Foforo nso ne gas-phase kwan, Chemical Vapor Deposition (CAV) kwan, a wɔsan frɛ no pyrolysis kwan, dry kwan anaa combustion kwan. Mpɛn pii no, nneɛma a wɔde yɛ no ne silicon tetrachloride, oxygen (anaa mframa) ne hydrogen, a ɛyɛ adwuma wɔ ɔhyew a ɛkɔ soro mu.
The reaction equation is: SiCl4+2H2+O2 - >SIO2+4HCL. Wɔde mframa ne hydrogen hyɛ pressurization, mpaapaemu, onwini ne dehydration, silica gel drying, mfutuma a woyi ne filtration ase ansa na wɔde akɔ synthetic hydrolysis fononoo no mu. Bere a wɔde silicon tetrachloride a wɔde yɛ nneɛma no akɔ distillation column no mu awie no, wɔma ɛyɛ hyew na ɛyɛ hyew wɔ evaporator no mu, na afei wɔde kɔ hydrolysis fononoo a wɔde mframa a ɛyɛ nwunu ne nea wɔayɛ no mu sɛ nea ɛde no kɔ no mu. Silicon tetrachloride yɛ vaporized wɔ ɔhyew a ɛkɔ soro (flame temperature 1000-1800℃) na afei ɛfa gas-phase hydrolysis a hydrogen ne oxygen dodow bi (anaa mframa) (anaa mframa) bɛyɛ 1800℃. Saa bere yi, gas-phase silica nketenkete a ɛba no yɛ fɛ yiye na ɛyɛ aerosols a mframa wom, na ɛyɛ den sɛ wɔbɛkyere.
Enti, wodi kan boaboa wɔn ano yɛ no nketenkete wɔ aggregator mu, afei wɔde ahum a ɛpaapae mu boaboa ano, na wɔde kɔ fononoo a wɔde yɛ ade a ɛma ɛyɛ mmerɛw mu. Wɔde nitrogen-a hohoro gas-phase silica no kosi sɛ pH bo yɛ 4 kosi 6, a ɛyɛ ade a wɔawie no .