Many factors affect the whiteness of industry grade titanium dioxide , not only mineral resources, but also the impact of equipment and key technologies. Through the experiment and field experience, the main factors affecting the whiteness are: the quality of hydrolysis, the removal of impurity elements and the calcination conditions.
The hydrolysis technology of titanium dioxide include pressure hydrolysis and atmospheric hydrolysis , from the quality of hydrolysis and product quality to analyze, atmospheric hydrolysis get the better quality and uniform particle size. To ensure the quality of hydrolysis, we must control the quality of titanium liquid strictly , control iron and titanium ratio and solid content within the specified range, while increasing the hydrolysis process operating conditions control.
Another major factor affecting the whiteness of titanium dioxide is some impurity colored elements, such as iron, cobalt, nickel, etc., must take some measures to remove, for anatase titanium dioxide, if high iron content of 120ppm,whiteness will be affected , And even the occurrence of light color interaction phenomenon. The use of bleaching technology to increase the washing speed of high-speed rail, while adding some masking agents, such as: antimony trioxide and phosphoric acid, to iron complexation masking, reducing impurity elements on titanium dioxide whiteness of the influence.
Calcination conditions control, titanium dioxide crystal nucleus stereotypes of an important mitigation, good calcination temperature, can make titanium dioxide desulfurization, dehydration completely, try to avoid titanium dioxide crystal nucleus lattice defects, two affect its whiteness.
Therefore, increase the control of the key temperature point, while the amount of feed and kiln body speed reasonable match, increase the combustion chamber, to avoid the material and flame contact, the occurrence of sintering.
18 Knowledge Points Of Powder Coatings
