Titanium dioxide (TiO2) is an important inorganic chemical product, which has important uses in coatings, inks, papermaking, plastic rubber, chemical fiber, ceramics and other industries. Titanium dioxide (English name: titanium dioxide) is a white pigment whose main component is titanium dioxide (TiO2). The scientific name is titanium dioxide (titanium dioxide), and the molecular formula is TiO2. It is a polycrystalline compound whose particles are regularly arranged and have a lattice structure. The relative density of titanium dioxide is the smallest. The production process of titanium dioxide has two process routes: sulfuric acid method and chlorination method.
Main features:
1) Relative density
Among the commonly used white pigments, the relative density of titanium dioxide is the smallest. Among the white pigments of the same quality, the surface area of titanium dioxide is the largest and the pigment volume is the largest.
2) Melting point and boiling point
Since the anatase type transforms into a rutile type at high temperature, the melting point and boiling point of anatase titanium dioxide do not actually exist. Only rutile titanium dioxide has a melting point and boiling point. The melting point of rutile titanium dioxide is 1850 ° C, the melting point in air is (1830 ± 15) ° C, and the melting point in oxygen-rich is 1879 ° C. The melting point is related to the purity of titanium dioxide. The boiling point of rutile titanium dioxide is (3200±300)°C, and titanium dioxide is slightly volatile at this high temperature.
3) Dielectric constant
Titanium dioxide has excellent electrical properties due to its high dielectric constant. When determining some physical properties of titanium dioxide, the crystallographic direction of titanium dioxide crystals should be considered. The dielectric constant of anatase titanium dioxide is relatively low, only 48.
4) Conductivity
Titanium dioxide has semiconductor properties, its conductivity increases rapidly with temperature, and it is also very sensitive to oxygen deficiency. The dielectric constant and semiconductor properties of rutile titanium dioxide are very important to the electronics industry, and these properties can be used to produce electronic components such as ceramic capacitors.
5) Hardness
According to the scale of Mohs hardness, the rutile titanium dioxide is 6-6.5, and the anatase titanium dioxide is 5.5-6.0. Therefore, in the chemical fiber extinction, the anatase type is used to avoid the wear of the spinneret holes.
6) Hygroscopicity
Although titanium dioxide is hydrophilic, its hygroscopicity is not very strong, and the rutile type is smaller than the anatase type. The hygroscopicity of titanium dioxide has a certain relationship with the size of its surface area. Large surface area and high hygroscopicity are also related to surface treatment and properties.
7) Thermal stability
Titanium dioxide is a material with good thermal stability.
8) Granularity
The particle size distribution of titanium dioxide is a comprehensive index, which seriously affects the performance of titanium dioxide pigments and product application performance. Therefore, the discussion of covering power and dispersibility can be directly analyzed from the particle size distribution.
The factors affecting the particle size distribution of titanium dioxide are complex. The first is the size of the original particle size of hydrolysis. By controlling and adjusting the hydrolysis process conditions, the original particle size is within a certain range. The second is the calcination temperature. During the calcination of metatitanic acid, the particles undergo a crystal transformation period and a growth period, and the appropriate temperature is controlled to make the growth particles within a certain range. The last step is the pulverization of the product. Usually, the modification of the Raymond mill and the adjustment of the analyzer speed are used to control the pulverization quality. At the same time, other pulverizing equipment can be used, such as: high-speed pulverizer, jet pulverizer and hammer mills.
Post time: Jul-28-2023