Reichert cone separators have been used for classification in the mineral processing industry for over six decades now. However, their application has always been limited to wet processing. In this paper, we assess the potential of their modification and use in gravitational dry solid-solid separation. A theoretical model was formulated, describing the motion of particles along inverted cone-shaped series of inclined screens with increasing aperture sizes under the force of gravity. A mathematical model to quantify the rate of separation was also suggested based on the theory. Three important design parameters were proposed to aid the actual engineering design of the system. The two models were test-run by numerical simulation under computer-generated, uniformly distributed random sized particles on a hypothetical 0.254. m radius cone, from which a theoretical screening rate of 32.52. g/s was achieved. The simulations were verified experimentally by designing a prototype system of equal effective screening area, and with equal input masses of glass beads, an overall screening rate of 23. g/s and a maximum separation efficiency of 66.4% was achieved.