Abstract: Polycrystalline silicon fragments are sorted into defined particle fractions in a flexible manner independent of initial particle size distribution and desired fraction size by a first mechanical screening into a fine fraction and residual fraction, followed by optoelectronic sorting of the residual fraction.

Abstract: Polysilicon rods from the Siemens process are crushed into fragments and further processed to fragments having very low metal contamination in an economical manner by purposefully fabricating parts contacting the polysilicon from materials which cause high metal contamination, and removing the metal contamination by a cleaning bath or baths tailored to the particular metal contamination. By this process, economical materials previously scrupulously avoided, such as low alloy steel, can be used for crushers, conveyors, and other polysilicon-contacting parts of the crushing and classifying system.

Abstract: The invention provides a process for producing polycrystalline silicon, including introduction of a reaction gas containing a silicon-containing component and hydrogen by means of one or more nozzles into a reactor including at least one heated filament rod on which silicon is deposited, wherein an Archimedes number Arn which describes flow conditions in the reactor, as a function of the fill level FL which states the ratio of one rod volume to one empty reactor volume in percent, for a fill level FL of up to 5% is within the range limited at the lower end by the function Ar=2000×FL?0.6 and at the upper end by the function Ar=17 000×FL?0.9, and at a fill level of greater than 5% is within a range from at least 750 to at most 4000.

Abstract: The invention provides a process for producing polycrystalline silicon, including introduction of a reaction gas containing a silicon-containing component and hydrogen by means of one or more nozzles into a reactor including at least one heated filament rod on which silicon is deposited, wherein an Archimedes number Arn which describes flow conditions in the reactor, as a function of the fill level FL which states the ratio of one rod volume to one empty reactor volume in percent, for a fill level FL of up to 5% is within the range limited at the lower end by the function Ar=2000×FL?0.6 and at the upper end by the function Ar=17 000×FL0.9, and at a fill level of greater than 5% is within a range from at least 750 to at most 4000.

Abstract: The invention relates to a device for comminuting and sorting polycrystalline silicon, comprising an instrument for feeding a coarse polysilicon fraction into a crushing system, the crushing system associated with a sorting system for classifying the polysilicon fraction, wherein the device is provided with a controller which allows variable adjustment of at least one crushing parameter in the crushing system and/or at least one sorting parameter in the sorting system.

Abstract: Polysilicon rods from the Siemens process are crushed into fragments and further processed to fragments having very low metal contamination in an economical manner by purposefully fabricating parts contacting the polysilicon from materials which cause high metal contamination, and removing the metal contamination by a cleaning bath or baths tailored to the particular metal contamination. By this process, economical materials previously scrupulously avoided, such as low alloy steel, can be used for crushers, conveyors, and other polysilicon-contacting parts of the crushing and classifying system.

Abstract: Polycrystalline silicon fragments are sorted into defined particle fractions in a flexible manner independent of initial particle size distribution and desired fraction size by a first mechanical screening into a fine fraction and residual fraction, followed by optoelectronic sorting of the residual fraction.

Abstract: The invention relates to a device for comminuting and sorting polycrystalline silicon, comprising an instrument for feeding a coarse polysilicon fraction into a crushing system, the crushing system associated with a sorting system for classifying the polysilicon fraction, wherein the device is provided with a controller which allows variable adjustment of at least one crushing parameter in the crushing system and/or at least one sorting parameter in the sorting system.