49 results about "Chromic acid" patented technology

The invention relates to the technical field of alloy processing, and discloses a high-performance corrosion-resistant nickel-based alloy plate and a preparation method thereof, and the method comprises the following steps: raw material preparation, smelting treatment, casting treatment, hot rolling treatment, solution treatment, aging treatment and surface passivation treatment. According to the invention, when a composite acid system is adopted for passivation treatment, the concentration of chromium / molybdenum atoms in a passivation film is optimized and balanced due to the specific ratio of nitric acid to chromic acid, a chromium oxide provides a compact passivation barrier, and a molybdenum oxide endows the film layer with a self-repairing characteristic to synergistically inhibit pitting nucleation; meanwhile, nano titanium dioxide particles pretreated by silane are embedded into the passivation film in situ under the action of ultrasonic oscillation, organic pollutants adsorbed on a film layer can be decomposed by the photocatalytic characteristic of the nano titanium dioxide particles, the local corrosion effect of a battery caused by dirt coverage is avoided, and the performance of the battery is improved through double upgrading of components and the structure of the passivation film. And the alloy plate has excellent pitting corrosion resistance and fouling resistance in a chloride ion-containing medium.

A method of selectively metallizing a multi-component molded plastic part. The multi-component molded plastic part comprises at least one first region to be metallized formed of a first plastic and at least one second region that is not to be metallized formed of a second plastic. The method includes the steps of (a) contacting the multi-component molded plastic part with a chromic acid-free etchant, wherein the chromic acid-free etchant comprises manganese sulfate; (b) optionally, neutralizing the manganese sulfate to Mn2+ ions; (c) activating surfaces of the plastic part with an activator; (d) contacting the activated surfaces of the plastic part with an accelerator; and (e) depositing an electroless plating layer on the surfaces of the multi-component molded plastic part with an electroless plating electrolyte comprising nickel and copper to form an electroless copper-nickel layer on substantially only the first region formed of the first plastic.

The present invention provides a heat exchanger capable of stably and continuously recovering heat over a long period of time, even when the target gas for heat recovery is an extremely corrosive gas, and an exhaust gas treatment device using such a heat exchanger. [Solution] The heat exchanger of the present invention is characterized by comprising a partition plate (14) made of refractory castable material that divides the inside of the casing (12) so that the low-temperature side fluid (LF) and the high-temperature side fluid (HF) flow in countercurrents, and a plurality of solid heat transfer rods (16) made of at least one ceramic selected from the group consisting of alumina, zirconia, silicon carbide, silicon nitride, molybdenum silicide, and lanthanum chromite, which are arranged to airtightly penetrate the front and back surfaces of the partition plate (14) and cross the flow paths of the low-temperature side fluid (LF) and the high-temperature side fluid (HF).

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 application discloses a high-strength steel unqualified zinc-cadmium alloy plating layer stripping method, and its stripping process is as follows: 80-150 g / L of sodium nitrite, 50-100 g / L of ammonium bicarbonate, 50-100 g / L of ammonium chloride, the pH of the stripping solution is 6-8, and normal temperature operation is adopted. The sodium nitrite is used as an oxidizing agent and a steel base inhibitor for the zinc-cadmium alloy plating layer, the ammonium bicarbonate is used as a complexing agent for zinc ions and cadmium ions and a pH buffer for the plating solution, and the ammonium chloride is used as a complexing agent for zinc ions and cadmium ions and a promoter for dissolving the zinc-cadmium alloy plating layer. When the pH of the stripping solution is too high, dilute nitric acid is used to reduce the pH, and when the pH is too low, sodium carbonate solution is used to increase the pH. The technical scheme of the application is used to replace the chromium acid stripping method, and the high pollution problem caused by the use of the chromium acid is overcome.

The invention relates to the technical field of biomedical detection and functional organic fluorescent materials, in particular to synthesis and application of a single-molecule probe combining BODIPY (boron dipyrromethene) and a semi-cyano dye. Comprising the following steps: preparing an intermediate 1: reacting 4-hydroxybenzaldehyde with 2, 4-dimethyl pyrrole to generate BDP-OMe, and then reacting with pyridinium chlorochromate to obtain the intermediate 1; preparation of an intermediate 2: carrying out reflux reaction on 2, 3, 3-trimethyl-3H-indole and 2-bromoethanol in ethanol to obtain the intermediate 2; and synthesizing a final product: heating the intermediate 1 and the intermediate 2 in toluene to react, and performing post-treatment and column chromatography purification to obtain the probe CyB-C. The bimodal detection capability enables the probe to simultaneously distinguish the microenvironment difference between normal cells and cancer cells and monitor diseases related to viscosity abnormity.

The invention discloses a recovery method of a catalyst containing platinum, silver, chromium, vanadium, molybdenum and aluminum, which comprises the following steps: uniformly mixing a waste catalyst, caustic alkali and iron powder, reacting at high temperature, cooling to obtain a melt, dissolving the melt, and filtering to obtain a first filter residue and a first filtrate; dissolving the first filter residue with nitric acid, and filtering to obtain platinum-containing waste filter residue and second filtrate; adding a sodium chloride solution into the second filtrate, and filtering to obtain silver chloride filter residues and third filtrate which contains chromic nitrate; adding a barium chloride solution into the third filtrate, reacting at room temperature, and filtering to obtain barium chromate solid filter residues and fourth filtrate; adjusting the pH value of the first filtrate to 7-8 by using an acid, reacting at room temperature, and filtering to obtain activated aluminum oxide filter residues and a fifth filtrate; adding ammonium chloride into the fifth filtrate, reacting at room temperature, and filtering to obtain ammonium vanadate filter residues and sixth filtrate; and adjusting the pH value of the sixth filtrate to be less than 1 by using sulfuric acid, reacting at room temperature, and filtering to obtain molybdic acid filter residues and a seventh filtrate.

The invention discloses a carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance, a preparation method and application, and relates to the technical field of corrosion inhibition of metal materials. The technical problems that in the prior art, a carbon dot corrosion inhibitor is prone to aggregation and instability in a high-temperature and strong-acid environment, and application is single are solved. The method comprises the following steps: firstly, taking citric acid and propargyl-PEG2-amine as raw materials, and dissolving the raw materials in deionized water to obtain a mixed solution; the mixed solution is placed in a high-pressure reaction kettle to be subjected to a hydrothermal reaction, and citric acid carbon dots modified by propargyl-PEG2-amine are prepared; sequentially carrying out centrifugation, dialysis and freeze drying treatment on the citric acid carbon dots modified by the propargyl-PEG2-amine, so as to obtain the citric acid carbon dots modified by the propargyl-PEG2-amine. The prepared carbon dot corrosion inhibitor can be used as a corrosion inhibition material in a high-temperature-resistant strong-acid environment, and can also be used for in-situ monitoring of dichromate ions in industrial wastewater and in-situ monitoring of iron ions and ferrous ions in underground water, surface water and drinking water so as to judge whether the content of the iron ions and the ferrous ions exceeds the standard or not.

The invention relates to a chromic acid recovery device and a control method thereof, and belongs to the technical field of alkali corrosion machine auxiliary equipment.The chromic acid recovery device comprises a floor plate, a corrosion machine is arranged at the upper end of the floor plate, a chromic acid recovery tank is arranged below the floor plate, and a chromic acid recovery pipe is arranged between the lower portion of the corrosion machine and the upper end of the chromic acid recovery tank; a recovery host is arranged at the lower end of the chromic acid recovery tank, and a liquid level sensor communicated with the recovery host through a circuit is arranged on the corrosion machine. The chromic acid recovery tank comprises an outer tank body, and an inner tank container fixedly attached to the outer tank body is arranged in the outer tank body. Through structural innovation, material upgrading, automatic control and circulating purification, the pain point of a traditional technology is effectively solved, efficient recovery and resource utilization of chromic acid are achieved, and remarkable economic and environment-friendly values are achieved.

The application discloses a high-chlorine-resistance NiFe bulk alloy electrolytic seawater oxygen evolution catalyst and a preparation method thereof, and is prepared according to the following steps: (1) placing the bulk NiFe foam alloy in anhydrous ethanol and ultrasonically cleaning; (2) drying the cleaned NiFe foam alloy, and placing the NiFe foam alloy in a hydrochloric acid solution for pickling; (3) placing the pickled NiFe foam alloy into a prepared corrosion solution, and corroding and constructing for 5-20 hours at a corrosion and construction temperature of 20-30 DEG C; the corrosion solution is one of an ammonium tungstate aqueous solution, an ammonium molybdate aqueous solution and an ammonium chromate aqueous solution; (4) taking out the constructed NiFe foam alloy, and rinsing the surface of the NiFe foam alloy with deionized water to obtain the high-chlorine-resistance NiFe bulk alloy electrolytic seawater oxygen evolution catalyst. The application can effectively resist chlorine ion erosion, realizes excellent activity and long-term stability of the NiFe bulk alloy in an oxygen evolution reaction under a large current density, and simultaneously considers low preparation cost.

The invention discloses an electroplating waste gas treatment method. The electroplating waste gas treatment method comprises the following steps: S1, collecting and conveying waste gas; s2, a pre-treatment stage: pre-treating the acid waste gas and the particulate matters through a high-efficiency turbulent flow spray tower; s3, a core treatment stage: under the working condition that the VOCs with medium and high concentrations are greater than 1.5 g / m < 3 >, the waste gas is thoroughly decomposed into CO2 and H2O at a high temperature (greater than or equal to 800 DEG C) based on a heat accumulating type thermal incinerator; in the working condition of low-concentration VOCs, a third-stage spray tower is additionally arranged based on the efficient turbulence spray tower in the step S2 to absorb trace VOCs; s4, a post-treatment stage: capturing trace particles or aerosol possibly escaping from the core treatment unit through a fine filter; and S5, an air inducing and discharging stage. According to the electroplating waste gas treatment method, acid waste gas and chromic acid mist are treated through the efficient turbulent flow spray tower, the gas-liquid contact area and the mass transfer efficiency are increased through the turbulent flow design, and compared with a traditional spray tower, the removal rate of acidic substances can be remarkably increased.

The application discloses an angle-adjustable hoisting device and method, and designs the hoisting device including a lifting ring, a positioning rod, a lifting hook and a nut for a crossbeam part. The lifting ring contains at least one sleeve joint hole and multiple adjustment holes. The lifting ring is sleeved on the outside of the part to be hoisted through the sleeve joint hole. The minimum inner diameter of the sleeve joint hole is greater than the maximum outer diameter of the part to be hoisted. The multiple adjustment holes are distributed on a closed curve outside the sleeve joint hole. A part of the positioning rod is inserted into the adjustment hole of the lifting ring. The end of the positioning rod further includes an outer thread section with an outer diameter smaller than the inner diameter of the adjustment hole. The nut is connected with the outer thread section on the positioning rod. When the crossbeam part is subjected to chromic acid anodization, the lifting ring, the positioning rod and the nut are assembled on the crossbeam part first, then the lifting hook is inserted into the adjustment holes at different positions through a lifting device at intervals, the crossbeam part is hoisted and turned over, and the internal bubbles are discharged. The application is simple in operation, can timely discharge the bubbles generated in the chromic acid anodization, and ensures the normal generation of the oxide film.

This utility model discloses a waste gas treatment system, including a pretreatment recovery unit. The inlet of the pretreatment recovery unit is connected to the outlet of the waste gas pipeline. The outlet of the pretreatment recovery unit is connected to the inlet of a cold recovery mechanism. The outlet of the cold recovery mechanism is connected to the inlet of a reduction absorption mechanism. The outlet of the reduction absorption mechanism is connected to the inlet of an exhaust stack via a centrifugal fan. This utility model can perform preliminary and deep recovery of chromic acid mist in waste gas, thereby effectively improving the recovery degree of chromic acid mist in waste gas. This reduces the amount of reducing agent required for chromic acid mist absorption and purification during subsequent purification, thus lowering the cost of reducing agent consumption.

The invention discloses a preparation method of ternary composite doped modified lithium manganate, which comprises the following steps: by taking Li2CO3 as a lithium source, a multivalent manganese oxide mixture as a manganese source and aluminum isopropoxide, magnesium isopropoxide and tetrabutyl titanate as a ternary doping source, preparing precursor powder by a sol-gel method, and then performing segmented sintering to obtain a ternary doped lithium manganate matrix; the preparation method comprises the following steps: preparing a composite coating solution from tert-butyl chromate, tetrabutyl titanate and Y2O3, carrying out fluidized bed spray coating, and carrying out segmented heating and cooling sintering, screening and demagnetizing treatment to obtain a target product. According to the preparation method, the lattice structure is synergistically optimized through a multivalent manganese source and ternary doping, the Cr2O3-TiO2 / Y2O3 composite coating layer can effectively block direct contact between a matrix and an electrolyte, the occurrence probability of interface side reactions is reduced, and the lattice stability and interface performance of the material are remarkably improved in cooperation with process regulation and control. The initial discharge specific capacity of the product is excellent, the high-temperature cycle and storage stability are greatly improved, and the manganese ion dissolving amount and the interface impedance are effectively reduced.

The invention discloses a tungsten delay powder and a preparation process thereof, and belongs to the field of energetic materials. The tungsten delay powder provided by the invention comprises a tungsten powder compound and potassium perchlorate, the tungsten powder compound comprises tungsten powder and barium chromate loaded on the surface of the tungsten powder; the mass ratio of the tungsten powder to the barium chromate to the potassium perchlorate is (30-40): (50-60): 10; according to the invention, the tungsten delay powder is prepared by adopting a dispersion charging mode under specific conditions, so that barium chromate can be loaded on the surface of tungsten powder in a more uniform mode to form a state that the tungsten powder is coated with barium chromate, a structure similar to a core (tungsten powder) and a shell (barium chromate) is presented, and the granularity and form of a tungsten powder compound can be well controlled; and finally, the delay time of the second-level delay powder as a final product can be effectively prolonged, so that the second-level delay powder has a good delay effect and good delay precision.

The invention provides a method for preparing 1, 2-disubstituted 1, 2-dihydro-3H-pyrazol-3-ketone, which comprises the following steps: by taking 1, 2-disubstituted pyrazol-3-ketone as an initial raw material, 1, 2-dichloroethane as a reaction solvent and pyridinium chlorochromate as an oxidizing agent, carrying out dehydroaromatization reaction on the 1, 2-disubstituted pyrazol-3-ketone to obtain the 1, 2-disubstituted 1, 2-dihydro-3H-pyrazol-3-ketone, and reacting the 1, 2-disubstituted 1, 2-dihydro-3H-pyrazol-3-ketone with 1, 2-dichloroethane to obtain the 1, 2-disubstituted 1, 2-dihydro-3H-pyrazol-3-ketone. The synthesis method comprises the following steps: preparing 1, 2-dihydro-3H-pyrazole-3-ketone. According to the present invention, the 1, 2-disubstituted 1, 2-dihydro-3H-pyrazole-3-ketone can be prepared, the reaction conditions are mild, the process is simple, the yield of the product 1, 2-disubstituted 1, 2-dihydro-3H-pyrazole-3-ketone is high, and the method is suitable for industrial production.

The invention discloses an etchant solution for a doped structure of a medium-low voltage MOS device, and relates to the technical field of semiconductors. Comprising chromic acid solution, hydrofluoric acid and nitric acid; x is the volume of hydrofluoric acid, y is the volume of the chromic acid solution, z is the volume of nitric acid, and the unit is mL; the ratio of x to y to z is (1: 1: 6)-(1: 1: 10). Chromic acid and HF further react to generate dichromic acid with higher oxidability, and the dichromic acid directly reacts with silicon, so that a highly-doped N-type region has a higher reaction rate, and the region is preferentially corroded to form a recess; the nitric acid oxidizes the silicon surface to generate a layer of ultra-thin silicon dioxide film, and the hydrofluoric acid efficiently dissolves the SiOO film generated by oxidation of the nitric acid, so that the pure silicon surface below is exposed, the pure silicon surface can be oxidized again, and the P-type region and the low-doped N-type region are circularly corroded. While the boundary of each doped region is ensured to be clearly displayed, the overall corrosion reaction time is effectively shortened, a fine device structure is protected from being excessively damaged in the process, and the process analysis efficiency is greatly improved.

The application discloses a method for separating vanadium and chromium elements from vanadium slag, which comprises the following steps: (1) roasting the vanadium slag with sodium carbonate, mixing and roasting the vanadium slag and the sodium carbonate at a certain temperature to convert vanadium and chromium elements in different valence states in the vanadium slag into the highest valence state; (2) low-temperature leaching, leaching the roasting product obtained in the first step with calcium salt and water at low temperature to obtain a calcium chromate crude liquid and a calcium vanadate leaching residue; (3) acid leaching and vanadium precipitation, separating residual chromium in the calcium vanadate leaching residue to obtain a vanadium-containing filter cake; (4) preparing vanadium pentoxide, adding water to the filter cake obtained in the third step, adding NaOH and (NH4)2SO4 to adjust the pH, and then performing water bath heating to obtain polyvanadic acid ammonium precipitate, which is dried and calcined to obtain V2O5 powder; and (5) preparing chromium trioxide, adjusting the pH of the chromium solution obtained in the second step, adding Na2SO3, reducing Cr 6+ to Cr 3+ , combining Cr 3+ with OH ‑ to form Cr(OH)3 precipitate, filtering, and calcining to obtain Cr2O3.

The invention discloses an electroplating platinum anode which comprises a conductive plate, an electrode plate and a platinum net, one end of the electrode plate is detachably connected with the conductive plate, the conductive plate is used for electrifying the electrode plate and fixing the electrode plate in an electrolytic tank, and the platinum net is fixed on one side of the electrode plate. The current-conducting plate is made of red copper, the electrode plate is a copper bar of which the outer surface is coated with a titanium metal layer, and the platinum net is a planar plate of which the outer surface is plated with a platinum layer; according to the invention, the platinum net is arranged on the electrode plate to form an electroplating anode made of a platinum material, and a lead-tin anode used in a traditional chromium plating process is replaced, so that the problems that the quality of the electroplating process and the service life of a bath solution are influenced by derivatives such as lead chromate generated in the chromium plating process are avoided, and meanwhile, the later environment-friendly treatment cost is avoided.

The application belongs to the field of non-oxide ceramic powder, and discloses a porous high-entropy carbide powder, a preparation method and application thereof. The porous high-entropy carbide powder is prepared by the following steps: adding mixed powder of ammonium metavanadate, ammonium chromate, ammonium niobate oxalate, ammonium molybdate, ammonium metatungstate and ammonium citrate into deionized water, heating in a water bath at 70-80 DEG C until the powder is completely dissolved, drying the obtained ammonium salt aqueous solution at 45-75 DEG C to obtain a high-entropy carbide ammonium salt precursor; then drying and pressing the high-entropy carbide ammonium salt precursor into a blank body, performing heat treatment in a nitrogen atmosphere, heating to 1500-1600 DEG C and keeping the temperature, and cooling after the temperature is finished. The high-entropy carbide powder has a single high-entropy carbide phase, and the surface has a porous structure; the powder particle size is 0.47-0.79 mu m; and the powder is applied in aerospace parts or chemical catalysis.

The utility model provides a closed type chromic acid mist collection treatment of chromeplate production line relates to the chromeplate field, include: electroplating bath and recovery box, the upper side of electroplating bath is provided with the fairing, and the upper end of fairing is connected with the gas collecting pipe, and the upper end of gas collecting pipe is connected with the suction pipe, the outer end of suction pipe is connected with the acid and alkali resistant draught fan, and the recovery box is connected with the acid and alkali resistant draught fan. The outer end of the acid and alkali resistant induced draft fan is connected with a recycling box through an air outlet pipe, the outer side of the recycling box is provided with cooling-water machine circulation equipment, the two ends of the recycling box are connected with guide covers, the box walls of the two sides of the recycling box are provided with an air inlet and an air outlet respectively, and meanwhile a condensation pipe is arranged in the recycling box; a water inlet pipe and a water return pipe are connected to the outer side of the cooling-water machine circulation equipment and connected with the two ends of the condensation pipe. The chromic acid mist filtering device has the function of conveniently condensing and recycling chromic acid mist, and the effect of conveniently disassembling, assembling and replacing the filtering assembly is achieved.

The invention provides a thermal control coating with high temperature, high infrared radiation and high solar spectrum reflection performance, a coating and a preparation method. The thermal control coating comprises a prime coating and a surface coating, the bottom layer coating takes a silica sol modified lithium silicate solution as a bottom layer binder, takes mixed powder of copper chromite and zinc orthotitanate as a bottom layer filler, and takes water as a solvent; and the surface layer coating takes a silica sol modified lithium silicate solution as a surface layer binder, takes mixed powder of zinc orthotitanate and 8YSZ (8mol% Y2O3 doped ZrO2) as a surface layer filler, and takes water as a solvent. The thermal control coating is formed by spraying a thermal control coating, the bottom layer is obtained by spraying the bottom layer coating, and the surface layer is obtained by spraying the surface layer coating on the bottom layer. Through coating structure optimization and ingredient improvement, the high-temperature heat dissipation coating has high high-temperature emissivity and low solar absorptivity, the infrared emissivity at 600 DEG C can reach 0.80-0.85, the solar absorptivity is 0.30-0.40, and the high-temperature heat dissipation coating has a good high-temperature heat dissipation effect.

This invention provides a method for detecting dichromate ions based on surface-enhanced Raman spectroscopy, belonging to the field of analytical chemistry. The method includes: mixing the sample to be tested with a solution containing a thiol compound, adjusting to acidic conditions to allow dichromate ions (Cr(VI)) to undergo a redox reaction with the thiol-containing compound; constructing a SERS substrate, i.e., preparing a ZnO / Ag heterostructure substrate; mixing a suspension of the ZnO / Ag heterostructure substrate with the reaction system to obtain a mixed solution, allowing the ZnO / Ag heterostructure substrate to adsorb the thiol-containing compound and enhance the Raman signal; dropping the mixed solution onto the surface of a solid support, acquiring the Raman spectral signal using a Raman spectrometer, and quantifying the Cr(VI) concentration by the change in signal intensity. This invention achieves rapid and highly sensitive detection of Cr(VI), exhibiting strong selectivity and anti-interference capabilities, and is suitable for detection in fields such as environmental monitoring, food safety, and pharmaceutical analysis.

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.

This invention discloses a method for grain boundary display of high boron alloy steel, comprising the following steps: (1) Sample preparation: the sample to be tested is inlaid, ground, and polished to obtain a scratch-free mirror surface; (2) Initial grain boundary etching: the polished sample is immersed in an etching solution for 5-30 seconds; the etching solution is prepared from perchloric acid, citric acid, benzotriazole, sodium dodecylbenzenesulfonate, and deionized water; (3) the sample is quickly removed, rinsed with anhydrous ethanol, and dried; (4) Anodizing: the sample is used as the anode and placed in a 5%-10% chromic acid electrolyte for constant-voltage anodizing treatment; (5) after rinsing with deionized water, dehydrating with anhydrous ethanol, and drying, it is observed under a microscope. The method of this invention has the advantages of simple operation, good reproducibility, continuous and clear grain boundary display, and minimal damage to the matrix structure, providing a reliable technical means for the grain size assessment, microstructure analysis, and performance research of high boron alloy steel.

The invention discloses a copper-chromium contact and a preparation method thereof, and belongs to the technical field of contact materials. The copper-chromium contact contains a trace amount of nickel element, so that the wettability between copper and chromium can be effectively improved, the rolling efficiency is improved, the interior of the copper-chromium contact is free of obvious pores or cracks, and interfaces of the copper phase and the chromium phase are tightly combined; ammonium dichromate and copper oxide powder are adopted for co-reduction, the obtained copper-chromium composite powder has better uniformity, cold pressing property and sinterability, and the density, conductivity and mechanical property of the copper-chromium contact can be effectively improved; meanwhile, chromium particles obtained through reduction treatment are small in average particle size, uniform in distribution and high in dispersion degree, and the ablation resistance of the copper-chromium contact can be effectively improved; in addition, the cold pressing-hot rolling technology is adopted, so that the hardness of the copper-chromium contact is improved on the basis of ensuring the electrical conductivity and thermal conductivity of the copper-chromium contact.

This invention discloses a lightweight concrete for mine filling and its preparation method, relating to the field of lightweight building materials technology. The method includes sequentially subjecting chopped polypropylene fibers to chromic acid oxidation etching, nano-alumina coating deposition, and aminosilane grafting to obtain modified polypropylene fibers; sequentially subjecting fumed silica nano-coating to methyltriethoxysilane hydrophobic grafting, hexadecyltrimethoxysilane secondary reinforcement, and stearic acid co-assembly treatment to obtain a composite hydrophobic modifier; mixing mine tailings, cement, fly ash, slag powder, the modified fibers, the composite hydrophobic modifier, polyvinyl alcohol, and nano-calcium carbonate to form a slurry, adding foam, and then pouring and curing to obtain the final product. This invention, through the synergistic effect of multi-level fiber modification and the superhydrophobic structure of nanoparticles, solves the problem of the shielding interference of hydrophobic components on the fiber interface, achieving simultaneous optimal improvement in the mechanical strength and impermeability of concrete.

The invention discloses a composite passivated and insulated coated low-loss FeNi / FeSiAl soft magnetic material as well as a preparation method and application thereof. The composite passivated and insulated coated low-loss FeNi / FeSiAl soft magnetic material comprises a FeNi / FeSiAl inner core, a composite phosphate-chromate conversion film attached to the surface of the inner core and a composite layer of kaolin and white carbon black. And the mixed alloy powder is passivated through a phosphoric acid-chromic acid composite passivation solution, and a composite phosphate-chromate conversion film is formed. The preparation method comprises the following steps: mixing a phosphate-chromate film with composite insulating slurry containing kaolin and white carbon black, further carrying out coating treatment, and finally carrying out drying and heat treatment to form a composite insulating structure with the phosphate-chromate film as a bottom layer and the kaolin / white carbon black as an outer layer on the surface of the mixed metal powder. The effective magnetic conductivity of the soft magnetic material under MHz is 80-140, the magnetic core loss is lower than 900mW / cm < 3 >, and the soft magnetic material is particularly suitable for the fields which are extremely sensitive to loss, such as high-frequency switching power supplies, MHz-level power inductors and radio frequency devices.

This invention discloses a method for separating vanadium and chromium in a vanadium-chromium solution, belonging to the field of wet separation of vanadium-chromium solutions. This method addresses the problem that existing technologies cannot achieve deep separation of vanadium and chromium. The method first adds a reducing agent to the vanadium-chromium solution, converting the highly soluble hexavalent chromate anion into a lower valence state, easily precipitated Cr. 3+ Cations, then add Mn 2+ The chromium removal agent efficiently precipitates trivalent chromium ions from vanadium-containing solutions, achieving deep separation of vanadium and chromium in the liquid phase. Compared with traditional chemical precipitation methods, the vanadium-chromium separation method of this invention has advantages such as high separation coefficient, simple and easy-to-use process, low equipment requirements, convenient operation, and suitability for industrial production.

The invention discloses a salt spray resistant plate and a preparation method thereof. The plate is a composite plate which is prepared by coating a single plate with a salt-spray-resistant resin composition and then hot-pressing, curing and molding a plurality of layers of single plates. The salt-fog-resistant plate disclosed by the invention has good salt-fog-resistant performance in a humid environment under the condition of keeping high toughness and bonding strength. The combination of the N, N, N ', N'-tetraglycidyl-2, 6-bis (3-aminophenoxy) cyanobenzene epoxy resin and bisphenol A epoxy resin improves the toughness of the material, the combination of 4, 4 '-bis (2-trifluoromethyl-4-aminophenoxy) benzophenone and methylhexahydrophthalic anhydride improves the bonding strength of the material, and the combination of zinc phosphate and strontium chromate improves the bonding strength of the material. The salt spray resistance of the material is improved, and the synergistic interaction is realized.