How to Produce White Carbon Black?
There are three main production methods of white carbon black(SiO2):
The first is chemical vapor deposition. We also call it pyrolysis, dry process or combustion method. The raw materials are silicon tetrachloride, oxygen (or air) and hydrogen, which are generated through high-temperature reaction. The reaction formula is:
SiCl4+2H2+O2=SiO2+4HCl
The second method: precipitation method is also called sodium silicate acidification method. Silica is prepared by reacting water glass solution with acid through precipitation, filtration, washing, drying and calcination. The reaction formula is:
Na2SiO3+2H+->white carbon black+2Na++H20
Third, the new method mainly uses nonmetallic ores and their extensions as silicon sources. Silica was prepared by precipitation method. The key technology is to convert crystalline silicon dioxide and silicate into amorphous silicon dioxide. Raw materials mainly include wollastonite, opal, halloysite, olivine, serpentine, kaolin, hard kaolin, coal gangue, fly ash, etc.