17 results about "Chromium sesquioxide" patented technology

The invention provides near-infrared adjustable double-perovskite type mechanoluminescence fluorescent powder as well as a preparation method and application of the near-infrared adjustable double-perovskite type mechanoluminescence fluorescent powder. The expression general formula of the double perovskite type mechanoluminescence fluorescent powder is Sr2M1-xSbO6: xCr < 3 + >, wherein M is Al, Ga, Sc, In or Y; x is equal to 1%-7%. The preparation process of the fluorescent powder comprises the following steps: a, weighing strontium carbonate, an oxide of M, antimony pentoxide and chromium sesquioxide according to the element proportion in the chemical general formula Sr2M1-xSbO6: xCr < 3 + >; b, mixing the weighed raw materials, and uniformly grinding to obtain a mixture; and c, carrying out high-temperature calcination on the obtained mixture to obtain the near-infrared adjustable double perovskite type mechanoluminescence fluorescent powder. By regulating and controlling the components of the substrate, the emission main peak can be adjusted from 780nm to 946nm. The fluorescent powder provided by the invention can show a self-recovery near-infrared stress luminescence characteristic without pre-irradiation under continuous stress stimulation, is simple to prepare and convenient for industrial batch production, and has a wide application prospect.

The invention relates to the field of refractory materials, in particular to a high-erosion-resistance refractory material based on boron nitride modification and a preparation method of the high-erosion-resistance refractory material. The problem that an existing refractory material is poor in erosion resistance is solved. The refractory material is prepared by taking zirconium dioxide, silicon dioxide, calcium oxide, ferric oxide and aluminum oxide as matrixes and adding samarium lanthanum magnesium aluminum composite gel powder and boron nitride loaded chromium sesquioxide, magnesium nitrate, aluminum nitrate, samarium nitrate, lanthanum nitrate and citric acid form gel, high-temperature treatment is performed to obtain the samarium lanthanum magnesium aluminum composite gel powder, and the samarium lanthanum magnesium aluminum composite gel powder is added to the boron nitride loaded chromium sesquioxide. Boron nitride is loaded with chromium sesquioxide after being treated by tannic acid, the corrosion resistance of the material is enhanced through the synergistic effect of all the components, and the material is suitable for high-temperature furnaces, high-temperature reactors and other industrial environments needing high-temperature resistance and high corrosion resistance.

The invention discloses a petuntse composition, ceramic and application, and relates to the technical field of ceramic. The ceramic disclosed by the invention is obtained by sequentially carrying out ageing treatment, sieving treatment, injection molding, airing, drying and sintering treatment on a petuntse composition. The petuntse composition comprises a ceramic waste material A, a ceramic waste material B and modified particles with gallium-coated cuprous oxide as a core and aluminum oxide as a shell in a specific proportion. And the components such as a high-entropy oxide solid solution generated by the reaction of hafnium oxide, tantalum pentoxide, niobium pentoxide, titanium dioxide, zirconium dioxide, chromium sesquioxide and carbon powder, and chromium heptacarbide are introduced, so that the ceramic prepared from the ceramic waste has excellent fracture toughness, bending strength, wear resistance, high temperature resistance and self-repairing ability. Therefore, the method has a wide application prospect.

The invention belongs to the technical field of solid waste recycling and wastewater treatment, and particularly relates to a method for treating chromium-containing wastewater by adopting organic amine flue gas desulfurization residues. According to the method, the organic amine flue gas desulfurization slag is adopted as a reducing agent, hexavalent chromium is reduced into trivalent chromium, the trivalent chromium is separated from water in a precipitate form, and the precipitate is roasted to obtain chromium sesquioxide powder with relatively high purity in supernate; hexavalent chromium and total chromium can reach the national standard. According to the method, the treatment cost of the hexavalent chromium wastewater and the flue gas desulfurization slag is remarkably reduced, and meanwhile, the resource utilization of the flue gas desulfurization waste in a waste-to-waste manner is also realized.

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 invention relates to the field of electronic materials, and particularly discloses a low-gradient zinc oxide varistor and a preparation method thereof. The invention relates to a low-gradient zinc oxide piezoresistor disc, which is prepared from the following raw materials in parts by weight: 88 to 96 parts of zinc oxide, 1.5 to 3 parts of antimony trioxide, 2 to 5 parts of bismuth trioxide, 0.2 to 1.8 parts of nickel oxide, 0.1 to 0.9 part of cobalt sesquioxide, 0.1 to 0.4 part of manganese oxide, 0.02 to 0.07 part of chromium sesquioxide, 0.15 to 0.18 part of lithium acetate, 1.2 to 1.8 parts of dispersing agents, 1.8 to 2.5 parts of binding agents, 0.12 to 0.15 part of aluminum nitrate and 0.001 to 0.003 part of silver nitrate. Under the synergistic effect of all the components, by adjusting the use ratio of all the components, the potential gradient of the resistor disc can be reduced, the large-current endurance capacity of the resistor disc is improved, and the change of electrical performance after impact is reduced.

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 discloses an Nb-Cr-Al ternary intermediate alloy and a preparation and application method thereof. The Nb-Cr-Al ternary intermediate alloy is prepared by taking aluminum as a reducing agent, niobium pentoxide and chromium sesquioxide as oxidants, calcium fluoride as a slag former and potassium chlorate as a heat generating agent through smelting by adopting a metallothermic reduction method; the Nb-Cr-Al ternary intermediate alloy is evenly mixed with sponge titanium, aluminum shots and Cr70Al alloy in proportion and pressed into an electrode block, then a plasma beam welding box is used for welding the electrode block, a primary electrode is manufactured, vacuum consumable electric arc melting is conducted through a vacuum consumable electric arc furnace, Ti-Al-Nb-Cr alloy is obtained, and the Ti-Al-Nb-Cr alloy is obtained. The high-melting-point Nb-Al intermetallic compound is effectively prevented from appearing in the cast ingot, the uniformity of chemical components of the cast ingot is guaranteed, the stability of the structure and performance of the alloy is guaranteed, and the metallurgical quality and the yield of the cast ingot are effectively improved.

The invention belongs to the technical field of solid waste recycling and wastewater treatment, and particularly relates to a method for combined treatment of organic amine flue gas desulfurization residues and chromium-containing wastewater. According to the method, organic amine flue gas desulfurization residues are used as a reducing agent, phosphoric acid is used for controlling the pH value of wastewater, hexavalent chromium is reduced into trivalent chromium under the acidic condition, meanwhile, desulfurization ash is converted into a melamine phosphate flame-retardant material, and trivalent chromium is separated from water in a precipitation form under the neutral condition; and roasting the precipitate to obtain chromium sesquioxide powder with relatively high purity, and separating and recovering excessive phosphate radicals from the wastewater in the form of calcium phosphate. While the flue gas desulfurization slag and the chromium-containing wastewater are treated, melamine phosphate, chromium trioxide and calcium phosphate byproducts can be recovered, the treatment cost of the wastewater and solid wastes is reduced, and cyclic utilization of resources is realized.

The present application relates to the technical field of firebrick, in particular to a kind of chrome-zirconia corundum composite brick for waste incinerator grate furnace, the composite brick includes the following components by weight parts: white corundum powder 60-75 parts, chromium sesquioxide 7-14 parts, zirconia-silicon carbide composite powder 12-20 parts, magnesium oxide 2-5 parts, kaolin 3-6 parts, binder 1-4 parts;The zirconia-silicon carbide composite powder is made from the following raw materials by weight parts: tetraethyl orthosilicate 0.8-2 parts, anhydrous ethanol 2.5-6 parts, nano zirconia 0.8-1.5 parts, sucrose 2-3 parts, trimethoxysilane 0.4-1 part, deionized water 5.5-6.5 parts.The composite brick of the present application has high density, few internal defects, excellent refractory performance, small deformation under high temperature environment, excellent corrosion resistance, and the damage of incineration slag to the composite brick is small, which can effectively reduce the occurrence of fracture phenomenon and improve the service life of incinerator.

The application discloses a phosphoric acid-containing graphene oxide modified high-temperature anticorrosion ceramic coating material and a high-temperature anticorrosion ceramic coating and belongs to the technical field of high-temperature ceramic coating. The coating material preparation raw material comprises a high-temperature anticorrosion ceramic masterbatch and a phosphoric acid-containing graphene oxide dispersion solution, and the masterbatch components are as follows: 20-30% of silicate adhesive; 10-20% of nano-aluminum nitride; 5-10% of boron nitride; 1-5% of talcum powder; 5-10% of zirconium boride; 10-25% of chromium sesquioxide; 10-20% of aluminum oxide; 1-5% of cerium oxide; and the balance of water. The phosphoric acid-containing graphene oxide dispersion solution is directly applied to the high-temperature ceramic coating material, on the one hand, the problem of utilization of wastewater containing phosphoric acid prepared by a chemical method is solved, and on the other hand, the graphene oxide is used as a hydrophilic two-dimensional network structure to improve the properties of the coating, such as high-temperature resistance, oxidation resistance, high strength, high-temperature gas erosion resistance and the like, in cooperation with the high-temperature anticorrosion ceramic masterbatch.

The invention discloses a method for preparing a chromic oxide and sodium sulfate solution from chromium-containing sodium hydrogen sulfate, which comprises the following steps: preparing chromium-containing sodium hydrogen sulfate into a sheet by a sheet preparation machine, and calcining to obtain a calcined product; adding the calcined product into water to prepare a feed liquid, then adding sodium hydroxide for neutralization to prepare a mixed solution of chromic hydroxide and sodium sulfate, carrying out heat preservation and curing, then carrying out filter pressing to obtain a filter cake, then washing and carrying out filter pressing on the filter cake to obtain a chromic hydroxide filter cake, and carrying out filter pressing to obtain a filtrate which is a sodium sulfate solution; and calcining the chromium hydroxide filter cake to obtain chromium sesquioxide. According to the resource utilization method for the by-product chromium-containing sodium hydrogen sulfate in the chromic anhydride production process, the chromium-containing sodium hydrogen sulfate is converted into chromium sesquioxide and sodium sulfate solutions with high additional values, the problem of poison of waste is solved, and efficient recycling of chromium and sodium hydrogen sulfate is achieved; in addition, the method is simple in process, low in cost and suitable for industrial production.

The invention relates to the field of metallurgy, and provides a vanadium-chromium precursor alloy for hydrogen storage and a preparation method thereof.The method comprises the steps that vanadium pentoxide, chromium sesquioxide, aluminum particles and a slag former are mixed to obtain a mixed furnace burden; the mixed furnace burden is put into a furnace body to be smelted in advance, ignition smelting and electrified refining are carried out, and an alloy cake is obtained; and putting the alloy cake into a water tank for water quenching, soaking for a preset time, and then crushing and screening to obtain the vanadium-chromium precursor alloy. According to the method, the aluminothermic reduction formula and process are deeply optimized, and the high-quality vanadium-chromium alloy is directly prepared from the oxide. The oxygen content and the impurity level in the alloy can be effectively reduced, the alloy purity is remarkably improved, accurate regulation and control of vanadium and chromium components can be achieved, the subsequent hydrogen storage alloy synthesis requirement is met, rich slag generated after refining can be returned to the technological process to be reused, the resource utilization rate is greatly increased, and the production cost is reduced.

The present application belongs to the technical field of ceramic surface treatment, and particularly relates to a ceramic surface protective agent and a preparation method and use method thereof. The ceramic surface protective agent comprises, in parts by weight, 79-92 parts of a condensate, 2-5 parts of an intermediate, 1-3 parts of an emulsifier, 3-8 parts of a zirconium sol, 0.5-2 parts of a nano filler, and 1-3 parts of a hardening agent. The condensate is solid paraffin, the intermediate is glycerol or 1,2-propanediol, the nano filler is a mixture of one or more of zirconium oxide, yttrium sesquioxide and chromium sesquioxide, and the hardening agent is polyethylene wax. The present application aims to develop a new type of ceramic protective agent and a preparation method and use method thereof, greatly improve the corrosion resistance of ceramic plates, and simultaneously have excellent antifouling performance.

The invention relates to the technical field of preparation of high-purity chromium metal, in particular to a preparation method of high-purity chromium metal. The method comprises the following steps: (1) preparing a chromium trichloride solution; (2) purification: purifying the prepared chromium trichloride solution by an ion exchange method; (3) performing spray pyrolysis to prepare chromium sesquioxide; (4) gas-solid separation; and (5) chromium sesquioxide is reduced to prepare high-purity metal chromium. The method comprises the following steps: preparing a chromium trichloride solution by using metal chromium of 3N5, purifying the chromium trichloride solution by using an ion exchange method to remove heavy metal impurities in the chromium trichloride solution, and performing spray pyrolysis on the purified chromium trichloride solution to prepare high-purity chromium sesquioxide powder. Metal and interstitial element impurities such as oxygen, nitrogen and the like and low-melting-point metal impurities in the chromium sesquioxide are removed through a reduction method, and the purity of the prepared high-purity metal chromium reaches 99.999% or above. The preparation method is simple in process and few in control parameters, and the prepared chromium metal is high in purity.

The application provides an antioxidant low-abrasion heat-resistant steam turbine blade coating and a preparation method thereof, and relates to the technical field of material surface treatment, and comprises the following components in mass ratio: nickel-cobalt-chromium-aluminum-yttrium alloy 20-30 parts, zirconia-yttria-alumina composite ceramic 30-40 parts, hafnium powder and rhenium powder mixture 10-15 parts, chromium sesquioxide 5-10 parts, rare earth oxide 3-5 parts, cerium dioxide 2-4 parts, silicon dioxide 3-5 parts, titanium carbide 5-8 parts, and zirconium boride 2-4 parts; the nickel-cobalt-chromium-aluminum-yttrium alloy and the zirconia-yttria-alumina composite ceramic are used in the application, a stable oxide film can be formed at high temperature, the further diffusion of oxygen is effectively prevented, the rare earth oxide and the cerium dioxide can promote the repair and stability of the oxide film, the antioxidant capacity of the coating is improved, and the blade can maintain good performance in a high-temperature environment for a long time.

The invention provides a method for preparing chromium sesquioxide powder by taking chromium-containing wastewater as a raw material, and belongs to the field of sewage treatment. The method for preparing the chromium sesquioxide powder by taking the chromium-containing wastewater as the raw material comprises the following steps: mixing the chromium-containing wastewater and a pH regulator, carrying out precipitation reaction, and then carrying out solid-liquid separation to obtain a dichromate solution; the pH value of the precipitation reaction is 2-4; after the dichromate solution flows through weak base anion resin to be treated, hexavalent chromium adsorption saturated resin is obtained; ammonia water is adopted to analyze the hexavalent chromium adsorption saturated resin, and a mixed solution is obtained; the mixed solution is a mixed solution of ammonium chromate and ammonium dichromate; the mixed solution is sequentially subjected to evaporation concentration, spray drying and calcination, and chromium sesquioxide powder is obtained. The method provided by the invention is simple in preparation steps, the obtained chromium sesquioxide powder is uniform in particle size, the purity can reach 99.6%, and the purity requirement of pigment-grade chromium sesquioxide is met.