A new method to produce high voltage static electric load for electrostatic separation – Triboelectric charging

Abstract

Numerous methods for generating electric charge on material surfaces through friction and contact have been applied in many industries. Triboelectric charging is one of these methods that achieve this phenomenon by frictional charging. The resulting electric field can be manipulated to control the directional path of falling particles. In a triboelectrostatic separator, particles are charged by the triboelectric effect before electrostatic separation.The purpose of this work is to develop a new system to provide the required electric potential to the electrodes of a separator by triboelectric charging, and to use the resulting charge for mineral separation. Experimental studies mainly covered the investigation of the effect of varying belt/roller combinations, belt speeds, brush lengths, and electrode surface areas on triboelectric charge generation. Belts were selected from wool, polyester, polyethylene/acrylic, PVC, nylon woven, nylon, and fiber/nylon materials. Additionally; teflon, polyamide, aluminum, polyoxymethylene and polyethylene rollers had been used. Following the investigation of operational parameters, mineral separation tests were performed with artificially prepared samples by using the designed setup.The results showed that static electric charge can be increased to a maximum of ±35kV on an electrode by tribocharging. Investigation of the operational parameters proved that increasing the belt speed causes an increase in surface charge, and the measured surface charge increases with an increase in the width of harvesting brushes. Furthermore, the separation test results revealed that non-conductive and conductive particles can be separated in an electrostatic separator using the high voltage directly produced by tribocharging.