METHOD AND DEVICE FOR PRODUCING GRANULATED POLYCRYSTALLINE SILICON IN A FLUIDISED-BED REACTOR

摘要

The invention relates to a method for producing granulated polycrystalline silicon in a hot surface and fluidised bad reactor consisting in deposing a reaction gas containing a gaseous silicon compound in the form of a silicon metal on silicon particles, which are fluidised into a fluidised bed by means of a fluidising gas at a reaction temperature ranging from 600 to 1000 °C and in extracting particles containing the thus deposited silicon from said reactor in such a way that the reaction and fluidising gases do not react. The inventive method is characterised in that the reactor surface contains a gaseous composition consisting of 99.5-95 mol % hydrogen and 0.5 to 5 mol % gaseous silicon compound and said reactor surface is heated to a temperature ranging from 700 to 1400 °C which is equal to or greater than the silicon particle temperature.