53 results about "Chromic salt" patented technology

The application provides a one-dimensional high-entropy alloy, a preparation method and application of the one-dimensional high-entropy alloy in CO2 ring addition reaction, and relates to the technical field of high-entropy alloys.The molar ratio of iron salt, cobalt salt, nickel salt, manganese salt, chromium salt and cerium salt in the one-dimensional high-entropy alloy is 1:1:1:1:1:1;the high-entropy alloy has a fiber structure, the fiber has a hierarchical pore structure which is interconnected, including macropores or mesopores formed by decomposition of the self-sacrificing template 1, and mesopores or micropores formed by decomposition of the self-sacrificing template 2.Through improvement of the process conditions, the one-dimensional high-entropy alloy material with a unique structure can be prepared under relatively mild conditions, so that the whole reaction process is safer and more economical, and meets the goal of green chemistry and sustainable development.Meanwhile, the one-dimensional high-entropy alloy material prepared provides a large specific surface area, fully exposes active sites, and can realize efficient and stable conversion of the carbon dioxide ring addition reaction.

The invention discloses a chromium-free and formaldehyde-free synergistic tanning method for high-flexibility ecological Tan sheep skin, which comprises the following steps: firstly, pre-tanning the Tan sheep skin by using a 6-10g / L biomass-based aldehyde tanning agent, and then carrying out zirconium tanning and synergistic tanning to obtain chromium-free and formaldehyde-free tanned Tan sheep skin. The bio-based aldehyde tanning agent is prepared through selective oxidation of glycerin, the structure of the bio-based aldehyde tanning agent contains aldehyde groups and hydroxyl groups, polyglyceraldehyde with a long-chain structure can be formed through polymerization by adjusting the pH value, and then the polyglyceraldehyde is covalently cross-linked with collagen amino groups; the introduction of the zirconium tanning agent not only can be complexed with collagen carboxyl, but also can be coordinated with hydroxyl on the structure of the biomass-based aldehyde tanning agent to form a multi-point cross-linked network, so that the flexibility and damp-heat resistance stability of the Tibet lamb skin are remarkably improved, and meanwhile, the health and environmental risks caused by chromium salt and formaldehyde are thoroughly eliminated.

The invention discloses a preparation method of ethylhexyl palmitate, and relates to the technical field of ethylhexyl palmitate. According to the method, firstly, isooctanol is gasified and then introduced into a methyl palmitate solution, ethylhexyl palmitate is prepared through transesterification, gaseous feeding can improve the instantaneous concentration of alcohol in a liquid phase, the reaction is promoted to be carried out in the positive direction, the reaction rate is increased, meanwhile, methanol generated through the transesterification method can be gasified and taken out of a system, and the yield of ethylhexyl palmitate is increased. Forward proceeding of the reaction is further promoted, so that the reaction is more thorough; secondly, chromium salt is used as a metal source precursor and a 2-sulfo-4, 4 '-biphenyldicarboxylic acid ligand to synthesize a catalyst, a biphenyl group in the ligand provides rigid and hydrophobic large pore channels and provides a local high-concentration reaction environment, gaseous isooctanol can be easily diffused into the pore channels of the catalyst and is in contact with enriched methyl palmitate, and the reaction efficiency is improved; and sulfonic acid groups uniformly distributed in the ligand serve as solid superacid, strong acid sites are provided, and the production efficiency is improved.

The invention discloses a method for preparing benzyl borate compounds through chromium catalysis, and belongs to the technical field of organic synthesis. According to the method, aryl carboxylic ester is taken as a raw material, pinacolborane is taken as a boron source and a hydrogen source, metal chromium salt is taken as a catalyst, a specific ligand and elemental magnesium are added, and reaction is performed in a tetrahydrofuran solvent, so that the deoxidation boronization reaction of the aryl carboxylic ester is realized. Benzyl monoborate or benzyl subunit diborate can be selectively prepared through ligand regulation and control. The method has the advantages of mild reaction conditions, cheap catalyst, wide raw material source, simple operation and good chemical selectivity.

The application relates to the technical field of long-afterglow materials, and particularly provides a preparation method of a near-infrared long-afterglow luminescent nano probe and application thereof. The preparation method of the near-infrared long-afterglow luminescent nano probe comprises the following steps: dissolving water-soluble zinc salt, water-soluble tin salt, water-soluble gallium salt, water-soluble chromium salt and water-soluble yttrium salt in water to prepare a metal mixed solution with a salt concentration of 0.1-2 mol / L; adding mesoporous silica powder into the metal mixed solution, uniformly dispersing, stirring for 30 min-48 hours, adding an alkaline precipitant drop by drop until the pH is 8-10, collecting the precipitate, drying, high-temperature calcining, and obtaining doped particles; and coating manganese dioxide on the surface of the doped particles, and the near-infrared long-afterglow luminescent nano probe has the characteristics of slow afterglow decay.

The invention is suitable for the technical field of electrochemical catalysts, and provides a preparation method and application of an MOF-derived NiCr2O4 (at) C catalyst, and the method comprises the following steps: mixing nickel salt, chromium salt and terephthalic acid in a solvent to form a mixed solution; wherein the molar ratio of the nickel salt to the chromium salt is (1-2): 1; carrying out solvothermal reaction on the obtained mixed solution at 120-160 DEG C for 6-18 hours, and washing and drying a reaction product to obtain a NiCr-MOF precursor; and carrying out heat treatment on the NiCr-MOF precursor in an inert atmosphere at 450-650 DEG C for 1-3 hours to obtain the NiCr2O4-C catalyst. The obtained catalyst has an MOF-derived porous carbon composite structure, shows about 100% H2O2 selectivity, high catalytic activity and excellent stability in alkaline electrolyte, is simple in preparation method and good in repeatability, and provides a high-performance and low-cost solution for green electrosynthesis of hydrogen peroxide.

The invention relates to a hollow high-entropy transition metal hydroxide crystal and a preparation method thereof. The preparation method comprises the following steps: providing a cuprous oxide crystal; the preparation method comprises the following steps: respectively adding a nickel salt precursor, a cobalt salt precursor, a chromium salt precursor, a manganese salt and / or iron salt precursor and cuprous oxide crystals into an ethanol / water mixed solvent to prepare uniformly dispersed suspension liquid; adding polyvinylpyrrolidone into the suspension, and fully mixing to obtain a mixed solution; and dropwise adding a reactant containing thiosulfate radicals into the mixed solution, reacting, and separating to obtain the hollow high-entropy transition metal hydroxide crystal. The method is simple in process, mild in condition, short in reaction time, low in requirement for precision of equipment and instruments, high in controllability of product morphology, good in repeatability and especially suitable for large-scale industrial production.

The application provides a metal-carbon skeleton nano-microparticle and a preparation method thereof, and belongs to the field of nanometer material preparation, wherein the metal-carbon skeleton nano-microparticle is prepared from raw materials through a solvothermal reaction; the raw materials comprise, in percentage by mass, 3-15% of polymerizable monomers, 0.05-1.5% of initiators, 0.01-1.5% of metal salts and the balance of solvents; the active functional groups of the polymerizable monomers comprise nitrogen and / or oxygen; and the metal salts comprise at least one of aluminum salts, zirconium salts, chromium salts and zinc salts. The application uses metal ions and organic precursors containing active groups as raw materials, realizes controllable adjustment of the particle size of the nano-microparticles in the range of 1-5000 nanometers through metal crosslinking, induced nucleation and in-situ carbonization processes. The preparation process of the application is simple and controllable, the obtained nano-microparticles are uniform in size, stable in structure, high in temperature resistance and salt resistance, and can be widely applied in the fields of catalysis, sensing or oil displacement.

The invention provides an inorganic antioxidant carbon-coated nickel-chromium catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: uniformly mixing nickel salt, chromium salt and a carbon source to obtain a precursor; the molar ratio of the nickel element to the chromium element is (1: 1)-(5: 1); the carbon source is selected from one or more of citric acid, tartaric acid, nitrilotriacetic acid, malic acid, ethylenediamine tetraacetic acid and ethylenediamine tetraacetic acid sodium salt; and pyrolyzing the precursor in an inert atmosphere to obtain the carbon-coated nickel-chromium catalyst. According to the method, a chromium element is introduced and carbonized in an inert atmosphere to form a Ni-Cr metal / oxide-carbon coated integrated structure, an inorganic anti-oxidation system taking a Cr oxygen-containing phase and a carbon shell as a core is constructed, and the anti-oxidation capability and the structural stability of metal Ni under air and oxygen-containing conditions are improved on the premise of not depending on an organic ligand or an organic coating layer; the catalyst is especially suitable for hydrogenation reaction of styrene and other aromatic olefins.

The application relates to the technical field of electroplating, and discloses a chromium electroplating process for improving the hardness of a connector terminal, which comprises the following steps: performing surface pretreatment on the connector terminal, removing surface impurities through ultrasonic cleaning and micro-etching treatment; performing heating treatment on the connector terminal; performing electroplating treatment on the connector terminal by using an electroplating solution comprising trivalent chromium salt, boron nitride nanoparticles, ferroferric oxide nanoparticles, nickel ions, sodium dichromate and chromium alloy additives, so as to form a chromium plating layer; performing passivation treatment on the plating layer; performing low-temperature treatment on the plating layer; and spraying a protective layer on the chromium plating layer. Through the trivalent chromium salt and the sodium dichromate, the trivalent chromium salt is used to reduce hexavalent chromium ions into trivalent chromium, the toxicity of the hexavalent chromium is reduced, the sodium dichromate is used to provide a stable chromium source, the deposition of chromium elements in the electroplating process is ensured, the pollution of hexavalent chromium to the environment and the harm of hexavalent chromium to the health of operators are solved, and the environmental protection and safety of the electroplating process are improved.

This invention discloses a copper-chromium catalyst, its preparation method, and its application. The preparation method of the catalyst includes: (1) mixing polylactic acid with dichloromethane and ethanol to obtain a polymer solution, adding a soluble copper salt to it, stirring, and obtaining a spinning solution; (2) using a coaxial electrospinning nozzle to perform electrospinning with the obtained spinning solution, and collecting the obtained solid; (3) placing the obtained solid in an ethanol solution of trimesic acid to react, washing and drying after the reaction, and collecting the obtained solid; (4) dissolving a soluble chromium salt in ethanol and reacting it with the obtained solid, then washing and drying, and collecting the obtained catalyst precursor; (5) calcining the obtained catalyst precursor to obtain an unformed catalyst, then pressing it into tablets to obtain the copper-chromium catalyst. This catalyst can improve the conversion rate and selectivity of the catalyst in the hydrogenation of dimethyl maleate to prepare 1,4-butanediol and co-production of γ-butyrolactone and tetrahydrofuran.

The invention relates to the technical field of metal surface treatment, in particular to a magnesium alloy surface composite film and a preparation method thereof. The invention provides a preparation method of a magnesium alloy surface composite film. The preparation method comprises the following steps that a magnesium alloy matrix is sequentially subjected to surface degreasing, acid pickling activation, first passivation through a first passivator, second passivation through a second passivator and hole sealing treatment; wherein the first passivating agent comprises the following components in percentage by mass: 2%-8% of trivalent chromium salt, 0.5%-5% of rare earth salt, 0.5%-2% of sodium fluoride and 1%-3% of citric acid; the second passivator comprises the following components in percentage by mass: 3-10% of trivalent chromium salt, 1-5% of rare earth salt, 1-5% of sodium silicate, 0.5-2% of sodium nitrate and 1-3% of citric acid; the problem that corrosion resistance is poor due to the fact that a magnesium alloy passivation surface treatment film is poor in compactness and high in porosity is solved.

The invention discloses a preparation method of an iron-based catalyst for synthesizing 2, 3, 6-tricresol, and belongs to the technical field of chemical catalysts. According to the method, aiming at the problems of long ammonia water dripping time, long aging time, multiple washing times, large wastewater discharge amount and the like in a traditional process, the ammonia water dripping time is shortened to 3-5 hours, the aging time is compressed to 10-12 hours, the washing end-point conductivity is improved to 1500-2000 [mu] S / cm, and the washing times are reduced to 3-5 times by optimizing precipitation reaction kinetic parameters. The preparation method comprises the following steps: mixing ferric salt, chromium salt, indium salt and sodium silicate according to a molar ratio of 100: (0.5-5): (1-10): (1-10), dissolving with deionized water at 60 DEG C, dropwise adding ammonia water with the mass concentration of 10-20% under a stirring condition until the pH is 8-9, aging, carrying out filter pressing, washing, drying and calcining. According to the method, the production period is remarkably shortened to 13-18 hours, the energy consumption is reduced by 50%, the wastewater discharge is reduced, meanwhile, the conversion rate of the catalyst in the reaction for synthesizing the 2, 3, 6-tricresol reaches 99% or above, and the selectivity is kept to be 95% or above.

The invention relates to the technical field of methane catalytic oxidation, in particular to a methane-poor gas catalyst and a preparation method and application thereof.The preparation method comprises the steps that S1, nickel salt, ferric salt, chromium salt and water are mixed, and a mixed solution is obtained; s2, mixing the mixed solution, a precipitant and water, stirring, co-precipitating, aging and drying to obtain an aged product; and S3, calcining the aged product in a mixed atmosphere to obtain the methane-poor gas catalyst. The methane-poor gas catalyst obtained by the preparation method disclosed by the invention can realize 50% of methane conversion rate at 250 DEG C and 90% of conversion rate at 410 DEG C under the condition of not containing noble metal, and has excellent low-temperature catalytic activity. For the methane-poor gas with the volume concentration smaller than 1%, the activity is high in the low-temperature section (150-550 DEG C), the methane removal rate is high, and almost all the gas is converted into CO2 with the relatively low greenhouse effect after the reaction.

The invention provides an aqueous zinc ion battery interface protection material, a preparation method thereof and an application of the aqueous zinc ion battery interface protection material in negative electrode interface regulation and control. The preparation method of the water-based zinc ion battery interface protection material comprises the following steps: adding a copper salt, a manganese salt, a cobalt salt, a zinc salt and a chromium salt into water, dissolving, adding glycine, uniformly stirring, and roasting twice to obtain the water-based zinc ion battery interface protection material. The preparation method of the water-based zinc ion battery interface protection material is simple in preparation process, low in preparation cost, mild in condition and free of environmental pollution. The electrode interface protection material with large specific surface area, high porosity and high stability can be obtained through an economical and efficient method, the obtained interface protection material is used for zinc negative electrode interface modification, zinc dendritic crystal growth, hydrogen evolution and corrosion can be inhibited, and therefore the problems of a negative electrode are solved.

The application relates to the technical field of inorganic pigments and chrome salt fine chemicals, and discloses a preparation method of superfine chromium oxide green based on airflow crushing and purification modification, wherein the crude chromium oxide green is prepared from sodium bichromate, the particle size is precisely regulated through fluidized bed airflow crushing, D50 is less than 0.8 microns, D90 is less than 1.30 microns, and the particle size concentration degree is high; residual chromium is simultaneously reduced, the crystal form is optimized, the color, dispersibility, compatibility and weather resistance are improved, the product has high purity, the residual chromium reaches the standard, the crystal form is complete, is suitable for high-end pigments, functional materials and industrial manufacturing, the process is stable and can be scaled up, and the pain points of traditional products, such as wide particle size, high residual chromium, poor dispersibility and poor color, are solved.

The invention provides electroplating liquid of an electrochemical deposition trivalent chromium coating doped with rare earth elements, a preparation method and a use method of the electroplating liquid and a bathroom product. The electroplating liquid comprises the following components in parts by mass: 1000 parts of water, 20-60 parts of trivalent chromium salt, 0.1-1 part of a rare earth element doping agent, 0.5-5 parts of a transition metal element doping agent, 50-80 parts of a complexing agent, 40-75 parts of conductive salt, 30-60 parts of boric acid, 1-5 parts of a metal cation blackening agent and 0.5-2 parts of a nonionic surfactant. A chromium layer obtained by electroplating a product through the electroplating liquid remarkably improves the corrosion resistance of the product.

The application discloses a porous chromium-based composite denitration catalyst and a preparation method and application thereof, and belongs to the technical field of denitration catalyst preparation. The preparation method of the porous chromium-based composite denitration catalyst is as follows: a chromium salt, an organic ligand and an Anderson-type polyoxometalate are dissolved in water to perform a hydrothermal reaction to obtain a precursor; wherein the Anderson-type polyoxometalate is selected from one or more of (NH4)4[NiMo6O 24 H6]·5H2O, (NH4)3[CoMo6O 24 H6]·7H2O or (NH4)3[FeMo6O 24 H6]·6H2O; and the precursor is calcined, and the porous chromium-based composite denitration catalyst is obtained. Compared with a single MOF porous chromium-based catalyst, the denitration efficiency of the porous chromium-based composite denitration catalyst can be increased by more than 90%. Meanwhile, the preparation method is simple, easy to control, low in requirement on a synthesis device, can save the amount of active components, reduces the production cost of the catalyst in an all-round way, and is suitable for large-scale industrial production.

The application provides a Li3Al 1‑x M x The application provides a high-nickel layered oxide positive electrode material coated with a F6 layer and a preparation method, wherein the high-nickel layered oxide is LiNi x1 Co y1 Mn 1‑x1‑y1 O2, M is one or more of Mg, Fe, Cr, La, Ce and Y, 0 < x ≤ 0.1, and the coating layer has high conductivity; in the preparation, the high-nickel layered oxide powder is added into a mixed aqueous solution of metal salt, lithium salt, ammonium fluoride and aluminum salt, the molar ratio of the lithium salt, the ammonium fluoride and the aluminum salt is 3:6:(0.9-1), the metal salt is one or more of magnesium salt, iron salt, chromium salt, lanthanum salt, cerium salt and yttrium salt, the mixed system is stirred, and then centrifuged and dried in sequence to obtain a precursor; the precursor is subjected to high-temperature calcination treatment at 300-800 DEG C under a protective atmosphere, and the electrochemical performance of the high-nickel layered oxide of the high-nickel ternary lithium ion battery positive electrode material under high pressure can be improved.

The application discloses a preparation method of cis-1-chloro-2,3,3-trifluoropropene and belongs to the technical field of organic synthesis. The method is characterized in that: firstly, a mixed slurry is prepared by using a soluble aluminum salt, a soluble chromium salt, a soluble zinc salt, a surfactant and water as raw materials; the mixed slurry is dried, calcined and fluorinated to obtain a Cr / Al / Zn fluorination catalyst; and then, under the action of the Cr / Al / Zn fluorination catalyst, gas-phase fluorination reaction is carried out by using 1,1,2,3,3-pentachloropropane and hydrogen fluoride gas as reaction raw materials to obtain cis-1-chloro-2,3,3-trifluoropropene. The method is simple and efficient, the reaction is carried out under the action of a specific catalyst, the selectivity of the product is high, the conversion rate of the raw material is high, the method is green and environment-friendly, and less "three wastes" are generated.

The invention discloses a catalyst for aniline alkylation and a preparation method, and belongs to the technical field of catalysts. The preparation method of the catalyst comprises the following steps: roasting a catalyst carrier precursor, and adding desalted water into a roasted product to prepare slurry; preparing a mixed solution of copper salt, zinc salt and chromium salt; additionally preparing an alkali solution; adding a metal salt mixed solution and an alkaline solution into the slurry, carrying out a co-precipitation reaction, and then aging; repeatedly filtering and pulping the aged slurry to obtain a catalyst precipitation filter cake; and drying, forming and calcining to obtain the catalyst. The invention also discloses the catalyst for aniline alkylation, which is prepared by the method. The catalyst provided by the invention can realize concerted catalysis of aniline alkylation and methanol steam cracking in a single reactor, methanol and aniline are taken as raw materials, N-methylaniline is synthesized with high selectivity, high-purity hydrogen is co-produced, and no wastewater is discharged in the reaction process.

The invention provides a preparation method of a positive electrode substrate modified material and a zinc-manganese battery, and belongs to the field of battery materials. The invention provides a preparation method of a positive electrode material, which comprises the following steps: dipping carbon cloth in a chromium salt solution, and drying to obtain chromium salt-loaded carbon cloth; and heating the carbon cloth loaded with the chromium salt by using a Joule heat technology, and generating chromium oxide from the chromium salt to obtain the positive electrode material. According to the prepared positive electrode material, the conductivity and stability of the carbon cloth are improved, and the active sites of the carbon cloth are increased.

The application provides a purification method of a chromium-containing mixed salt, the mixed salt comprising sodium carbonate, sodium bromide and a heavy metal chromium compound, in the method, a high-purity sodium bromide aqueous solution is prepared from the mixed salt and chromium salt is recovered, and the method comprises the following steps: preparing a crude sodium bromide solution, preparing a chromium removal agent by using a barium compound or a calcium compound, removing chromium from the crude sodium bromide solution by using the chromium removal agent and collecting a filtrate A; and treating the filtrate A to obtain a high-purity sodium bromide aqueous solution. In the method, the sodium carbonate in the crude sodium bromide solution is all converted into sodium bromide; by using the method, the chromium in the sodium bromide is removed and converted into barium chromate or calcium chromate products; the obtained sodium bromide no longer contains the heavy metal chromium and can be directly used for preparing high-purity sodium bromide or preparing a sodium bromide aqueous solution.

The invention provides nano-micron particles of a metal-carbon skeleton structure and a preparation method of the nano-micron particles, and belongs to the field of nano material preparation, and the nano-micron particles of the metal-carbon skeleton structure are prepared from preparation raw materials through solvothermal reaction; the preparation raw materials comprise, by mass, 3%-15% of a polymerizable monomer, 0.05%-1.5% of an initiator, 0.01%-1.5% of a metal salt and the balance a solvent; active functional groups of the polymerizable monomer comprise nitrogen and / or oxygen; the metal salt comprises at least one of aluminum salt, zirconium salt, chromium salt and zinc salt. According to the preparation method, metal ions and an organic precursor containing active groups are taken as raw materials, and controllable adjustment of the particle size of nano-micron particles within the range of 1-5000 nanometers is realized through metal crosslinking, induced nucleation and in-situ carbonization processes. The preparation process is simple and controllable, and the obtained nano-micron particles are uniform in size, stable in structure and high in temperature resistance and salt resistance and can be widely applied to the fields of catalysis, sensing or oil displacement and the like.

The invention discloses a CrFeCoNiCuZnS six-membered single-phase high-entropy sulfide photocatalytic material, a preparation method thereof and application of the photocatalytic material in treatment of uranium-containing wastewater, the preparation method of the photocatalytic material comprises the following steps: (1) adding metal salts into a solvent, and stirring to form a uniform metal salt solution, the metal salts comprising a chromium salt, an iron salt, a cobalt salt, a nickel salt, a copper salt and a zinc salt; (2) adding a sulfur source and other additives into the metal salt solution, and stirring to form a mixed solution; and (3) carrying out nitrogen plasma treatment on the mixed solution to obtain a precursor solution, then heating the precursor solution, and after heating, naturally cooling, washing and drying to obtain the composite material. According to the invention, the CrFeCoNiCuZnS six-element high-entropy system is constructed to realize division and cooperation of active site functions and series coupling of an adsorption-catalysis process, so that efficient, high-selectivity and stable photocatalytic separation of uranyl ions in a complex water environment is realized.

The application discloses a method for in-situ transformation and chromium removal of aluminum mud in chromium salt production, and belongs to the field of chromium-containing aluminum mud resource utilization, and solves the problems of harsh process conditions, low recovery rate and difficult chromium removal in the utilization method of the chromium-containing aluminum mud.The method comprises the following steps: adding a sodium chromate alkaline solution into a reaction kettle, spraying a sodium chromate solution from the top of the reaction kettle, continuously stirring, and keeping the reaction temperature at 80-90 DEG C; keeping the pH value of the reaction slurry at 9-9.5, continuously discharging from the bottom of the reaction kettle, realizing continuous production, washing the product after filtration and separation, and obtaining the chromium-containing aluminum mud; and washing the chromium-containing aluminum mud three times by using a sodium hydroxide solution to obtain the aluminum mud after chromium removal.The application utilizes the reaction between the alkali and the chromium-containing aluminum mud by using the in-situ chemical conversion method, deeply removes the hexavalent chromium in the aluminum mud, and prepares qualified aluminum hydroxide, so that the defects of the traditional method, such as complicated process, low product quality and long production cycle, are avoided.

The invention discloses a nickel alloy electrode and a preparation method and application thereof.The preparation method comprises the steps that a nickel current collector is placed in electroplating liquid to be electroplated so that a nickel alloy layer can be formed on the surface of the nickel current collector, the electroplating liquid comprises nickel salt, cobalt salt, chromium salt, ferrous salt and auxiliaries, the concentration of the nickel salt in the electroplating liquid is 85-115 g / L, and the concentration of the cobalt salt in the electroplating liquid is 80-100 g / L; the concentration of the cobalt salt in the electroplating solution is 15-25 g / L, the concentration of the chromium salt in the electroplating solution is 5-15 g / L, the concentration of the ferrous salt in the electroplating solution is 3-7 g / L, the atomic ratio of nickel in the nickel alloy layer to doped elements cobalt, chromium and iron is larger than or equal to 2.8, and the pH value of the electroplating solution is 3-5. The Co, Cr and Fe element doped nickel-based alloy layer is prepared by adopting an electroplating solution with a specific formula through an electro-deposition method, atomic-scale combination between a substrate and a catalyst layer is realized, and not only is the excellent interface bonding strength achieved, but also the good durability is achieved.

The application discloses a carbon-composite high-entropy metal oxide electromagnetic functional material and a preparation method thereof, and relates to the technical field of microwave absorbing materials. The electromagnetic functional material is composed of (Fe 0.2 Co 0.2 Ni 0.2 Mn 0.2 Cr 0.2 )3O4 / C, and the preparation method comprises the following steps: adding equimolar iron salt, cobalt salt, manganese salt, chromium salt and nickel salt into water together with urea, polyvinylpyrrolidone and a carbon source to configure a mixed solution, then heating and reacting, centrifuging and drying the reaction product after the reaction is completed, and obtaining the electromagnetic functional material. By introducing the carbon material with high dielectric constant, the electric conduction performance and the electric loss performance are enhanced, the impedance matching is optimized, the overall density is reduced, the absorption bandwidth is widened, the effective absorption bandwidth covers the full wave band of 2-18GHz, the electromagnetic functional material is suitable for multi-wave bands, and the problems of low absorption rate and narrow frequency band are solved. Moreover, the preparation process is simple, and the one-time hydrothermal reaction can be completed, so that the scale production is facilitated.

This invention discloses an alkaline zinc plating black passivating agent and its preparation method. The alkaline zinc plating black passivating agent includes component A and component B. Component A, by weight, comprises: 20-35 parts of trivalent chromium salt, 7-15 parts of complexing agent, 5-15 parts of pH adjuster, 5-15 parts of auxiliary blackening agent, 10-20 parts of oxidant, and 30-40 parts of water. Component B, by weight, comprises: 15-25 parts of main blackening agent, 1-10 parts of film-forming accelerator, and 70-90 parts of water. This passivating agent has good stability and salt spray resistance, and is low in cost. It is suitable for galvanized screws, bolts, and other parts. The passivation film obtained using this passivating agent is black, bright, and uniform. The production process is simple and easy to operate, with minimal environmental pollution, meeting green environmental protection standards.

The utility model discloses a chromium slag recovery device in chromium salt production, which comprises a recovery box, the top end and the bottom end of the side wall of the recovery box are respectively communicated and connected with a conveying pipe and a discharging pipe, the recovery box is fixed on a box seat, the chromium slag recovery device also comprises a filter box, the top end of the filter box is provided with a fixing plate, and the filter box is detachably connected in the recovery box; a movable plate is arranged at one end of the fixed frame, and the other end of the fixed frame is detachably connected with the fixed plate; an adjusting assembly is hinged to the limiting plate, the other end of the adjusting assembly is hinged to the moving plate, and the limiting plate is fixedly installed on the side face of the recycling box; and the vibration assembly is provided with a vibration motor, and the vibration motor is installed at the bottom of the box base. According to the utility model, the problem that the recovery efficiency is low because the recovery progress of the chromium slag cannot be mastered in real time in the prior art is solved.