Titanium dioxide, titanium dioxide (TiO2), molecular weight: 79.88, is a white inorganic pigment, non-toxic, the best opacity, the best whiteness and brightness, is considered to be the world's best performance of a white pigment , Widely used in coatings, plastics, paper, printing inks, chemical fiber, rubber, cosmetics and other industries.
Titanium dioxide has two main crystalline forms: anatase, abbreviated A and rutile, or R for short.
The paint industry is the largest user of titanium dioxide, especially rutile titanium dioxide, which is consumed by the paint industry. With the development of China's automobile industry and construction industry, the coating industry not only needs more titanium dioxide in quantity, but also has higher requirements on the variety and quality. Coatings made of titanium dioxide, colorful, high hiding power, strong coloring, dosage, many varieties, the physical stability of the media can play a protective role, and can enhance the mechanical strength and adhesion of paint film, to prevent cracks Prevent ultraviolet light and moisture penetration and extend the life of the paint film.
The plastics industry is the second largest user of titanium dioxide. The addition of titanium dioxide in plastic can improve the heat resistance, light resistance and weather resistance of plastic products, improve the physical and chemical properties of plastic products, enhance the mechanical strength of the products and prolong their service life.
The paper industry is the third largest user of titanium dioxide. Titanium dioxide is used as a paper filler and is mainly used in fine paper and thin paper. Adding titanium dioxide to the paper can make the paper have good whiteness, good gloss, high strength, thinness and smoothness, and it does not penetrate during printing, and its quality is light. Titanium dioxide for papermaking generally uses anatase titanium dioxide that has not been surface-treated. It can act as an optical brightener and increase the whiteness of the paper. However, laminates require the use of surface-treated rutile titanium dioxide to meet the light and heat resistance requirements.
Titanium dioxide is an indispensable white pigment in advanced inks. The ink containing titanium dioxide is durable without discoloration, has good surface wetting and is easy to disperse. The titanium dioxide used in the ink industry is rutile and anatase.
Textile and chemical fiber industry is another important application field of titanium dioxide. Titanium dioxide for chemical fiber is mainly used as matting agent. Anatase is generally used because anatase is softer than rutile. Titanium dioxide for chemical fiber generally does not need surface treatment, but some special varieties need to be surface treated in order to reduce the photochemical effect of titanium dioxide and avoid degradation of the fiber under the photocatalytic action of titanium dioxide.
Titanium dioxide in the rubber industry both as a colorant, but also with reinforcing, anti-aging, filling effect. Titanium dioxide is added to white and color rubber products. Under sunlight exposure, it is resistant to sunlight, no cracking, no discoloration, and high stretch rate and acid and alkali resistance. Titanium dioxide for rubber is mainly used for automobile tires and rubber shoes, rubber flooring, gloves, sports equipment, etc., and is generally based on anatase type. However, when used in the production of automobile tires, a certain amount of rutile-type products are often added to enhance their ozone resistance and UV resistance.
Titanium dioxide is also increasingly used in cosmetics. Since titanium dioxide is nontoxic, it is far superior to white lead, so almost all kinds of powders use titanium dioxide instead of white lead and zinc white. Only the addition of 5-8% titanium dioxide powder in the powder can get permanent white, make the spices more creamy, there is adhesion, absorption and hiding power. Titanium dioxide in gouache and cold cream can reduce greasy and transparent feeling. Titanium dioxide is often used in other spices, sunscreens, soap tablets, white soaps, shaving creams and toothpastes.
The enamel prepared with titanium dioxide has strong transparency, light weight, strong impact resistance, good mechanical properties, vivid colors, and no pollution.
There are also two methods of titanium dioxide production: Sulphate Process and Chloride Process.
Sulfuric acid method is the titanium iron powder and concentrated sulfuric acid acid hydrolysis reaction of production of titanium sulphate, hydrolyzed to generate metatitanic acid, and then calcined, crushed to obtain titanium dioxide products. This method can produce anatase and rutile titanium dioxide. The advantage of the sulfuric acid method is that it can use ilmenite and sulfuric acid, which are easily available at low prices, as the raw material. The technology is mature, the equipment is simple, and the anti-corrosion material is easy to solve. The disadvantages are the long process, which can only be based on intermittent operation, wet operation, high consumption of sulfuric acid, water, waste and by-products, and environmental pollution.
Chlorination method is the mixture of rutile or high titanium slag powder and coke, high temperature chlorination to produce titanium tetrachloride, after high temperature oxidation, and then filtered, washed, dried.