31 results about "Barium salt" patented technology

The present application relates to the technical field of dielectric ceramic powder preparation, and particularly relates to a multilayer ceramic capacitor, a high-activity nano-barium titanate powder for the multilayer ceramic capacitor and a preparation method of the high-activity nano-barium titanate powder, the method comprising the following steps: (1) reacting a soluble barium salt with a precipitator to obtain barium carbonate precursor particles with high specific surface area; (2) uniformly coating nano-titanium dioxide particles on the surface of the barium carbonate precursor particles by using a supercritical fluid flash technology to form a composite precursor; and (3) performing a solid-phase synthesis reaction on the composite precursor and sintering to obtain nano-barium titanate powder. The present application, through the synergistic effect of the two means of "high-activity precursor preparation" and "nano-level uniform coating", prepares a composite precursor with extremely high specific surface area, surface energy and micro-uniformity, effectively reduces the heat sintering temperature, suppresses abnormal grain growth and lattice distortion, and significantly improves the tetragonality of the nano-barium titanate powder.

The invention relates to an adsorbent based on an X molecular sieve and preparation and application thereof, and a preparation method of the adsorbent comprises the following steps: (1) mixing the X molecular sieve with a binder, molding and roasting to obtain a molded body; (2) treating the molded body obtained in the step (1) with an alkali solution to perform in-situ crystallization on the binder in the molded body to obtain a crystallized product; (3) carrying out partial barium ion exchange on the crystallized product obtained in the step (2) by using a barium salt solution, and drying to obtain a dried product; (4) carrying out ammonium ion exchange on the dried product obtained in the step (3) by using an ammonium salt solution, and roasting in a flowing atmosphere to obtain a roasted product; and (5) performing barium ion exchange and optional potassium ion exchange on the roasted product obtained in the step (4), and then drying to obtain the adsorbent. The adsorbent has at least two kinds of mesoporous channels with different apertures, has high barium ion exchange capacity, high adsorption capacity and compressive strength, and shows good adsorption selectivity and mass transfer performance when used for adsorption separation of p-xylene.

This invention provides a method for removing impurities and recovering nickel anolyte from electrolytic nickel. The method includes the following steps: (1) mixing the electrolytic nickel anolyte with liquid alkali, separating the solid and liquid components to obtain nickel hydroxide and filtrate, evaporating the filtrate to obtain sodium sulfate; mixing the electrolytic nickel anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution with barium salt for lead removal; (3) adjusting the pH of the material obtained after lead removal with nickel hydroxide to obtain an arsenic removal solution, mixing the arsenic removal solution with polyferric sulfate for arsenic removal; (4) mixing the material obtained after arsenic removal with an oxidant to obtain an iron removal solution, performing solid-liquid separation on the iron removal solution to obtain lead-, arsenic-, and iron-removed cathode liquid and iron-containing slag, adding sodium sulfate to the lead-, arsenic-, and iron-removed cathode liquid, and reusing it in the electrolytic nickel process. The method of this invention can efficiently and quickly remove lead, arsenic, and iron from electrolytic nickel anolyte and reuse it.

The invention relates to an impurity removal method for rare earth feed liquid, and belongs to the technical field of rare earth metallurgy. The impurity removal method of the rare earth feed liquid comprises the following steps: (1) performing oil removal on rare earth extraction raffinate wastewater, and adding an alkaline precipitator for precipitation to obtain an impurity removal agent; (2) adding barium salt into the rare earth feed liquid to obtain primary impurity-removed liquid; (3) adding the impurity removal agent into the primary impurity removal liquid to obtain secondary impurity removal liquid and impurity removal residues; and (4) extracting the secondary impurity removal liquid by adopting an extracting agent to obtain a tertiary impurity removal liquid and raffinate wastewater, and recycling the obtained raffinate wastewater for preparing the impurity removal agent in the step (1). According to the impurity removal method disclosed by the invention, on the premise of not changing the original raffinate wastewater precipitation treatment flow and meeting the original raffinate wastewater discharge water quality, while the raffinate wastewater is treated, the multi-impurity rare earth feed liquid can be effectively subjected to impurity removal, the comprehensive utilization of resources is realized, and the green and healthy development of the rare earth industry is facilitated.

The invention provides a method and a system for recovering chromium and aluminum from a waste chromium catalyst. The method comprises the following steps: carrying out alkali fusion reaction on the waste chromium catalyst and sodium hydroxide to obtain alkali fusion clinker; mixing the alkali fusion clinker with water, pulping, leaching, and carrying out solid-liquid separation to obtain a water leaching solution containing Na2CrO4 and NaAlO2 and a filter cake containing Al2O3; adding a barium salt solution or solid into the aqueous extract containing Na2CrO4 and NaAlO2, reacting to generate a BaCrO4 precipitate, and carrying out solid-liquid separation to obtain a BaCrO4 filter cake and a sodium metaaluminate filtrate; reacting the BaCrO4 filter cake with an inorganic acid, and carrying out solid-liquid separation to obtain a chromic acid solution and a barium sulfate precipitate; and adding an acid solution into the sodium metaaluminate filtrate, adjusting the pH value to 7-8, and carrying out solid-liquid separation to obtain an Al (OH) 3 filter cake. According to the method, Cr (III) in the waste catalyst is directionally converted into Cr (VI) through an alkali fusion oxidation process, then the solubility difference of sodium chromate and sodium metaaluminate in an aqueous solution is fully utilized, the high-selectivity separation characteristic of barium chromate precipitation is combined, the chromium-aluminum separation problem is fundamentally solved, and the finally obtained product is excellent in purity.

The invention relates to a preparation method of a negative electrode material applied to a nickel-zinc battery. The preparation method comprises the following steps: dissolving a complexing agent in a solvent to obtain a first solution; adding zinc and / or zinc oxide particles into the first solution to obtain a first mixture; adding a water-soluble barium salt to the first mixture to obtain a second mixture; dissolving a precipitating agent in a solvent to obtain a second solution; adding the second solution into the second mixture for reaction to obtain a third mixture; a step for performing solid-liquid separation on the third mixture and washing and drying the collected solids; the molar ratio of the complexing agent to the barium element in the soluble barium salt is (1-2.5): 1. According to the preparation method, a precipitation method regulated by a complexing agent is adopted, soluble barium salt and the complexing agent are complexed in advance, then the precipitating agent is slowly added, and a uniform coating layer is generated on the surface of zinc and / or zinc oxide particles in situ.

The invention discloses a rare earth radioactive slag reduction and barium sulfate slag recycling method based on transformation and decomposition of barium sulfate. The method comprises the following steps: drying, ball-milling and screening rare earth radioactive slag, adding water into sodium hydroxide, and mixing to obtain rare earth slag; roasting and transforming the rare earth slag under the condition of introducing carbon dioxide; washing the roasted and transformed rare earth slag with water; the washed rare earth slag is subjected to acid dissolution and solid-liquid separation, and high-silicon slag without radioactive elements and an acid solution with the radioactive elements are obtained; sulfuric acid is added into the acid solution step by step for fractional precipitation and radium removal, and barium and radium residues containing radioactive elements and barium sulfate residues without radioactivity are obtained through solid-liquid separation; adjusting the mass ratio of the barium sulfate slag and sodium hydroxide, then carrying out alkali conversion and acid dissolution to obtain a barium chloride solution, and recycling the barium chloride solution for removing sulfate radicals from the rare earth feed liquid. According to the method, barium sulfate in the rare earth radioactive slag can be transformed into more than 95% of soluble barium salt, the amount of the rare earth radioactive slag is reduced by more than 85%, and the barium circulation rate reaches more than 90%.

The application provides an accurate determination method of barium sulfate content in a brake pad for an automobile, S1: XRF element of a sample to be measured is preliminarily screened to check whether Ba and S elements exist, if yes, step S3 is performed, and if not, the test is ended; S2: the sample is ashed, inorganic fillers are extracted, and then are acid-dissolved and filtered to collect inorganic fillers insoluble in acid; S3: the inorganic fillers insoluble in acid in step S2 are subjected to semi-melting reaction to obtain a salt solution, and leaching of sulfate is performed; S4: soluble barium salt is added, and a precipitate is obtained through filtration; S5: the precipitate obtained in step S4 is calcined to obtain an experimental product, and is weighed; and S6: the barium sulfate content in the pad is obtained through calculation. The accurate determination method of barium sulfate content in the brake pad for the automobile is accurate in quantification, good in data repeatability, simple and convenient to operate, and provides a test method reference for quality control, formula upgrading and improvement.

The invention discloses a liquid barium-zinc stabilizer and a preparation method and application thereof, and the liquid barium-zinc stabilizer is prepared from the following raw materials in parts by weight: 5-15 parts of oleic acid, 5-20 parts of p-tert-butylbenzoic acid, 2-8 parts of isocaprylic acid, 5-10 parts of diethylene glycol butyl ether acetate, 5-10 parts of cycloalkane, 5-10 parts of D80, 2-5 parts of zinc oxide, 4-10 parts of barium hydroxide monohydrate, 10-20 parts of barium salt and 2-6 parts of dibenzoylmethane. 15-25 parts of phenol-free phosphite ester and 2-6 parts of an antioxidant. The liquid barium-zinc stabilizer prepared by the invention cannot be subjected to curing reaction with an adhesive to cause degumming, and has excellent heat resistance and heat-resistant stability.

A wastewater treatment apparatus includes a wastewater storage tank configured to store wastewater including sulfate ions, a first reactor configured to generate calcium sulfate by receiving the wastewater and an aqueous calcium salt, a second reactor configured to accelerate the generation of calcium sulfate by receiving first effluent supplied from the first reactor and a hydrophilic alcohol, a first separator configured to separate calcium sulfate from second effluent supplied from the second reactor, a third reactor configured to generate barium sulfate by receiving third effluent supplied from the first separator and an aqueous barium salt, a second separator configured to separate barium sulfate from fourth effluent supplied from the third reactor, and a treated water storage tank configured to store treated water filtered by the second separator.

The invention relates to the technical field of in-situ leaching solution sulfate radical monitoring, in particular to an in-situ leaching solution sulfate radical monitoring method and an in-situ leaching solution sulfate radical monitoring system. The monitoring method comprises the following steps: adding an acidic barium salt solution into a reaction cup; adding a preset amount of a to-be-determined water sample into the acidic barium salt solution, and fully stirring to obtain a to-be-determined mixed solution; predicting the sulfate radical concentration of the to-be-measured mixed solution through turbidimetry, and obtaining a supplementary sampling amount according to a prediction result; quantitatively supplementing a to-be-measured water sample into the reaction cup according to the supplementary sampling amount, and fully stirring to obtain a to-be-titrated sample; titrating the to-be-titrated sample to an end point by adopting the EDTA standard solution, and determining the sulfate radical concentration of the in-situ leaching solution according to a titration result. The sampling amount of the to-be-measured water sample is automatically adjusted according to the preset concentration range of sulfate radicals, additional new reagents are not needed, repeated analysis is avoided, the monitoring speed is increased, and the labor cost is reduced.

The invention discloses a preparation method and application of a BaZrO3 material with adjustable piezoelectric property. The preparation method comprises the following steps: (1) mixing a zirconium salt precursor solution and a barium salt precursor solution, and dropwise adding the mixture into an alkali solution to form colloid; (2) carrying out hydrothermal reaction on the colloid, filtering, washing and drying to obtain BaZrO3 powder; and (3) grinding and mixing the BaZrO3 powder and a reducing agent, carrying out heat treatment for 0.5-10 hours in an inert atmosphere, cooling, washing and drying to obtain the catalyst. The high symmetry of a BaZrO3 crystal structure is broken by regulating and controlling the mass ratio of BaZrO3 to the reducing agent, so that accurate regulation and control of the piezoelectric property of barium zirconate are realized. The BaZrO3 material with the adjustable piezoelectric property has a wide application prospect in the field of implantable or close-contact medical equipment, the field of conversion of signals such as vibration, noise or pressure into electric energy, and many fields such as synthesis ammonia and hydrogen production by water decomposition related to piezoelectric catalysis.

The invention relates to oxalate high-purity barium titanate powder and a preparation method thereof. The method comprises six steps of preparation of a titanium salt stabilizing solution, preparation of a barium salt solution, preparation of a dispersant modified solution, a dispersant synergistic homogeneous precipitation reaction, microwave drying purification and microwave gradient calcination. The purity of the prepared barium titanate powder is greater than or equal to 99.9%, the average particle size is 30-60nm, the aggregate content is less than or equal to 1.5%, the dielectric property is excellent, the barium titanate powder can be widely applied to high-end electronic components such as multilayer ceramic capacitors, the process is stable and controllable, and industrial production is easy.

A method for making barium titanate nanopowders, includes mixing barium salt, titanium source, carbohydrate, and urea in a container according to a first ratio, stirring the barium salt, the titanium source, the carbohydrate, and the urea in the container under a heating condition approximately from 60° C. to 120° C. to obtain a molten mixture, heating the molten mixture to dehydrate and carbonize the carbohydrate to obtain a dark brown solid, and performing a heat treatment on the dark brown solid to obtain the barium titanate nanopowders.

The invention relates to the technical field of manganese-based material recovery, in particular to a manganese-based tailing multi-treatment method, which comprises the following steps: crushing and grinding manganese sulfate tailings to a target particle size, adding a pyrophosphoric acid solution for pretreatment, and performing microwave activation and dissolution to obtain a pretreated leachate; adjusting the pH value, adding amino modified hydroxyethylidene diphosphonic acid for complexing and removing impurities, removing arsenic through barium salt, performing secondary purification through hydrogen peroxide, and removing calcium and magnesium through phosphonate; subsequently, accurately filtering and intercepting impurities through a ceramic membrane, and performing vacuum crystallization, washing and drying to obtain high-purity manganese sulfate. According to the method, a multi-stage synergistic treatment system is constructed through the working procedures of crushing and grinding the manganese sulfate tailings, performing microwave activation and dissolution, complexing amino modified phosphonic acid to remove impurities, performing targeted calcium and magnesium removal through phosphonate, performing precise filtration through a ceramic membrane, performing vacuum crystallization and the like. All links have a synergistic effect to improve the purity of manganese sulfate and the recovery rate of manganese, calcium and magnesium residues are reduced, resource utilization of manganese-based tailings is achieved, and the product can stably adapt to application scenes of battery-grade and pharmaceutical-grade high-purity manganese sulfate.

The present application belongs to the technical field of titanium alloy investment casting, and relates to a medium-entropy shell for titanium alloy casting and a preparation method and application thereof. The method comprises the following steps: mixing barium salt, calcium salt and strontium salt with zirconia to obtain a mixture through dilution, drying and crushing, calcining, cooling and sieving to obtain a shell surface layer filler; mixing the shell surface layer filler with yttrium sol binder, wetting agent and defoaming agent to obtain a surface layer slurry; mixing mullite with silica sol binder, wetting agent and defoaming agent to obtain a back layer slurry; uniformly coating the surface layer slurry on the surface of a wax mold and sanding with yttrium oxide powder until solidification and shaping, and repeating the coating, sanding and freezing to obtain a surface layer; uniformly coating the back layer slurry on the surface layer and sanding with mullite powder until solidification and shaping, and repeating the coating, sanding and freezing to obtain a back layer, and then freezing and drying; and finally performing dewaxing and sintering treatment to obtain a finished shell. The present application effectively solves the problems of the existing shell, such as severe reaction with titanium liquid, easy cracking and low precision.

The invention belongs to the field of thermistors, and discloses PTCR (positive temperature coefficient) heating ceramic without NTC (negative temperature coefficient) effect before Curie temperature and a preparation method of the PTCR heating ceramic. The preparation method comprises the following steps: (1) preparing a main material containing a barium salt, a lead salt, a calcium salt and a titanium salt according to the stoichiometric ratio of cations in BaxPbyCazTiO3; then mixing the main material, a semiconducting agent and an AST auxiliary material, and carrying out wet ball milling to obtain powder slurry; wherein 0 lt; xlt; 1, 0lt; yt; Yt; 1, 0.05 < = z < = 0.10, 0.97 < = (x + y + z) lt; 1.08, and x + y + z is not equal to 1; and (2) adding an adhesive into the powder slurry, drying, sequentially granulating and tabletting, sintering in a sintering furnace to obtain a PTCR ceramic chip, and preparing an electrode on the ceramic chip to obtain the PTCR heating ceramic. Compared with a traditional AST system, the heating ceramic formula system has the advantages that no NTC effect exists below the Curie temperature Tc, the impact current is small, and the starting speed is high.

The present application relates to a kind of oxalate high-purity barium titanate powder and its preparation method, which comprises six steps of titanium salt stabilizing liquid preparation, barium salt solution preparation, dispersant modification liquid preparation, dispersant synergistic homogeneous precipitation reaction, microwave drying purification and microwave gradient calcination.The purity of barium titanate powder prepared by the present application is ≥99.9%, the average particle size is 30-60nm, the agglomerate content is ≤1.5%, and the dielectric performance is excellent.The present application can be widely applied to high-end electronic components such as multilayer ceramic capacitor, and the process is stable and controllable, easy to industrial production.

The present application relates to the technical field of manganese-based material recycling, and particularly relates to a method for multiple processing of manganese-based tailings, wherein manganese sulfate tailings are crushed and ground to a target particle size, a pyrophosphoric acid solution is added for pretreatment, and then microwave activation and dissolution are performed to obtain a pretreatment leaching solution; after adjusting the pH, amino-modified hydroxyethylidene diphosphonic acid is added for complexation and impurity removal, and then barium salt is used for arsenic removal, hydrogen peroxide is used for secondary purification, and phosphonate is used for decalcification and magnesium removal; subsequently, ceramic membrane is used for precise filtration to retain impurities, vacuum crystallization, washing and drying are performed to obtain high-purity manganese sulfate. The present application constructs a multi-stage collaborative processing system through processes such as crushing and grinding of manganese sulfate tailings, microwave activation and dissolution, amino-modified phosphonic acid complexation and impurity removal, phosphonate targeted decalcification and magnesium removal, ceramic membrane precise filtration and vacuum crystallization. The collaborative effect of each link improves the purity of manganese sulfate and the manganese recovery rate, reduces the residual calcium and magnesium, realizes the resource utilization of manganese-based tailings, and the product can stably adapt to the application scenarios of battery-grade and pharmaceutical-grade high-purity manganese sulfate.

The invention discloses a preparation method of tantalum-doped barium bismuthate tungstate with an X-ray absorption function. The preparation method comprises the following steps: preparing the following raw materials in molar mass: 0.2 to 0.5 mol of bismuth compound, 0.2 to 0.5 mol of tantalum compound, 0.1 to 0.2 mol of barium salt and 0.1 to 0.2 mol of tungsten compound; the preparation method comprises the following steps: dissolving the raw materials in 500-2000mL of polar solvent, and carrying out hydrothermal reaction; alternately washing the obtained precursor with distilled water and absolute ethyl alcohol to remove impurities, and then carrying out drying treatment; and finally, calcining to finally form the nano powder. The invention provides a preparation method of tantalum-doped barium bismuthate with an X-ray absorption function, solves the problems of a traditional lead-containing protective material, and also has the X-ray absorption function, and the invention also provides an application of the tantalum-doped barium bismuthate with the X-ray absorption function in the X-ray protective material.

The invention belongs to the technical field of alumina production. The invention provides a deep purification process of a sodium aluminate solution. The deep purification process comprises the steps of pretreatment, quaternary synergistic impurity removal, first-stage solid-liquid separation, oxalic acid selective decalcification, second-stage refined filtration and residue treatment. According to the method, a four-element synergistic impurity removal system of barium salt, sodium sulfide, quick lime and a desiliconizing agent is innovatively constructed, impurities such as silicon, iron, phosphorus, titanium, vanadium, copper, lead and zinc ions and organic matters in the sodium aluminate solution are synchronously and deeply removed through function division and synergistic interaction, calcium ions are selectively removed through oxalic acid, and finally the high-purity sodium aluminate solution is obtained for producing high-purity aluminum oxide. According to the method, the problems of poor impurity removal pertinence, high impurity residue and large secondary pollution risk of a traditional single agent are solved, the removal rate of various impurities is larger than or equal to 99%, Ca in the purified solution is smaller than or equal to 0.001 g / L, the method adapts to the Bayer process and sintering process aluminum oxide production process, the purification efficiency is high, the process is compact, and the method is environmentally friendly and economical.

The present application relates to a kind of methods for separating and recovering nickel and iron in nickel-iron phosphoric acid waste liquor, and belongs to the technical field of waste recovery.The present application removes solid precipitate by solid-liquid separation of nickel-iron phosphoric acid waste liquor to obtain impurity-removed nickel-iron phosphoric acid waste liquor;The nickel-iron phosphoric acid waste liquor contains nickel ions, iron ions and phosphate ions, and the pH value of the nickel-iron phosphoric acid waste liquor is 1.2-2.1;The impurity-removed nickel-iron phosphoric acid waste liquor is heated to a temperature of 30-60℃, and carbonates solution is added dropwise into the impurity-removed nickel-iron phosphoric acid waste liquor under stirring to obtain waste liquor A;Then barium salt solution is added dropwise into waste liquor A under stirring to obtain waste liquor B and Ba3(PO4)2 precipitate;Ammonium sulfate solution is added dropwise into waste liquor B under stirring to obtain waste liquor C and (NH4)2Ni(SO4)2·6H2O precipitate;Lye is added dropwise into waste liquor C under stirring to obtain waste liquor D and Fe(OH)3 precipitate.The present application can realize efficient recovery of nickel, iron and phosphate.

The invention relates to the technical field of wastewater treatment, in particular to a treatment method of fluorine-containing wastewater. The treatment method comprises the following steps: adding water-soluble barium salt into the fluorine-containing wastewater to carry out precipitation reaction, and carrying out solid-liquid separation after the reaction to obtain pre-desulfurization intermediate treatment liquid and a barium sulfate product; the fluorine-containing wastewater contains fluorine ions, calcium ions and sulfate ions; and evaporating and concentrating the pre-desulfurized intermediate treatment liquid, and then cooling and carrying out solid-liquid separation in sequence to obtain a calcium fluoride product and treated effluent. According to the method, a collaborative recovery system driven by step-by-step selective precipitation and solubility product difference is constructed, barium salt is utilized for pretreatment, interference of sulfate ions in wastewater is eliminated, high-purity barium sulfate is recovered, and preferential precipitation and efficient separation of calcium fluoride are achieved by combining an evaporation and concentration process subsequently. According to the process, calcium source reagents such as lime and calcium chloride do not need to be added, and the technical bottleneck that the yield and purity of calcium fluoride recovered in fluorine-containing wastewater treatment are difficult to obtain at the same time is broken through.

The invention relates to the technical field of waste liquid treatment, in particular to a continuous process method for deeply removing lead from a rare earth chloride solution. The method solves the problems of hydrogen sulfide escape, sulfur ion residue, discontinuous process and the like in the traditional sulfide precipitation method. The method comprises the following steps: adjusting the pH value of a solution to remove thorium, and enabling the solution to sequentially pass through a first fixed bed reaction column filled with a surface activated porous reduced iron filler and a second trapping and polishing column filled with magnetic iron oxide trapping particles and titanium dioxide coating polishing particles under an anoxic condition to realize reduction precipitation and deep removal of lead; then, barium salt precipitation is used for removing radium, and cerium hydroxide wet glue is used for adsorbing co-precipitated residual radioactive elements; the process does not need to introduce sulfides, can realize whole-process continuous operation, and has the advantages of radioactive purification, high rare earth recovery rate and good process stability.

The invention provides a preparation method of a magnesium alloy surface corrosion-resistant self-repairing coating based on barium salt, and relates to the technical field of metal surface treatment.The preparation method comprises the following specific steps that firstly, a magnesium alloy sample is polished, washed and dried for pretreatment; preparing an electrolyte solution, sequentially adding the main film-forming agent and the auxiliary film-forming agent into the deionized water, stirring for 20 minutes, adding the additive, and stirring until the solution is clear and transparent; then micro-arc oxidation treatment is conducted, the magnesium alloy serves as an anode, a graphite plate serves as a cathode, a micro-arc oxidation coating is generated in the electrolyte solution, and then washing and blow-drying are conducted; and finally, the magnesium alloy subjected to micro-arc oxidation is soaked in a barium salt solution containing barium salt, an oxidizing agent, a complexing agent and a corrosion inhibitor and reacts for 10-180 minutes at the temperature of 30-90 DEG C, and the self-repairing coating is deposited. The process is simple and environment-friendly, and the obtained coating not only has the inherent high hardness and wear resistance of micro-arc oxidation, but also realizes excellent and lasting corrosion resistance through inorganic salt hole sealing.

The invention belongs to the technical field of ceramic materials, and particularly discloses a preparation method of barium titanate powder, which comprises the following steps: mixing a barium salt solution and a rare earth salt solution to obtain a mixed solution; mixing the mixed solution, a titanium source solution and bacterial cellulose to obtain a barium titanate precursor; and sintering the barium titanate precursor to obtain the barium titanate powder. According to the preparation method, the bacterial cellulose is used as a template, rare earth elements are introduced for doping, the superfine high-purity tetragonal-phase nano barium titanate powder is formed through calcination at low temperature, used reaction equipment is simple, the process is stable, self-polymerization can be achieved without heating, energy consumption is low, and efficiency is high; wherein the unique three-dimensional network of the bacterial cellulose is barium titanate reaction confinement, and the problem of abnormal grain growth caused by infinite confinement of a traditional liquid phase method is solved; the rare earth elements are doped to generate lattice distortion, so that the conversion temperature of the tetragonal phase is reduced, and the energy consumption in the calcination stage is greatly reduced.

The invention discloses a method for recovering tin from low-concentration complex tin-containing waste liquid. According to the method, tin is enriched into a tin-rich slag product through neutralization precipitation, oxidation transformation, tin selection alkaline leaching, barium salt arsenic removal and neutralization tin precipitation, and tellurium is enriched in leaching slag obtained after tin leaching. The method solves the problems of low arsenic / tin separation efficiency, large tin and tellurium loss and environmental pollution in the traditional process, no toxic gas is generated in the whole process, the tin content in the obtained tin-rich slag is larger than or equal to 50 wt%, and the tin recovery rate is larger than or equal to 90%. The method is suitable for recycling and innocent treatment of multiple metals in smelting wastewater and electronic waste recovery liquid.

This invention discloses a method for preparing a hollow fibrous barium ferrite, specifically in the field of composite materials. The method comprises three steps: First, polyvinylpyrrolidone is dissolved in a polar solvent and stirred until completely dissolved. A soluble barium salt, a soluble iron salt, and citric acid are then added in proportion to prepare a spinning precursor sol. Second, the spinning precursor sol is extruded through an injection device, with an air source flow at the outlet to blow the sol into filaments, which are then collected to obtain a barium ferrite precursor fiber sponge. Third, the barium ferrite precursor fiber sponge is heated and sintered until fully sintered, and then naturally cooled to obtain the hollow fibrous barium ferrite. The hollow barium ferrite synthesized by this invention achieves adjustable grain configuration and macroscopic hollow structure. Its impedance matching performance and electromagnetic wave attenuation characteristics are good, making it suitable for applications in high-density perpendicular magnetic recording materials, microwave devices, and microwave absorbing materials.

The present application relates to a kind of barium-doped carbon-supported iron nanoparticle materials and its preparation method and application in catalytic ammonia pyrolysis hydrogen production, the barium-doped carbon-supported iron nanoparticle material is obtained by mixing the iron-based carbon material that organic iron is uniformly dispersed in phenol formaldehyde resin after carbonization with barium salt solution, freeze-drying and calcination again, iron nanoparticles are uniformly distributed on the surface and inside of the barium-doped carbon-supported iron nanoparticle material, and barium element is uniformly dispersed on the surface of the barium-doped carbon-supported iron nanoparticle material.The barium-doped carbon-supported iron nanoparticle material provided by the present application has good catalytic ammonia pyrolysis hydrogen production performance, and the conversion efficiency of ammonia gas reaches more than 90% under the condition of 550 DEG C, space velocity 6000h ‑1 , and the cost is low, and it has good industrial application prospect.

The utility model relates to the technical field of cosmetic preparation, in particular to a spherical barium sulfate reaction device for preparing cosmetics, which comprises a reaction tank, the upper part of the outer surface of the reaction tank is fixedly connected with a bottom plate and a fixed plate, the bottom plate is positioned on the lower side of the fixed plate, and the rear part of the upper end of the reaction tank is fixedly connected with a connecting plate; a control mechanism is installed at the lower end of the fixing plate in a penetrating mode, the lower end of the control mechanism is fixedly connected with the upper end of the bottom plate, a sulfuric acid feeding pipe and first control valves are fixedly connected to the right portion of the upper end of the reaction tank, and the first control valves are movably installed on the lower portion of the outer surface of the sulfuric acid feeding pipe and the lower portion of the outer surface of a barium salt feeding pipe in a penetrating mode; a discharging assembly is fixedly connected to the lower part of the outer surface of the reaction tank in a penetrating manner. According to the reaction device for preparing spherical barium sulfate for cosmetics, the stirring assembly is driven by the control mechanism to work to stir reaction liquid, so that sufficient contact reaction of sulfuric acid and barium salt is ensured, and the reaction efficiency is improved.