JPS57140310A - Manufacture of silicon - Google Patents

Abstract

PURPOSE: To avoid the discharge of fine silicon particles together with silicon granules by depositing silicon formed by the thermal decomposition of chlorosilane or other method on silicon particles in a fluidized bed reactor and taking out the resulting silicon granules from the system while bringing it into countercurrent contact with gaseous hydrogen.

CONSTITUTION: Fine silicon particles, gaseous chlorosilane and gaseous hydrogen are fed to a fluidized bed reactor 1 from a leading inlet 2, leading pipes 4 and a feeding pipe 5, respectively. The particles are fluidized, the chlorosilane is thermally decomposed or reduced with hydrogen, and the formed silicon is deposited on the fluidized fine silicon particles. An excess of the reactive gas is exhausted from a pipe 3. The grown silicon granules having about 1W2mm diameter drop into a cilicon granule storing tank 6 through the hydrogen feeding pipe 5 owing to the empty weight. At this time, the granules contact countercurrently with gaseous hydrogen fed from a leading pipe 7 and rising in the 5, so fine silicon particles dropped together with the granules are returned to the reactor 1 by the gaseous hydrogen.

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