Investigation of the separation of conductive and insulating objects on a laboratory made electrostatic separator

Abstract

Electrostatic separators are widely used to separate conductive and insulating objects up to some millimetres in size. Modelling of such equipment has been presented in several studies; laboratory and numerical models have been analysed. However, there are such situations, where larger samples of the order of centimetres have to be separated, as milling them into smaller size particles is not allowed or feasible. It was found that electrostatic separation can be used even in such cases but in a different arrangement than in the “traditional” constructions.This paper is a continuation of a previous study, in which the separation of a constructed laboratory separator was examined. The model was built in a circular plate arrangement with high voltage needle electrodes above the edge of cylinder’s mantle, where the discharges are generated. The slope of the circular plate is steadily decreasing, so the samples on the edge of the plate produce an increasing angle of inclination along the circumference. Charged samples stick to the plate, uncharged ones fall off. Some key parameters as rotation speed, electrode distance, voltage level and position of ionizer electrodes were varied.