63 results about "Barium salt" patented technology

The invention provides an impurity removal and recovery method of electrodeposited nickel anolyte, which comprises the following steps: (1) mixing the electrodeposited nickel anolyte with liquid caustic soda, carrying out solid-liquid separation to obtain nickel hydroxide and filtrate, and evaporating the filtrate to obtain sodium sulfate; mixing the electrodeposited nickel anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution with barium salt, and carrying out lead removal treatment; (3) adjusting the pH value of a material obtained after lead removal treatment by using nickel hydroxide to obtain a solution to be subjected to arsenic removal, and mixing the solution to be subjected to arsenic removal with polyferric sulfate for arsenic removal treatment; and (4) a material obtained after arsenic removal treatment is mixed with an oxidizing agent, a solution to be subjected to iron removal is obtained, solid-liquid separation treatment is conducted on the solution to be subjected to iron removal, catholyte with lead, arsenic and iron removed and iron-containing slag are obtained, sodium sulfate is supplemented into the catholyte with lead, arsenic and iron removed, and the catholyte is reused in the nickel electrodeposition process. According to the method, lead, arsenic and iron in the electrodeposited nickel anolyte can be efficiently and rapidly removed and recycled.

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.

The invention provides a barium slag harmless treatment method which comprises the following steps: mixing barium slag and desulfurized waste gypsum, adding water, beating into slurry, adding diluted industrial acid, stirring, acidifying, and heating, so that most of barium in the slurry forms BaSO4; adding a coupling agent, stirring, and carrying out coupling and competitive coordination reaction with free barium ions and barium salt in the product; adding a sulfate solution, and carrying out double decomposition reaction with the chelate barium to generate a non-toxic BaSO4 precipitate; and adding a ferrous sulfate solution to combine the rest of ferrous ions and sulfur ions in the product to form an iron sulfide precipitate, carrying out filter pressing to obtain filter residues with the water content of 20-30%, and drying. According to the method, toxic metal barium in the barium slag can be converted into nontoxic barium sulfate, and sulfur ions are converted into stable ferric sulfate, so that the barium ions, sulfide and corrosive pH value in the treated product all reach the national general solid waste first-class slag standard. The invention also provides an application of the barium slag treated by the method in building and building material industries.

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 present invention discloses a graded extraction method for barium toxic substances and its application, which belongs to the field of chemical detection technology. The present invention utilizes a graded extraction method to extract and separate acid-soluble barium in rock cuttings samples, thereby avoiding this part of barium from combining with other substances in the subsequent detection process and reducing the accuracy of the detection; utilizing a composite carbon thermal reduction technology, the barium sulfate in the rock cuttings is reduced and converted into barium chloride detectable by ICP-OES, while the sulfate ions are reduced to soluble sulfides, and no oxidizing agents such as nitric acid are used in the subsequent extraction method, thereby avoiding the sulfide being further oxidized to sulfate ions and reducing the detection accuracy of barium. The graded extraction method of the present invention can separate barium salts of different toxicities in the sample, and realize quantitative analysis and detection of barium toxic substances of different toxicities in the sample.

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%.

Barite (barium sulfate) scale may be a problem in subterranean formations, wellbores, pipelines and other locations, and may be difficult to remove in many cases. An aqueous fluid composition effective to remove barite scale may include a concentrated mineral acid, a first salt including an iodide anion, and a second salt including an anion that forms a water-soluble barium salt. A suitable aqueous fluid composition may include concentrated hydriodic acid, an alkali metal iodide, and an alkali metal hypophosphite. The aqueous fluid composition may be used in combination with a second treatment stage comprising a fluid composition comprising at least one acid gas trapping agent. The at least one acid gas trapping agent may comprise a first component reactive to hydrogen sulfide and optionally a second component reactive to carbon dioxide.

The present invention relates to the technical field of barium carbonate, and specifically proposes a method for preparing electronic-grade barium carbonate, comprising: mixing a barium salt solution with a carbonate solution, and performing a double decomposition reaction; during the double decomposition reaction, periodically adjusting the pH value of the reaction system so that it fluctuates within the range of 6.0-9.0, with a fluctuation period of 10-60 min, a fluctuation cycle number of not less than 2 times, and a fluctuation being a process in which the pH value is adjusted from a minimum value to a maximum value and then adjusted to a minimum value; after the reaction is completed, solid-liquid separation, washing, drying, and electronic-grade barium carbonate are obtained. The present application adopts a dynamic pH oscillation method, which significantly improves the purity and morphology control level of electronic-grade barium carbonate. Dynamic pH fluctuations interfere with the growth of crystal nuclei without the need for growth, making it easier for crystal nuclei to form crystalline spherical or cubic particles, with a higher size concentration, substantially no additional impurities are introduced, and the post-processing steps are simple and efficient, with good application prospects.

Processes for the recovery or purification of lithium species from various sources are described. Such sources include natural sources or deposits, such as in mining applications, and synthetic or non-natural sources, such as in the recycling of lithium species from batteries. In embodiments, the process comprises treating a Li2SO4-comprising aqueous solution with one or more barium salts to form a precipitate comprising barium sulfate (BaSO4). In embodiments, the processes may further comprise the preparation of a lithium sulfate-containing solution via treatment of the starting material or mixture with sulfuric acid. In embodiments, further treatments may be performed, for example prior to and / or subsequent to treatment with one or more barium salts, for example for initial or further sulfate removal, and / or removal of other metal species that may be present. The recovered lithium species be used directly, or converted into other forms, for use in a variety of applications.

The present invention is applicable to the technical field of electrocatalytic water decomposition, and provides a barium-modified iron oxyhydroxide, a preparation method thereof, and an application thereof. The preparation method comprises: growing a barium-modified iron oxyhydroxide nanosheet array on a metal foam substrate having a porous structure by a hydrothermal method. The specific steps comprise placing a metal foam having a large specific surface area in a polytetrafluoroethylene reactor, adding a mixed solution containing urea, ammonium fluoride, iron salt, and barium salt, and performing a hydrothermal reaction to obtain a barium-modified iron oxyhydroxide nanosheet array. The present invention utilizes a one-step hydrothermal method to grow a barium-modified iron oxyhydroxide nanosheet array on a metal foam substrate. The method is simple and efficient. Furthermore, the barium-modified iron oxyhydroxide nanosheet array is used as a neutral water oxidation electrode, which has abundant active sites and a unique electronic structure, and exhibits excellent neutral water electrolysis catalytic activity and stability.

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.

The invention relates to the technical field of barium carbonate, and particularly provides a preparation method of electronic-grade barium carbonate, which comprises the following steps: mixing a barium salt solution with a carbonate solution for double decomposition reaction; in the metathesis reaction process, the pH value of the reaction system is periodically adjusted to fluctuate in the range of 6.0-9.0, the one-time fluctuation period is 10-60 min, the fluctuation cycle is not less than 2 times, and the one-time fluctuation is the process that the pH value is adjusted to the maximum value from the minimum value and then adjusted to the minimum value; and after the reaction is finished, carrying out solid-liquid separation, washing and drying to obtain the electronic-grade barium carbonate. According to the method, a dynamic pH oscillation mode is adopted, the purity and morphology control level of electronic-grade barium carbonate are remarkably improved, dynamic pH fluctuation interferes crystal nucleuses without growth, the crystal nucleuses are easier to form crystalline spherical or cubic particles, the size concentration degree is higher, extra impurities are basically not introduced, the post-treatment steps are simple and efficient, and the method is suitable for industrial production. Good application prospects are realized.

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.

An asbestos-free friction material composition and related brake pads for vehicles, comprising organic and / or inorganic and / or metallic fibers, at least a binder, at least a friction modifier or lubricant, at least a filler or abrasive, and at least soluble salts of barium and / or calcium and / or aluminum and / or silver in a proportion of between 0.5 and 10% by weight, of which barium carbonate, calcium hydroxide, aluminum triacetate, and silver acetate are preferred.

The application belongs to the technical field of nano ceramic powder preparation, discloses a calcium-doped barium titanate powder and a preparation method and application thereof, and aims to solve the technical problems of needing a mineralizer in the preparation process of the calcium-doped barium titanate powder, large particle size of the prepared powder, uneven element doping, poor dispersibility and low tetragonal phase content. The steps are as follows: (1) preparing a barium salt solution containing a calcium source; (2) taking anatase titanium dioxide obtained by calcining titanium nanotubes as a titanium source, and adding the titanium source into the barium salt solution containing the calcium source to obtain a calcium-doped barium titanate precursor solution; (3) performing hydrothermal reaction on the precursor solution; (4) performing filtration, washing, drying and grinding to obtain the calcium-doped barium titanate powder. The calcium-doped barium titanate powder prepared by the application has the characteristics of small particle size, narrow distribution, good dispersibility and high tetragonal phase content. Meanwhile, the reaction can avoid using a large amount of mineralizer, the method has low cost, good safety, simple process, can realize large-scale production of the powder, and meets the development requirements of subsequent high-temperature, thin-layer multi-layer ceramic capacitor products.

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 discloses a method for purifying 4-acetylbenzoic acid, wherein 4-acetylbenzoic acid crude product, water and alkali are added to a reaction vessel, stirred and dissolved, and pH is adjusted to alkaline; an aqueous solution of calcium halide or barium halide is added thereto, solid is precipitated by stirring, and 4-acetylbenzoic acid calcium salt or 4-acetylbenzoic acid barium salt is filtered to obtain; 4-acetylbenzoic acid calcium salt or 4-acetylbenzoic acid barium salt is added to water, acid is added dropwise to adjust pH to acidity, filtered, and filtration cakes are dried to obtain purified 4-acetylbenzoic acid. The method of the present invention can more easily obtain highly purified 4-acetylbenzoic acid, and greatly improves the purity of 4-acetylbenzoic acid, has simple process operation, low equipment requirements, low cost of raw materials used, high product yield, high purity, and is easy to industrialized production.

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.

This raw material solution is for use in production of an oxide superconducting material using a coating pyrolysis method. The raw material solution contains, as a solute, a carboxylic acid rare earth salt, a carboxylic acid barium salt, and a carboxylic acid copper salt, and contains, as a solvent, water, an alcohol having 1-4 carbon atoms, and a carboxylic acid having 1-4 carbon atoms. In the solvent, the water is contained in an amount of 0.01-35 vol%, the alcohol is contained in an amount of 45-99.99 vol%, and the carboxylic acid is contained in an amount of 20 vol% or less.

The present invention relates to a novel method for manufacturing a diaphragm, comprising the following steps: 1) dissolving a soluble barium salt in deionized water, then mixing and stirring with a binder to obtain slurry A; 2) dissolving a soluble sulfate in deionized water to obtain solution B; 3) applying slurry A to the surface of a porous substrate by roller coating, followed by spraying solution B. The sprayed porous substrate is then cured, washed, and dried to obtain the diaphragm. This invention improves the coating process for the inorganic porous layer, resolving the technical challenge of dispersing nano-inorganic materials within the coating material, enhancing the homogeneity of the coating layer, and contributing to improved quality and stability of the diaphragm.

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.