11 results about "Chromium phosphate" patented technology

The application relates to the field of fireproof bricks, and discloses a baking-free fireproof brick and a preparation method thereof. The baking-free fireproof brick comprises iron tailings, cement, fly ash, a functional additive, fine aggregate, quartz sand, a chromium aluminum phosphate binder, a water reducing agent and water. The functional additive is prepared by using aluminum chloride hexahydrate and alkaline silica sol as raw materials, ammonium molybdate tetrahydrate as a catalyst, growing mullite whiskers on the surface of silicon carbide fibers through vacuum impregnation and heat treatment, modifying the prepared composite silicon carbide fibers through 3-(methacryloxy) propyl trimethoxysilane, and then copolymerizing the modified composite silicon carbide fibers with acrylic acid and 4-hydroxybutyl vinyl ether. The chromium aluminum phosphate binder is prepared by using aluminum hydroxide, phosphoric acid and chromium trioxide as raw materials and calcium hydroxide as a curing agent. The baking-free fireproof brick prepared through the synergistic effect of the components has high compressive strength and bending strength, small water absorption and good baking-free fireproof and heat insulation performance.

The invention relates to the field of vanadium and chromium separation, and particularly discloses a method for removing impurities phosphorus, chromium and silicon in a sodium modified vanadium solution, which comprises the following steps: S100, adjusting the pH value of the sodium modified vanadium solution to enable the pH value of a solution system to be 8.0-9.0 at room temperature to obtain a pretreated sodium modified vanadium solution; s200, heating the pretreated sodium vanadium solution, sequentially adding a reducing agent and a polyelectrolyte into the solution while stirring, and carrying out phosphorus and chromium removal reaction while stirring; s300, after the removal reaction of phosphorus and chromium is carried out for a period of time, adding a silicon removal agent, and carrying out a removal reaction of silicon; and S400, after the silicon removal reaction is finished, standing sedimentation and solid-liquid separation are carried out, impurity-removed slag is washed with water and then merged into the filtrate, and purified vanadium liquid is obtained. According to the method, firstly, glucose is adopted to selectively reduce hexavalent chromium into trivalent chromium under the weakly alkaline condition, pentavalent vanadium is not reduced, the trivalent chromium forms chromium phosphate and chromium hydroxide precipitates in a weakly alkaline solution, and meanwhile, the chromium removal efficiency is improved in a polyelectrolyte coagulation mode.

This application provides a wide-temperature-range modified phosphate-based self-lubricating coating, its preparation method, and its application. The method includes: adding CrO3 solution to polyphosphoric acid at 90°C under stirring, adding Al(OH)3 in batches, continuing stirring for 2-3 hours, and cooling to room temperature to obtain a chromium-aluminum phosphate adhesive; heating the chromium-aluminum phosphate adhesive to 110-120°C, adding fumed silica, stirring, and then adding B2O3 in batches to obtain a modified chromium-aluminum phosphate adhesive; preparing the wide-temperature-range modified phosphate-based self-lubricating coating: mixing the modified chromium-aluminum phosphate adhesive with silica sol, mixing evenly, and then adding deionized water and filler to obtain a wide-temperature-range modified phosphate-based self-lubricating coating; spraying the wide-temperature-range modified phosphate-based self-lubricating coating onto the substrate surface and sintering to form a wide-temperature-range modified phosphate-based self-lubricating coating. The self-lubricating coating provided by this application can be applied to the field of wide-temperature-range self-lubrication and corrosion protection from room temperature to 800°C.

According to the preparation method, chromium-aluminum phosphate is used as a binder, graphene oxide is used as a modified material, superfine chrome green, magnesium oxide, zinc oxide, zinc powder, alpha-alumina micro powder, mica powder, talcum powder and the like are used as fillers, and the inorganic salt fireproof anticorrosive coating is prepared under the cooperation of a plurality of functional assistants. And preparing the inorganic phosphate fireproof anti-corrosion coating. The coating is used for coating protection on metal and alloy surfaces in a high-temperature environment, and the corrosion resistance and oxidation resistance of the metal surfaces can be remarkably improved. When the coating is used for protecting metal and alloy-based engines, exhaust pipes, incinerators and the like, the service life of the metal and alloy-based engines, the exhaust pipes, the incinerators and

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.

The invention discloses a high-voltage titanium-manganese-sodium phosphate and chromium-manganese-sodium phosphate positive electrode material nanofiber and a preparation method thereof, and belongs to the technical field of sodium ion batteries. The method comprises the following steps: replacing a traditional phosphorus source with a phosphorus-containing chelating agent, dissolving the phosphorus-containing chelating agent in an organic solvent, sequentially adding a manganese source, a sodium source, a titanium source or a chromium source and a high-molecular polymer, and carrying out heating and stirring reaction to form a uniform precursor solution; then, a nanofiber precursor is prepared through an electrostatic spinning technology; and finally, a target product is obtained through step-by-step carbonization heat treatment. By utilizing the dual functions of the phosphorus-containing chelating agent, the problems that a traditional inorganic phosphorus source is difficult to dissolve in an organic solvent and is non-uniform in mixing are solved, molecular-level mixing of the raw materials is realized, and the prepared positive electrode material has a high-purity NASICON structure, uniform nanofiber morphology and an in-situ carbon-coated network, and can be applied to the field of lithium ion batteries. The charge-discharge specific capacity, the high-voltage stability and the cycle life of the sodium-ion battery are improved. The process is simple and suitable for large-scale production.

The invention relates to a high-strength long-life RH dip pipe gunning mix and a preparation method thereof. The gunning mix is prepared from the following raw materials in parts by weight: 55-70 parts of a waste magnesite-chrome brick reworked material of which the particle size is less than or equal to 5mm, 18-28 parts of fused magnesite skin sand of which the particle size is 180-240 meshes, 3-7 parts of chromium aluminum phosphate, 2-5 parts of a complexing magnesium-aluminum cementing agent, 1-3 parts of activated bentonite, 0.2-0.5 part of calcium lignosulphonate, 0.5-1.5 parts of lanthanum oxide, 0.2-0.6 part of modified carbon fiber and 0.3-0.8 part of polyacrylamide. The RH gunning mix is low in rebound, high in adhesion, rapid in hardening, high in sintering strength, resistant to erosion and scouring, low in cost and long in service life.

The application discloses a wide-temperature-range high-temperature-resistant self-lubricating composite coating and a preparation method thereof, and belongs to the technical field of high-temperature lubricating coating. The coating is composed of a chromium aluminum phosphate-based binder and a composite functional filler, wherein the mass ratio of the chromium aluminum phosphate-based binder to the composite functional filler is (0.5-2):1; the composite functional filler is composed of dimolybdenum ditelluride and rare earth oxide, the dimolybdenum ditelluride accounts for 30-80% of the total mass of the composite functional filler, and the rare earth oxide accounts for 20-70%. The application further provides a preparation method of the coating, which comprises mixing raw materials to prepare a coating slurry, coating the coating slurry on the surface of a substrate, and obtaining the coating through stepwise solidification. Through the synergistic effect of the dimolybdenum ditelluride and the rare earth oxide, the coating has excellent lubricating performance and high-temperature stability in a wide temperature range from room temperature to 900 DEG C, the friction coefficient is stable below 0.3, the bonding strength with a metal substrate is high, the preparation process is simple, and the coating can be widely applied to high-temperature moving parts in the fields of aerospace, gas turbines, metallurgy and chemical industry.

This invention discloses a gas-liquid dual-repellent anti-corrosion composite coating for magnesium-aluminum alloy surfaces and its preparation method. The method includes: immersing a pretreated magnesium-aluminum alloy with α-phase and β-phase microstructures into a phosphate-chromium salt mixed etching solution under no applied current conditions; selectively etching using the natural potential difference between the two phases; preferentially dissolving the α-phase to construct micron-level "valleys" while simultaneously depositing a phosphate-chromium salt conversion film in situ covering the surface of the continuous network of β-phase "peaks," resulting in a tightly interwoven "peak-valley" multi-level micro / nano composite structure; subsequently, immersing it in an ethanol solution containing fluorinated silane for treatment; and drying to obtain the composite coating. This coating has an integrated structure with the substrate, possessing excellent gas-liquid dual-repellent properties, long-term anti-corrosion performance, and good mechanical stability. This invention features a simple process, low cost, and safe and controllable operation, making it suitable for applications such as corrosion protection in marine equipment and underwater transmission components, and has great potential for industrial application.

The application discloses a preparation method of a high-efficiency environment-friendly chromium phosphate passivation solution, and comprises the following steps: stirring and reacting a chromium phosphate solution, an oxidizing agent and a complexing agent to obtain component A; adding a film forming promoter and a stabilizer into deionized water and heating to obtain component B; slowly adding the component A into the heated component B, mixing, heating and stirring, and filtering to obtain a chromium phosphate passivation solution product. The chromium phosphate passivation solution has excellent passivation effect, can form a dense and uniform passivation film on a metal surface, effectively improves the corrosion resistance of the metal, prolongs the service life of the metal, and has a neutral salt spray resistance time of more than 100 hours. The trivalent chromium in the passivation film will not produce hexavalent chromium to cause harm to the environment with the lapse of time. The preparation method of the chromium phosphate passivation solution is simple, raw materials are easy to obtain, the cost is low, and the method is suitable for industrial production and has good environmental protection performance. The chromium phosphate passivation solution does not contain harmful hexavalent chromium, and harm to the environment and human bodies is reduced.

This invention provides a high-entropy alloy high-temperature self-lubricating spherical plain bearing, belonging to the field of spherical plain bearing technology. The high-entropy alloy high-temperature self-lubricating spherical plain bearing includes an inner ring and an outer ring. The inner ring is made of a high-entropy alloy, and the outer ring is made of a high-temperature alloy. The outer spherical surface of the inner ring has several blind holes filled with a composite solid lubricant and a binder. The binder is aluminum chromium phosphate or zirconium silicate; the composite solid lubricant is a combination of barium fluoride, calcium fluoride, silver, hexagonal boron nitride, graphite, molybdenum disulfide, tungsten disulfide, and lead oxide. The self-lubricating spherical plain bearing provided by this invention has high reliability, excellent high-temperature load-bearing capacity and high-temperature friction and wear performance, and can be used up to 900℃. It can meet the requirements of harsh working conditions such as high temperature and heavy load, and has good application prospects in aviation, aerospace, weaponry, and equipment manufacturing.