Physical properties of Titanium Dioxide

Titanium dioxide is an important inorganic chemical pigment, the main component is titanium dioxide. The production process of titanium dioxide has two process routes: sulfuric acid method and chloride method. It has important applications in coatings, inks, papermaking, plastics and rubber, chemical fiber, ceramics and other industries.
Physical properties of titanium dioxide
1) Relative density
Among the commonly used white pigments, titanium dioxide has the smallest relative density. Among white pigments of the same quality, titanium dioxide has the largest surface area and the highest pigment volume.

2) Melting point and boiling point
Since anatase will transform into rutile at high temperature, the melting point and boiling point of anatase titanium dioxide are practically non-existent. 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 enrichment 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
Due to the high dielectric constant of titanium dioxide, it has excellent electrical properties. When determining certain physical properties of titanium dioxide, the crystal orientation of the titanium dioxide crystal should be considered. The dielectric constant of anatase titanium dioxide is relatively low, only 48.
4) Conductivity
Titanium dioxide has the properties of a semiconductor, its conductivity increases rapidly with the rise of temperature, and it is also very sensitive to hypoxia. The dielectric constant and semiconductor properties of rutile titanium dioxide are very important to the electronics industry, which can be used to produce ceramic capacitors and other electronic components.
5) Hardness
According to the scale of Mohs' hardness, rutile titanium dioxide is 6-6.5, and anatase titanium dioxide is 5.5-6.0. Therefore, anatase is used in chemical fiber matting to avoid abrasion of 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. The surface area is large and the hygroscopicity is high. It is also related to the surface treatment and properties.
7) Thermal stability
Titanium dioxide is a substance 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 hiding power and dispersibility can be directly analyzed from the particle size distribution.
The factors affecting the particle size distribution of titanium dioxide are more complicated. The first is to hydrolyze the size of the original particle size. 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 process of metatitanic acid, the particles undergo a crystalline transformation period and a growth period. The appropriate temperature is controlled to keep the growing particles within a certain range. Finally, the product is crushed. The Raymond mill is usually modified and the analyzer speed is adjusted to control the crushing quality. At the same time, other crushing equipment can be used, such as: universal mill, jet mill and hammer mill.