Patent ID: 11944983
Assignee: KAWASAKI JUKOGYO KABUSHIKI KAISHA
Field: Chemical engineering (Chemistry)
Classification: CPC B | IPC B

Claim 8:
9. An electrostatic separation method that separates conductive particles from raw materials including the conductive particles and non-charged insulating particles, the electrostatic separation method comprising:
applying a voltage between a lower electrode located at a bottom portion of a raw material layer including the raw materials or in the raw material layer and an upper electrode located above the raw material layer, to generate an electric field between these electrodes;
fluidizing the raw material layer and bringing the conductive particles and the lower electrode into contact with each other in the raw material layer to charge only the conductive particles such that polarity of the conductive particles becomes the same as polarity of the lower electrode;
generating polarity, which is the same as polarity of the upper electrode, by dielectric polarization on a downward-facing conveyance surface of a conveyor belt which passes through a capture region that is located above the raw material layer and under the upper electrode, the downward-facing conveyance surface including a nonconductor;
monitoring a distance between the upper electrode and the surface of the raw material layer and lifting or lowering the upper electrode such that the distance between the upper electrode and the surface of the raw material layer falls within a predetermined reference range in which a spark does not occur
selectively separating the charged conductive particles from a surface of the raw material layer by electrostatic force and making the conductive particles adhere to the conveyance surface of the conveyor belt; and
separating and collecting the conductive particles from the conveyance surface that has moved to an outside of the electric field.