The most efficient ionizing electrode used in roll-type electrostatic separators consists of a small diameter ionizing wire attached to a metallic cylinder. Previous studies concerning the numerical computation of the electric field and ionic charge and also the simulation of the metallic and dielectric particle charge processes in the zone located between the ionizing electrode and the grounded roll showed that the geometrical characteristics of the wire-cylinder ionizing electrodes play a very important role for the separator’s operation. This paper presents an experimental study concerning the influence of the wire-cylinder and wire-grounded roll distances on the ionic current level and their distribution on the grounded electrode. Finally, the obtained results are discussed and it is shown that, for a given application, the separation efficiency can be increased through the optimization of the ionizing electrode geometry

Keywords: Electrostatic separation, Corona discharge, Dual ionizing electrode