When E171 is part of a food product, it passes through the digestive system without causing harm because E171 combines with the other ingredients.
1. 296 to 1.357 g/cm3 is obtained. The reaction solution is subjected to pressure filtration through a plate frame to obtain a cake-like lithopone powder having a water content of not more than 45%. The mixture is calcined in a dry roaster to change the crystal form of the lithopone, and then acid-washed with sulfuric acid at a temperature of 80 °C. Finally, it is washed with water, reinforced with coloring agent, pressure filtration, drying and milling.
There are two primary forms of titanium dioxide commercially available: anatase and rutile. The rutile form is typically used in sunscreens due to its superior ability to handle UV rays and stability in the presence of UV light. The anatase form is typically used in other types of products, such as paint. Another plus of the rutile form is that its UVA protection extends past 400 nanometers, which is the upper limit of UVA.
Natural barite and anthracite containing more than 95% barium sulfate are mixed and fed at a ratio of 3:1 (mass). After being crushed to a diameter of less than 2cm, it enters the reduction furnace. The furnace temperature is controlled to be 1000-1200°C in the front section and 500-500 in the back section. 600°C, the reduction furnace rotates at a speed of 80 seconds per revolution, and the reaction conversion rate is 80% to 90%.