Classifying polysilicon
AssigneeWacker Chemie AG
InventorsAndreas Schneider, Peter Gruebl, Rainer Hauswirth, Reiner Pech
Life of this patent
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Abstract
A method for mechanically classifying polycrystalline silicon chunks or granules with a vibratory screening machine, involves setting silicon chunks or granules present on one or more screens each comprising a screen lining in vibration such that the silicon chunks or silicon granules perform a movement which causes the silicon chunks or silicon granules to be separated into various size classes, wherein a screening index is greater than or equal to 0.6 and less than or equal to 9.0.
Claims16
A method for decreasing an overlap of particle sizes between adjacent size fractions in mechanically classifying polycrystalline silicon chunks or granules with a vibratory screening machine, comprising:
- introducing the chunks or granules into a gravity screening machine;
- setting the silicon chunks or granules present on one or more screens of the gravity screening machine in vibration, each screen comprising a screen lining such that the silicon chunks or silicon granules perform a throwing movement and which causes the silicon chunks or silicon granules to be separated into various size classes, wherein the screening index is greater than or equal to 1.6 and less than or equal to 3.0, and the screens of the gravity screening machine are characterized by an amplitude of vibration of 0.5 to 8 mm, a speed of rotation of 400 to 2000 rpm and a throwing angle of 30 to 60° relative to a screen plane, with the screen plane inclined by an angle of 0 to 15° relative to the horizontal.
Dependencies are inferred from the claim text.