Abstract: Apparatus and methods are described for transporting and cooling silicon-coated granules produced in a fluidized bed reactor. The described system allows consistent silicon-coated granule production with fewer impurities than traditional silicon granule coolers. Granules flow from the reactor into a cooling vessel and subsequently are transported to a post production treatment system below the cooler. The cooling vessel is constructed as a single standpipe, vertical or near vertical, with a pipe diameter that allows granules to flow freely while providing adequate residence time for cooling. The standpipe is cooled by flowing a cooling medium through a passageway that extends along an external surface of the standpipe. The passageway can be provided by a pipe jacket or conduit.

Abstract: Embodiments of a method for reducing or mitigating metal contamination of polycrystalline silicon are disclosed. In particular the disclosure relates to a method of mitigating metal contamination of granulate polycrystalline silicon, during its manufacture in a fluidized bed reactor unit, resulting from contact with a metal surface of components of the supporting transportation and auxiliary infrastructure by use of a protective coating comprising silicon or a silicon-containing material.