Zirconium is a chemical element, its chemical symbol is Zr, its atomic number is 40, is a high melting point metal, was light gray. Density of 6.49 g / cm3. The temperature of 1852 ± 2.001 ° C, the boiling point of 4377 ° C. Valence + 2, + 3 and +4. The first ionization energy is 6.84 eV. Zirconium surface is easy to form a layer of oxide film, with a gloss, so the appearance and steel similar. Corrosion resistance, soluble in hydrofluoric acid and aqua regia, high temperature, with non-metallic elements and many metal elements to produce solid solution compounds. The article details the history of zircon discovery, development history, physical and chemical properties, preparation methods, content distribution, use, safety measures and so on.
Basic properties Zirconium easily absorbs hydrogen, nitrogen and oxygen; zircon has a strong affinity for oxygen, and 1000 ° C of oxygen is dissolved in zirconium to increase its volume significantly. Zirconium surface is easy to form a layer of oxide film, with a gloss, so the appearance and steel similar. Corrosion resistance, but soluble in hydrofluoric acid and aqua regia. High temperature, with non-metallic elements and many metal elements to generate solid solution. Zirconium plasticity is good, easy to process into a plate, silk and so on. Zirconium in the heating can absorb a lot of oxygen, hydrogen, nitrogen and other gases, can be used as hydrogen storage materials. The corrosion resistance of zirconium is better than that of titanium, close to niobium and tantalum. Zirconium and hafnium are similar in chemical properties, but also together with the two metals, and contains radioactive material.
Zirconia is a natural mineral raw material, mainly oblique zircon and zircon. Zirconite igneous rock deep mineral, the color is yellow, brown, yellow and green, etc., the proportion of 4.6-4.7, hardness of 7.5, with a strong metallic luster, ceramic glaze for raw materials. Pure zirconia is a high grade refractory material with a melting temperature of about 2900 ° C. It can improve the high temperature viscosity of the glaze and increase the viscosity of the temperature range, with good thermal stability, its content is 2% -3% , Can improve the anti-cracking performance of glaze. But also because of its chemical inertia, it can improve the chemical stability of glaze and acid and alkali resistance, but also play the role of opacifying agent. In the construction of ceramic glaze in the use of zircon, the general amount of 8% -12%. And for the "underglaze white" the main raw material, zirconia for the yellow-green pigment good auxiliary agent, if you want to get a better vanadium zircon yellow pigment must be selected pure pure zirconia.
ZrSiO4, high refractive index of 1.93-2.01, chemical stability, is a high quality, inexpensive emulsion, is widely used in a variety of building ceramics, sanitary ceramics, ceramics for daily use, a ceramic crafts, In the ceramic glaze processing production, the use of a wide range of applications. Zirconium silicate is widely used in ceramic production, but also because of its good chemical stability, which is not affected by ceramic firing atmosphere, and can significantly improve the ceramic glaze bonding performance, improve the ceramic glaze hardness. Zirconium silicate is also in the television industry color picture tube, glass industry, emulsified glass, enamel glaze production has been further applied. Zirconium silicate high melting point: 2500 degrees Celsius, so in refractory materials, glass kiln zirconium ramming material, castable, spray paint is also widely used.
Zr index, the post-treatment process used to measure the degree of solvent degradation indicators. 95Zr is an important lobes, and the degraded solvent has a high selectivity for 95Zr. The greater the zirconium index, the more serious degradation of the solvent. The zirconium index (Z value) is measured by the following steps: the organic phase is washed with sodium hydroxide, water and nitric acid after stripping, equilibrated with the tracer amount 95Zr and the organic phase is washed 3 times with 3mol / L nitric acid. TBP extraction of 95Zr. The amount of zirconium retained in the solvent phase was determined, and the number of moles of Zr95 retained per 109 L of solvent was the Z value of the solvent. As the zirconium in the aqueous solution of complex behavior, with the measurement conditions are different, Z value will be different, and thus commonly used to characterize the stability of the solvent stability: Goldberg - Hoghes box.
Storage often with less than 25% water wetting, passivation. Store in a cool, ventilated warehouse. Away from fire, heat. Packaging sealed. Should be stored separately with the acid, should not be mixed storage. Explosion-proof lighting, ventilation. Prohibit the use of mechanical equipment and tools that are prone to sparks. The storage area should be equipped with suitable materials to contain spills. In the transport process to prevent rain, shock. Be careful when handling, to prevent collision and rolling, to prevent mechanical damage