The reaction liquid is filtered through plate and frame pressure to obtain lithopone in the form of a filter cake with a moisture content of no more than 45%. It is then roasted in a drying furnace to change the crystal form of lithopone, and is then pickled with sulfuric acid at a temperature of 80°C. Finally, it is washed with water, reinforced with colorants, filtered, dried and ground into powder.
Titanium dioxide, or TiO2, sometimes referred to as E171, is an inorganic, solid substance used in a wide range of consumer goods including cosmetics, paint, plastic and food, according to the American Chemistry Council.
The main treatment objects in coagulation stage are suspended organisms and colloidal impurities in water. The perfection of coagulation process has a great influence on subsequent treatment, such as sedimentation, filtration and chlorination, so it is a very important link in Water Treatment process. Polyaluminum chloride and polyferric sulfate are often used in most waterworks.