Electrostatic separation of particulate material

An electrostatic separation apparatus for separating an electrically conducting particulate material from an electrical insulator particulate material, the apparatus comprising a rotating carrier electrode having an electrically conducting surface, disposed above which electrode is supply means for the particles to be separated and a corona discharge device, the corona discharge device comprising a series of corona discharge pins, the corona discharge device being connected to a high voltage electrical supply and being operable to provide an electrical charge to the particles to be separated, disposed in lateral relationship to the carrier electrode and the discharge device is a separating electrode positioned to attract discharged electrically conducting particulate material, the separating electrode being a charged electrode plate, and the voltage supplied to the corona discharge device being of the same potential as the voltage supplied to the carrier electrode.

A method of separating electrically conducting tobacco particles from electrically insulating filtration material particles, the moisture content of the tobacco particles supplied to a carrier electrode being greater than 10%, the method comprising the steps of passing a mixture of carbon particles and tobacco particles onto a rotating carrier electrode having an electrically conducting surface, a corona discharge device disposed above the carrier electrode providing an electrical charge to the particles, the charged electrically conducting particles discharging to the electrically conducting surface of the carrier electrode, which electrode is earthed, the discharged carbon particles being attracted towards a separating electrode, the arrangement of the separating electrode being such as to laterally separate the carbon particles from the tobacco particles.

A method of separating electrically conducting carbon particles from electrically insulating filtration material particles, the method comprising the steps of passing a mixture of carbon particles and tobacco particles onto a rotating carrier electrode having an electrically conducting surface, a corona discharge device disposed above the carrier electrode providing an electrical charge to the particles, the charged electrically conducting particles discharging to the electrically conducting surface of the carrier electrode which electrode is earthed, the discharged carbon particles being attracted towards a separating electrode, the arrangement of the separating electrode being such as to laterally separate the carbon particles from tobacco particles.

A method of separating electrically conducting tobacco particles from electrically insulating material particles, the moisture content of the tobacco particles supplied to the carrier electrode being greater than 10%, the method comprising the steps of passing a mixture of carbon particles and tobacco particles onto a rotating carrier electrode having an electrically conducting surface, a corona discharge device disposed above the carrier electrode providing an electrical charge to the particles, the charged electrically conducting particles discharging to the electrically conducting surface of the carrier electrode, which electrode is earthed, the discharged carbon particles being attracted towards a separating electrode, the arrangement of the separating electrode being such as to laterally separate the carbon particles from the tobacco particles.