Лако-красочные материалы — производство

The burning ofTiCl4 with oxygen usually results in rutile pigments, whereas the cal­cination ofTiO2 hydrolyzates produces either anatase or rutile pigments, depending on the doping and lattice stabilization. Most of the pigments sold are coated with oxides or hydroxides of various elements. Different treatments necessarily depend on the field of application, and all major pigment producers have a large number of pigment grades. Product groups are listed in Table 2.7. Pigments of all grades are available with or without organic treatment. More than 100 different TiO2 pigment grades are produced and marketed by the major TiO2 suppliers. Including the grades from small suppliers, there are several hundred TiO2 grades in the market. Table 2.8 lists the capacities and processes of the most important pigment producers.

A considerable increase of capacity has been achieved by debottlenecking and building new plants. Pigment plant capacity will continue to grow, especially due to new capacities in China.

Powdered TiO2 pigments are usually supplied in 25 kg sacks (50 lbs, USA) or in big bags containing 0.5-1 t pigment. Aqueous suspensions with solids contents of 68-75% are also available and can have advantage concerning the distribution and metering of the pigment in aqueous systems. The dust formation that occurs with dry pigment is also avoided. With the development of products with improved flow properties and modern pneumatic delivery technology, supply in silo trucks is rapidly increasing.

Tab. 2.8: T1O2 pigment producers (2003).

2.1.5