The plate/screen-type electrostatic separator presented in this article provides a friendly environment for the experimental modeling of existing industrial units user and facilities investigations aiming at identifying new possibilities for using electric field forces for processing mixed granular solids. This multifunctional unit can be equipped with two different active electrodes, which can be energized from one or two independent high-voltage supplies, and the operator has the choice between two types of grounded electrodes: plate and plate/screen. The experiments carried out on a 50% quartz-50% magnetite mixture demonstrate that the efficiency of the separation can be increased by using a grounded plate/screen electrode and two high-voltage electrodes, energized from different supplies.