White carbon black and black carbon black are both produced from carbon black through different treatment methods, where white carbon black is oxidized, while free silicon refers to the silicon element that does not form chemical bonds with other elements. Therefore, white carbon black does not contain free silicon.
In the process of manufacturing white carbon black, it is exposed to a high-temperature oxygen environment and undergoes an oxidation reaction, oxidizing the surface active groups into hydrophilic groups such as carboxyl and hydroxyl groups, thereby making white carbon black highly hydrophilic and dispersible. During this process, some carbon atoms may combine with oxygen atoms to form compounds such as carbon dioxide, but they will not form compounds related to silicon, so free silicon will not be produced.
In short, white carbon black does not contain free silicon because silicon is not added during the manufacturing process, and oxidation reactions do not form silicon related compounds.