Zirconia special refractory products have become a very important furnace lining for ultra-high temperature industrial applications due to their high operating temperature (2200 ° C ~ 2400 ° C), wide adaptability (various atmospheres in the kiln), and strong slag corrosion resistance. Material.

　　1、Slurry cast molding products

　　Zirconia slurry casting products are produced by acid slurry casting.

　　Using high-purity zirconia and high-purity calcium hydroxide as raw materials, mixed and finely ground according to ZrO2:CaO=95:5, pressed into blocks, and kept at 1250 ℃ for 4 hours for stabilization treatment. After the stabilizer is pulverized, 15% monoclinic zirconia is added, and the particle size is finely ground to less than 3µm. If the fine abrasive is used in the iron ball mill, pickling is also required to remove iron, and the metal iron content is less than 0.01%.

　　The density of zirconia mud is required to be 1.9～2.1g/cm3, and the pH value=1.7～1.9. It is formed by casting with plaster mold, and the mold setting rate is 15%. The operation method is the same as that of alumina slurry casting products. The product was put into an electric furnace immediately after demoulding, and was calcined at 850°C for 2 hours. After cooling, it is trimmed and shaped with sandpaper, and finally fired in a high-temperature kiln at 1800-1850 °C for 4-6 hours.

　　2、Hot pressure injection molding heating element products

　　The zirconia heating element can be used as the heating element of the high temperature resistance furnace at 1700℃～2000℃.

　　Using high-purity gas valve through zirconium, calcium oxide, yttrium oxide, and cerium oxide as raw materials, the ingredients can be as follows: zirconia 87%, gas valve through calcium 13%, zirconia 90%, yttrium oxide 10%; zirconia 75% %, cerium oxide 25% three ingredients. The ingredients are mixed and finely ground in a ball mill, and the particle size is less than 3µm and more than 80%. Add 6% polyvinyl alcohol aqueous solution (concentration 10%) to the finely ground powder, mix it evenly, pass through a 0.5mm sieve, make a green body with a pressure of 100MPa, and keep it at 1730 °C for 4 hours to make a stable zirconia clinker.

　　After stabilization, the fine grinding particle size of the clinker is less than 95% of the point less than 10µm. If it is ground in an iron ball mill, it should be pickled to remove iron, dried and pulverized.

　　The preparation of wax slurry is 85% stabilized zirconia dry powder, 13.5% paraffin wax, 1% yellow wax, and 0.5% mixed fatty acid. Hot mixing is carried out at a temperature of 70-80°C. The wax slurry should be free of powder lumps and bubbles.

　　It is formed on a hot press injection machine with a metal mold, the temperature of the wax slurry is kept at 60 ~ 70 ° C, and the mold release rate is 13% ~ 15%. The specific operation method is the same as that of alumina hot pressure injection products.

　　The hot-pressed green body was filled with industrial alumina in a sagger, and was dewaxed at 1200°C for 4h. The product is sintered by hanging method in a vacuum furnace with a vacuum degree of 1×10-5kPa (1×10-4mmHg), and kept at 1650°C for 3h.

　　3、Isostatic pressing products

　　Using yttria-stabilized zirconia as raw material, after fine grinding, granulation is carried out, and TZP zirconia ceramic grinding media balls are produced by dry pressing method on an isostatic press. The medium ball has high density, good toughness, high hardness, high grinding efficiency and good effect, and can be used as grinding medium ball for special refractory materials.

　　Physical and chemical performance index of slide bricks for steelmaking and continuous casting by isostatic pressing: ZrO2≥94%, Y2O3≥1.5%, Y2O3+CaO+MgO%～5%, Al2O3<0.2%, stability 70%～80℃ , bulk density 4.65～5.0g/cm³, apparent porosity 15%～20%, compressive strength 100MPa, thermal shock resistance (1100℃ water cooling) ≥3 times.

　　4、Pressed zirconia bricks

　　Using fused stabilized zirconia as raw material, according to the machine pressing method, the zirconia bricks fired at 1800°C for 6 to 10 hours can be used for the thermal lining of various ultra-high temperature electric furnaces and the lining of carbon black furnaces. The temperature can reach 2000℃～2400℃.

　　5、Zirconium oxide brick formed by fusion casting method

　　This product is mainly used in various low alkali glass furnaces, such as hard borosilicate glass furnaces (laboratory glass, cooking glass, closed headlight glass and E-glass furnaces), aluminosilicate glass furnaces Glass kilns (photomask glass, glass ceramic and S glass fiber kilns). The fused cast brick has high density, strong resistance to glass liquid erosion, good use effect, and does not produce streaks and spots on various glass.

　　The production process of this product is to use a three-phase electric arc furnace to fuse zirconia and cast it in a zirconium mold, and then perform slow cooling treatment in an incubator or an annealing furnace to prevent cracks.

　　6、Application of zirconia products

　　The melting point of zirconia is 2650℃, the true density is 5.63g/cm³, the Mohs hardness is 6.5, the temperature is 20～1000℃, the average linear expansion coefficient (℃-1) is 10×10-6, and the thermal conductivity is 3～4W/(m ·k). The chemical stability of zirconia material is excellent, it is not easy to decompose, it is not easy to react with other oxides, and it has strong corrosion resistance to slag, molten steel and glass liquid. With electrical conductivity at high temperature, zirconia products are widely used.　

      Iron and steel industry: continuous casting long nozzle, sliding nozzle, sizing nozzle, uneven continuous casting separation ring

      Building materials industry: glass kiln, glass fiber kiln, high temperature kiln furniture

      High temperature engineering: 2000～2300℃ high temperature furnace, intermediate frequency furnace, high frequency furnace, molybdenum wire furnace, tungsten rod furnace, fuel (steam) furnace, carbon black furnace and other furnace lining products can be used

      Ceramic products: smelting rare metals, precious metal crucibles, high-temperature furnace tubes, protective tubes, wear-resistant balls, plunger pump cores, wire drawing dies, engine structural ceramics, scissors tools, bearings, springs

      Conductive products: heating element, zirconium tube for oxygen fixer, magnetic fluid power generation electrode

      Unshaped material: zirconia fiber, light brick, plasma spray coating, titanium alloy precision casting sand, castable