Dynamics of particle motion during electrical separation

This article presents a mathematical model of the motion of ilmenite and quartz particles within an electric drum corona separator. The model incorporates specific formulas to calculate the forces exerted by the electrostatic field and the mirror image force acting on ilmenite and quartz particles as they exit the interelectrode space. A theoretical relationship between the specific electrical forces and particle size was established for both ilmenite and quartz, demonstrating that as particle size increases, the electrical forces acting on the particles decrease. This behavior was further studied in an in-depth analysis of ilmenite and quartz particle motion within a three-drum corona separator. At a drum speed of 140 rpm, quartz particles smaller than 0.07 mm were efficiently separated into the non-conductive fraction. With drum speeds reduced to 110 and 80 rpm, the size threshold of quartz in the non-conductive fraction increased to 0.12 and 0.15 mm, respectively. To remove quartz particles of 0.25 mm into tailings, the middling product has to be directed toward the non-conductive fraction. Theoretical calculations of particle dynamics allow the establishment of key process parameters and optimal settings for the separator based on the electrical properties and particle size distribution. These findings support the effective implementation of three-drum electric separators in industrial applications. However, to achieve more accurate predictions of drum corona-electrostatic separation results, the process model has to be further developed to account for the electrical flocculation of conducting and non-conducting particles of various sizes. This phenomenon is linked to the mutual attraction between positively charged ilmenite particles and negatively charged quartz particles.