Preparation method of zirconia ceramic powder

Zirconia ceramic powder is the main component for preparing zirconia ceramics. The preparation methods of zirconia ceramic powder are mostly chemical and also physical methods. Below, let's take a look at the Kezhong Ceramic Factory to explain its preparation methods.

Zirconia ceramics are usually white, odorless, and tasteless crystals that are difficult to dissolve in water, hydrochloric acid, and dilute sulfuric acid. Its chemical properties are inactive, and its properties of high melting point, high resistivity, high refractive index and low thermal expansion coefficient make it an important high-temperature resistant material, ceramic insulating material and ceramic sunscreen, as well as a main raw material for manual drilling.

Pyrolysis of zirconium oxychloride: zircon and caustic soda are fused at 650 ℃, the molten body is leached by hot water, and silicon is separated from sodium zirconate in the form of sodium silicate. Treat with sulfuric acid to obtain a zirconium sulfate solution, further remove impurities, add ammonia water, and precipitate zirconium hydroxide. Dissolve zirconia hydroxide in hydrochloric acid to obtain zirconia chloride, which is evaporated, concentrated, cooled, crystallized, crushed, and roasted to obtain zirconia dioxide finished product; In addition, easily purified zirconia compounds can be thermally or oxidatively decomposed to prepare high-purity zirconia.

Colloidal method: In a zirconia solution, silica sol is added to form a colloidal solution, which is formed by spraying and wire drawing methods. After drying, it is sintered into fibers.

Extrusion method: The zirconia sol or zirconia particles and thickener are used to make a billet, and the billet is extruded from the machine mouth using hydraulic pressure or the propulsion effect of a screw cutter to form fine wires, which are then sintered and solidified to form fibers. The fibers obtained by this method are thicker and have lower strength.

Immersion method: First, immerse the adhesive fiber or the entire fabric in a zirconia solution for a long time to make the adhesive fiber swell, and then undergo pyrolysis and calcination to obtain zirconia fiber with a certain tensile strength.

Hydrolysis method: High purity ultrafine zirconia is prepared by hydrolysis of zirconium oxychloride as raw material. A high purity zirconium oxychloride solution of 0.2-0.3mol/L is hydrolyzed with deionized water, and the zirconium oxychloride solution is boiled for a long time to continuously evaporate and remove the hydrogen chloride generated by hydrolysis. The hydrolysis reaction is carried out under boiling for more than 50 hours, then filtered, washed with deionized water, dried, and calcined to obtain the product.

High temperature hydrolysis method: A 1mol/L high-purity zirconium oxychloride solution is sprayed into a decomposition furnace at a temperature of 1000 ℃. Small zirconium oxychloride droplets first evaporate water, and then hydrolyze to produce zirconia. The decomposed zirconia is collected by a cyclone separator, and then subjected to acid washing, water washing, and drying to obtain the product.

Sol gel method: add alcohol and water into zirconium alcohol [ZrO (C3H7) 4], then add catalyst, after full mixing, start decomposition, place it to make it gelatinize and become viscous liquid, select appropriate viscosity, dry it, heat it to 500~1000 ℃, and then burn it at high temperature to obtain the product.

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