A process for preparing hyperpure

The invention relates to a process for the production of high-purity silicon, characterized by the steps of: DOLLAR A a) reacting metallurgical silicon (with silicon tetrachloride SiCl¶4¶), hydrogen (H¶2¶) and hydrogen chloride (HCl) at a temperature of 500 to 800 DEG C. and a pressure of 25 to 40 bar to give a trichlorosilane-containing (SiHCl¶3¶) raw gas stream a DOLLAR b) removing impurities from the resultant trichlorosilane-containing raw gas stream by scrubbing with condensed chlorosilanes at a pressure of 25 to 40 bar and a temperature from 160 to 220 ° C in a multi-stage distillation column to obtain a purified crude gas stream trichlorsilanhaltiger and a solid-containing chlorosilane suspension, and distillative separation of the result purified crude gas stream in a substantially from SiCl¶4¶ and consisting essentially of SiHCl¶3¶ partial flow, DOLLAR A c) disproportionation of SiHCl¶3¶-containing partial stream u SiCl¶4¶ nd wherein the disproportionation in several reactive / distillative reaction zones, which are flowed through in counter-current of vapor and liquid is performed on catalytically active solids at a pressure of 500 mbar to 50 bar and wherein SiH¶4¶, a first reaction region SiHCl¶3¶ is supplied to the lower-boiling SiH¶4¶-containing disproportionation product produced there in the temperature range from -25 DEG C to 50 DEG C is zwischenkondensiert that not condensed SiH¶4¶-containing product mixture in a ...