Method for electrostatically separating particles, apparatus for electrostatically separating particles, and processing system

An electrostatic separation method of separating a powdered material containing a conductive components and an insulating component into the conductive component and the insulating component by an electrostatic force, comprising:

• applying a voltage across a bottom electrode of a substantially flat-plate shape that is formed by a gas dispersing plate having air permeability and a mesh electrode of a substantially flat-plate shape, the mesh electrode being provided above the bottom electrode and having a number of openings;
• generating a direct current electric field between one of the bottom electrode and the mesh electrode as a positive electrode and the other electrode as a negative electrode, to form a separation zone by an electrostatic force;
• introducing a dispersing gas into the separation zone from an underside of the gas dispersing plate;
• applying vibration or impact to at least one of the bottom electrode and the mesh electrode;
• feeding the material from one side of the separation zone to an upper end portion of the bottom electrode with the bottom electrode and the mesh electrode inclined, causing the conductive component in the material fed into the separation zone to move through the openings of the mesh electrode to be separated above the separation zone, and recovering remaining insulating particles from a lower end portion of the bottom electrode at another side of the separation zone.

An electrostatic separation apparatus for separating a powdered material containing a conductive component and an insulating component into the conductive component and the insulating component by an electrostatic force, comprising:

• a substantially flat-plate shaped bottom electrode that is provided on lower side and is formed by a gas dispersing plate having air permeability;
• a mesh electrode provided above the bottom electrode and spaced a predetermined distance apart from the bottom electrode and having a number of openings to allow particles to pass therethrough;
• and
• a material feed portion provided at one end portion between the bottom electrode and the mesh electrode;
• a recovery portion of the insulating component provided at another end portion between the bottom electrode and the mesh electrode;
• a direct current power supply connected to at least one of the mesh electrode and the bottom electrode;
• an air box provided under the gas dispersing plate for introducing a dispersing gas;
• and
• a vibration applying means or an impact applying means mounted to at least one of the bottom electrode and the mesh electrode, for applying vibration or impact to the electrodes, wherein
• a voltage is applied across the bottom electrode and the mesh electrode to form a separation zone between the electrodes,
• a suction device connected to a space above the separation zone;
• and
• wherein a gas is ejected from the air box through the gas dispersing plate.