Titanium dioxide is the main component of TiO2, chemical stability, in general, with most of the material does not react. Titanium dioxide in nature has three kinds of crystallization: titanium plate, anatase titanium dioxide and rutile titanium dioxide. Titanium type is unstable crystal type, no industrial use value, anatase titanium dioxide (Anatase) referred to as type A, and rutile titanium dioxide (Rutile) referred to as R type, have a stable lattice, is an important white Pigments and porcelain glazes, compared with other white pigments have excellent whiteness, tinting power, hiding power, weatherability, heat resistance, and chemical stability, especially without toxicity.
Titanium Dioxide Both Zinc White is durable and white white cover is high grade white pigment, the biggest advantage is non-toxic, in high-grade cosmetics as a brightener. Its coverage ability, high refractive index, also used to do advanced white paint. Can also be used as a high-grade coated paper surface covering agent, and used to produce whitening nylon. Ceramic can be added to improve the acid resistance of ceramics. Titanium dioxide also has a semiconductor performance, with its non-toxic, inexpensive, high catalytic activity characteristics, as a number of photocatalytic reactions in the most commonly used semiconductor materials. Also used as ethanol dehydration, dehydrogenation catalyst.
At present, the world's consumption of titanium dioxide in the rutile type accounted for 75 to 80%, anatase only 20 to 25%. Since the same belongs to the titanium dioxide series of these two kinds of titanium dioxide What is the difference?
1) Internal structure crystal
There are three different crystal structures of titanium dioxide, that is, we often say that rutile titanium dioxide, anatase titanium dioxide, titanium titanium dioxide, three crystal structure is not the same, which rutile titanium dioxide crystal structure is the most stable; The titanium titanium dioxide is very little use, which is mainly due to the instability of its internal structure of the crystal, so there is no way in the natural long-term stability of the preservation, there is no production value;
As the rutile type crystal products tend to hexahedron, compared with the more easy to disperse anatase evenly, the formation of the agglomerate more uniform. Particle size distribution is more narrow.
2) Melting point and boiling point
As the anatase in high temperature will be converted into rutile type, so the anatase titanium dioxide melting point and boiling point is actually not present. Rutile Titanium dioxide has a melting point of 1850 ° C, the melting point of the air (1830 ± 15) ℃, oxygen in the melting point of 1879 ° C, the melting point and the purity of titanium dioxide. The boiling point of rutile titanium dioxide is (3200 ± 300) ℃, at this high temperature titanium dioxide slightly volatile;
3) Dielectric constant
Due to the high dielectric constant of titanium dioxide, it has excellent electrical properties. In determining the physical properties of titanium dioxide, the crystallization direction of titanium dioxide crystals is taken into account. The dielectric constant of anatase titanium dioxide is relatively low, only 48%
Titanium dioxide has a semiconductor performance, its conductivity increases with the temperature and rapid increase, but also very sensitive to hypoxia. The dielectric constant and semiconducting properties of rutile titanium dioxide are very important to the electronics industry and can be used to produce electronic components such as ceramic capacitors.
According to Mohs hardness of the system scale, rutile titanium dioxide for the 6 to 6.5, anatase titanium dioxide 5.5 to 6.0, so in the chemical fiber extinction in order to avoid wear and tear hole and the use of anatase.
6) Production methods
Although rutile and anatase sulfuric acid production process is basically similar, but the specific parameters there is a big difference. Anatase products are mostly produced using sulfuric acid, but rutile products are now sulfuric acid and chlorinated two.
Anatase products in the basic calcined settlement, after Raymond grinding broken packaging sales, and rutile products in order to better improve its dispersion, weather and other characteristics, after calcination using alumina or zirconium for surface treatment, help with the same also There is a part of the organic processing.
It is not difficult to see through the production method, the cost of rutile titanium dioxide than the anatase high, the price is naturally high, the current situation, rutile titanium dioxide price about anteropium titanium powder higher than the 3000-4000 yuan per ton.
In addition, the A type of titanium dioxide is better than the whiteness, but the color strength is only 70 R-type, in the weather resistance to join the A-type titanium dioxide test piece only after a year after the start of cracking or debris peeling, and adding R-type titanium dioxide After a decade, its appearance is only a small change. As the R-type titanium dioxide coloring and weatherability is better, plastic coloring using R-type titanium dioxide as well.