OJSC “Giredmet”, Moscow, Russia:

A. N. Pochtarуev, Head of Laboratory, e-mail: ANP1945@mail.ru
V. A. Kozhemyakin, Leading Researcher
N. V. Antipova, Researcher

Results of laboratory researches of absorption chlorsilines by a solution caustic alkali are presented. Vent gases (an air plus chlorsilines: mixture vapors of threechlorsiline and tetrachlorsiline) in a vessel (barboter) with the solution caustic aikali are feeded. Contents of chlorsilines in the vent gases are 1–3% (volume). Degree absorption of chlorsilines, on barbotage, is 76%. The first concentration of caustic alkali in barboter is 25,6% NaOH. The last concentration of caustic alkali in barboter is 0,13% NaOH. The hydrochemical way from this alkaline solution to produce highly pure silica (SiO₂) and sodium chloride (NaCl) is developed. The last alkaline is neutralized by solution of a salt acid (18–20% HCl).The sediment of silica hydrated (mSiO₂·nH2O) is result neutralization of the last alkali. The sediment of silica filtered antigravity from the picle of sodium chloride. The speed of filtration is 1,3 m³/(m²·h). Contents of sodium chloride in the picle are 20–21% NaCl. Dry powder of the silicon dioxide to dry up at temperature 105 ^оC has density gravimetric ~140 g/dm³. Output of the silicon dioxide into the product of finish is 90–95% on the degree neutralization of alkaline ~90% and pH 2–3. The silicon dioxide is a useful product such as soot white ana aerosil. The sodium chloride is sutable as raw materials for electrolysis and production a chlorine and caustic alkali for recycling. Scheme technological of principal for utilization of silica in wastes of gaseous and liquid chlorsilines is presented.

1. Strelnikov A. S. Ekologiya i promyshlennost Rossii — Ecology and industry of Russia. 1999. January. pp. 8–12.
2. Zubchenko G. V. Tsvetnye Metally — Non-ferrous metals. 2009. No. 7. pp. 23–27.
3. Ayler R. Khimiya kremnezema (The chemistry of silica). Moscow : Mir, 1982. Part 1. 416 p.
4. Vasserman I. M. Khimicheskoe osazhdenie iz rastvorov (Chemical sedimentation from solutions). Leningrad : Khimiya, 1980. 208 p.
5. Stroenie i svoystva adsorbentov i katalizatorov (Structure and properties of adsorbents and catalysts). Moscow : Mir, 1973. 653 p.
6. Chapygin A. M., Nazarov Yu. N., Kokh A. A. et al. Giredmet — god obrazovaniya 1931 : sbornik statey (Giredmet — year of foundation: 1931 : collection of articles). Moscow : Giredmet, 2007. pp. 153–154.