299 results about "Chromium trioxide" patented technology

The palladium-base bimetal catalyst for selective hydrogenation includes active zinc oxide as carrier; metal palladium as the active component in 0.03-0.3 wt% of the catalyst; and one of Cr, Ag, Ni, Cs and Pb as cocatalyst in 0.4-1.2 wt%. Its preparation process includes the steps of: roasting dried active zinc oxide carrier, soaking the carrier in palladium chloride solution with palladium content of 0.08-0.1 % and chromium trioxide with chromium content of 0.7-0.9 %, drying, roasting and pre-reducing. The catalyst has high activity, high selectivity, high stability, long service life and high catalytic efficiency.

The invention relates to an improvement of a fire coal combustion improver. The improved fire coal combustion improver is characterized by being prepared by compounding and mixing the following components: 20 to 30 weight percent of dolomite powder, 5 to 15 weight percent of dicyclopentadieny iron, 3 to 10 weight percent of chromium trioxide, 3 to 10 weight percent of manganese dioxide, 3 to 15 weight percent of magnesium nitrate, 3 to 15 weight percent of sodium dichromate and/or potassium dichromate, 3 to 18 weight percent of zinc oxide, 15 to 30 weight percent of active clay. The fire coal combustion improver has a plurality of functions of combustion acceleration, sulfur solidification, smoke abatement and the like; the thermal efficiency of a boiler can be improved by 3 to 8 percent; the coal-saving efficiency is up to 5 to 15 percent; the Ringelmann smoke blackness is less than 1; the total removal rate of SO2, NOx and the like is 25 to 60 percent, and the combustion improver has remarkable coal-saving and environmental-protection effect. Since the combustion effect is improved, the inferior coal (such as coal gangue), which is difficult to combust normally, is combusted and comes into play. After the long use, the boiler is not corroded, the scaling of the calcium sulfate in the boiler can be reduced, the operation safety of the boiler can be improved and the service life of the boiler can be prolonged.

The invention discloses a pole lug aluminum strip surface treatment passivation solution. The pole lug aluminum strip surface treatment passivation solution comprises chromium trioxide, nickel nitrate hexahydrate, a pickling agent, a film formation accelerant and water. By means of the pole lug aluminum strip surface treatment passivation solution, the passivation film compactness and the salt mist can be improved, and the bonding performance between a film and pole lug glue can be improved.

The invention relates to a ventilated brick and a preparation method thereof. The ventilated brick is composed of the following raw materials: compact fused corundum, sintered tabular corundum, sintered spinel, fused magnesite, active alumina micro powder, industrial chromium trioxide, aluminium-enriched spinel micro powder, pure calcium aluminate cement, SM water reducing agent, SN-2 water reducing agent, sprayed aluminium powder and polypropylene fibre. The invention further relates to the preparation method of the ventilated brick. The ventilated brick prepared by the invention has the advantages of being strong in anti-pressure ability, long in service life, high in high-temperature resistant strength, good in anti-residue permeability and melting loss resistant peeling property, low in sintering temperature, low in energy consumption, clean, free from pollution, and simple and environment-friendly in preparation process; one ventilated brick can be used for above 90 times; and the sintering temperature is only 1200-1550 DEG C.

The invention relates to a de-coating liquid that includes vitriol and oxidant that includes at least from hydrogen peroxide, potassium permanganate, potassium dichromate and chromic anhydride. It also includes reserve salt inter-nitrobenzene sodium xanthate, and accelerating agent copper sulphate. It could effectively decrease the adverse effect of the plastic itself and could decrease environment pollution and decrease harm to human, etc.

The invention discloses a preparation method of a compound 19-desmethyl-4-androstene-3,17 diketone, comprises the following step of by taking compounds of 5alpha-chloro-3beta-hydroxy-6beta and 19beta-epoxy-androstane-17-ketone as raw materials, and carrying out oxidation reaction on the compounds of 5alpha-chloro-3beta-hydroxy-6beta and 19beta-epoxy-androstane-17-ketone as well as an intermediate compound 19-hydroxy-4-androstene-3,17-diketone with N-halogenated amide oxidant in a mixed solution of an organic solvent and an alkaline buffer solution in the presence of a catalytic amount of 2,2,6,6-tetramethylpiperidine-N-oxide (TENPO) in the mild condition. In the two steps of oxidation reaction, the catalytic amount of 2,2,6,6-tetramethylpiperidine-N-oxide and the N-halogenated amide oxidant are both adopted to replace a mixed solution of chromium trioxide, sulfuric acid and water. In the oxidation method, without using the chromium trioxide, the use of carcinogenic substances are avoided being used, limitation by environmental protection is avoided and a great amount of wastes containing heavy metals in preparation are avoided being generated and accumulated, thereby no money and labor is consumed for removing the wastes.

The invention provides a high-temperature resistant absorption enhancement nano coating and a preparation method and application thereof. The coating comprises metallic stuffing, metal oxides, nano ceramic, oxidant and adhesive. The coating is characterized in that the metallic stuffing comprises metallic silver, tungsten powder, barium powder and potassium; the metal oxides comprise titanium dioxide, ferric oxide, zinc oxide, manganese dioxide, chromium trioxide, cesium oxide and magnesium oxide; the adhesive comprises phosphate and silicate; and the oxidant is aluminum oxide. The preparation method comprises the following steps of: proportioning according to the proportion of the coating components, polishing, soaking, heating, reacting, stirring, mixing and filtering.

The invention relates to a preparation method of a glass glaze surface winebottle. The preparation method is characterized in that a glaze material is prepared from the following raw materials in parts by weight: 12-14 parts of talcum, 4-5 parts of limestone, 3-4 parts of calcium phosphate, 4-5 parts of B2O3, 1-2 parts of potassium chloride, 3-4 parts of tin chloride, 1-2 parts of boracic acid, 1-2 parts of chromium trioxide, 1-2 parts of Nb2O5, 13-14 parts of adhesives and a right amount of water. The glass winebottle prepared through the method disclosed by the invention is smooth and lustrous in glaze surface without cracks and can be used for achieving the sintering finished product ratio of 99% without damage.

The invention relates to an HTEE series nocturnal radiation paint which is a special energy-saving material for a high temperature furnace and is applicable to petrochemical engineering furnaces and furnaces in the metallurgic, electric power, ceramic, architectural and aviatic industries and other industries, as well as civil furnaces. The invention utilizes a Y2O3 rare-earth nanophase material for enhancing the strength and the aging resistance performance of nocturnal radiation paint and provides a high temperature nocturnal radiation paint which is directly coated on the lining of a metal heating device or on a heater or a fire-resistant ceramic material of the high temperature furnace. The high temperature radiation paint has the advantages of high thermal efficiency, high temperature resistance, stable adhesive property, capability of effectively saving energy, furnace-body service life prolonging, and the like. The invention adopts the hydro-thermal method to synthesize the Y2O3 rare-earth nanophase material, the solid material of the high temperature paint is selected to comprise 50% of zirconia, 20% of monox, 8-15% of aluminum oxide, 3-6% of ferric oxide, 10-14% of chromium trioxide, 3-9% of sodium sodium phosphate and 1-3% of calcium carbonate. A corresponding liquid material (adhesive agent) is a special high temperature adhesive agent and mainly comprises 0.5-3% of Y2O3, 2-6% of aluminum oxide, 1-3% of ferric oxide, 0.4-2% of manganese oxide, 1-3% of calcium carbonate, and the balance of tap water. The ratio of the solid material and the liquid material is maintained to be 3:2. The solid material and the liquid material are proportionally mixed and then evenly stirred at the normal temperature, and then the special nocturnal radiation paint for the high temperature furnace can be obtained. The use temperature of the nocturnal radiation paint ranges from 1,200 DEG C to 1,800 DEG C.

A hydrogen-generating material and method for generating hydrogen are provided. A plurality of metal particles and a plurality of modifier particles are mixed and than reacted with water to generate hydrogen. The metal particles are made of material including aluminum or aluminum alloy or combination thereof. The modifier particles preferably comprise titanium dioxide (TiO₂), chromium trioxide (Cr₂O₃), cobalt tetroxide (CO₃O₄), nickel oxide (NiO), iron oxide (Fe₂O₃), and/or iron tetroxide (Fe₃O₄) particles, and the average particle size of the modifier particles is preferably between about 10 nm to about 50 nm.

The invention relates to a high-temperature preventive coating process which is characterized by comprising the process flows of: preparing a caking agent, preparing slurry, spraying, solidifying and heating in a vacuum furnace, wherein the caking agent comprises the following ingredients in mass ratio: 700 to 900g of water, 60 to 90g of chromium trioxide, 70 to 90g of magnesium oxide and 270 to 400g of phosphoric acid; a preparation process of the caking agent comprises the following steps of: adding the phosphoric acid in water, adding the magnesium oxide and fully dissolving, and adding the chromium trioxide, wherein the step of adding the magnesium oxide and fully dissolving adopts a principle of adding in small amount and a plurality of times, that is to say, adding in small amount and then adding again after the solution become clear. The invention changes the traditional process flow, improves the coating performance, can be applied to components and parts that work for a long time in severe environment, and is particularly suitable for a gas turbine.

The invention provides a preparation method of graphene. The preparation method comprises the following steps: firstly, performing a reaction on graphite, chromium trioxide and concentrated hydrochloric acid to obtain an intercalated graphite compound; then mixing the intercalated graphite compound obtained in the previous step with hydrogen peroxide to obtain expanded graphite; and finally, peeling the expanded graphite obtained in the previous step in an aqueous phase to obtain the graphene. In order to overcome the defect of high temperature and high pressure of an existing conventional graphene liquid phase peeling method, a graphene preparation method of low-temperature intercalation, low temperature expansion and aqueous phase peeling is creatively achieved by optimizing and combining raw materials and refining the reaction steps by means of a low-temperature constant-pressure liquid phase peeling method. Therefore, the production cost is lowered, the environmental pollution caused by an organic solvent is also avoided, and the dispersing speed of graphene is also increased.

The invention relates to a refractory castable, and particularly relates to an acid-resisting alkali-resisting refractory castable for a garbage incinerator. The acid-resisting alkali-resisting refractory castable comprises the following raw materials: low-iron sintered mullite, boron carbide powder, silicon carbide, pure calcium aluminate cement, chromium trioxide powder, alpha-Al2O3 fine powder, uf-SiO2, zirconium oxide, magnesium oxide, a water reducing agent, a retarder, an explosion-proof agent and the like. The acid-resisting alkali-resisting refractory castable for the garbage incinerator, provided by the invention, has the advantages of good chemical corrosion resistance, good thermal shock stability, high operating temperature and long service life.

The invention relates to a galvanized layer chromium-free passivant and a use method thereof, wherein the passivant comprises a passivation film-forming agent, an adhesion promoter, an emulsifying agent, acetone and an aqueous solution, when using, the chromium-free passivant and water are diluted according to the proportion of 1: 4 and then put in a passivation tank, a galvanized part is bright-dipped through diluted acid at a plating bath outlet of a continuous electrogalvanizing production line, then enters into the passivation tank under the normal temperature for passivating 5-20 seconds, taken out, flushed with water and dried by hot air. The galvanized layer chromium-free passivant forms a passivation film on the metal surface by reasonably utilizing certain chromium-free organic acids, and the like, has corrosion inhibition property, adopts resin as the promoter as well as the acetone and water as solvents, is prepared by adopting a compound method, free of chromium and used for carrying out passivating treatment instead of chromate and chromium trioxide and eliminates hazards to the environment and the human body from chromium pollution.

The invention relates to a formula system for the abrasive layer of a resin cubic boron nitride (CBN) end face grinding wheel, belonging to the preparation technique of an accurate grinding wheel. The formula system in the invention special for the abrasive layer is designed aiming at the grinding wheel for the grinding processing of an air condition compressor piston. In the invention, graphite, cryolite and silicon dioxide are added in the formula of the abrasive layer of the known resin CBN grinding wheel and chromium trioxide is eliminated, and a bonding agent is still the common phenolic resin. The formula system provided by the invention has the advantages of cheap raw materials and no pollution, and the end face of the manufactured grinding wheel has the combination properties of high tenacity, high strength, high holding force and the like.

The invention relates to a chemical etching agent for displaying the metallurgical structure of INVAR steel and soldered joints thereof and a preparation method thereof. One part of the chemical etching agent comprises the following components: 3-10g of chromium trioxide CrO3, 30-100ml of hydrochloric acid HCL (analytically pure) and 30-100ml of water H2O. The method comprises the following steps: (1) weighing required raw materials based on the prescription of each part of etching agent; and (2) firstly adding the chromium trioxide to water, stirring until the chromium trioxide is completely dissolved to form a mixed solution, then slowly adding the analytically pure hydrochloric acid to the mixed solution, and uniformly stirring to obtain the required chemical etching agent. The chemical etching agent for displaying the metallurgical structure of the INVAR steel and the soldered joints thereof has the advantages of good etching effect, high etching speed and high efficiency, can be stored for long, and has extremely high popularization and application value for the metallographic examination of the INVAR steel and the soldered joints thereof.

The invention discloses a method for preparing a submicron/micron aluminum mold plate. The method comprises the following steps: sequentially putting a high-purity aluminum piece into absolute ethyl alcohol and deionized water for washing, subsequently polishing in an electrochemical mode, performing anode oxidation by taking the polished aluminum piece as an anode, graphite as a cathode and an oxalic acid-ethanol-water mixture solution as electrolyte, so as to obtain a porous aluminum oxide film with an aluminum substrate, regulating anode oxidation conditions such as the voltage and the current density to enter a submicron-order structure unit into a competitive growth mode, so as to form a micron-order structural unit cluster, and putting the porous aluminum oxide film with the aluminum substrate into a mixture solution of chromium trioxide and phosphoric acid for removing the film, thereby obtaining the aluminum mold plate with submicron/micron composite pits in the surface. The method has the advantages that the raw materials are easily available, the cost is low, the equipment is simple, the operation is convenient, the controllability is good and the like, and the feasibility that the method is applied to production is greatly improved.

The invention relates to a trivalent chromium white passivating liquid, wherein, under normal temperature and pressure, water is added into chromium trioxide for mixture and dissolution; seignette salt is added into mixture for stirring, dissolution and reaction; the mixture is kept for a plurality of hours and then stirred; when PH value is between 4 and 5, sulphuric acids are added into the mixture for even stirring; the mixture is kept for a plurality of hours; galvanized parts with over half brightness are immersed into the passivating liquid; the trivalent chromium white passivating liquid is obtained after washing by clear water and drying. The invention has the advantages of capability of directly exhausting cleaning water after passivation, stable nonirritant odor, safe operation and strong corrosion resistance.

The invention discloses a method for preparing a nano/submicron/micron multi-stage anode alumina template. The method comprises the following steps: firstly, washing a high-purity aluminum sheet, and subsequently performing electrochemical polishing; performing anodic oxidation by using an oxalic acid-water-ethanol mixed solution as electrolyte, thereby obtaining a porous anode alumina membrane with an aluminum substrate; enabling a submicron structural unit to enter into a competitive growth mode by adjusting the conditions of voltage and the current density, thereby forming island-shaped and strip-shaped micro-grade structure unit clusters of different shapes; putting the alumina membrane with the aluminum substrate into a chromium trioxide and phosphoric acid mixing solution so as to remove the membrane, subsequently performing low-voltage anode oxidation in an oxalic acid solution, and performing hole expansion treatment by using a phosphoric acid solution, thereby obtaining the anode alumina template of a nano/submicron/micron multi-stage pore pipeline structure. The method has the advantages that the raw materials are easily available, the cost is low, the equipment is simple, the controllability is good, and the like, and the feasibility of industrial production is greatly improved.

The invention discloses a pole lug nickel strap surface treatment passivation solution and a preparing method thereof. A composition comprises water, chromium trioxide, mineral acid and a film formation accelerant. By means of the pole lug nickel strap surface treatment passivation solution, the problems that the passivation film compactness is low, and the bonding performance between a film and pole lug glue is poor are solved.

The invention belongs to the field of plating of metal materials, in particular to technology for manufacturing a black chromium coating on a rotating anode X-ray tube. The plating solution is prepared, and the black chromium coating is directly deposited on a rotor matrix of the rotating anode X-ray tube through plating, without a middle transition plating layer. The plating solution is prepared from the following components by weight: 200 to 400 grams of chromium trioxide, 2 to 4 grams of barium carbonate, 15 to 25 grams of boric acid, 5 to 15 grams of sodium nitrate, 0.05 to 0.15 milliliters of fluosilicic acid and 1,000 milliliters of ionized water. The technology has the advantages that: compared with the prior art, the black chromium coating needs no middle transition plating layer and can be directly deposited on the rotor matrix; and the black chromium coating is applied to a vacuum state and has excellent high temperature resistance, can resist the temperature of between 600 and 700 DEG C, does not foam or wrinkle, has high bonding strength and does not fall off.

A method of preparing pyruvaldehyde by propylene glycol in low temperature liquid phase oxidation highly selectively is characterized in that below 50 to 55 DEG C and in the acidic solvent, taking chromium trioxide as the oxidant and highly selectively oxidizing 1, 2-propylene glycol to pyruvaldehyde. The conversion of the 1, 2-propylene glycol is 100 percent, and the selection of preparing pyruvaldehyde is from 95.6 percent to 99.6 percent.

A fuel pellet and a manufacturing method thereof are disclosed. The method includes S1) weighing raw materials including 0-2% of chromium trioxide, 0-2% of alumina, 0-2% of silicon oxide and 0-2% of niobium pentoxide, with the balance being uranium dioxide; S2) ball milling and fully mixing the raw materials to form a powder mixture; S3) compressing the powder mixture to form a uranium dioxide blank, and subjecting the blank to high-temperature pre-sintering; S4) crushing the blank, sieving the crushed blank, and grinding the crushed blank into uranium dioxide particles; S5) adding beryllium oxide powder into the uranium dioxide particles, mixing the mixture to form powder to be compressed, with each uranium dioxide particle being covered with a cover layer formed from the beryllium oxidepowder; and S6) subjecting the powder to be compressed to compression molding and densification sintering to obtain the fuel pellet. A manner of two times of compound addition and two times of sintering is adopted, and therefore sintering aids form solid solution or are distributed in the uranium dioxide matrix, diffusion or solid solution formation of the sintering aids into the beryllium oxide is reduced, and on the premise that the sintering aids do not influence heat conductivity of the BeO phase, the pellet crystal grain size is effectively increased, and sintering activity is improved.