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Anatase titanium dioxide belongs to pigment grade titanium dioxide, with strong covering power, high tinting power, good weather resistance and other characteristics, the following follow silver horse pigment to understand the method of improving anatase titanium dioxide application performance.

1, the main way to improve and stabilize the whiteness of titanium dioxide

The whiteness of titanium dioxide is influenced by many factors, including mineral source, equipment and key technology.  Through experiments and field experience, the main factors affecting its whiteness are: hydrolysis quality, removal of impurity elements and calcination conditions.

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At present, there are two kinds of hydrolysis technology of titanium dioxide in China, pressure hydrolysis and atmospheric hydrolysis. From the analysis of hydrolysis quality and product quality, atmospheric hydrolysis quality is better, hydrolysis particle size uniformity.  The quality of hydrolysis should be optimized, the quality index of concentrated titanium solution should be strictly controlled, the ratio of iron to titanium and the content of solid should be controlled within the prescribed range, and the operating conditions of hydrolysis process should be increased.

Another main factor affecting the whiteness of titanium dioxide is some impurities colored elements, such as: iron, cobalt, nickel, etc., must take certain measures to remove, for anatase titanium dioxide, high iron content in 120ppm, affect its whiteness, even light color alternation phenomenon.  Using bleaching technology, increase the washing strength of high iron, while adding some masking agents, such as antimony trioxide and phosphoric acid, to iron complex masking, reduce the influence of impurities on titanium dioxide whiteness.

The control of calcination conditions is an important part of the design of titanium dioxide crystal core, good calcination temperature, can make titanium dioxide desulfurization, dehydration completely, as far as possible to avoid the lattice defect of titanium dioxide crystal core, and affect its whiteness.  Therefore, increase the control of key temperature points, at the same time make the feed amount and kiln speed reasonable match, increase the combustion chamber, avoid contact between materials and flame, sintering.

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2, stable titanium dioxide particle size distribution, improve titanium dioxide dispersibility and covering power

The particle size distribution of titanium dioxide is a comprehensive index, which seriously affects the properties of pigment and product application of titanium dioxide. Therefore, the discussion of covering power and dispersion can be directly analyzed from the particle size distribution.

The factors affecting the particle size distribution of titanium dioxide are complicated. The first is the size of original particle size of hydrolysis. The original particle size can be kept in a certain range by controlling and adjusting the hydrolysis process conditions.  Secondly, the calcination temperature, in the process of calcination of mettitanic acid, particles undergo a crystal transformation period and growth stage, control the appropriate temperature, so that the growth of particles within a certain range.  The last is the grinding of the product, usually the transformation of Raymond mill and the adjustment of the speed of the analyzer, the control of grinding quality, at the same time, other grinding equipment can be used, such as: all energy mill, air mill and hammer mill device.

3, through surface treatment, improve the application performance of titanium dioxide

Titanium dioxide is a very polar powder, nature is hydrophilic and oleophobic, but if the surface adsorption of air, water and other pollutants, the dispersity in the water is reduced, often need for surface treatment, commonly used treatment agent for hydrated alumina and hydrated silicon oxide.  At present, there are also a lot of surface treatment agents on the market, such as: organic silicon, coupling agent, etc., or some other inorganic pigments such as: barium sulfate, aluminum hydroxide, etc., to improve the surface characteristics of titanium dioxide, improve its dispersity.


Post time: Nov-19-2021