5 results about "Chromium sesquioxide" patented technology

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 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 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 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.