 0.17 percent of Li2O. The ultralight foamed ceramic hollow sphere is prepared by using the iron lepidolite tailings, the silicon carbide, the bentonite, the sodium carbonate and the potassium carbonate as raw materials, can meet various market requirements of heat preservation, heat insulation, sound insulation, noise reduction and the like, and brings remarkable economic benefits and social benefits.

The invention relates to the technical field of composite catalyst materials, in particular to a ferrocobalt bimetal hydroxide / BCN composite material and a preparation method and application thereof.The preparation method comprises the steps that cobalt nitrate and ferric nitrate are used for preparing a metal salt solution, sodium carbonate and sodium hydroxide are used for preparing a precipitant solution, a B-doped carbon nitride BCN material is added into the metal salt solution to form a uniform suspension, and the suspension is dried to obtain the ferrocobalt bimetal hydroxide / BCN composite material; dropwise adding the precipitant solution into the suspension to obtain a precursor solution, performing hydrothermal reaction on the precursor solution, and performing centrifugal impurity removal and drying to construct a heterostructure between layered double hydroxide and BCN in situ to obtain the Co-Fe LDH-coated BCN composite material. Through boron doping and heterostructure construction, the charge separation capacity of graphite carbon nitride is enhanced, the electron migration efficiency is improved through a heterointerface structure, the metal ion release amount and the cycle stability are controlled, and the catalytic performance is remarkably improved.

The invention relates to the technical field of piezoelectric light-transmitting functional ceramics, and discloses a high-light-transmitting ceramic material and a preparation method thereof.The preparation method comprises the following preparation steps that sodium carbonate, potassium carbonate, niobium pentoxide, antimony trioxide, samarium oxide and zirconium dioxide powder raw materials are taken, and after primary ball milling and drying are conducted on the powder raw materials, mixed powder is obtained; carrying out pre-sintering and secondary ball milling on the mixed powder, carrying out compression molding to form a tablet, and sintering and polishing the tablet to obtain a ceramic matrix; and spraying the composite slurry to the surface of a ceramic matrix, carrying out heat treatment, and cooling to room temperature to obtain the high-transmittance ceramic material. The antimony trioxide, the samarium oxide and the zirconium dioxide are co-doped, an antimony-samarium-zirconium liquid phase is generated in the ceramic material, pores of the ceramic material are filled and eliminated, and the prepared ceramic material has excellent optical transmittance, piezoelectric property and mechanical strength.

The invention discloses a method for regenerating lithium iron phosphate in an electrode material. The method comprises the following steps: adding electrode material powder containing lithium iron phosphate, a photocatalyst and glacial acetic acid into water, and uniformly mixing to obtain a first reaction solution; introducing oxygen into the first reaction solution to obtain a second reaction solution; illuminating the second reaction liquid to perform a photocatalytic reaction to obtain a third reaction liquid; filtering and separating the third reaction liquid into filtrate and filter residues, drying the filter residues to obtain iron phosphate, adding a saturated sodium carbonate aqueous solution into the filtrate, heating and reacting, filtering, and taking precipitate to obtain lithium carbonate; and mixing the iron phosphate and the lithium carbonate, and calcining to obtain regenerated lithium iron phosphate. According to the method, the lithium iron phosphate battery is recycled by utilizing a photocatalytic means with mild reaction conditions, the operation process is simple, and the pollution of the generated wastewater is reduced. According to the method, the leaching rates of lithium and iron can reach 94.81% and 2.9%, efficient recovery of lithium carbonate and iron phosphate is achieved, and then the recovery efficiency of lithium iron phosphate is improved.

The present invention provides a system and method for extracting lithium from salt lake brine and preparing battery-grade lithium carbonate. The system includes a coagulation and precipitation system, a filtration system, an adsorption and desorption system, a calcium and magnesium removal system, a boron removal system, a concentration system, an evaporation system, and a lithium precipitation system connected in sequence. The calcium and magnesium removal system includes a first-stage reverse osmosis concentration unit, a first-stage nanofiltration calcium and magnesium removal unit, a second-stage reverse osmosis concentration unit, a multi-stage nanofiltration calcium and magnesium removal unit, and a calcium and magnesium ion exchange unit connected in sequence. The boron removal system includes a first-stage nanofiltration boron removal unit, a multi-stage nanofiltration boron removal unit, and a boron ion exchange unit connected in sequence. After the lithium precipitation system, there are also a precision filtration system and a water washing and drying system connected in sequence. By adopting the process of the present invention, the lithium recovery rate is improved, and the product is battery-grade lithium carbonate, greatly improving the resource utilization and recovery rate of the lithium extraction system, reducing the amount of externally added water and the consumption of sodium carbonate in the process of the lithium precipitation system.

The invention relates to the field of environmental protection, and discloses a composite sand solidification agent and a preparation method thereof. The cellulose-chitosan composite material comprises the following components: 40-50 parts of cellulose, 80-100 parts of chitosan, 2-4 parts of a cross-linking agent, 1-2 parts of an initiator, 2-4 parts of a dispersant, 20-30 parts of fly ash, 20-30 parts of silicate clinker, 200-240 parts of a sodium hydroxide solution, 10-15 parts of sodium carbonate, 80-100 parts of an ethanol solution of chloroacetic acid, 250-300 parts of a sodium acetate buffer solution, 80-100 parts of ethanol, 240-320 parts of ethylene glycol and 30-40 parts of water. The cellulose is modified and then copolymerized with the chitosan, then the copolymer is loaded with the fly ash and the silicate clinker hydrate, the prepared composite sand solidification agent has high strength and excellent water absorption and retention capacity and is environmentally friendly, and the raw materials cellulose and chitosan are derived from biological raw materials, are wide in source, are easy to degrade and are free of toxicity and pollution; the fly ash is subjected to roasting pretreatment, and degradation of the sand stabilization material in the later period has no obvious negative effect on the ecological environment.

The invention relates to the technical field of fluorine-containing sewage treatment, in particular to an adsorption type fluorine removal agent and a preparation method and application thereof.The preparation method comprises the following steps that 1, a sodium silicate solution is slowly added into a hydrochloric acid aqueous solution, and the pH is controlled to be 3-5; 2) adding a polyhydroxy high-molecular organic matter, stirring and dissolving, and reacting to obtain modified polysilicic acid; (3) adding a water-soluble dispersing agent into the modified polysilicic acid, gradually adding aluminum salt, magnesium salt and lanthanum salt, and uniformly stirring to obtain a modified polysilicate aluminum magnesium lanthanum mixed solution; 4) dropwise adding the modified polysilicate aluminum magnesium lanthanum mixed solution into a sodium carbonate solution, and soaking for 12-24 hours; and 5) leaching with pure water, draining water on the surface, pre-freezing, and then drying to obtain the adsorption type fluorine removal agent modified polysilicate aluminum magnesium lanthanum particles. The adsorption capacity of the adsorption type fluorine removal agent prepared by the method on fluorine ions reaches up to 480mg / g, the fluorine ion content of effluent can be as low as 0.1 mg / L or below, and meanwhile, the regeneration efficiency can reach 96% or above.

The invention belongs to the technical field of sandy soil reinforcement, and relates to a sandy soil reinforcement method combining modified chitosan film coating and cementation with biomimetic mineralization and application, the sandy soil reinforcement method comprises the following steps: S1, chitosan is subjected to swelling, alkalization, carboxymethylation and refining treatment to obtain modified chitosan; s2, respectively preparing a calcium chloride solution and a sodium carbonate solution with the same concentration; a calcium chloride solution is a cementing solution A; adding modified chitosan into a sodium carbonate solution, and uniformly stirring to form a cementing solution B; s3, the cementing liquid A is sprayed to the sandy soil, then the cementing liquid B is sprayed, and primary cementing is completed; carrying out circulating cementing for 5-20 times according to the spraying mode; and then air drying is conducted to complete sandy soil reinforcement. According to the invention, the agglomeration among calcium carbonate particles is enhanced by utilizing the cementing, film covering, mineralized crystal form adjusting and filling coupling effects of the modified chitosan, so that the calcium carbonate particles form effective cementing connection among sand particles, thereby improving the mechanical properties of the sand.

The invention discloses a fire extinguishing agent for battery fire prevention and control and a preparation method thereof, and relates to the technical field of fire extinguishing materials. When the fire extinguishing agent for battery fire prevention and control is prepared, lanthanum nitrate hexahydrate reacts with 1, 3, 5-tribenzoic acid to prepare a lanthanum organic metal framework; loading ammonium dihydrogen phosphate onto a lanthanum organic metal framework by adopting a solventing-out crystallization technology to prepare composite flame-retardant particles; reacting cellulose with sodium hydroxide and sodium acrylate in sequence to obtain modified cellulose; mixing the modified cellulose with the composite flame-retardant particles and expanded graphite, and carrying out cross-linking by using N, N '-methylene bisacrylamide, so as to prepare temperature-sensitive hydrogel; and mixing the temperature-sensitive hydrogel with sodium carbonate and glacial acetic acid, drying, and grinding into particles to obtain the fire extinguishing agent for battery fire prevention and control. The fire extinguishing agent for battery fire prevention and control has excellent fire extinguishing performance.

The invention relates to an oxygen delignification pulping method taking bagasse as a raw material, fine pulp and application of the fine pulp, and belongs to the technical field of pulping and papermaking. The pulping method comprises the following steps: preparing a cooking liquor with the alkali amount of 20-30% from sodium carbonate and sodium hydroxide in a mass ratio of (2-9): 1; mixing bagasse with the cooking liquor, and heating and preserving heat under an oxygen adding condition to obtain cooking slurry; washing and screening the cooked pulp to obtain fine pulp and black liquor; preparing green liquor from the black liquor, adding sodium hydroxide into the green liquor until the alkali consumption is the same as that of the cooking liquor, and recycling the green liquor to the cooking liquor. According to the invention, the used chemical agents are sodium carbonate as a main agent and sodium hydroxide as an auxiliary agent, so that corrosion to equipment is reduced, a causticization reaction process is omitted, harmful solid waste pollution caused by the causticization process is avoided, and direct cyclic utilization of the green liquor is realized. The content of silicon in the black liquor is relatively low, so that the risk of silicon interference in an alkali recovery section is reduced.

The invention discloses a modified current collector and a preparation method thereof, a positive plate and a negative-electrode-free sodium ion battery, and relates to the technical field of sodium ion batteries. The aluminum oxide and the solid electrolyte sodium titanium aluminum phosphate grow on the aluminum metal three-dimensional substrate in situ, so that a higher ion conduction rate can be provided, the injection amount of the electrolyte can be reduced, the growth of dendritic crystals can be reduced, and the safety performance of the battery can be improved. The solid electrolyte (sodium aluminum titanium phosphate) and the artificial SEI film (sodium carbonate / sodium fluoride) are formed on the surface of the three-dimensional current collector, so that the deposition of sodium metal in a three-dimensional substrate is facilitated, and sodium dendrites can be prevented from growing on the surface of the current collector so as to prevent the diaphragm from being punctured. The solid electrolyte, the artificial SEI membrane and the cathode-free metal battery are used together, so that the effects of reducing the cost, prolonging the cycle life and improving the battery capacity density and safety are achieved.

The invention discloses a method for recovering valuable metals from a waste hydrogenation catalyst, and relates to the technical field of waste catalyst recovery, and the method comprises the following steps: carrying out oxidizing roasting and oxygen pressure alkaline leaching on the waste hydrogenation catalyst to obtain an alkaline leaching solution and alkaline leaching residues; aluminum, vanadium and molybdenum are recycled from the alkaline leaching solution, wherein carbon dioxide is introduced into the alkaline leaching solution for aluminum precipitation; ammonium sulfate and magnesium sulfate are added into the filtrate subjected to aluminum precipitation to remove phosphorus, silicon and arsenic, molybdenum and vanadium are adsorbed through resin, and vanadium precipitation and molybdenum precipitation are carried out; and aluminum and nickel are recycled from alkaline leaching residues, specifically, aluminum is precipitated through oxygen pressure acid leaching, then alkali is added into filtrate to further recycle aluminum, and then sodium carbonate is added for nickel precipitation. By means of the method, molybdenum, vanadium, nickel, aluminum and other elements in the waste catalyst can be effectively recycled, the recycling rate is high, the molybdenum recycling rate can reach 97%, the vanadium recycling rate can reach 95%, the nickel recycling rate can reach 92%, comprehensive utilization of the waste catalyst is achieved, and good social value and economic value are achieved.

The invention provides a calcium carbonate synthesis experiment device capable of controlling pH. A reaction unit is arranged in a constant temperature box; the sample reaction unit comprises a constant-temperature heating type digital display magnetic stirrer and a reaction container; the reaction container is filled with a reaction solution and a magnetic stirrer, and the reaction solution is used for simulating seawater components; the pumping unit comprises an automatic injection pump with two independent channels and is used for continuously inputting sodium carbonate and calcium chloride solutions into the reaction solution at a stable speed so as to induce precipitation of calcium carbonate; the pH titration unit comprises an automatic potentiometric titrator and is used for monitoring pH and temperature in real time, a titration solution is composed of sodium hydroxide or hydrochloric acid, sodium hydroxide or hydrochloric acid is automatically dropped into a reaction solution, and the pH of the calcium carbonate in the reaction container in the precipitation process is kept stable. According to the present invention, the pH real-time in-situ monitoring during the calcium carbonate precipitation process can be achieved, the corresponding titration program is started according to the experiment setting so as to ensure the pH stability during the calcium carbonate synthesis experiment process, and the characteristics of simple operation and process visualization are provided.

The invention relates to the technical field of fluorite ore beneficiation, discloses a fluorite ore flotation composite collecting agent and a preparation method and application thereof, and aims to solve the problems that an existing collecting agent is limited in applicability, insufficient in selectivity, poor in environmental stability and the like and is difficult to deal with separation of fluorite ore containing various impurities or under complex working conditions. The composite collecting agent is composed of dehydroabietylamine, sodium oleoyl sarcosinate, sodium silicate-citric acid composite salt, ethylene glycol butyl ether and a sodium carbonate-sodium bicarbonate buffer pair, all the components have a synergistic effect, dehydroabietylamine provides selective collecting and fine particle agglomeration functions, sodium oleoyl sarcosinate enhances adsorption stability, the composite salt inhibits gangue in a targeted mode, and therefore the adsorption efficiency is improved. Buffer pairs and ethylene glycol butyl ether guarantee the environmental adaptability of a system. The collecting agent can adapt to various fluorite ores with high sulfur, high silicon, low temperature and the like, can stably play a role under different water quality and working conditions, realizes efficient separation of fluorite and impurities, improves the separation efficiency and the concentrate quality, and is flexible in preparation process and convenient for industrial application.