85 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.

The invention relates to the technical field of getters, and discloses a getter for a vacuum insulated panel and a preparation method of the getter. The getter for the vacuum insulated panel comprises the following components in percentage by mass: 55-65% of calcium oxide, 12-18% of activated aluminum oxide, 6-8% of manganese dioxide, 4-6% of copper oxide, 3-5% of yttrium oxide, 5-7% of zirconium dioxide and 1-2% of chromium powder. The preparation method of the getter comprises the following steps: S100, carrying out ball milling treatment on calcium oxide, activated aluminum oxide, manganese dioxide, copper oxide, yttrium oxide, zirconium dioxide and chromium powder to obtain powder, and drying the powder; s200, mixing the dried powder with deionized water and polyvinyl alcohol, and drying to prepare porous spherical particles; s300, after gradient sintering is conducted on the porous spherical particles, rapid cooling is conducted, and particles of a multi-stage pore channel structure are obtained; and S400, dipping the particles with the hierarchical porous structure in a chromic acid solution, and drying to obtain the getter. According to the technical scheme, the technical problems of low efficiency and insufficient adsorption capacity of a getter in the prior art are solved.

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.

To provide a pretreatment cleaning agent for electroless plating and a method for forming electroless plating using the same that eliminate the need of surface roughening to a substrate with a strong acid such as a chromic acid or permanganic acid, can perform cleaning of the surface of a substrate and coupling treatment at the same time, and can form metal plating having a flat contact surface to a substrate.SOLUTION: A pretreatment cleaning agent for electroless plating includes an inorganic alkali, a cleaning agent including a surfactant, and a silane coupling agent and can perform cleaning of the surface of a substrate and coupling treatment at the same time.SELECTED DRAWING: Figure 1

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 provides oleanolic acid, and a preparation method of the oleanolic acid comprises the following steps: S1, dissolving 5g of arginic acid in 500ml of dichloromethane, adding 7g of pyridinium dichlorochromate, stirring at room temperature for 18 hours, and detecting the reaction degree by thin-layer chromatography; s2, after the reaction is completed and vacuum concentration is carried out, a sample is mixed with 200-300-mesh silica gel, the mixture is volatilized to be dry and then placed on a silica gel column, column chromatography separation is carried out, petroleum ether / ethyl acetate is selected as a mobile phase, 2.87 g of oleanolic acid is obtained, the molecular formula is C30H46O3, and the yield is 57.6%. The oleanolic acid provided by the invention can be used for preparing medicines for treating oligospermia and medicines for improving dyszoospermia. The oleanolic acid provided by the invention is a natural product or an artificially synthesized product, is low in toxicity and small in side effect, and has good effects of improving dyszoospermia and promoting fertility.

The utility model discloses chromic acid recycling evaporation concentration equipment which comprises a tank body, the top of the tank body is fixedly connected with a detection meter, the front side of the tank body is fixedly communicated with a flange base, the front side of the flange base is rotatably connected with a turning cover through a rotating shaft, the bottom of the tank body is fixedly communicated with a discharging pipe, and the bottom of the tank body is fixedly communicated with a discharging pipe. The top of the discharging pipe is fixedly connected with a valve, and the top of the tank body is fixedly connected with a motor. By arranging the tank body, the detection meter, the flange base, the turning cover, the discharging pipe, the valve, the motor, the cleaning device, a threaded rod, a storage ring, a connecting block, a support, a cavity, a telescopic assembly, an electric cylinder, an extension arm, a cleaning wheel, a water injection assembly, a ring pipe, a supporting frame, a water outlet pipe, a water injection pipe and a control valve which are used in cooperation, the problem that the chromic acid solution is prone to damage due to the fact that the viscosity of the chromic acid solution is large is solved. And deposition and blockage in the equipment are easily caused, so that secondary corrosion or damage to the equipment is caused.

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 invention belongs to the technical field of plastic waste treatment, and particularly relates to a degradation and recovery method of a polyester material. The degradation and recovery method of the polyester material provided by the invention comprises the following steps: mixing the polyester material, a catalyst and a hydrogen donor, and then carrying out ball milling to obtain dimethyl terephthalate; the catalyst comprises copper chromite or chromium sesquioxide; the hydrogen supply reagent is methanol. According to the invention, copper chromite or chromium sesquioxide is taken as a catalyst, methanol is taken as a hydrogen donor, molecular chains can be activated, molecular chain breakage and strong mixing of reactants can be promoted under the action of mechanical force of ball milling, and the activation energy of reaction can be reduced due to good catalytic performance of the catalyst, so that efficient degradation of the polyester material under mild conditions is promoted. The degradation and recovery method provided by the invention does not need additional heating, is simple in process and low in energy consumption, can highly selectively degrade the polyester material into dimethyl terephthalate, and has remarkable high efficiency and economical efficiency.

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 a coating liquid for improving compatibility of silicon steel and insulating paint as well as a preparation method and application of the coating liquid, and belongs to the technical field of silicon steel sheet insulating coatings. The coating comprises a stabilizer solution and an insulating solution, the insulating liquid comprises the following raw materials: 1-10% of zinc chromate, 1-10% of magnesium chromate, 1-10% of calcium chromate, 1-5% of glycerol, 1-7% of boric acid, 1-8% of an acrylic emulsion and the balance of water; the stabilizer solution is prepared from the following raw materials in parts by mass: 0.25 to 0.5 part of trisodium citrate, 0.25 to 0.5 part of EDTA (Ethylene Diamine Tetraacetic Acid) disodium and 5.0 to 10.0 parts of water. According to the insulating liquid disclosed by the invention, the ternary chromate is used as an inorganic framework, the acrylic emulsion is used as an organic bridging phase, and the stabilizer is supplemented to form a two-component system, so that the interfacial compatibility between the silicon steel surface and the water-soluble insulating paint is remarkably improved.

The utility model discloses a convenient-to-assemble barium chromate quick filter component, which relates to the technical field of filter devices and comprises a filter, a liquid inlet pipe is arranged on one side of the filter, a liquid outlet pipe is arranged below the liquid inlet pipe in a matched manner, and a backwashing component is arranged on one side, far away from the liquid outlet pipe, of the filter; a quick-release base is arranged at the bottom of the filter in a matched mode, a sediment discharging pipe is arranged at the bottom of the quick-release base in a matched mode, quick-release assemblies are symmetrically arranged on the two sides of the quick-release base, a filter screen is rotationally connected to the upper portion of the quick-release base, and a sealing ring used for improving the sealing performance is further arranged between the quick-release base and the filter in a matched mode. The quick-release components are symmetrically arranged on the two sides of the quick-release base, quick assembly and disassembly between the quick-release base and the filter are achieved through the quick-release components, the filter screen is rotationally connected to the upper portion of the quick-release base, and the filter screens with different pore diameters can be quickly adjusted or replaced according to filtering requirements.

The application provides a method for rapid detection of barium ions in oil-based drilling fluid and a method for preventing drill pipe blockage, the method for rapid detection of barium ions comprising the steps of: mixing an oil-based drilling fluid sample and a demulsification solvent, stirring uniformly to obtain a mixed solution; mixing the mixed solution with distilled water, stirring and then standing until oil and water are separated; filtering the lower water phase to obtain a colorless and clear liquid, adding a sodium chromate solution, and observing whether a yellow precipitate appears, if a yellow precipitate appears, it indicates that the oil-based drilling fluid contains barium ions, and if no yellow precipitate appears, it indicates that the oil-based drilling fluid does not contain barium ions. The method for preventing drill pipe blockage comprises: taking an oil-based drilling fluid sample to be detected to detect whether it contains barium ions; and taking preventive measures in advance to prevent the internal circulation channel of the drill pipe from being blocked in the case that it is determined that the oil-based drilling fluid contains barium ions. The application has the advantages of simple and rapid operation, low cost, and the result can be obtained within 30 min without special instruments, equipment and medicines.

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 utility model discloses a safe and efficient chromium plating tool arranging rack which is characterized by comprising a base plate, a central stand column is arranged on the base plate, and a residual liquid collecting plate is arranged above the base plate after a hole is formed in the middle of the residual liquid collecting plate and penetrates through the central stand column; a plurality of rotating bearings are arranged on the central stand column up and down, a plurality of rotating supports inclining upwards are arranged on the bearing faces of the rotating bearings at intervals, and a plurality of clamping grooves are formed in the rotating supports. A rotary top ring is arranged at the top of the central stand column; a plurality of hanging ring structures are arranged in the circumferential direction of the rotary top ring. According to the safe and efficient chromeplate tool arrangement rack, chromeplate tools can be placed in order, accidents are reduced, residual chromic acid is prevented from dripping on the ground, and meanwhile the tools can be conveniently and rapidly found and taken for use.

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.