Zirconia Has A High Melting Point, High Resistivity, And High Refractive Index

Zirconium dioxide (chemical formula: ZrO2) is the main oxide of zirconium. It is white, odorless and tasteless crystals under normal conditions. It is insoluble in water, hydrochloric acid and dilute sulfuric acid. Usually contains a small amount of hafnium dioxide. The chemical properties are inactive, and have the characteristics of high melting point, high resistivity, high refractive index and low coefficient of thermal expansion, making it an important high temperature resistant material, ceramic insulating material and ceramic sunscreen, and it is also the main raw material for artificial drills. The band gap is about 5-7eV.

White heavy amorphous powder. Odorless. Tasteless. Soluble in a mixture of 2 parts sulfuric acid and 1 part water, slightly soluble in hydrochloric acid and nitric acid, slowly soluble in hydrofluoric acid, almost insoluble in water. Irritating. The relative density is 5.85. Melting point 2680 ℃. The boiling point is 4300 ℃. Hardness is inferior to diamond.

Used for making metal zirconium and zirconium compounds, making refractory bricks and crucibles, high-frequency ceramics, abrasive materials, ceramic pigments and zirconates, etc., mainly used for piezoelectric ceramic products, daily-use ceramics, refractory materials and precious metal smelting Zirconium brick, zirconium tube, crucible, etc. It is also used to produce steel and non-ferrous metals, optical glass and zirconium dioxide fiber. It is also used in ceramic pigments, electrostatic paints and baking paints. Used in epoxy resin can increase the corrosion of heat-resistant salt water.

Zirconia fiber is a polycrystalline refractory fiber material. Due to the high melting point, non-oxidation and other high temperature characteristics of ZrO2 itself, ZrO2 fiber has a higher use temperature than alumina fiber, mullite fiber, aluminum silicate fiber and other refractory fiber varieties. The zirconia fiber is used for a long time under an ultra-high temperature oxidizing atmosphere above 1500 ℃. The maximum operating temperature is up to 2200 ℃, and it can still maintain the complete fiber shape even to 2500 ℃, and the high temperature chemical stability, corrosion resistance, oxidation resistance, thermal shock resistance, Non-volatile and non-polluting, it is the most advanced refractory fiber material in the world. The resistance of ZrO2 to acid and alkali corrosion is much stronger than that of SiO2 and Al2O3. Insoluble in water, soluble in sulfuric acid and hydrofluoric acid; slightly soluble in hydrochloric acid and nitric acid. Can be eutectic with alkali to generate zirconate.