The fundamental properties of dielectric separation were studied to provide insight into the design and operating characteristics of a dielectric separator. Force equations on mineral particles were derived and evaluated experimentally. Responses to variations in the electrical voltage and frequency, feed rate, particle size, dielectric fluid, and dielectric constant were tested theoretically and experimentally, using a 5-cm-diam dielectric separator. High- dielectric mineral recovery was proportional to the calculated effective dielectric force volume that surrounded each drum- electrode wire. Electrode spacing was the most sensitive design parameter; spacing of less than 0.4 Cm was required for a good separation. Dielectric separation was effective for separating minerals with dielectric constants that differed by approximately 2 or more. This report is based upon work done under an agreement between the University of Alabama and the Bureau of Mines.