The authors consider the physical basics of operation of an electrostatic separator designed to separate particles different in density, size and shape. Separation of particles is performed depending on the mass and surface area in a corona-discharge radial field. The design of a separator provides separation in small operating units, their number being determined by the capacity and number of re-cleanings. The presented trial results refer to purification of quartz and other non-metallic ores used in the electronic industry, as well as quartz for ceramics and garnets used in abrasives. These minerals were purified of mica and fine fractions containing metal impurities. (C) 2002 Elsevier Science Ltd. All rights reserved.