| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: invention can be used in chemistry of high-purity polycrystalline silicon. A fraction of technical silicon which contains at least 90% particles with size between 90 and 450 mcm and size difference not greater than 250 mcm, undergoes hydrochlorination with hydrogen chloride at high pressure in a fluidised bed reactor. Solid silicon particles are then separated and the vapour-gas mixture is condensed with separation of hydrogen and hydrogen chloride to obtain a condensate which contains chlorosilane. The liquid condensate is purified from boron-containing impurities through "reaction" fractionation and holding for 48-72 hours. Chlorosilane vapour is then passed through a layer of boron-selective ion-exchange resins and trichlorosilane is extracted in the presence of a moist gas which is inert towards chlorosilane. Wastes formed on all steps of the process and containing silicon and its compounds undergo thermal hydrolysis in a hydrogen flame. ^ EFFECT: invention enables efficient purification of trichlorosilane from impurities and process production wastes to obtain a commercial grade product - fine-grained silicon dioxide with a highly developed surface. ^ 2 cl, 4 dwg, 3 tbl, 14 ex |
