Titanium dioxide

Physical properties：

　　1)Relative density

　　Among the commonly used white pigments, the relative density of titanium dioxide is the smallest, and the surface area of titanium dioxide is the largest and the pigment volume is the highest among the white pigments of the same quality.

　　2)Melting point and boiling point

　　The melting and boiling points of anatase titanium dioxide are practically non-existent because anatase will turn into rutile under high temperature. Only rutile titanium dioxide has a melting point and boiling point, the melting point of rutile titanium dioxide is 1850 ℃, the melting point in air is (1830 ± 15) ℃, the melting point in rich oxygen is 1879 ℃, the melting point is related to the purity of titanium dioxide. The boiling point of rutile titanium dioxide is (3200±300)℃, at this high temperature titanium dioxide is slightly volatile.

　　3) dielectric constant

　　Because of the high dielectric constant of titanium dioxide, so has excellent electrical properties. In the determination of certain physical properties of titanium dioxide, to consider the crystallization direction of titanium dioxide crystals. The dielectric constant of anatase titanium dioxide is relatively low, only 48.

　　4) Electrical conductivity

　　Titanium dioxide has the properties of a semiconductor, its conductivity increases rapidly with the rise of temperature, and is also very sensitive to the lack of oxygen. Rutile titanium dioxide dielectric constant and semiconductor properties of the electronics industry is very important, can use this property to produce ceramic capacitors and other electronic components.

　　5) Hardness

　　According to the Mohs hardness ten system scale, rutile titanium dioxide for 6 ~ 6.5, anatase titanium dioxide for 5.5 ~ 6.0, so in the chemical fiber matte to avoid wear spinneret hole and use anatase titanium type.

　　6) hygroscopicity

　　Although titanium dioxide has hydrophilic, but its hygroscopicity is not too strong, rutile type than anatase for small. The hygroscopicity of titanium dioxide has a certain relationship with the size of its surface area, large surface area, high hygroscopicity, but also with the surface treatment and nature.

　　7) Thermal stability

　　Titanium dioxide belongs to the material with good thermal stability.

　　8) Particle size

　　Titanium dioxide particle size distribution is a comprehensive index, which seriously affects the titanium dioxide pigment performance and product application performance, therefore, the discussion of coverage and dispersion can be directly analyzed from the particle size distribution.

　　The factors affecting the particle size distribution of titanium dioxide are more complex, the first is the size of the original particle size of hydrolysis, by controlling and adjusting the hydrolysis process conditions, so that the original particle size within a certain range. Second is the calcination temperature, metatitanic acid in the process of calcination, the particles undergo a crystalline transformation period and growth period, control the appropriate temperature, so that the growth of particles in a certain range. The last is the crushing of the product, usually the transformation of Raymond mill and the adjustment of the analyzer speed to control the crushing quality, while other crushing equipment can be used, such as: universal mill, airflow crusher and hammer mill device.