Zirconia, chemical formula ZrOtwo, YeszirconiumMain points ofoxide, usually white odorless and tasteless crystal, insoluble in waterhydrochloric acidandDilute sulfuric acid。Chemical property is inactive, and it has high melting point and highresistivity, HighRefractive indexandLow coefficient of thermal expansionWhich makes it importantHigh temperature resistant materialCeramic insulating materials and ceramic sunscreen are also the main raw materials for manual drills.
Chinese name
Zirconia[4]
Foreign name
Zirconium dioxide[4]; Zirconia
Alias
Zirconic anhydride[4]；Zirconia[4]
chemical formula
ZrOtwo
molecular weight
one hundred and twenty-three point two two three[4]
3. Zirconia is a kind ofAmphoteric oxideZirconate can be formed by co melting with alkali, but it is easy to hydrolyze and precipitate when encountering water[1]：
5. It is formed by interaction with carbon in the arcZirconium carbide：
Preparation method
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Production method
1. Pyrolysis of zirconium oxychloride:ZirconMelting with caustic soda at 650 ℃, hot water leaching of molten body, siliconSodium silicateForm andSodium zirconateSeparation.And then treated with sulfuric acid to obtainZirconium sulfateSolution, add after further impurity removalammonia, precipitatedZirconium hydroxide。plushydrochloric acidDissolve zirconia to obtainZirconium oxychlorideAfter evaporation concentration, cooling crystallization, crushing and roasting, the finished zirconia is obtained;In addition, zirconium compounds that are easy to be purified can also be thermally or oxidatively decomposed to prepare high-purity zirconia.
2. Colloid method: add silica sol into zirconia solution to prepare a colloidal solution, which is formed by injection and wire drawing, and sintered into fiber after drying.
3. Extrusion method: put zirconia sol or zirconia particles andThickening agentWhen the billet is made, the billet is extruded from the machine mouth into filaments by hydraulic pressure or by the propelling action of the spiral cutter, and then becomes fibers after sintering and curing.The fiber produced by this method is thicker and has lower strength.
4. Immersion method: First, the viscose filament or the whole fabric is immersed in zirconia hydroxide solution for a long time to make the viscose fiber swell, and then the zirconia fiber with certain tensile strength is obtained through pyrolysis and calcination.
5. Hydrolysis method: high-purity superfine zirconia is prepared by hydrolysis of zirconium oxychloride as raw material. 0.2~0.3 mol/L high-purity zirconia oxychloride solution is hydrolyzed by adding deionized water, and the zirconium oxychloride solution is boiled for a long time, so that the hydrogen chloride generated by hydrolysis is continuously evaporated and removed. The hydrolysis reaction is carried out under boiling for more than 50 hours, then filtered, washed, dried, calcined and crushed with deionized water to obtain the product.
6. High temperature hydrolysis method: 1 mol/L high-purity zirconium oxychloride solution is sprayed into the decomposition furnace at 1000 ℃. The tiny zirconium oxychloride droplets first evaporate water, and then hydrolyze to produce zirconia.The decomposed zirconia is collected by the cyclone separator, and then pickled, washed and dried to obtain the product.
sevenSol gel method: In zirconium alcohol [ZrO (CthreeH7)4]Add alcohol and water, and then add catalyst. After full mixing, it begins to decompose. Place it to make it gelatinize and become viscous liquid. Select appropriate viscosity, dry it, and then heat it to 500~1000 ℃. The product is fired at high temperature.
8. Alcoholic salt solution:Zirconium tetrachloride、ammoniaandPropanolIt is used as raw material to prepare high-purity superfine zirconia. In the presence of benzene solvent, high-purity zirconium tetrachloride reacts with propanol and ammonia at 5 ℃ to prepare zirconium alkoxide. After filtration, ammonium chloride is removed, and then hydrolyzed, precipitated and filtered with water. The product is dried, calcined and crushed at not less than 100 ℃. Hydrolysis conditions directly affect the particle size, shape and coagulation of the product.This method can produce ZrO with uniform particle size and shape and single structural phasetwo。
9. SetZirconium oxychloride（ZrCltwoO·8HtwoO) The product is recrystallized with hydrochloric acid or methanol and calcined at high temperature to obtain the finished product.
10. Distill and purify tetraalkoxy zirconium, and decompose its steam at 350~500 ℃ to obtain the finished product.
11. Distill and purify zirconium tetrachloride, and its vapor reacts with excess oxygen at 1200 ℃ to obtain zirconia.
Preparation process
The stabilized zirconia of industrial refractory materials is mostly produced by electric melting.In the process of zircon electrofusion, carbon and stabilizer calcium oxide are addedcalcium oxideThe stable zirconia can be prepared by crushing and granulating the solid solution generated by the reaction.The stabilized and partially stabilized zirconia used in fine ceramics is usually produced by wet process.The most mature and commonly used method is neutralization precipitation method, and its preparation process is shown in the figure below.Dissolve the purified zirconium oxychloride in pure water, filter to remove insoluble matters, adjust the zirconium concentration in the solution, and add the required amount ofYttrium chlorideAfter solution (or chloride solution of other rare earth metals or alkaline earth metals), add ammonia water and precipitate.The precipitate is washed with hot water and then filtered, dried and calcined.The calcined product can be crushed to obtain ultra fine stabilized zirconia powder.
Partially stabilized zirconia is prepared by controlling the amount of stabilizer added so that it is not sufficiently stable.Partially stabilized zirconia has high strength and thermal shock resistance, and is widely used in structural ceramics.[1]
flow chart
The following figure shows the process of preparing zirconia
Zirconia production flow chart[1]
application area
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Synthetic raw materials
It is used for making zirconium metal and zirconium compounds, refractory bricks and crucibles, high-frequency ceramics, abrasive materials, ceramic pigments and zirconates, etc. It is mainly used for piezoelectric ceramic products, daily ceramics, refractory materials and zirconium bricks, zirconium tubes, crucibles, etc. for smelting precious metals.It is also used to produce steel and non-ferrous metals, optical glass and zirconia fiber.It is also used for ceramic pigments, electrostatic coatings and baking paints.When used in epoxy resin, it can increase the corrosion of heat-resistant salt water.
Refractory
Zirconia fiber is a kind of polycrystalline refractory fiber material.Due to ZrOtwoThe high melting point, non oxidation and other high temperature characteristics of the material itself make ZrOtwoThe fiber has a higher service temperature than alumina fiber, mullite fiber, aluminum silicate fiber and other refractory fiber varieties.Zirconia fiber has been used for a long time in an ultra-high temperature oxidizing atmosphere above 1500 ℃. The maximum use temperature is up to 2200 ℃, and even up to 2500 ℃, it can still maintain a complete fiber shape, and has stable high-temperature chemical properties, corrosion resistance, oxidation resistance, thermal shock resistance, non volatilization, and no pollution. It is the world's top refractory fiber material.ZrOtwoIts acid and alkali corrosion resistance is much better than that of SiOtwoAnd AltwoOthree。Insoluble in water, soluble in sulfuric acid and hydrofluoric acid;Slightly soluble in hydrochloric acid and nitric acid.It can be fused with alkali to form zirconate.
gas turbine
The application of plasma sprayed zirconia thermal barrier coating in aviation and industrial gas turbines has made great progress, and has been used in the turbine part of gas turbines to a certain extent.Since this coating can reduce the temperature of air-cooled high-temperature components by 50~200 ℃, it can significantly improve the durability of high-temperature components, or allow to increase the gas temperature or reduce the demand for cooling gas while maintaining the temperature borne by high-temperature components, thus improving the efficiency of the engine.[3]
ceramic material
Zirconia is used as kiln raw material because of its large refractive index, high melting point and strong corrosion resistance.Piezoelectric ceramic products include filters, loudspeakers, ultrasonic underwater acoustic detectors, etc.There are also daily ceramics (industrial ceramic glaze), zirconium bricks and zirconium tubes for smelting precious metals.Nano zirconia can also be used as polishing agent, abrasive, piezoelectric ceramics, precision ceramics, ceramic glaze and high-temperature pigment matrix materials.
other
In addition, zirconia can be used in the manufacture of white hot gas lampshade, enamel, white glass, refractory crucible, etc.X-ray radiography.Abrasive material.It is used together with yttrium to manufacture light source lamps, thick film circuit capacitor materials, and piezoelectric crystal transducer formulas in infrared spectrometers.
Calculate chemical data
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data[5]：
1. Reference value for drainage parameter calculation (XlogP): None
2. Number of hydrogen bond donors: 0
3. Number of hydrogen bond receptors: 2
4. Number of rotatable chemical bonds: 0
5. Number of tautomers: none
6. Topological molecular polar surface area 34.1
7. Number of heavy atoms: 3
8. Surface charge: 0
9. Complexity: 18.3
10. Number of isotope atoms: 0
11. Determine the number of atomic structure centers: 0
12. Number of uncertain atomic structure centers: 0
13. Determine the number of chemical bond structural centers: 0
14. Number of indeterminate chemical bond structure centers: 0
15. Number of covalent bond units: 1
Molecular structure data
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data[5]：
1. Molar refractive index: None available
2. Molar volume (cmthree/Mol): None available
3. Isotonic specific volume (90.2K): none available
4. Surface tension (dyne/cm): none available
5. Dielectric constant: None available
6. Polarization (10-24cmthree）: No available
7. Single isotope mass: 121.894531 Da
8. Nominal mass: 122 Da
9. Average mass: 123.2228 Da
Storage and transportation
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It shall be stored in a dry warehouse and shall not be stored and transported together with strong alkali articles.
Security risk
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Dangerous goods mark:Xi
Irritant RTECS No.: ZH8800000[1]
Risk terminology
R36/37: Irritating to eyes and respiratory system.
Safety terminology
S26: In case of contact with eyes, please wash with plenty of water immediately and ask for doctor's advice.
S36/37: Wear appropriate protective clothing and gloves.
