Silicon seed particles for the production of polycrystalline silicon granules in a fluidized bed reactor

A process for producing silicon seed particles, suitable for producing polycrystalline silicon granules in a fluidized-bed reactor, comprising introducing a milling gas stream into a chamber containing polycrystalline silicon granules, accelereating individual particles of the polycrystalline silicon granules such that the accelerated particles collide with other particles of the polycrystalline silicon granules, and the polycrystalline silicon granules are comminuted, wherein the milling gas stream is introduced into the chamber by at least one jet nozzle comprising 84.5 to 93.4 wt. % tungsten carbide in a binder matrix of 15 to 6 wt. % cobalt, and also containing 0.5 to 0.6 wt. % of one or more metal carbides selected from the group consisting of titanium carbide, tantalum carbide, chromium carbide and vanadium carbide.