PRODUCTION OF SILICON WITH THE USE OF ALUMINIUM SUBCHLORIDE Russian patent published in 2014 - IPC C01B33/27 C01B33/33 

FIELD: metallurgy.

SUBSTANCE: proposed method comprises reduction of silicon from vapours of silicon compounds with chlorine or silicon with chlorine and hydrogen at mixing of said vapours with vapours of lower aluminium chlorides at 1000-1250°C in transfer gas flow. Said gas represents the mix of hydrogen with argon or the mix of hydrogen with helium containing 2-20 molar parts of hydrogen per one part of silicon compounds vapours. Note here that aluminium lower chlorides of required purity are produced from aluminium metal of 99.0-99.8% purity and gaseous aluminium trichloride or hydrogen chloride or chlorine by multiple reiteration of sublimation and decomposition of formed lower aluminium chlorides. Note also that precipitated silicon crystals are subjected to heat treatment at above 577°C and less than 1400°C, processed by hydrochloric acid and subjected to refining remelting.

EFFECT: higher purity of silicon, lower production costs.

2 dwg, 4 ex