The main component of white carbon black is silicon dioxide, which is a filler. Due to its large specific surface area, the addition of white carbon black to rubber mainly serves to reinforce or improve its thixotropy. Due to its large specific surface area and porous structure, as well as the presence of hydroxyl groups on the surface, it is prone to hydrogen bonding and therefore has adsorption properties. The solution can be to use hydrophobic white carbon black, which can be treated with hydrophobic agents such as silicone oil or hexamethyldisilazane.
The main raw materials for producing white carbon black by precipitation method are quartz sand, soda ash, industrial hydrochloric acid or sulfuric acid or nitric acid or carbon dioxide. In general, the process route is: first, use fuel oil or high-quality coal to react quartz sand with soda ash at high temperature to produce industrial sodium silicate, then use industrial sodium silicate water to prepare a dilute solution of a certain concentration, then add some acid under certain conditions to precipitate silica, and then wash, filter, dry (drying or spray), crush, and produce white carbon black. From this process, it can be seen that the production of white carbon black by precipitation method is basically an inorganic reaction process. Due to the use of alkali and acid in the production process, the main components of the wastewater are also salts that are secondary due to neutralization. The most important salt is sodium sulfate, and other inorganic salts mainly containing K, Na2S ions, solid insoluble substances, and suspended solids. There is basically no involvement of organic matter in the production process, and the COD value of wastewater is low, which is not the focus of treatment. Based on the characteristics of white carbon black wastewater, the following treatment processes can be adopted to achieve effective treatment and zero discharge of white carbon black wastewater, further recover the required heat during the wastewater treatment process, and reduce the comprehensive operating cost of wastewater.