17 results about "Chromic anhydride" patented technology

The application relates to an insulating coating liquid, an insulating coating and oriented silicon steel, components of the insulating coating liquid comprising: a dihydrogen phosphate, a silica sol, phosphoric acid, a zirconium oxide dispersion liquid and chromic anhydride; wherein the content of the zirconium oxide dispersion liquid is 1-5% in mass fraction. The zirconium oxide dispersion liquid can be dissolved into the phosphate coating liquid, and zirconium phosphate generated after heat treatment can reduce the coating expansion coefficient and thus improve the coating tension. The phosphoric acid and the zirconium oxide dispersion liquid can be dissolved in the water-based coating, and zirconium phosphate can be generated after heat treatment. The low expansion coefficient of the zirconium phosphate can improve the coating tension, so that the technical problem of low coating tension existing in the prior art phosphate insulating coating is solved.

The utility model discloses an industrial chromic anhydride barrel hoop automatic locking device which comprises a rack, a positioning mechanism arranged on the rack and used for positioning the two sides of a barrel body, a supporting plate arranged on the upper side of the positioning mechanism and used for limiting the placement height of a barrel hoop, and a locking assembly used for fastening the barrel hoop. And the limiting mechanism is fixed on the supporting plate and is used for limiting the longitudinal displacement of the barrel hoop. According to the automatic locking device for the industrial chromic anhydride barrel hoop, the limiting mechanism is arranged to limit the longitudinal position of the barrel hoop in the locking process, it is guaranteed that the bottom of the barrel hoop is attached to the supporting plate in the fastening process, the barrel hoop and a barrel body are not dislocated, it is guaranteed that capping is conducted smoothly, work efficiency is improved, and automatic production is facilitated.

The invention discloses a method for preparing chromic anhydride from a sodium chromate neutral solution, which comprises the following steps: transferring the sodium chromate neutral solution into a storage tank of an anode head tank by using a pump, adjusting the temperature, transferring a sodium hydroxide solution into a storage tank of a cathode head tank, and adjusting the temperature; overflowing the sodium chromate neutral solution after temperature regulation to an anode chamber of an electrolytic bath and then overflowing to an anode circulating tank, and overflowing the sodium hydroxide solution after temperature regulation to a cathode chamber of the electrolytic bath and then overflowing to a cathode circulating tank; electrifying a cathode plate and an anode plate of the electrolytic bath with direct current to start electrolysis; pumping out an anode solution after electrolysis, adding the anode solution into a reaction kettle after evaporation, adding concentrated sulfuric acid, heating and dehydrating, and standing in a clarifier until layering; the upper layer is sodium hydrogen sulfate, and the lower layer is chromic anhydride liquid, cooling and flaking to obtain the high-quality chromic anhydride. The method can effectively shorten the production period, greatly improve the production yield, reduce the labor intensity of workers, avoid high cost of an electrolytic method and avoid a large amount of byproduct chromium-containing sodium hydrogen sulfate of a sulfuric acid method, and is economical and practical.

The invention discloses a grain boundary corrosive liquid and a corrosion method for 5xxx and 7xxx series aluminum alloys, and belongs to the technical field of aluminum alloy metallographic corrosion, the grain boundary corrosive liquid comprises the following substances: 5-10 mL of nitric acid with the concentration of 85%, 1-2 mL of hydrofluoric acid with the concentration of 50%, 10-15 mL of hydrochloric acid with the concentration of 85%, 2-3 g of ferric chloride, 3-6 g of chromic anhydride, and the balance of distilled water to 100 mL. The corrosion step comprises pre-corrosion and heating corrosion, when the corrosive liquid is used for corroding the 5xxx and 7xxx series aluminum alloy, the requirement for equipment is low, operation is easy, cost is saved, the grain boundary of the aluminum alloy can be clearly observed, and the corrosive liquid is suitable for researching the grain morphology, the grain size, the microstructure performance and the like of the 5xxx and 7xxx series aluminum alloy.

The invention discloses a method for electroplating gold on a molybdenum-copper alloy, relates to the technical field of surface treatment, and aims to solve the technical problems that the binding force between the existing molybdenum-copper alloy and a gold-plated layer is weak, and the requirements of severe environments and long-time use are difficult to meet. The method for electroplating the gold on the molybdenum-copper alloy comprises the following steps: immersing the molybdenum-copper alloy into an activating solution for activating treatment; the activating solution comprises chromic anhydride, sulfuric acid and nitric acid; the molybdenum-copper alloy is subjected to impact nickel plating through the first solution; the components of the first solution comprise nickel chloride and hydrochloric acid; carrying out nickel electroplating on the molybdenum-copper alloy by using a second solution; the second solution comprises the following components: nickel aminosulfonate, nickel chloride, boric acid and lauryl sodium sulfate; immersing the molybdenum-copper alloy into a third solution for gold plating, and forming a gold-plated layer on the surface of the molybdenum-copper alloy; and the third solution comprises the following components: potassium aurous cyanide, potassium citrate and sodium sulfite.

The invention belongs to the technical field of metal surface treatment, and discloses an efficient and low-corrosivity ash removal agent as well as a preparation method and application thereof. The ash removal agent comprises the following components: organic acid, an oxidizing agent, organic amine ester TPP, methylbenzotriazole, polyaspartic acid, a complexing agent, a nonionic surfactant and water. The ash removal agent is high in ash removal efficiency and small in corrosion to an aluminum (alloy) matrix, and meanwhile, the ash removal agent does not contain nitric acid, chromic anhydride and other ammonia nitride components which severely pollute the environment.

A method for electroplating palladium-nickel alloy on the surfaces of copper and copper alloy parts comprises the steps that S1, the surfaces of the copper and copper alloy parts are degreased; s2, pre-corrosion is carried out; the part without oil stains on the surface is placed in a hydrochloric acid solution to be pre-corroded, and after corrosion is completed, the part is rapidly washed clean with running water; s3, emitting light; the pre-corroded part is placed in a mixed solution of chromic anhydride and sulfuric acid to be continuously shaken for bright dipping treatment; s4, scrubbing with magnesium oxide; degreasing cotton is soaked with water, then pasty magnesium oxide is dipped, the surface of the bright part is scrubbed, and the surface of the bright part is washed clean with deionized water; s5, weak corrosion; the part without water drops on the surface is placed in a hydrochloric acid solution to be continuously shaken for weak corrosion treatment; S6, copper plating is conducted; placing the part subjected to weak corrosion in a mixed solution composed of cuprous cyanide, potassium cyanide and sodium hydroxide for copper electroplating to obtain a part with a copper plating layer on the surface; s7, plating a palladium-nickel alloy; and S8, the part with the copper plating layer on the surface is placed in palladium-nickel alloy electroplating liquid to be electroplated with palladium-nickel alloy, and drying is conducted.

The invention discloses a method for preparing a sodium sulfate solution and chromic oxide of different grades from chromium-containing sodium hydrogen sulfate, which comprises the following steps: calcining the chromium-containing sodium hydrogen sulfate at high temperature to obtain a solid product and a gas product; putting the solid product into a pulping tank, adding water, pulping and dissolving until the solid product is completely dispersed, preparing a feed liquid, and carrying out filter pressing to obtain a primary filter-pressed filter cake and an acidic solution; adding alkali into the acidic solution for neutralization, preserving heat and curing, and then carrying out filter pressing to obtain a secondary filter-pressed filter cake and a slightly acidic solution; washing and filter-pressing the primary filter-pressed filter cake, and calcining to obtain low-grade chromium sesquioxide; and washing the secondary filter-pressed filter cake, carrying out filter pressing, and calcining to obtain the high-grade chromium sesquioxide. The invention provides the method for efficiently recycling the by-product chromium-containing sodium hydrogen sulfate in the production process of chromic anhydride, the problem of poison of wastes is solved, the process is simple and easy to operate, environmental protection benefits and economic benefits are considered, and the method is suitable for industrial production.

The invention relates to a chemical thick copper deposition process and application thereof. A chemical copper deposition treatment method comprises the following steps: providing a copper-free substrate; carrying out roughening treatment; carrying out presoaking treatment; activating treatment; acceleration processing; chemical copper deposition treatment; wherein in the roughening treatment, a roughening solution is adopted to carry out roughening treatment on the surface of the substrate, and the roughening solution comprises the following components with the following concentrations: 50-400 g / L of chromic anhydride, 20-400 ml / L of concentrated sulfuric acid and 0.5-20 g / L of ceric sulfate; thus, the stepped treatment process can significantly improve the binding force between the electroless plating copper and the base material, the copper layer is not prone to falling off, the density of the catalyst layer is improved, the deposition rate of the electroless plating copper is increased, and the thickness of the electroless plating copper is increased. Particularly, a chromic anhydride / ceric sulfate composite coarsening system is innovatively adopted, so that the controllable roughness of 0.3-0.8 mu m is formed on the surface of the substrate, and the binding force is remarkably improved.

This invention provides a method for regenerating chromic anhydride copper stripping solution used in the aerospace industry, solving the current technical problem of not being able to regenerate chromic anhydride copper stripping solution while simultaneously considering economic cost, environmental protection, and meeting process requirements. The method consists of two parts: copper ion separation and hexavalent chromium regeneration. First, after experimental screening, the effectiveness of oxalate as a copper ion precipitant in a chromic acid environment was verified. Although there is a drawback that some hexavalent chromium is reduced to trivalent chromium by the precipitant, a reasonable oxidation method is subsequently proposed to fully oxidize and regenerate the total trivalent chromium in the failed solution back to hexavalent chromium, thus overcoming the drawback of the first step of copper separation. Simultaneously, it also oxidizes and regenerates the original trivalent chromium in the solution.

The invention provides a roller EDT texturing electroplating technology which comprises the following steps that heat treatment, pretreatment, EDT electric spark texturing and electrochemical surface treatment are conducted on a roller, so that the surface of the roller is plated with a chromium layer, the electrochemical surface treatment technology comprises reverse etching, electroplating and polishing which are sequentially conducted, the current density of reverse etching is 22-30 A / dm < 2 >, and the current density of electroplating is 20-30 A / dm < 2 >. The reverse etching time is 30 to 120 seconds; the current density of electroplating is 25-35 A / dm < 2 >, and the electroplating time is 10-15 minutes; polishing until the roughened working surface is a non-uniform rough surface; the electroplating solution comprises 200-300 g / L of chromic anhydride, 2-3 g / L of sulfuric acid and 10-50 g / L of a composite additive, and the composite additive comprises a film-forming agent, a stabilizer and a conductive agent; by means of the EDT texturing electroplating technology for the roller, the roller can have the Vickers hardness of 900 or above after chromium plating, and the service life of the roller is greatly prolonged.

Disclosed in the present invention is a passivation treatment liquid for a tinplate, which passivation treatment liquid comprises: chromic anhydride, which has a content of 15-30 g / L; metaphosphoric acid and / or a metaphosphate, which has a content of 5-15 g / L; ammonium bromide, which has a content of 1-5 g / L; and a nitrogen-containing organic compound, which has a content of 0.2-2 g / L. Further disclosed in the present invention are a tinplate treated with the passivation treatment liquid and a method for manufacturing the tinplate. The surface of the tinplate has good coating wettability and better paint film adhesion.

The invention provides a metallographic detection method for a zinc alloy grain structure. The metallographic detection method comprises the following steps: S1, immersing the zinc alloy into a corrosive agent for surface treatment, and then carrying out first cleaning and drying to obtain the treated zinc alloy; wherein the corrosive agent is a chromic anhydride-sodium sulfate mixed aqueous solution; and S2, carrying out grain structure detection on the treated zinc alloy in a polarized light mode by adopting a polarized light metallographic microscope so as to measure the grain size. The chromic anhydride-sodium sulfate mixed aqueous solution is used as the corrosive agent, and a layer of film can be formed on the surface of the zinc alloy. The interface between the thin film and alloy crystal grains can generate a specific optical effect, and especially under the action of polarized light, the crystal grains with different orientations present different color contrast. According to the method, the contrast between the grains can be remarkably enhanced, the grain boundary is clearer and distinguishable, and subsequent grain size measurement is facilitated.

The invention relates to a preparation method of a zinc alloy metallographic specimen, and belongs to the technical field of metal material processing. The method comprises the steps that firstly, a zinc alloy sample is sequentially subjected to three-stage manual grinding through 600 #-1000 # silicon carbide waterproof abrasive paper, 1200 #-1500 # silicon carbide waterproof abrasive paper and 2000 #-3000 # silicon carbide waterproof abrasive paper, and in the process, the sample is cooled through flowing water and rotated to ensure that scratches are uniform; then the ground sample serves as an anode, electrolytic polishing is conducted in an electrolytic polishing solution with the volume ratio of phosphoric acid to ethyl alcohol being (1-1.5): 1, and the polishing conditions are that the direct-current voltage is 10-15 V, the time is 1-3 min, and the electrode distance is 1-2 cm; and finally, washing with absolute ethyl alcohol and blow-drying to obtain the metallographic specimen. According to the method, the steps of fine mechanical polishing and chemical corrosion in the traditional process are omitted, the preparation period is shortened to be within 8 minutes, and the sample preparation efficiency is remarkably improved; meanwhile, the adopted electrolytic polishing solution does not contain toxic substances such as chromic anhydride and nitric acid, and the method has the advantages of being safe to operate and environmentally friendly.

The invention discloses a preparation method of a high-binding-force chromium layer on the surface of a titanium alloy based on composite activation, relates to the technical field of surface treatment, and aims to solve the problems that an activated state suitable for high-binding-force chromium plating is difficult to form on the surface of an existing titanium alloy matrix due to poor compatibility between the existing titanium alloy matrix and an existing chromium plating pretreatment process; and a chromium plating layer is easy to strip and is poor in wear resistance. The preparation method of the titanium alloy surface high-binding-force chromium layer based on composite activation comprises the steps that a titanium alloy matrix is obtained; the method comprises the following steps: respectively carrying out mechanical activation, chemical activation and electrochemical activation on a titanium alloy matrix, and then carrying out chromium plating treatment to form a chromium layer on the surface of the titanium alloy matrix; a solution system for chemical activation and / or electrochemical activation comprises glacial acetic acid, hydrofluoric acid, sodium molybdate and ammonium citrate; a chromic acid system is adopted for chromium plating treatment, and the chromic acid system comprises chromic anhydride, sulfuric acid and trivalent chromium.

The invention discloses a catalyst for synthesis of 2, 6-dichlorobenzonitrile and a preparation method thereof, and belongs to the technical field of catalysts. The preparation method comprises the following steps: impregnating a gamma-Al2O3 carrier in an ethanol solution of tetrabutyl titanate, volatilizing, drying and calcining to obtain a TiO2-coated Al2O3 composite carrier; mixing and dissolving ammonium metavanadate, chromic anhydride, ammonium molybdate, cerium nitrate hexahydrate, water and ethanol to obtain an active component precursor solution; and mixing and soaking the TiO2-coated Al2O3 composite carrier and the active component precursor solution, drying, and calcining to obtain the catalyst for synthesis of 2, 6-dichlorobenzonitrile. Through collaborative innovation of the composition, the structure and the preparation process, the catalyst which is excellent in comprehensive performance and particularly suitable for industrial synthesis of 2, 6-dichlorobenzonitrile is successfully provided, and the bottleneck problem existing in the prior art for a long time is effectively solved.

The invention relates to the technical field of stainless steel preparation, in particular to stainless steel flaky powder and a preparation method thereof. The preparation method comprises the following steps: (1) crushing a stainless steel raw material to 100-200 meshes, and smelting to obtain molten metal liquid; the crushing is carried out in an atmosphere with the oxygen content of less than 500ppm; the smelting is carried out under the condition that the oxygen content is less than or equal to 400ppm; (2) crushing the molten metal liquid into micro-droplets by adopting a gas atomization method, and cooling at the rate of 10 <-2 >-10 <-3 > K / s to form spherical powder; (3) mixing the spherical powder, a passivation solution and a dispersing agent, and performing ball milling by using zirconium oxide beads to obtain flaky powder; the passivation solution comprises chromic anhydride, sulfuric acid and nitric acid. The flaky powder prepared through the preparation method is high in forming rate, and the defects that the existing oxygen content is generally high, pollution is likely to be introduced, and wet ball milling mass production does not exist in the market are overcome.